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From the list of research reports, select the report you wish to review. Choose any of the options shown — abstract, final report or others — by clicking on the hyperlink. Patrons can perform subject searches of ITD's reports via the ITD Resource Library Catalogue.

Report Listing

RP 232 Highway User Expectations for ITD Winter Maintenance D. Veneziano, L. Fay, X. Shi, B. Foltz, M. Reyna, J. D. Wulfhorst, (2014).
  • RP 232

    Providing a high Level of Service (LOS) to ensure the safety and mobility for the travelling public is a key objective for winter maintenance operations. The goal of this research was to obtain a better understanding of Idaho highway users’ expectations for the Idaho Transportation Department’s (ITD) winter maintenance efforts. Input about Idaho residents’ preferences for winter maintenance was obtained through a web-based survey and focus groups meetings. Idaho residents were generally satisfied with ITD’s winter maintenance operations, and 3 out of 4 felt safe on Idaho’s highways following winter storm events. The majority of respondents (60 percent) felt that ITD should maintain the current LOS, and the remaining 40 percent felt the LOS for winter maintenance should be increased. Survey respondents indicated a preference for the use of abrasives (45.5 percent), followed by the use of chemicals (15 to 19 percent depending on material). Based on the survey findings, it is recommended that the current approach to LOS be maintained, with enhancements (e.g. use of corrosion inhibitors should they prove to have a positive cost-benefit relationship). In some cases, it may be possible to reduce the quantities of materials being used while maintaining the same LOS. Additional efforts could be made to expedite the time required to achieve bare pavement (4 hours) which the residents expect. There is a need for public campaign detailing when and why different materials are used for treating winter roads.
Abstract  Final Report
RP 231 Impacts of Using Salt and Salt Brine for Roadway Deicing P. C. Casey, C. W. Alwan, C. F. Kline, G. K. Landgraf, K. R. Linsenmeyer, (2014).
  • RP 231

    Idaho Transportation Department (ITD) uses a variety of methods to help ensure safe travel on the state highway system following winter storm events. These methods include plowing, use of sand to improve traction, and use of salt and chemical compounds for deicing. While the use of salt and salt brines can help keep roads free of snow and ice, improving safety and mobility, questions have been raised about their contribution to wildlife-vehicle collisions (big-game animals may be attracted to salt used on roadways), their environmental impacts, and the corrosive effects on vehicles. To better understand these impacts, ITD requested a review of literature and state practices in each of these three areas of concern.
Abstract  Final Report
RP 221 Economic Analysis for Projects Selection Study. Cambridge Systematics, Inc. (2012). Final Report
RP 220 Improving Emergency Response to Motor Vehicle Crashes: The Role of Multi-media Information. Benjamin Schooley, Thomas Horan, Abdullah Murad, Yousef Abed, (2013).
  • RP 220

    The motivation for this study is to reduce the adverse impacts of trauma caused by motor vehicle crash (MVC), including rural regions, where crashes account for a high percentage of trauma injury and death. One key aspect of reducing adverse effects of MVCs is to improve emergency medical services (EMS)—that is, to increase the efficiency and effectiveness of emergency and transportation services to respond, clear the scene of the crash, provide patient care, and take a patient to the correct hospital. The study centered on a 6-month demonstration of a multi-media (voice, video, pictures, data) EMS application (“CrashHelp”) in the greater Boise area. For the pilot test period, 1,513 CrashHelp reports, 306 digital images, and 1,121 voice recordings were sent by 81 paramedics to 8 hospital emergency departments (EDs). EMS and ED staff generally thought the system was easy to use, captured useful information, and could play a role in enhanced clinical decision-making. The voluntary nature of the pilot program did result is some inconsistency of use over time and this limited the extent to which the information was utilized. In summary, when the system was used it was found to be helpful. Therefore, future efforts should focus on protocols and procedures that would allow for easy integration of multi-media information in the workflow of crash response and subsequent hospital care.
Abstract  Final Report
RP 218 Evaluation of the Impacts of Differential Speed Limits on Interstate Highways in Idaho. Michael P. Dixon, Ahmed Abdel-Rahim, Sherief Elbassuoni, (2012).
  • RP 218

    In this research, an evaluation of the impacts of differential speed limits on rural interstate highways in Idaho was completed. The main purpose for this research was to determine if there have been any speed or safety effects after enacting the DSL, and also to study some of the geometric effects, like rumble-strips, on the safety of vehicles on rural Idaho interstates. Regarding the effects of DSL on speed, it was found that passenger car and truck speeds stabilized since the DSL policy implementation date. More specifically, the DSL reduced truck speeds, resulting in mean passenger vehicle and truck speeds of 74.7 and 65.6 mph, respectively. Regarding the DSL effect on speed compliance, Passenger vehicle compliance slightly worsened, while truck compliance improved. Establishment of the DSL policy also contributed to a decrease in the crash rates on Idaho’s rural interstates.
Abstract  Final Report
RP 217 Native Plants for Roadside Revegetation: Field Evaluation and Best Practices Identification. Robert Ament, Monica Pokorny, Stuart Jennings, Dr. Jane Mangold, Noelle Orloff, (2014).
  • RP 217

    Establishing native vegetation communities on roadsides can be a proactive approach to sustainable roadways. Revegetation with native species is the preferred management practice on Idaho roadways. The environmental and economic benefits of increasing desirable vegetation along Idaho roadways include: improving slope stabilization, soil conservation, roadway safety while reducing erosion, roadside maintenance costs and noxious weeds in right-of-ways. Selecting appropriate plant species for revegetation is the foundation for successful roadside revegetation. This report provides practical information for improving roadway revegetation in Idaho. The overall objective was to monitor vegetation and soil attributes to determine effective means for establishing perennial native vegetation, reducing surface erosion, and preventing weed encroachment. The results provide guidance and recommendations on species selection, seeding methods and site preparation techniques. Bluebunch wheatgrass and Idaho fescue were the best performing grasses. Grass species that consistently establish where seeded but have a low canopy cover include sheep fescue, western wheatgrass, and basin wildrye. Forbs and shrub species had low establishment success rates and low percent canopy cover on roadside revegetation projects. If forbs are desired, it is recommended to use species that are known to establish well, relatively inexpensive, and tolerant of the herbicides being applied to control weeds.
Abstract  Final Report   Final Report Presentation (PowerPoint)
RP 214 Positive Community Norm Survey 2011: Methodology and Results. M. A. Reyna, J. C. Smith, S. L. Kane, B. E. Foltz, (2012).
  • RP 214

    This survey established a baseline understanding of the positive norms that exist in Idaho, plus reveal the gaps in knowledge and perceived norms with regard to impaired driving. These gaps will indicate the most effective opportunities for future communication efforts (i.e. Media Messages) to change driver behavior. The project objectives included:
    1. Measuring self-reported attitudes, behaviors and perceptions of norms of adult drivers in Idaho regarding alcohol and driving.
    2. Obtaining information that can help establish a baseline understanding of the positive norms that exist in Idaho as well as reveal the gaps in knowledge and perceived norms. These gaps indicate the most effective opportunities for future communication efforts to change driver behavior and reduce fatalities.
    3. Providing information that researchers can use to identify important messages that can be shared with key leaders at the community, county and state levels to support efforts to reduce impaired driving. These leaders include local law enforcement officials, county leaders, and state policy makers.
Abstract  Final Report
RP 212 Lithologic Characterization of Active ITD Aggregate Source and Implications for Aggregate Quality. V. S. Gillerman, K. N. Weppner, (2014).
  • RP 212

    Aggregate from 40 material sources across Idaho were sampled and the lithologies identified quantitatively. Aggregate compositions are compared with commercial AASHTO T 303 and ASTM C1293 results and the geologic map of Idaho to identify those rock types and geographic areas most susceptible to alkali-silica reactivity (ASR). Petrography on I-84 concrete and the commercial and experimental mortar bars confirmed the conclusion that rhyolites from young Snake River Plain (SRP) volcanism as well as certain “siliceous quartzites” in the mid-SRP region have very high ASR potential. However, much of Idaho has ASR reactive aggregate. The geographic regions with the most consistent, lowest ASR values in aggregate are in the Boise and Payette River drainages.
Abstract  Final Report  Map
RP 211 Road Map for Implementing The AASHTO Pavement ME Design Software for the Idaho Transportation Department.  J. Mallela, H. L. Von Quintus, M. I. Darter, B. B. Bhattacharya, Applied research Associates, Inc., (2014).
  • RP 211

    This report provides a Road Map for implementing the AASHTOWare Pavement ME Design software for the Idaho Transportation Department (ITD). The Road Map calls for a series of three stages: Stage 1 - Immediate, Stage 2 - Near Term, and Stage 3 - Future or Long Range. Within each stage are various specific steps to achieve the required objectives for implementation. The general implementation plan is to develop for ITD the Idaho AASHTOWare Pavement ME Design User’s Guide, Version 1.1 under Stage 1 for use by designers and others for preliminary design and training purposes. Specific deficiencies in inputs and calibrations are identified in the draft guide for further improvement under the next stage. Stage 2 represents a major work effort over several years to fill the deficiencies for inputs, to conduct local Idaho calibration of distress and IRI models, and to provide training. Stage 3 represents future long-term work to improve various inputs and to maintain unbiased models.
Abstract  Final Report  User Guide
RP 209 Media Messages and Tools to Reduce Serious Single Vehicle Run-Off-the-Road Crashes Resulting from Impaired Driving. J. W. Linkenbach, S. Keller, J. Otto, S. Swinford, N. Ward, (2012).
  • RP 209

    The Center for Health and Safety Culture conducted research for the Idaho Transportation Department to develop media messages and tools to reduce fatalities and serious injuries related to Run-Off-the-Road, single-vehicle crashes in Idaho using the Positive Community Norms framework. After a review of Idaho’s Crash Database and a sample of police reports, the research team proposed to focus on impaired driving, a major risk factor for these crashes, by increasing bystander engagement. The theory of planned behavior was the theoretical basis for a survey of Idaho adults implemented by the University of Idaho’s Social Science Research Unit. The survey results informed key media messages to increase the likelihood adults would engage in prodding others from impaired driving. Recommendations for communications, implementation and evaluation are provided.
Abstract  Final Report
RP 207 Interim Real Time Snow Slope Stability Modeling of Direct Action Avalances. S. Havens, H. P. Marshall, C. Covington, B. Nicholson, H. Conway, (2012).
  • RP 207 Interim

    Improved prediction of the timing of direct action avalanches that occur during storms is needed for highway forecasting operations. A SNOw Slope Stability model (SNOSS) compares the overburden stress caused by new snow to the estimated strength within the new snow. This provides estimates of the stability of the new snow layer and whether a regional direct action avalanche cycle can be expected. For the first time during the winter of 2011/2012, SNOSS was run in real time at Banner Summit, Idaho for the Idaho Transportation Department (ITD) and Little Cottonwood Canyon, Utah for the Utah Department of Transportation (UDOT). SNOSS results were displayed automatically on a webpage hourly, using weather observation downloaded from MESOWEST. Little Cottonwood Canyon has a unique dataset of weather and avalanche observations dating back to the early 1970’s. We investigate SNOSS performance using detailed avalanche observations from avalanche forecasters and infrasound arrays. We present SNOSS model runs for the years 2001-2010 and compare the results to detailed avalanche observations. The results of the study will be used to improve the real time application of SNOSS, to provide a useful tool for avalanche forecasters.
Abstract  Report
RP 205B Assessment of ITD Customer Service Performance 2011. G. D. Proctor, (2011).
  • RP 205B

    This report assesses customer satisfaction with the Idaho Transportation Department. It also compares and contrasts the results of customer satisfaction surveys conducted for the Idaho Transportation Department with the results from other state transportation agencies. In addition, the report suggests means by which customer service performance could be improved.
Abstract  Final Report
RP 205A 2011 ITD Customer Service Survey. S. L. Kane, B. E. Foltz, (2011).
  • RP 205A

    In the spring and summer of 2011, the Idaho Transportation Department (ITD) commissioned a statewide customer satisfaction survey of Idaho residents to assess their perception of ITD's performance in several key areas of customer service. The areas of service assessed by the survey were highway maintenance, Division of Motor Vehicle (DMV) services, alternative transportation, public involvement in the planning process, communication from ITD, direct customer service, and the value and focus of ITD. This study repeats a similar study conducted in 2009 and is part of an effort to track changes in customer satisfaction over time. As in 2009, in most areas of service ITD was rated relatively highly, with approximately two-thirds or more of respondents awarding ITD a grade of "A" or "B" in the areas of highway maintenance, DMV services, communication, and direct customer services. In the area of public involvement in the planning process, residents expressed higher satisfaction than they had in 2009, although improvements could still be made in this area. This report also provides recommendations for how ITD could continue to improve in the various areas of customer service.
Abstract  Final Report
RP 204 Analytical Tools for Identifying Bicycle Route Suitability, Coverage, and Continuity. Michael B. Lowry, Ph.D., Daniel Callister, (2012).
  • RP 204

    This report presents new tools created to assess “bicycle suitability” using geographic information systems (GIS). Bicycle suitability is a rating of how appropriate a roadway is for bicycle travel based on attributes of the roadway, such as vehicle volumes, shoulder width, and bike lane width. The new GIS tools are based on the Bicycle Level-of-Service method in the 2010 Highway Capacity Manual (HCM). The Idaho Transportation Department (ITD) can use the new tools to assess state highways when conducting corridor planning. The tools can be used to prioritize improvement strategies, such as wider bike lanes or new shared-use paths. Local planners, perhaps working with ITD, can use the tools to evaluate the “bikeability” of their community, i.e. the ability to access important destinations by bicycle. Example output is provided for three case study communities. This report also summarizes a literature review on bicycle suitability and presents the results from a survey that was conducted to determine data availability and GIS skills throughout Idaho. Over 100 responses were received from engineers and planners across the state. The results suggest many Idaho communities already have key data to calculate bicycle suitability and most communities have access to GIS software and personnel with GIS skills.
Abstract  Final Report
RP 203 Growing the Idaho Economy: Moving Into the Future. G. Hiemstra, (2010).
  • RP 203

    A report on transportation and the possible future economy of the State of Idaho from 2010 to 2030, including current assets to leverage, driving forces shaping the future, long-range economic opportunities for Idaho including four future scenarios, risks to a preferred future, strategic implications for transportation, regional case studies, and final conclusions. The economic opportunities stressed in the report are next generation energy technology, leadership in tourism and recreation, sustainable agriculture and food security, attracting the creative class to communities, and leveraging higher education. The key implications for transportation in Idaho are: focusing on critical commerce corridors, preserving and maintaining the current system, planning for significant vehicle transition and related infrastructure change, planning for increased freight traffic, increasing density, doubling transit capacity, adding lane miles, joining intelligent transportation efforts, improving systems performance with information, exploring new materials, enhancing rail and ports, and thinking more broadly than just transportation systems.
Abstract  Final Report
RP 200 Potential Safety Effects of Lane Width and Shoulder Width on Two-Lane Rural State Highways in Idaho.  A. Abdel-Rahim, J. Sonnen, (2012).
  • RP 200

    This study provides a comprehensive evaluation of the relationship between crash rates and shoulder width and lane width for two-lane rural state highways in Idaho. Crash Modification Factors (CMFs) for shoulder width and lane width were developed using Idaho crash data covering the period from 1993 to 2010. The CMFs developed as part of this project will allow ITD to assess the potential safety benefits of shoulder widening projects. In addition to all crashes, models for single-vehicle and multiple-vehicle crashes were also developed. The CMFs presented in this study follow the general trends of prior knowledge and research. The results of the analysis showed that there is no significant difference between 12 ft lanes and 11 ft lanes in terms of safety for all types of crashes. The CMF for highways with 11 ft lanes was 1.02 indicating a marginal 2 percent increase in all crashes in comparison to highways with standard 12 ft lanes. The CMFs for highways with very small shoulders (less than 1 ft) were 1.16, 1.17, and 1.15 for all crashes, single-vehicle crashes, and multiple-vehicle crashes, respectively. This corresponds to an average increase in crashes of 16 percent when compared to highways with a 3-ft shoulder width. For highway sections with a shoulder width of 8 ft or more, the CMFs were 0.87, 0.90, and 0.83 for all crashes, single-vehicle crashes, and multiple-vehicle crashes, respectively, indicating an average reduction in crashes of approximately 13 percent when compared to highways with a 3-ft shoulder width. Idaho’s crash data was also used to investigate the characteristics of pedestrian and bicycle crashes on two-lane rural highways. The results show that roadway sections with a right paved shoulder width of 4 ft to 6 ft had the lowest number of pedestrian and bicycle crashes. The probability for a pedestrian/bicycle crash increases significantly for roadway sections with shoulder widths less than 3 ft. The likelihood of a crash also increases for roadway sections with shoulder widths of 8 ft or more.
Abstract  Final Report
RP 199 Study of the Effectiveness of ITD Pavement Design Method Fouad Bayomy, Sherif El-Badawy, (2011).
  • RP 199

    The current ITD design method for flexible pavement is an empirical procedure based on R-value of the subgrade. There are claims that this design method is conservative and that ITD’s calculated Equivalent Single Axle Loads (ESALs) are also conservative compared to the surrounding states. Thus, the main objective of this research was to compare the pavement design using the ITD’s current design method with the pavement design using the AASHTO 1993 design guide and the Mechanistic-Empirical Pavement Design Guide (MEPDG). Furthermore, the research aimed to evaluate the methods of ESAL calculations as well as the traffic volume projection methods that are adopted in Idaho. A total of 8 in-service pavement sections located in different regions in the state were selected in coordination with ITD engineers. The key factor was the availability of design information for these sections. For each pavement section, the ITD design was checked, and the section was redesigned using the AASHTO 1993 design guide and MEPDG. All designs using AASHTO 1993 and MEPDG were developed at 50 and 85 percent reliability levels. The nationally calibrated MEPDG software (Version 1.1) was used to predict the performance of the 3 design methods. Design inputs for MEPDG were established as Level 2 for Hot Mix Asphalt and subgrade materials. All other MEPDG inputs were selected as Level 3. To evaluate the designs by various methods, MEPDG was used to predict performance for the pavement sections designed by the three methods, and then compared to each other. Also, the performance predicted by MEPDG was compared to actual performance to the extent of performance data available in ITD pavement management system. For ESAL and traffic evaluation, ITD’s ESAL calculation method and traffic volume projection methods were studied, analyzed, and compared with other states. New truck factors were developed for ITD based on the analysis of weight-in-motion (WIM) data located in Idaho. ITD climatic factors were also analyzed and compared with MEPDG. Results showed that, relative to AASHTO 1993 and MEPDG procedures, ITD design method leads to thicker unbound layer(s) than the other methods. On the other hand, the AASHTO 1993 and MEPDG guides show reasonable agreement on the resulting pavement structure. ITD’s current truck classification system and truck factors yield highly conservative ESALs compared to other state factors as well as regional and statewide factors developed. Finally, current ITD climatic zones are not consistent and yield different stresses based on MEPDG analysis.
Abstract  Final Report
RP 198 Market Research for Idaho Transportation Department Linear Referencing System (LRS). Yushuang Zhou & Bruce Spear, (2009).
  • RP 198

    For over 30 years, the Idaho Transportation Department (ITD) has had an LRS called MACS (MilePoint And Coded Segment), which is being implemented on a mainframe using a COBOL/CICS platform. As ITD began embracing newer technologies and moving toward a more client-server based computing environment, it is becoming increasingly burdensome to access MACS. Initial studies have been conducted to review the needs for a new LRS system, including an LRS Needs and Recommendations Study in 2006. The scope of this research task (BP – 198) is to review the findings from the 2006 LRS study, and reevaluate the agency’s needs for LRS and the extent to which commercially available LRS systems or the LRS systems being used for other states will satisfy these needs. Based on the review findings, strategies are proposed and recommendation is made regarding how ITD can incrementally move to a GIS-enabled LRS system and what would be the cost and benefit implications.
Abstract  Final Report
RP 197 2009 Customer Satisfaction Survey. S. Kane, B. Foltz, (2010).
  • RP 197

    In the summer and fall of 2009, the Idaho Transportation Department (ITD) commissioned a statewide customer satisfaction survey of Idaho residents in order to assess the overall level of satisfaction with several key areas of service provided by the department. The topics covered in the survey included highway maintenance, highway construction, Division of Motor Vehicle (DMV) services, alternative transportation, public involvement, communication, and customer service. In most areas of service, ITD was rated highly: over two-thirds of respondents awarded the department either an “A” or a “B” in the areas of highway maintenance, highway construction, DMV driver licensing services, DMV vehicle titling and registration services, online DMV services, and customer service. In the areas of alternative transportation, public involvement, and communication, respondents indicated there was some room for improvement. The report provides several recommendations that ITD could consider to improve its customer service.
Abstract  Final Report
RP 196 2009 Partnership Survey. S. Witt, Ph.D; C. Nemnich, MPA, and S. Donohue, (2010).
  • RP 196

    The report discusses the results of an electronic survey of 1,500 individual stakeholders of the Idaho Transportation Department (ITD). The purpose of this survey, which was conducted in August and September 2009, was to gauge stakeholders’ satisfaction with ITD partnership efforts and methods. In general, stakeholders felt ITD did a good job partnering with other agencies. Overall partnership effectiveness, commitment to collaborative work, and responsiveness to partners’ ideas were rated good or very good by stakeholders. In open-ended comments and in focus groups, stakeholders indicated that communication was the most important aspect of partnerships, and suggested that some aspects of communication, decision-making, and planning could be improved. Many stakeholders recommended improving the quality of existing partnerships, rather than creating more partnerships.
Abstract  Final Report
RP 194 Investigation of Concrete Sealer Products to Extend Concrete Pavement Life - Phase 1. Justin Nielsen, George Murgel, Arvin Farid, (2011).
  • RP 194

    Five surface applied concrete sealer treatments were evaluated in the laboratory for water vapor transmission, saltwater absorption, alkali resistance, depth of penetration, UV exposure and cyclic saltwater ponding, chloride content, and freeze-thaw resistance. The five treatments included silane, high molecular weight methacrylate (HMWM), epoxy, silane basecoat/HMWM top coat, and silane basecoat/epoxy top coat. The same treatments were applied in four locations in Southwestern Idaho to initiate a long-term (4 year) field evaluation of the treatments. In the laboratory tests, the dual treatments of a silane basecoat followed by an epoxy or HMWM exhibited the best performance. Of the single compound applications, the epoxy, silane, and HMWM exhibited the best performance in descending order for saltwater absorption, alkali resistance and freeze-thaw resistance. Only the silane had a measurable depth of penetration and had the best water vapor transmission ability.
Abstract  Final Report
RP 193 Implementation of the MEPDG for Flexible Pavements in Idaho. Fouad Bayomy, Sherif El-Badawy, Ahmed Awed, (2012).
  • RP 193

    This study was conducted to assist the Idaho Transportation Department (ITD) in the implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) for flexible pavements. The main research work in this study focused on establishing a materials, traffic, and climatic database for Idaho MEPDG for hot-mix-asphalt (HMA) and binders typically used in Idaho was established. The influence of the binder characterization input level on the accuracy of MEPDG predicted dynamic modulus (E*) was investigated. The prediction accuracy of the NCHRP 1-37A viscosity-based Witczak Model, NCHRP 1-40D-binder shear modulus (G*) based Witczak model, Hirsch model, and Gyratory Stability (GS) based Idaho model was also investigated. MEPDG Levels 2 and 3 inputs for Idaho unbound materials and subgrade soils were developed. For Level 2 subgrade material characterization, 2 models were developed. First, a simple R-value regression model as a function of the soil plasticity index and percent passing No. 200 sieve was developed based on a historical database of R-values at ITD. Second, a resilient modulus (Mr) predictive model based on the estimated R-value of the soil and laboratory measured Mr values, collected from literature, was developed. For Level 3 unbound granular materials and subgrade soils, typical default average values and ranges for R-value, plasticity index (PI), and liquid limit (LL) were developed using ITD historical data. For MEPDG traffic characterization, classification and weight data from 25 weigh-in-motion (WIM) sites in Idaho were analyzed. Site-specific (Level 1) axle load spectra (ALS), traffic adjustment factors, and number of axles per truck class were established. Statewide and regional ALS factors were also developed. The impact of the traffic input level on MEPDG predicted performance was studied. Sensitivity of MEPDG predicted performance in terms of cracking, rutting, and smoothness to key input parameters was conducted as part of this study. MEPDG recommended design reliability levels and criteria were also investigated. Finally, a plan for local calibration and validation of MEPDG distress/smoothness prediction models for Idaho conditions was established.
Abstract  Final Report
RP 191A Potential Crash Reduction Benefits of Safety Improvement Projects - Part A: Shoulder Rumble Strips A. Abdel-Rahim, M. Khan, (2012).
  • RP 191A

    This research provides a comprehensive evaluation of the safety benefits of shoulder rumble strips in rural highways in Idaho. The effectiveness of shoulder rumble strips in reducing the number and severity of run-off-the-road (ROR) crashes was examined based on Idaho’s crash experience for 3 different roadway types: 2-lane rural highways, 4-lane rural highways and rural freeways. All ROR, severe ROR crashes, and truck ROR crashes were analyzed as part of this study. The evaluation was done using two different evaluation methods: Comparison Groups (CG) before-and-after analysis and Empirical Bayes (EB) before-and-after analysis. For cases where control section data was limited or not available, naïve before-and-after analysis was used. Based on Idaho’s crash data, the installation of shoulder rumble strips on 2-lane rural highways resulted in a 15 percent reduction in all ROR crashes and a 74 percent reduction in severe ROR crashes. The benefits seem higher in roadway segments that have little to moderate roadway curvature. For rural freeways, the percent reduction in all ROR crashes and severe ROR crashes was 29 percent and 67 percent, respectively. The big difference between the two numbers is because there seems to be a higher percentage of minor (less severe) crashes on the freeway segments tested. The percent reduction in all ROR crashes and severe ROR crashes when shoulder rumple strips were installed in 4-lane rural highways were 60 percent and 45 percent, respectively, which is statistically significant. Truck crashes in all rural highways also decreased after shoulder rumble strips installation by a range of 42 to 62 percent.
Abstract  Final Report
RP 190 Performance Evaluation of Chip Seals in Idaho. M. Zoghi, A. Ebrahimpour, and V. Pothukutchi, (2010).
  • RP 190

    The intent of this research project is to identify a wide variety of parameters that influence the performance of pavements treated via chip seals within the State of Idaho. Chip sealing is currently one of the most popular methods of maintenance for paved road surfaces. It entails spraying the pavement surface with asphalt (or “binder”) and then immediately covering it with aggregate (or “chips”) and using rollers to compress and settle the application. Chip sealing is used to seal non-structural cracks, increase surface friction, and improve ride quality. There are a variety of techniques and formulas (“design methods”) for mixing the binder and aggregate used in chip sealing. In Idaho, these design methods lack uniformity: empirical methods are used, based on an informal rule-of-thumb, the experiences of the parties making the chip seal, and the materials that are readily available. This project compares the methods used in Idaho with several different design methods that have been developed in various parts of the world. The project’s research focus is a series of laboratory experiments using different binders and aggregates obtained from all six Idaho Transportation Department districts. The results of these experiments have been compiled and analyzed, with the findings included herein. Chief among these findings, it was observed that the ratio of median size to flakiness index of the aggregate exhibits a better correlation with the percentage aggregate retained rather than the least dimension (as used in the commonly used McLeod Design Method). It was also found that the cleanness value of the aggregate is a critical factor for retaining aggregate -- i.e., keeping the chips on the treated road surface, rather than breaking free from the binder. This report concludes with a series of sodd recommendations for improving chip sealing practice in Idaho, and with a list of eight areas worthy of additional research.
Abstract  Final Report
RP 185 Developing Statistical Correlations of Soil Properties with R-Value for Idaho Pavement Design. Stanley Miller, (2009).
  • RP 185

    Historical geotechnical soil testing results have been collected, sorted, and culled from ITD materials reports and soil-profile scrolls to investigate relationships between basic soil properties and R-value. Several thousand data records (dated from 1953 through 2008) representing all 25 classes of soils prescribed by the Unified Soil Classification (USC) system were initially input to Excel® files; after editing, there were 8243 records retained for subsequent statistical analyses. This database is unique in that the exudation pressure used for ITD R-value testing (Idaho T-8) is 200 psi (1,380 kPa), rather than the traditional level of 300 psi (2,070 kPa). Because ITD changed its testing procedure in June of 1971, two-sample statistical tests were used to compare Pre-1971 R-value data with the Post-1971 data to assess whether the earlier results should be adjusted to the Post-1971 levels. The adjustments for the Pre-1971 R-values primarily were needed for the clayey soils. Multiple regression analysis of the culled data indicated that three soil properties had significant influence on R-value: USC code, plasticity index (PI), and percent finer than the No. 200 sieve. Soil resistivity also can be useful in predicting R-value, but primarily for coarse-grained soils. Additional regression analyses were used to develop and recommend predictive models for R-value.
Abstract  Final Report
RP 184 Investigation into the Influence of Bridge Deck Design Methodology on Bridge Deck Cracking. R. Nielsen, E. R. Schmeckpeper, C. Shiner, and M. Blandford, (2010).
  • RP 184

    At present, the Idaho Transportation Department (ITD) Bridge Design Manual allows engineers to use the AASHTO empirical method to design concrete bridge decks. However, the ITD Bridge Section would like to compare their design practices to those employed by other state DOTs. The Bridge Section is also interested in the ability of the empirical deck design method to control deck cracking. AASHTO’s empirical deck design method and traditional design method are summarized. We reviewed the literature regarding the effect of bridge deck design methodology on deck cracking. Many researchers agree that the empirical bridge deck design method needs to be modified to limit cracking. For example, Frosch and Radabaugh believe that the empirical method does not require a large enough reinforcement ratio to adequately control cracking. Others such as Krauss believe that the deck-to-girder stiffness has a greater effect on deck cracking and should be increased in the empirical method.

    We also surveyed bridge deck design methods and typical deck designs for all of the states in the U.S. Bridge deck properties such as deck thickness, rebar size and rebar spacing from other states were compared to those specified by ITD. Most states and Canada use a significantly smaller spacing and larger reinforcement bar size. We believe that reducing the spacing and increasing the size of rebar would mitigate ITD’s deck cracking problem, although the degree to which deck crack spacing and width would be mitigated would require further research.
Abstract  Final Report
RP 183 Evaluation of ITD Automated System Needs for Pavement Management, Maintenance Management and GIS. (2008).
  • RP 183

    The Idaho Transportation Department (ITD) is facing a critical point in the maintenance and management of its highway system. The number of deficient miles is increasing, paving costs are rising exponentially, and roddue is not keeping pace with the increased costs of construction. The situation is further complicated by the fact that the Department’s existing maintenance management system is no longer used due to incompatibility with the Department’s recently acquired financial management system and the pavement management system is not meeting the Districts’ needs. To help address this situation, ITD initiated this research project (RP 183) to conduct an evaluation of the Department’s current maintenance management and pavement management needs as the first step towards acquiring new software packages. The selected research team reviewed existing documentation and interviewed approximately 40 ITD personnel to identify critical needs. Strategies were developed for addressing the needs and recommendations for enhancements were provided. Detailed findings are presented in the final report.
Abstract  Final Report
RP 182 B Material Acceptance Risk Analysis: Superpave Hot Mix Asphalt. H. Sadid, R. Wabrek, and S. Dongare, (2010).
  • RP 182 B

    The objective of this study is to review Superpave Hot Mix asphalt used by other state DOTs and make recommendation to Idaho Transportation Department (ITD) in using this product in its roadways and in particular in low-traffic roadways. Based on the literature review, it is concluded that Superpave mix design provides better performance for roadways that experience heavy to medium traffic volumes. For low-traffic roadways, Superpave, Marshall, and Hveem-designed mixes perform about the same. Considering the unit price, it appears that there are no significant differences among the three mix-design methods.
Abstract  Final Report
RP 182 A Material Acceptance Risk Analysis: Pavement Markings. H. Sadid, R. Wabrek, and S. Dongare, (2010).
  • RP 182 A

    This study involves examination of pavement markers as requested by the Idaho Transportation Department (ITD). A comprehensive literature review of various types of pavement markings and markers used by different transportation departments was performed to identify the most cost effective markings based on performance, durability, and useful life expectancy. This study revealed that there were no conclusive findings and recommendations by different investigations and field studies for various types of pavement markings. The performance characteristics of pavement markings and their effectiveness in guiding roadway users depend on many factors including but not limited to: product quality, application process, surface preparation, environmental conditions, annual average daily traffic (AADT), driver’s age and visual performance, vehicle type, type of headlights, and pavement type. In addition, the results of field studies conducted by different investigators show that the conclusions were highly dependent upon the method of studies, the study models used, the type of measurement devices, and the accuracy of their operation. However, some investigators and transportation departments are in agreement on certain issues including: the performance characteristics, life expectancy, and the associate cost.

    The most cost effective pavement marking identified and utilized by different transportation departments on low level traffic volume is paint followed by epoxy. Tape is commonly used on high volume AADT roadways by different agencies. Ninety-eight percent of pavement markings used in Idaho are paint with the other two percent consisting of tape or other types including Methyl Methacrylate (MMA). The Idaho Transportation Department’s current practice in using pavement markings is the most cost effective. ITD is in line with many other transportation departments throughout the country that deal with similar climate conditions.
Abstract  Final Report
RP 181 Phase B Prediction of the dynamic modulus of Superpave mixes. A. Abu Abdo, F. Bayomy, R. Nielsen, T. Weaver, S.J. Jung & M.J. Santi, (2010).
  • RP 181 Phase B

    This project addresses the development and evaluation of simplified test procedures to augment the Superpave mix for its implementation in Idaho. The project has two phases. Phase A, which focused on the deformation characteristics and Phase B, which focused on the fatigue/fracture properties of the mix. Hence the final report is developed in two parts. Part 1 addresses Phase A and Part 2 for Phase B. In phase B, a two stage study was initiated to improve the evaluation of hot mix asphalt (HMA) fracture and fatigue resistance. The study focused on using semi-circular notched sample to overcome the difficulty of preparation of HMA beam samples for fatigue testing,. The first stage was to investigate and compare the stress intensity factor (KIC) determined by two test setups; the semi-circular notched bending fracture (SCNBF) and the single-edge notched beam (SENB) tests. In Stage 2, the potential of correlating a simple monotonic (static) test to a cyclic (dynamic) SCNBF test was investigated. Two additional Superpave mixes were modified to obtain 14 different mixes which were evaluated. Overall, the results of KIC determined by monotonic and cyclic SCNBF followed the same trend. Further, several models that predict fatigue parameters using monotonic SCNBF results were developed to simplify the estimation of fatigue life of an asphalt mix. Overall, results in both stages suggested that the SCNBF test was beneficial in characterizing the fracture and fatigue resistance of asphalt mixes. The SCNBF test is simple and repeatable; it can be used as a screening tool at the mix design stage to assess the fracture resistance of mixes, and help to eliminate weak mixes before conducting more sophisticated and time consuming tests.
Abstract  Final Report
RP 181 Phase A Prediction of the dynamic modulus of Superpave mixes. A. Abu Abdo, F. Bayomy, R. Nielsen, T. Weaver, S.J. Jung & M.J. Santi, (2010).
  • RP 181 Phase A

    The purpose of this project is to develop and evaluate simplified test procedures that can augment the Superpave volumetric mix design system. The project has two phases. Phase A, which focused on the deformation characteristics and Phase B, which focused on the fatigue/fracture properties of the mix. This report focuses on Phase A results. In Phase A, the mix stability index referred to as the Gyratory Stability (GS) was evaluated. Soddteen lab mixes were selected for evaluation. In addition to the lab mixes, sodd different field mixes were procured from various projects in Idaho. Mixes were tested for GS, dynamic modulus (E*) and flow number (FN). Rutting was measured with the Asphalt Pavement Analyzer (APA). The Mechanistic-Empirical Pavement Design Guide (MEPDG) was employed to predict permanent deformation for most of these mixes using E* results as Level-1 data input in MEPDG. Results of GS for these mixes indicated that the GS ranked mixes similarly to the APA and FN tests as well as the MEPDG results. When GS results were compared to actual pavement rutting measured in MnRoad, it was found that GS ranked mixes in a similar manner. Overall, results indicate that the GS can be sued as a mix performance indicator. A predictive model for estimating E* from the mix constituents was developed. The model shows E* as a function of binder G*, and mix volumetric properties and GS. In conclusion, the project revealed the GS as a mix performance indicator. An E* model was developed. The E* model was based on the binder G* and the mix GS and volumetric properties. In addition, a rutting prediction viscoplastic model was developed based on APA test results.
Abstract  Final Report  Conference
RP 180 An Automated Testing Tool for Traffic Signal Controller Functionalities. A. Abdel-Rahim, Ph.D.; R. Wall, Ph.D.; Sk. Monsur Ahmed, C. Browne, (2010).
  • RP 180

    The purpose of this project was to develop an automated tool that facilitates testing of traffic controller functionality using controller interface device (CID) technology. Benefits of such automated testers to traffic engineers include reduced testing time, enhanced repeatability and consistency of testing, reduced testing costs, and improved testing quality and productivity. The automated tester can be operated in a static mode using the graphical user interface. The timing of input changes is strictly controlled by the person operating the testing system. It uses XML script files to specify which inputs are activated, the timing of those activations and verifying the controller response(s). The software provided is for a limited set of NEMA TS1 controllers running a specific firmware version as specified by the Idaho Transportation Department. Other traffic controllers can be tested provided that the testing program has been modified to communicate with that specific controller. Software modifications to the testing software are required because there is no standard communications protocol used by various traffic controller manufacturers that allow the traffic controller settings to be read from the controller. A version of the automated tester has been developed and tested that interfaces with NEMA TS2 type 1 and type 2 controllers. This version uses the National Transportation Communications for ITS Protocol (NTCIP) via either the asynchronous RS232 serial port or the Ethernet port. However, our investigation has shown that various vendors have significant differences in the interpretation of the NTCIP standard, and the automated testing software must still be verified with specific traffic devices running specific firmware versions. The automated tester also includes a CID-based suitcase tester emulator that can replace or supplement manual testing.
Abstract  Final Report
RP 179 Synthesis of Research on Work Zone Delays and Simplified Application of QuickZone Analysis Tool. A. Abdel-Rahim, Ph.D.; M. Khanal, Ph.D.; H. Cooley, S. Gould, (2010).
  • RP 179

    The objectives of this project were to synthesize the latest information on work zone safety and management and identify case studies in which FHWA’s decision support tool QuickZone or other appropriate analysis tools could be applied. The results of the analysis showed that QuickZone was an efficient tool to macroscopically analyze traffic operations at work zones. It provides reliable planning-level estimates of delay and queue length that are comparable to that reported by microscopic simulation models. It can be used to analyze work zones in urban freeways, rural freeways, four-lane divided urban arterials and corridors, and two-lane rural highways. QuickZone, provides DOT staff with the opportunity to effectively analyze work zone projects and fully assess their impacts. It also provides DOT staff with a tool that can be used to reliably estimate work zone user cost, in the form of vehicular delay, for different project scheduling, phasing, delivery methods, and other traffic management alternatives. QuickZone, a Microsoft Excel application, is a fairly simple-to-use analysis tool. However, it requires extensive data input to fully represent the traffic flow profile throughout the work zone. QuickZone delay and queue length output are highly sensitive to calibration parameters such as saturation flow headway and lane capacity. Using site specific parameters will improve the model output. Average saturation flow headway and the corresponding lane capacity values for different road types in Idaho are provided in Table 4 in this report. These values are based on field measurements of saturation flow headway at different sites throughout Idaho. Realistic capacity estimates can be obtained using these values as base capacity values with adjustments following the Highway Capacity Manual 2000 procedures. Adjustments to the base value include: duration and intensity of work activity, effect of heavy vehicles, and presence of ramps in close proximity to the work zone.
Abstract  Final Report
RP 176 Contamination of Weathering Steel During Construction. (2007).
  • RP 176

    The Idaho Transportation Department (ITD) Standard Specifications for Highway Construction requires that all steel surfaces of unpainted weathering steel structures are to be blast cleaned in the shop. Despite precautions taken to protect faying surfaces during the fabrication, transportation, and erection processes, some rusting or contamination of the faying surfaces, by oil, dust, road salts, or cleaning fluids may occur.
    The effects of the accumulation of small amounts of rust have been documented. Yura, et al. (1981) found that when subject to normal atmospheric exposures, a Class B (blast-cleaned) slip coefficient could be maintained for up to one year prior to joint assembly. However, the effects of contaminates on the faying surfaces are not known. In addition, the effects of attempts at removing the contaminates are not known. It is hypothesized that the residues remaining from attempts at removing contaminates from the faying surface might reduce the slip coefficient more than the presence of the original contaminates.
    The objective of this project was to provide guidance to ITD inspectors for judging the acceptability condition of steel faying surfaces. This would include guidelines to determine when the accumulation of contaminates on the faying surface has reached objectionable levels, and appropriate methods for removing contaminates from faying surfaces. These guidelines and methods could be incorporated into the ITD specifications.
Abstract  Final Report
RP 175 Performance of Idaho HMA Mixes Using Gyratory Stability. (2007).
  • RP 175

    The primary goal of this project was to evaluate the validity of the Contact Energy Index, a concept that was developed in a previous ITD project, to the Hveem mixes in Idaho. Also to establish threshold design values for the CEI that can be used for the HMA mix design in Idaho.
Abstract  Final Report
RP 174 Using Real-Time Hardware-in-the-Loop Simulations (HILS) to Develop, Test and Implement New Traffic Signal Timing Plans
  • RP 174

    The purpose of this project was to assist ITD staff in the development, testing and implementation of new traffic signal timing plans. As part of the project, controller interface devices were purchased for use by ITD district traffic engineers. In addition training classes were held to assist staff in the use of real-time hardware-in-the-loop (HILS) on the development of signal timing plans. No written report was developed as part of this project.
Abstract
RP 173 Implementing PONTIS Bridge Management Syste/Bridge Rating from Perrine Bridge. (2007).
  • RP 173

    The I.B. Perrine Bridge spans across the Snake River on US 93 north of Twin Falls, Idaho. The bridge carries a significant volume of truck traffic and the Idaho Transportation Department receives regular requests for permits to run overweight and other over-permit trucks across this span. Current bridge rating procedures make typical assumptions for load distribution factors and load paths that only approximately match the geometry of the bridge. To more accurately estimate load demands on the structure, the University of Idaho has created a three-dimensional, finite element model of the I.B. Perrine Bridge using LARSA 2000 Plus. Different vehicles can be simulated moving accross the bridge deck and the resulting member reaction envelopes are calculated. In addition, an Excel worksheet has been created which imports analysis data generated in LARSA and calculates and summarizes load rating factors for the various structural components of the bridge. Load rating is performed using a LRFR strength limit state for permit vehicles. The finite element analysis and load rating program can be operated efficiently. A concise load rating summary report is generated so that an engineer can clearly determine if permit vehicles can safely cross the bridge. Once the finite element model is calibrated, the Idaho Transportation Department will be able to use this software to more accurately load rate the bridge for permit vehicles.
Abstract  Final Report  Instruction Manual
RP 172 Guidelines for Designing and Implementing Traffic Control Systems for Small- and Medium-Sized Cities in Idaho. Adbel-Rahim, Ahmed; Dixon, Michael
  • RP 172

    The State of Idaho Intelligent Transportation Systems Strategic Plan identified traffic signal upgrades and signal integration projects as high-priority projects for major cities throughout Idaho. There is a need to determine the merits of different signal control alternatives and to precisely quantify the magnitude of the incremental benefits that might be achieved through changing the signal control system to a more advanced centralized or closed loop systems. The objective of this research report is to provide the Idaho Transportation Department (ITD) staff with guidelines on how to select the most appropriate signal control system for situations encountered in Idaho cities and how to design, procure and operate advanced control systems such as closed-loop and centralized control systems. The report documents the characteristics of traffic signal systems in different Idaho cities as well as the resources available for ITD staff in different districts. It includes a review of the state of the traffic signal control industry covering both hardware and software. The report provides developmental guidelines pertaining to the concepts of operations for signal integration projects and includes a case study for a signal integration project followed by an example of setting and managing closed-loop software. A summary of the workshop that presents guidelines for designing and implementing traffic control systems for small and medium-sized cities is presented in Appendix C.
Abstract  Final Report
RP 171 Native Plants for Idaho Roadside Restoration and Revegetation Programs. Sara Robson & James Kingery, (2006).
  • RP 171

    This guide profiles a selection of plants native to the state of Idaho. It is intended for the benefit of Idaho Transportation Department (ITD) roadside managers, native plant enthusiasts and travelers throughout the state interested in the use of native plant species along Idaho roadways. The goal is to incorporate more native plant species into future revegetation and restoration programs along Idaho roadsides. The plants described in this guide have the capacity to increase road cut stability, decrease soil erosion, and diminish the presence of weedy species.
Abstract  Final Report  Tech Brief
RP 170 Valuation of Indirect Losses Due to Proximity Damages on Residential Property in Idaho - Final Report. Ruby Miles Stroschein; Sarah E.Miles; Zac Moore; & James Nelson, (2005).
  • RP 170

    Valuation of Indirect Losses Due to Proximity Damages on Residential Property in Idaho Statewide transportation planning needs require forecasting and assessing property damages that result from a road project. As the traffic flow and traffic demands in Idaho change, the Idaho Transportation Department continuously evaluates transportation elements of comprehensive plans, determines impacts of proposed land use changes, and determines the transportation needs for the state. Meeting transportation needs often requires building or widening roadways, which necessitates that the state exercise their eminent domain right, the right to take private property for a public use upon payment of just compensation.
    Two basic forms of damages have been identified in eminent domain litigation: 1) the taking of physical property and 2) the conclusion of hypothetical damages in value to the remaining portion of the property after road improvements are complete. The problem in the past has been that the methods used to estimate the value of these damages employed limited comparable data, usually three to five direct comparisons, with subjective adjustments applied based on experience and arbitrary judgment.
    In this study, a six region forecasting model was developed to explain residential property values in Idaho based on multivariate regression analysis with an additional soddth category of rural residential sales added to the model in 2004. The model uses factors, or characteristics that commonly affect the sales price of a home and less common characteristics such as street-traffic classification and setback from the street or road, to conclude what portion of home value is attributable to proximity and to street-traffic classifications.
    A multi-regional or state wide model was developed and tested, as were separate models for each region. The regions from which data were collected and analyzed are: the Idaho Falls region, the Pocatello region, the Boise region, the Lewiston region, the Moscow region, and the Coeur d’Alene region as well as randomly selected rural residential sales. The statewide model, which incorporates statistically estimated adjustments for each region, was the strongest and most complete model. With it, statistically reliable as-is and hypothetical estimates of residential property values can be calculated within the tested regions statewide for residential properties that have been or will be affected by damages associated with designing new routes or widening existing streets and roads. The model will also assist in providing more quantitative benchmarks for assessing whether damages have odd occurred at all.
Abstract  Final Report
RP 167 The Effects of Errors in Annual Average Daily Traffic Forecasting: Studies of Highways in Rural Idaho. Michael Dixon, (2004).
  • RP 167

    Accurate forecasting of annual average daily traffic data (AADT) minimizes errors in design decisions. Several methods produce unfavorable results in rural Idaho where traffic data are available and growth trends are not identifiable. The classification and regression tree (CART) method can reduce the variability in the AADT annual growth rate. The maximum errors for different data subgroups were calculated and the effects of the prediction errors were evaluated. Following an asphalt overlay, using both the actual and forecasted AADT values, differences in the thickness required for each were evaluated. Second, a level of service analysis studying the differences between the values using both actual and forecasted AADTs showed that significant differences did not occur unless the ESALs were high enough to warrant more than the minimum thickness. In those cases, only ESALs with errors of greater than 20 percent exhibited large differences between the forecasted and actual AADT values. Only eight percent of the cases would have resulted in incorrect design decisions. Because incorrect design decisions rarely occurred in either case, using forecasting methods as those depicted in this study is recommended. The CART method should also be implemented to improve the classification of AADT data points.
Abstract  Final Report
RP 165 A Video-Based Method for the Detection of Truck Axles. James F. Frenzel, (2002).
  • RP 165

    This paper describes the development of a video-based system for the determination of truck axle positions and inter-axle spacing. Such information can be used to determine axle configurations for calculating maximum permissible load. The main tasks of the video-based system are to detect trucks in two-lane highway traffic, identify wheels and record the center as an axle location, and calculate the inter-axle spacing. Motion images were sampled to detect the presence of vehicles matching truck characteristics. Edge detection was performed on the truck images and the wheel positions were determined using the Hough transformation. A single truck spanned multiple frames, hence wheel positions from several frames of the truck are combined and the distance traveled between frames determined to obtain the inter-axle spacing. Performance results are presented under various lighting conditions. Computational complexities of the algorithms were estimated and a stand-alone portable system is proposed.
Abstract  Final Report
RP 163 Valuation of Indirect Losses Due to Proximity Damages on Residential Property in Idaho - Interim Report. Ruby Stroschein, Sarah E. Miles & James Nelson, (2003).
  • RP 163

    Statewide transportation planning needs require forecasting and assessing property damages that result from a road project. As the traffic flow and traffic demands in Idaho change, the Idaho Transportation Department continuously evaluates transportation elements of comprehensive plans, determines impacts of proposed land use changes, and determines the transportation needs for the state. Meeting transportation needs often requires building or widening roadways, which necessitates that the state exercise their eminent domain right, the right to take private property for a public use upon payment of just compensation.
    A multi-regional or state wide model was developed and tested, as were separate models for each region. The regions from which data were collected and analyzed are: the Idaho Falls region, the Pocatello region, the Boise region, the Lewiston region, the Moscow region, and the Coeur d’Alene region. The statewide model, which incorporates statistically estimated adjustments for each region, was the strongest and most complete model. With it, statistically reliable as-is and hypothetical estimates of residential property values can be calculated within the tested regions statewide for residential properties that have been or will be affected by damages associated with designing new routes or widening existing streets and roads. The model will also assist in providing more quantitative benchmarks for assessing whether damages have odd occurred at all.
Abstract  Final Report
RP 162 Using TWOPAS Simulation Model to Provide Design and Operations Information on the Performance of Idaho's Two-Lane Highways. Michael P. Dixon, (2003).
  • RP 162

    Two-lane rural highways are the predominant highway facility in the State of Idaho and ITD has given much attention in recent years to improving the operations and safety of these highways. Some of the design options that have been considered for these facilities are the introduction of passing lanes, improvement of sight distance, and roadway realignment. Software packages are available for evaluating these different design alternatives. In the past ITD has occasionally used a software package called TWOPAS to analyze these design options, but currently ITD has limited capability in using the TWOPAS software because of the time required to learn the program. Furthermore, recent change in the program have rendered obsolete some of the experience that ITD has with TWOPAS.
Abstract  Final Report
RP 160 Analysis of the Long-term Pavement Performance Data for the 3 Idaho GPS and SPS Sections. Fouad Bayomy, (2007).
  • RP 160

    This project addresses the analysis of the Long-Term Pavement Performance (LTPP) data for the LTPP sites in Idaho. The goal was to determine the performance trends for the pavement in Idaho as found in the LTPP experiments. The research also investigate into the use of the data to develop models that enable the prediction of the seasonal variation effects on the pavement materials (soils and asphalt mixes). In addition, the project looks into the applicability of the LTPP data in Idaho for the use and implementation of the new Mechanistic-Empirical Pavement design Guide (MEPDG).
    Analysis of the performance data including roughness and rutting revealed that Continuous concrete pavements performed best, followed by jointed concrete pavements. The asphalt pavements on granular bases and existing asphalt overlays on asphalt pavements showed mediocre performances. That was largely due to the big gap in data at these sites. For SPS sites regarding cracking and rutting, the various types of surface treatments tested at the SPS 3 experiment were not effective at improving pavement conditions. Results showed that to improve pavement roughness, a thin overlay is the best treatment option, followed by the placement of a slurry seal coat. Placing chip and crack seal treatments did not show significant impact on pavement roughness.
    As part of the outcomes of this project, a mini-LTPP database for the LTPP sections in Idaho was developed in MDB file format and series of Excel files that include all Idaho data. In addition, models were developed based on analysis of national data for the subgrade and asphalt concrete moduli. An investigation into the implementation of the MEPDG in Idaho indicated that the current performance data in the Idaho sites are not sufficient for any meaningful calibration of the performance models in the new design guide.
Abstract  Final Report
RP 159 The Development of “Roadway Name” Table for the Idaho Transportation Department’s Milepost and Coded Segment (MACS) System. Mandar Khanal, (2003).
  • RP 159

    A software tool was designed to merge spatial and attribute information from 2 different sources to create the transportation framework layer for urban areas in Idaho. Spatial data used was obtained from ITD. The attribute data was from the TIGER database.
Abstract  Final Report
RP 158 Phase II Freeway Incident Detection and Arterial Systems Management for the I-84 Corridor, Phase II. Ahmed Abdel-Rahim & Mandar Khanal, (2003).
  • RP 158 Phase 2

    The purpose of this project, Freeway Incident Detection and Arterial Systems Management for the I-84 Corridor, is to enhance and build upon the work that will be completed as part of the Treasure Valley ITS integration project to accomplish some additional, and important, objectives:
    • Test and evaluate standard incident detection algorithms that are used in practice today and help to determine which ones may be suitable for use in the I-84 corridor.
    • Develop and test signal control strategies for actuated coordinated traffic control systems in the I-84 corridor.
    • Develop a set of materials that can be used to train practicing professionals and university engineering students to operate a freeway traffic management center.
Abstract  Final Report
RP 158 Phase I Freeway Incident Detection and Arterial Systems Management for the I-84 Corridor, Phase I. Ahmed Abdel-Rahim & Mandar Khanal, (2001).
  • RP 158 Phase 1

    Freeway incident management has become an important issue in departments of transportation nationwide. While incidents on freeways cannot be proddted entirely, the implementation of an effective incident detection and management system can mitigate the impacts of the resultant congestion.
    It has long been known that the weakest elements of incident management programs are the Automated Incident Detection (AID) algorithms and the incident recovery phase, particularly the utilization of traffic diversion strategies. An Incident Management Plan (IMP) was recently developed for Idaho’s Treasure Valley corridor, which identified possible diversion routes and established incident response plans for a wide range of scenarios. The Treasure Valley includes the cities of Boise, Garden City, Meridian, Eagle, Kuna, Star, Middleton, Nampa, and Caldwell in Ada and Canyon counties. To maximize the benefit of these diversion routes, effective signal control and management strategies need to be devised that use the actuated controllers already deployed in the I-84 corridor.
Abstract  Final Report
RP 157 Synthesis into the Causes of Concrete Bridge Deck Cracking and Observations on the Initial Use of High Performance. (2008).
  • RP 157

    In recent years, the Bridge Section of the Idaho Transportation Department has observed increased cracking in concrete bridge decks. This increased in cracking has occurred in concrete bridge decks that have used designs that historically produced satisfactory performance. The cracking has occurred both in new decks and in decks that have been subjected to traffic for various periods of time. To determine possible reasons for the increased cracking, researchers at the University of Idaho have performed a literature review of articles, papers and standards focused on bridge deck cracking. In addition, the deck of a bridge for highway US95 constructed over the South Fork of the Palouse River was instrumented with strain and temperature gauges. This project was the first in the State of Idaho involving the use of HPC for the bridge deck. The weather and concrete placement procedures were also monitored and material testing was performed on the deck concrete. The decks were placed in 2 stages: the 1st stage portion of the deck was constructed using the conventional Idaho Class 40A mix, while the 2nd stage portion was constructed using a high performance concrete mix. The results of the monitoring and testing on both stages of the bridge deck were then compared to the literature review to determine if the high performance concrete mix provided any improvement with respect to cracking. Finally, the report presents recommendations on how to reduce cracking. Results from the monitoring and testing of the Stage 1 deck indicated that cracking in the concrete was mostly due to restraint of the deck by the girders and parapet wall. Uplift from skew and high heat of hydration temperatures were the main causes of tensile stress build up in the deck, compounded by the low creep and high modulus of elasticity of the concrete used. Results from the monitoring and testing of Stage 2 indicated that cracking in the concrete was also mostly due to restraint of the deck by the girders and parapet wall. Reducing the cement, adding fly ash to the mix, decreasing skew, and /or reducing deck restraint appear to be effective in reducing deck cracking.
Abstract  Final Report
RP 155 Implementing Pontis as a Bridge Management Tool in Idaho. Jarrod H. Milligan, Richard J. Nielsen & Edwin R. Schmeckpeper, (2004).
  • RP 155

    Engineers who hold responsibility for managing bridges face a daunting task because of the large number of bridges which need work and the limited funds with which to accomplish the work. Bridge management software, such as Pontis, provides a way to manage the large quantity of data available to the engineer. This report outlines the capabilities of Pontis to assist the Idaho Transportation Department (ITD) in their bridge management work. Currently, ITD uses only the inventory and inspection management capabilities of Pontis. In the future, ITD is planning to expand their use of Pontis at the Needs Analysis or Project Planning levels. The required input data is summarized, with the element unit costs and failure costs examined in detail. Element unit costs developed for Idaho were similar to the default values from California, and resulted in similar recommendations in the Preservation Policy. However, the unit costs from Oregon were very different, reflecting a different approach to policy decisions by having non-zero costs specified for all of the “do-nothing” actions and very high costs for some other actions. As a result, the Preservation Policy based on element unit costs from Oregon resulted in very different recommendations. As funding levels increase, the condition of the network also improves, as may be expected. However, for odd “unlimited” levels of funding, the condition of the network always declines over time, indicating that the optimal condition of the bridges on the network is below the current condition based on current estimates of element unit costs, user costs and failure costs. The projected needs for Idaho’s bridge network using Oregon's cost data were substantially higher than those based on California’s and Idaho’s cost data. Projected benefits based on Oregon’s cost data were also much higher than those based on California’s and Idaho’s. The Preservation Policy derived from Oregon's element costs resulted in a slightly better network condition, based on the Sufficiency Rating and Bridge Health Index, although the differences are much smaller than the projected needs and benefits.
Abstract  Final Report
RP 154 Evaluation and Treatment of Expansive Volcanic Soils - US 95, Owyhee County, Idaho. J. H. Hardcastle, (2003).
  • RP 154

    Soils at several locations along the first 18.5 miles of US95 in Owyhee County, Idaho, were found to meet the diagnostic criteria for highly expansive soils. The cause of the soil expansion is intake of water into the montmorillonite, an expanding lattice clay mineral. Swelling results from an initial water deficient condition as a result of stress and/or climate, followed by available water as a result of a change in the soil’s environment. Pavement heaving may take several years to become noticeable. To reduce the amount of swelling and delay its occurrence when the soils are remolded during construction and when pavement structural sections are to be placed on incoherent colluvial soils of high swelling potential, stabilization techniques must be employed. The laboratory test program showed that lime is an effective stabilizer of the Owyhee soils, and the treatment did not produce detrimental expansive sulfate reactions odd though the soils contain small amounts of gypsum. Use of lime treatment for the Owyhee soils is limited to new pavement construction. Hydraulic barriers in the form of horizontal and vertical membranes coupled with shoulder and ditch paving are recommended for both new construction and existing pavements in areas currently exhibiting distress.
Abstract  Final Report
RP 150 Erosion Control and Revegetation Demonstration Project, Horseshoe Bend Hill, Idaho State Highway 55. (1997).
  • RP 150

    This demonstration project sought to demonstrate the comparative benefits of using commercially available products and technologies to help in the rapid and successful establishment of desired vegetation on disturbed sites to control erosion. The site is precipitous, .1 to 1 or steeper; the surface medium is decomposed granite strewn with rocks and boulders. Six different seed mixes were used with three different organic or compost based mulches to determine which would perform best under these difficult conditions. Replication of the natural succession process in using early seral stage plants that inhabit disturbed sites was the selection criteria for species. Dormant seeding was conducted.

    Mycorrhizal associations (fungal colonies) are present in the root systems of most indigenous plant species on semiarid land. Loss of significant portions of the bacterial biomass, or loss of fungi and microorganisms such as nitrifying bacteria, severely limit the ability of a site to support vegetative cover. In the subject region, over 95% of the dominant indigenous plant species are dependent on mycorrhizal associations. Nutrient cycling is in large part controlled by mycorrhizal bacteria and their relative interactions with local biomass. These root-inhabiting fungi colonize both inside and outside the root system. The host plant supplies the mycorrhizal fungi with simple carbohydrates (sugars) from photosynthesis. In return, the fungi, using energy derived from the host plant, extend hyphal strands (feeding tubes) far into the soil, increasing the feeding area of the roots to improve water and nutrient absorption for its host. Reestablishment of mycorrhizae and associated microorganisms at disturbed sites in the semiarid West is essential to be successful in reestablishing vegetation to control erosion. Redistribution of topsoil collected on site is the most effective method to reestablish mycorrhizal colonies required for re-vegetation following construction. Managing excavation projects to include topsoil retention for re-vegetation purposes in the American West is both necessary and cost effective. The physical and biological properties of topsoil have characteristics necessary to grow vegetation that are not present in other construction materials, such as subsoil or borrow material. Topsoil reclamation needs to be recognized as a high priority in road building construction projects. Absent topsoil reclamation, the use of organic soil amendments and time release organic mulch compounds are necessary to initiate the soil building process necessary for re-vegetation and erosion control.

    Comparison of the various seed mixes and soil amendment mulch products used at the Horseshoe Bend Hill demonstration site show that those products that accelerated development of soil organisms enhanced plant growth and establishment. Kiwi Power organic soil amendment and Kiwi Fertile-Fibers time release organic mulch out-performed the other compost products, using criteria of plant density and establishment. Plant species that performed well include Intermediate wheatgrass, Siberian wheatgrass, Bluebunch wheatgrass, Canby bluegrass, Yarrow, Lewis blue flax, Sainfoin, Rabbit brush, and Farewell to spring. These are early seral stage plants; pioneer species that act as soil builders that will enable higher seral stage plants to inhabit the site at a later time. The seed for this undertaking was obtained from areas similar in elevation and rainfall to the subject site. Seeding was conducted in early winter, the dormant period, enabling the seeds to germinate and begin establishment during the spring when more moisture is available. The vegetative cover, especially the shrubs, helps reduce water erosion and hold slopes through absorption of water and by slowing the transport of water off a given site by reducing kinetic energy. Further analysis of these sites will help focus future re-vegetation efforts at this and other similar sites in the region.
Abstract  Final Report
RP 149 Catalytic Igniter to Support Combustion. (2002).
  • RP 149

    Lean ethanol-water/air mixtures have potential for reducing NOx and CO emissions in internal combustion engines. Igniting such mixtures is not possible with conventional ignition sources. An improved catalytic ignition source is being developed to aid in the combustion of aqueous ethanol. The operating principle is homogeneous charge compression ignition in a catalytic pre-chamber, followed by torch ignition of the main chamber. In this system, ignition timing can be adjusted by changing the length of the catalytic core element, the length of the pre-chamber, the diameter of the pre-chamber, and the electrical power supplied to the catalytic core element.
    A multi-zone energy balance model has been developed to understand ignition timing of ethanol-water mixtures. Model predictions agree with pressure versus crank angle data obtained from a 15 kW Yanmar diesel engine converted for catalytic operation on ethanolwater fuel. Comparing the converted Yanmar to the stock engine shows an increase in torque and power, with improvements in CO and NOx emissions. Hydrocarbon emissions increased significantly, but are largely due to piston geometry not well suited for homogeneous charge combustion. Future engine modifications have the potential to lower emissions to current emission standards, without requiring external emission control devices.
Abstract  Final Report
RP 148 Development and Performance Prediction of Idaho Superpave. (2006).
  • RP 148

    This report starts developing the long-term needs to be executed in a stepwise approach. ITD’s main need was to find out a measureable and objective mix design indicator that can be augmented to the volumetric based Superpave mix design. Thus for this project the main objective was to target the first step in the implementation of Superpave.
Abstract  Final Report
RP 147 Development, Adaptation, and Monitoring of Interactive Training Courses to the Idaho Transportation Department’s Intranet and World Wide Web. Donald F. Haber
  • RP 147

    In 1996, the American Association of State Highway and Transportation Officials (AASHTO) developed three training courses for highway maintenance personnel. The courses covered the topics of “Snow and Ice Control”, “Work Zone Traffic Control” and “Motor Grader Operation” using a CD-I interactive format. Because of this format, special viewing equipment was needed. Shipping throughout the state and heavy use resulted in the original units being no longer completely functional. Since replacement units are no longer manufactured and computers are widely accessible at maintenance station, the courses needed to be converted to a computer format. Phase One addressed the proper software to capture the information contained in the CD-I. Due to the size of video files, they were replaced with single frame pictures. Phase Two addressed the software available to format the information captured from the CD-I into a useable format. The team reviewed a number of samples of software and selected Authorware because of its robust performance and the program's ability to track student’s activity when used on a local area network or the web. Due to the poor quality of the captured pictures and the out dated materials contained in the program, it was decided to redevelop this course from the beginning, adding additional information. Additionally, the interaction between the viewer and program was greatly increased. Also, navigation in the program was enhanced.
Abstract
RP 143 Evaluation of Potential Earthwork Savings in Road Design Using ROADZ. Mandar Khanal & Richard Zimmerman, (1999).
  • RP 143

    Designers hope to accomplish earthwork optimization, which included cut and fill volumes and mass haul, in their road design. Commonly used road design software packages, however, cannot explicitly account for earthwork optimization. This is true of INROADS, the software used by ITD for road design. The TOC also recommended the conversion of ROADZ from DOAS to Windows operating environment. These recommendations will be implemented as part of a new research project in 1999-2000.
Abstract  Final Report
RP 142 Phase 1 Rockfall Hazard Classification and Mitigation. Stanley M. Miller, Shari Silverman, (2000).
  • RP 142 Phase 1

    Following initiatives and recommendations from the Federal Highway Administration (FHWA), a number of state highway departments over the last 12 years have developed and implemented rockfall hazard management programs for highways. The primary goal is to improve highway safety, but reductions in maintenance and detour costs also result when slope hazards are mitigated. Additionally, a systematic method for agencies to identify and prioritize slope hazard sites allows for highway funds to be allocated efficiently for construction projects or counter-measures to deal with the recognized hazards. Some state highway departments have expanded the original focus on rockfall hazards to also include other types of unstable slope activity, such as landslides, debris flows, and accelerated erosion. A systematic highway slope hazard assessment protocol has been developed for the State of Idaho, which consists of a two-step procedure for hazard ratings: 1) a survey rating by maintenance personnel to classify pertinent slope segments as having a very high, high, or moderate potential of rockfall or erosional debris on the roadway; and 2) a detailed slope hazard rating based on extensive modifications of the FHWA Rockfall Hazard Rating System. The Idaho Transportation Department slope hazard management system has been developed for its centralized, intranet web server that will allow real-time operations from multiple users within the transportation agency. This intranet web-based system is known as Idaho HiSIMS (Highway Slope Instability Management System).
Abstract  Final Report
RP 142 Development and Implementation of the Idaho Highway Slope Instability and Management System (HiSIMS). Stanley M. Miller, Ph.D., (2003).
  • RP 142

    Following initiatives and recommendations from the Federal Highway Administration (FHWA), a number of state highway departments over the last 12 years have developed and implemented rockfall hazard management programs for highways. The primary goal is to improve highway safety, but reductions in maintenance and detour costs also result when slope hazards are mitigated. Additionally, a systematic method for agencies to identify and prioritize slope hazard sites allows for highway funds to be allocated efficiently for construction projects or counter-measures to deal with the recognized hazards. Some state highway departments have expanded the original focus on rockfall hazards to also include other types of unstable slope activity, such as landslides, debris flows, and accelerated erosion. A systematic highway slope hazard assessment protocol has been developed for the State of Idaho, which consists of a two-step procedure for hazard ratings: 1) a survey rating by maintenance personnel to classify pertinent slope segments as having a very high, high, or moderate potential of rockfall or erosional debris on the roadway; and 2) a detailed slope hazard rating based on extensive modifications of the FHWA Rockfall Hazard Rating System. The Idaho Transportation Department slope hazard management system has been developed for its centralized, intranet web server that will allow real-time operations from multiple users within the transportation agency. This intranet web-based system is known as Idaho HiSIMS (Highway Slope Instability Management System).
Abstract  Tech Brief  Final Report
RP 140 WINPSBRG USER'S MANUAL (Prestressed Bridge Girder Design Program). Edwin Schmeckpeper, (2001).
  • RP 140

    No additional information available at this time.
Abstract
RP 138 Optimal Statewide Roadway Weather Information System. S. Edward Boselly, (1998).
  • RP 138

    The purpose of this study was to optimize an initial Remote Weather Information System (RWIS) site plan developed by the Idaho Transportation Department (ITD). Questionnaires were sent to ITD District personnel to obtain information on perceived weather and pavement condition needs, snow and ice control practices employed by the personnel, and weather-related problems in various regions. Additionally, interviews were conducted in each District to further understand the needs. Finally, over 4000 miles of roads in Idaho were traveled to survey in a general sense the highway environment and the potential locations of RWIS sites. Following the analysis of the information gathered, lists of potential sites in each District were developed and sent to each District for their prioritization of site locations. The resulting lists of prioritized sites were consolidated into a single list of sites for initial implementation. Experience in the use of RWIS and evolving proactive maintenance practices may show that additional sites are necessary. As part of the analysis, additional sources of important weather information were identified, including RWIS sites in Montana, Washington and Oregon. Developing a formal RWIS implementation plan will be key to successful implementation, as will the management of all aspects of RWIS implementation and operations.
Abstract
RP 137 Development of ITD Design Standards for Integral Abutment Bridges. Richard J. Nielsen
  • RP 137

    No additional information is available at this time.
Abstract
RP 136 Monitoring the In-Situ Stresses in the Goff Bridge
  • RP 136

    No additional information is available at this time.
Abstract
RP 135 Idaho Statewide Transportation Planning Project. Karl Chang, Chhang Ream, Michael P. Dixon
  • RP 135

    No additional information is available at this time.
Abstract
RP 134 Traffic Signal Controller Interface. Zaher Khatib, (1999).
  • RP 134

    Traffic signal controller interface (AAP2LMS) was created as a link between popular signal optimization software and signal controller software. After performing signal optimization with the Arterial Analysis Package (AAP), using either PASSER II-90 or TRANSYT-7F, AAP2LMS effectively translates optimized signal timings into the format of interface software for TCT traffic signal controllers or other NEMA controllers. LM System Software is the interface software for TCT models LMD 8000 and LC 8000 controllers. If AAP and AAP2NEMA are installed on a system, as well as Microsoft Excel version 97, AAP2LMS can be used to translate any file group from AAP that has been optimized with PASSER II-90 or TRANSYT-7F and translated from single ring sequential to dual ring concurrent with AAP2NEMA. An example of this process is included within this paper.
Abstract  Final Report  User Manual
RP 132 Control Strategy for Signalized Intersections. Zaher Khatib & Fusan Linn, (1998).
  • RP 132

    Corridor traffic signal-timing synchronization is one of the most cost-effective methods for reducing delays and improving the overall operation along a congested corridor for all vehicles. Long delays at a series of signalized traffic intersections on US-95 in northern Idaho connecting Coeur d’Alene to Hayden has generated complaints by the local motorists. Traffic congestion due to the rapid population growth of Coeur d’Alene and long queuing times at critical intersections resulting from large number of visitors during the summer months are at the heart of these complaints. In order to provide smooth progression and fewer delays along the US-95 and its cross streets, TRANSYT-7F, PASSER II-90, TEAPAC, and CORSIM models were used to study and re-coordinate the signal-timing of the existing twelve coordinated fully actuated controlled intersections. The research project utilized PASSER II-90 and TRANSYT-7F to optimize progression and minimize delays, respectively, for motorists at all intersections. The PRENETSIM/TEAPAC was then used to create a preliminary input file for the CORSIM simulation model. This file was further calibrated to reflect the field data. The simulation output of the validated CORSIM model produced many measurements of effectiveness (MOE). MOEs such as speed, time delays, and queue length were compared among the EXISTING, APPLIED and PROPOSED signal-timing plans. The PROPOSED signal-timing plan showed significant improvements along the studied corridor.
Abstract  Final Report
RP 131 Development of Microstation Tools to Compute Circuit Requirements and Lighting Design Elements. Barry Klas, Michael Kyte & Melissa Lines, (1999).
  • RP 131

    This research consists of two projects: 1- developing a software tool, called Circuit Comp that runs within MicroStation and provides lighting circuitry graphics and also calculates the minimum wire gauges for various electrical circuits in illumination and signalization; 2 - researching the feasibility of developing a software tool that provides complete computer aided road lighting design, also within MicroStation. For the first project, development of Circuit Comp, the Software Requirements Specification (SRS) and the Software Design Description (SDD) have been completed (see Appendices A and B of this report), along with a prototype of the program’s circuit calculation algorithm, called Wire Comp. Phase II of this project will consist of completing development of the Circuit Comp software. For the second project, researching the feasibility of a comprehensive road lighting design program, the study suggests the program be developed in three stages: first, write a program that would calculate the illumination of a given light configuration; second, consider expanding the program to include pre-existing roadway templates with pre-set light placement patterns; third, develop the program further to perform all calculations and automatically place light units on the design plan. Phase III of this project will consist of development of the light fixture placement software.
Abstract
RP 130 Statewide and Sub-area Transportation Model Feasibility Study. Zaher Khatib; Karl Chang; Yanmei Ou; & Monica Bielenberg, (1997).
  • RP 130

    In this research, a feasibility study to develop an Idaho statewide transportation model is conducted. Review of statewide transportation models from Florida, Wyoming, Michigan, Vermont, Indiana, and Pennsylvania is conducted to summarize the most appropriate procedure for developing a statewide model. On the local level, the transportation planning effort in Idaho is reviewed. This effort includes review of the metropolitan planning organization models as well as Idaho commodity flows, which will be the basis for the statewide model. A review of the transportation planning software packages is conducted to select the most appropriate package for statewide modeling. The research team recommends Transplan as the outweighing package for Idaho statewide modeling. A transportation model requires the input of a transportation network, traffic data and land use data. Therefore, the availability of existing digital databases is assessed. This study has constructed the foundation for developing the Idaho statewide travel demand model. On the basis of this feasibility study, ITD will implement phase two of this project, the development of the Idaho Statewide Transportation Model. The proposal for the model is represented in the final section of this report.
Abstract  Final Report
RP 129 Economic Impact of Work Zone Travel-Time Delays. Donald F. Haber
  • RP 129

    No additional information is available at this time.
Abstract
RP 128 Camber Growth in Prestressed Concrete Bridge Girders. Krista M. Brown; Richard J. Nielsen & Edwin R. Schmeckpeper, (1998).
  • RP 128

    In this study, the author examines existing models for predicting camber growth of precast prestressed concrete bridge girders including the present method utilized by the Idaho Transportation Department (ITD). The camber growth of these girders is affected by time-dependent concrete properties, which include modulus of elasticity, creep and shrinkage. The types of girders and manufacturers’ practices are also factors. To allow a detailed analysis, this study focuses on the types of bridge girders designed by ITD and manufactured by local prestressed concrete plants. As a result, the author proposes a time-dependent model for predicting the camber of precast prestressed concrete bridge girders at any age. The author also develops a simple formula for estimating the camber at erection. The camber that is predicted by both methods is compared to data that were provided by girder manufacturers. The coefficients presented in the simple formula are appropriate for the types of bridge girders designed by ITD and manufactured locally. However, the general procedures described in the time-dependent model provide for the derivation of coefficients suitable elsewhere.
Abstract  Final Report
RP 127 Brief 4 Installation of Soil-Pinned Geosynthetic Reinforcement for Slope Stabilization. Stanley M. Miller, (1997).
  • RP 127 Brief 4

    No additional information is available at this time.
Abstract  Final Report
RP 127 Brief 3 Initial Evaluation of Shrub Transplanting Programs for Highway Slopes. Stanley M. Miller, (1997).
  • RP 127 Brief 3

    No additional information is available at this time.
Abstract  Final Report
RP 127 Brief 2 Back-Analysis of Failed Roadway Slopes. Stanley M. Miller, (1997).
  • RP 127 Brief 2

    No additional information is available at this time.
Abstract  Final Report
RP 127 Brief 1 Initial Evaluation of Organic Soil Amendments for Disturbed Highway Slopes. Stanley M. Miller, (1997).
  • RP 127 Brief 1

    No additional information is available at this time.
Abstract  Final Report
RP 127 Integrated Erosion Control Methods For Highway Construction and Slope Maintenance. Stanley M. Miller PhD., James L. Kingery PhD., (1998).
  • RP 127

    A multi-disciplinary research project was funded in late 1996 to investigate new technologies for erosion and sediment control, including a focus on shallow-seated slope failures. The research utilized an approach involving plant science, geotechnical engineering, and new technology regarding soil biostimulants and organic soil amendments used to enhance low-fertility sites, such as those common to disturbed highway slopes. Field demonstration plots were established and monitored at several locations across southwestern Idaho and northern Idaho. Existing slope failures in the Moscow-Lewiston area were mapped and described for engineering back-analysis and investigation. The primary goal was to provide technical information and field experiences that would lead to enhanced highway slope design, planning, construction, maintenance, and rehabilitation. Deep-rooted shrub species were identified and transplant studies were conducted to evaluate survivability and potential erosion control benefits. Initial field tests and demonstration plots were used to evaluate seeding prescriptions and soil treatments that provide organic matter to enhance biological activity on sterile, disturbed sites. Shallow-seated slope failures were investigated through soil direct-shear testing and engineering back-analysis of existing failures; potential treatments were studied and a case study was conducted for a geosynthetic slope reinforcement system.
Abstract  Final Report
RP 125 ITD Update of Winter Maintenance Complement Prediction Model. Donald F. Haber, (1996).
  • RP 125

    Two models that were developed for Idaho Transportation Department in 1989-1990, one for predicting Cost/Benefits for changes in Winter Level of Service and one for Winter Maintenance complement determination were revised to include data up to 1994. The Benefit/Cost computer prediction model was completely rewritten to include the new data on yearly traffic volume and yearly winter maintenance costs. The revised model software was written in Visual Basic and was developed to be compatible with the six maintenance districts computer facilities. An output from a hypothetical change in winter maintenance levels is illustrated. The Average Storm Hours for ten winter seasons (1984-1994) for 42 foreman areas and the six districts were determined. The Average Storm Hours for each of the six districts were compared with the overall state average value. This comparison was then used to recommend priorities for changes in winter complements in the six districts.
Abstract  Final Report
RP 124 Phase 1 Monitoring and Modeling Subgrade Soil Moisture For Pavement Design and Maintenance in Idaho. James Hardcastle, Fouad M. Bayomy, (1996).
  • RP 124 Phase 1

    The objective of this project was to monitor and evaluate moisture conditions in the subgrade and base in pavement sections constructed with both "Rock Cap" and crushed aggregate base. Frost depth, soil temperature and deflection measurements will be included. With these data, the value of the "Rock Cap" in increasing pavement life and in allowing a thinner surface course will be evaluated. Phase I included 1) identification of instrumentation equipment and development of data collection protocol, 2) identification of pavement sites to reflect different regions of the state and 3) development of work plan and budget for the entire project period (3-5 years).
Abstract  Final Report
RP 124 Monitoring and Modeling Subgrade Soil Moisture for Pavement Design and Maintenance in Idaho, Phase III: Development of Scope of Work. James H. Hardcastle & Fouad M. Bayomy, (2005).
  • RP 124

    Environmental changes have a direct impact on the structural capacity of the pavement, and consequently its performance. While the subgrade soil and the unbound materials are sensitive to moisture variation, the Asphalt Concrete (AC) layers are more sensitive to temperature variations. Quantifying the effect of these two environmental factors, moisture and temperature, is necessary for incorporation in the pavement design process. The main goal of this research was to quantify the variation of subgrade moisture and asphalt surface temperature at various sites in Idaho and determine their effects on the structural capacity of the pavement layers, and hence determine their influence on the pavement performance. In addition, the impact of the existence of a rockcap base layer on the moisture regime in the subgrade and its effect on the overall pavement structural capacity was to be evaluated.
    Results of the mechanistic analysis, which incorporated the developed models, indicated that the incorporation of the seasonal variation in pavement design process leads to the prediction of significantly shorter pavement service life. This finding is critical to pavement designers, since the lack of consideration of such seasonal variations could result in a premature failure.
    To determine the rockcap base layer effectiveness, moisture data at the Moscow and Weiser sites were analyzed. Results showed conflicting trends. In Moscow site, the subgrade experienced more moisture under the rockcap base while the opposite was observed in Weiser. It is believed that the extension of the rockcap layer to the open side ditches, as in Weiser site, allows the surface water to drain away relieving the subgrade from the excess moisture. On the other hand, where the rockcap is enclosed, as in Moscow site, the water in rockcap is entrapped and it drains downward causing the subgrade moisture to increase. However, the mechanistic analysis performed at these two sites, showed that the section with rockcap layer was consistently stronger than the section with aggregate base, odd though the subgrade moisture content under rockcap layer was greater. The predicted rutting life, for the pavement section with rockcap layer, was about 5 times greater than the other section with aggregate base. Thus, the presence of rockcap base was always effective in increasing the pavement structural capacity and increasing the fatigue and rutting service lives.
Abstract  Final Report
RP 122 Prestressed Bridge Girder Design Program (WINPSBRG.EXE: Windows Version of PSBRG.EXE). Edwin R. Schmeckpeper, (1999).
  • RP 122 Brief

    The ITD Bridge Design Section has utilized the computer program PSBRG (PreStressed Bridge Girder) since the early 1970s. Originally, this program, written in FORTRAN computer language, operated on a main frame computer. Since that time, the program has been upgraded on several occasions and rewritten in BASIC computer language for use on personal computers. Over the years, the program has been modified to accommodate ITD standards and requirements and is a useful and extremely productive program for the Bridge Section. This project revised and updated PSBRG into a Windows-based program.
Abstract
RP 121 WINFLEX - Mechanistic Empiracal Overlay Design System for Flexible Pavement - Program Documentation. Fouad M. Bayomy, (2006).
  • RP 121

    The development of this computer program was performed through a series of contracts with ITD. The first contract (Research Project RP 121, Agreement No. 95-60) dealt with the system development and its implementation in computer software. The first version of the software was DOS-based due to the fact that Fortran computer language was only available in the DOS environment. The first version of the program was named FLEXOLAY. It was developed using two computer languages - Fortran 77 and Visual Basic for DOS. It was released in 1996. Shortly after Microsoft release of the Fortran Power Station 4.0 for Windows, an upgrade of the FLEXOLAY program to operate under Windows was requested by ITD. Hence, the first windows-based program (WINFLEX 97) was developed under ITD project RP 121 Phase. The upgrade included not only the transfer to a new computer environment, but also included new design features in the program. For example, FLEXOLAY could only design an overlay for a single pavement section, while WINFLEX 97 can design overlay for multiple pavement sections at the same run. The next release of WINFLEX was developed under Windows 2000 operating system. The WINFLEX 2000 was developed under NIATT project No. KLK456 and has been included in the ITD materials manual. It contained two main codes using two computer languages - Visual Basic 6.0 and Fortran Power Station 4.0.
    The latest version is the WINFLEX 2006, which was initiated under NIATT project No. KLK492. It built on the WINFLEX 2000 and addressed many programming bugs that were discovered during the previous several years.
Abstract  Final Report
RP 121 Phase 2 V 2 Development of Recommendations and Guidelines For Pavement Rehabilitation Design Procedures For The State of Idaho. Fouad M. Bayomy, Walid M. Nassar, Fawzi Al-Kandari, (1996).
  • RP 121 Phase 2 Volume 2

    This report presents the WINDOWS 95 version of the previously developed FLEXOLAY program by the University of Idaho. It is a mechanistic-based overlay design procedure which incorporates the in-situ pavement layer moduli values evaluated by deflection based non-destructive testing using the Falling Weight Deflectometer. The upgrade was not only a transfer to a new language, but also an enhancement of design features. In WINFLEX, a damage analysis is conducted to assess the remaining life of the existing pavement using fatigue and rutting failure criteria. The program provides the user with the ability to choose from nine different fatigue models and six different rutting models used by agencies around the world. Shift factors account for construction variability, differences between laboratory and actual field state of stress, and other unknown factors. WINFLEX also addresses temperature correction for different asphalt, environmental factors, and multiple location designs. Enhancements were also made to the output, printing and storage capabilities. An export feature was added in order to export the output to other Windows applications, such as: MSWord, Excel, and Notepad. WINFLEX contains two main codes using two computer languages: Visual Basic 4.0 and FORTRAN Power Station 4.0 (FORTRAN 90).
Abstract  Final Report
RP 121 Phase 2 V 1 Development of Recommendations and Guidelines For Pavement Rehabilitation Design Procedures For The State of Idaho. Fouad M. Bayomy, Walid M. Nassar, Fawzi Al-Kandari, (1996).
  • RP 121 Phase 2 Volume 1

    This report presents the WINDOWS 95 version of the previously developed FLEXOLAY program by the University of Idaho. It is a mechanistic-based overlay design procedure which incorporates the in-situ pavement layer moduli values evaluated by deflection based non-destructive testing using the Falling Weight Deflectometer. The upgrade was not only a transfer to a new language, but also an enhancement of design features. In WINFLEX, a damage analysis is conducted to assess the remaining life of the existing pavement using fatigue and rutting failure criteria. The program provides the user with the ability to choose from nine different fatigue models and six different rutting models used by agencies around the world. Shift factors account for construction variability, differences between laboratory and actual field state of stress, and other unknown factors. WINFLEX also addresses temperature correction for different asphalt, environmental factors, and multiple location designs. Enhancements were also made to the output, printing and storage capabilities. An export feature was added in order to export the output to other Windows applications, such as: MSWord, Excel, and Notepad. WINFLEX contains two main codes using two computer languages: Visual Basic 4.0 and FORTRAN Power Station 4.0 (FORTRAN 90).
Abstract  Final Report
RP 121 Phase 2 WINFLEX for WINDOWS 95 - A Mechanistic-Empirical Overlay Design System for Flexible Pavements (User's Guide and Tutorial Examples). Fouad M. Bayomy & Walid M. Nassar, (1997).
  • RP 121 Phase II

    This report presents the WINDOWS 95 version of the previously developed FLEXOLAY program by the University of Idaho. It is a mechanistic-based overlay design procedure which incorporates the in-situ pavement layer moduli values evaluated by deflection based non-destructive testing using the Falling Weight Deflectometer. The upgrade was not only a transfer to a new language, but also an enhancement of design features. In WINFLEX, a damage analysis is conducted to assess the remaining life of the existing pavement using fatigue and rutting failure criteria. The program provides the user with the ability to choose from nine different fatigue models and six different rutting models used by agencies around the world. Shift factors account for construction variability, differences between laboratory and actual field state of stress, and other unknown factors. WINFLEX also addresses temperature correction for different asphalt, environmental factors, and multiple location designs. Enhancements were also made to the output, printing and storage capabilities. An export feature was added in order to export the output to other Windows applications, such as: MSWord, Excel, and Notepad. WINFLEX contains two main codes using two computer languages: Visual Basic 4.0 and FORTRAN Power Station 4.0 (FORTRAN 90).
Abstract  Final Report
RP 119(C) Ground Penetrating Radar Evaluation. Joseph Sener, (1999).
  • RP 119C

    The Idaho Transportation Department (ITD) conducted a series of ground penetrating radar (GPR) surveys as a non-destructive testing (NDT) method to evaluate the thickness of asphalt and Portland cement concrete pavements, and assess the progressive deterioration and structural condition of bridge decks in Idaho during 1995 and 1996. GPR surveys employed both air coupled (A-C) and combination air and ground coupled (A-G-C) systems with their associated equipment and software. A total of 30 miles of pavements and three bridge decks were evaluated by GPR surveys to assess the applicability of GPR to conditions encountered in Idaho. The obtained results were correlated with the site-specific ground-truth data (GTD). For conditions identified in Idaho, it is recommended both GPR systems could be considered to determine the pavement surface course thickness for both project and network level surveys, although it has been noticed that the A-G-C system (Road Radar TM) is capable of predicting the GTD more accurately than the A-C system (Infrasense). The proper estimation of the base course layer thickness should include occasional cores to provide higher accuracy to collected data by both GPR systems. The estimation of the depth to reinforcing steel (concrete thickness) and the asphalt overlay thickness at bridge decks should include cores to provide reliability for collected GPR data. Finally, the reliability of the GPR bridge deck condition survey evaluation results can not be assessed objectively.
Abstract  Final Report
RP 119A Ground Penetrating Radar Evaluations. (1998).
  • RP 119A

    The Idaho Transportation Department (ITD) conducted a series of ground penetrating radar (GPR) surveys as a non-destructive testing (NDT) method to evaluate the thickness of asphalt and Portland cement concrete pavements, and assess the progressive deterioration and structural condition of bridge decks in Idaho during 1995 and 1996. GPR surveys employed both air coupled (A-C) and combination air and ground coupled (A-G-C) systems with their associated equipment and software. A total of 30 miles of pavements and three bridge decks were evaluated by GPR surveys to assess the applicability of GPR to conditions encountered in Idaho. The obtained results were correlated with the site-specific ground-truth data (GTD). For conditions identified in Idaho, it is recommended both GPR systems could be considered to determine the pavement surface course thickness for both project and network level surveys, although it has been noticed that the A-G-C system (Road Radar TM) is capable of predicting the GTD more accurately than the A-C system (Infrasense). The proper estimation of the base course layer thickness should include occasional cores to provide higher accuracy to collected data by both GPR systems. The estimation of the depth to reinforcing steel (concrete thickness) and the asphalt overlay thickness at bridge decks should include cores to provide reliability for collected GPR data. Finally, the reliability of the GPR bridge deck condition survey evaluation results can not be assessed objectively.
Abstract  Final Report  Presentation
RP 117 Evaluation of Unpainted Weathering Steel Bridges in Idaho. Richard A. Jobes, (1996).
  • RP 117

    Some states have reported problems with excessive corrosion of unpainted A588 weathering steel bridges. Considerable savings in initial and life cycle costs are anticipated when using weathering steel, but only if good long range performance is attained. The Idaho Transportation Department conducted its first in-depth study of a representative group of 12 weathering steel bridges to determine their present condition. Weathering steels develop a protective oxide coating that shields the underlying steel base from further corrosion when certain conditions are met. All weathering steel bridges in Idaho were identified and current inspection reports were reviewed. Data collected from the field inspections includes: visual observations of the conditions of the protective oxide coating (color, texture, adherence), conditions and details that cause corrosion problems, and plate thickness measurements with an ultrasonic gage. Samples of the oxide coating were tested for chlorides. Field inspections indicate the unpainted weathering steel on the bridges inspected is performing very well. Small areas of localized corrosion were found on four bridges. These problems can be corrected with proper design and maintenance. Continued use of unpainted weathering steel in bridges appears justified.
Abstract  Final Report
RP 116(B) Applications of Video Based Traffic Detection Systems in Idaho: A Progress Report. Michael Kyte; Matthew Zoll; Joanne Buteau & Melissa Lines, (1999).
  • RP 116B

    The infrastructure that makes up Intelligent Transportation Systems (ITS) includes elements such as traffic control systems, freeway management systems, and incident management programs. One technology common to these infrastructure elements is machine vision technology, known as video based traffic detection. Video based traffic detection uses computing, video and communications technologies to provide critical information on the operation of a highway or traffic system. In 1992, the University of Idaho's National Institute of Advanced Transportation Technology (NIATT) developed a laboratory to study video based traffic detection. This report describes the results of six research projects focused on video based traffic detection technology NIATT and ITD have jointly conducted. Video based traffic detection systems produce accuracy levels that are comparable to or exceed results produced by standard in-pavement loop detectors. The systems can be installed without disrupting either traffic flow or the pavement structure. Video based systems are not subject to the same freeze-thaw pavement cycles that commonly break in-pavement loop detector connections. Based on the positive findings, the application of video based traffic systems should be seriously considered for traffic signal control, freeway traffic management and data collection.
Abstract  Final Report
RP 116(A) AutoPayItem User’s Manual (API Version 3.0). (2002).
  • RP 116(A)

    AutoPayItem User’s Manual (API Version 3.0).
User Manual
RP 115 The Effects of Over-Tightening High-Strength Bolts Used in Bolt Connections in Bridges. Guy Phillips; Edwin R. Schmeckpeper; & Richard J. Nielsen, (1994).
  • RP 115

    This report describes the research program conducted on high-strength bolts and connectors that have been over-tightened. Direct-tension indicators (DTI) may be specified for use on high-strength bolts to verify that the bolts have been sufficiently tensioned. This research was initiated at the request of the Idaho Transportation Department in order to resolve questions concerning the use of bolts installed with DTI which had been tightened to zero gap readings.
Abstract  Final Report
RP 112(C) Idaho Statewide Trip Generation Rates and Friction Factors. Karl Chang, Chhang Ream, Joe Geigle & Michael Dixon, (2001).
  • RP 112C

    In June 1999, ITD in collaboration with the Department of Commerce and other agencies participated in a statewide travel survey, “1999-2000 Idaho Resident and Nonresident Motor Vehicle Travel Survey.” Using the highway intercept method and a mail-back questionnaire, the survey collected data on traveler characteristics, trip characteristics, and many other variables from resident and nonresident travelers in Idaho. This report describes the activities that have been completed for the Idaho Statewide Trip Generation Rates and Friction Factors project, the purpose of which was to use the survey data to develop Idaho-specific trip generation rates and friction factors.
Abstract  Progress Report  Final Report
RP 112(B) Development of Recommendations and Guidelines for Pavement Rehabilitation Design Procedures for the State of Idaho - Phase I: Software Evaluation and Data Analysis. Fouad M. Bayomy & Rahat Zafar Ali Shah, (1993).
  • RP 112(B)

    This report presents the results of a project meant to develop design procedures for pavement rehabilitation including inlay and overlay design for the State of Idaho. Specific objectives addressed included 1) survey of existing programs, 2) investigation of FWD data at ITD and verification of modului calculation, 3) identification of possible causes of deviations and errors affecting prediction of modului values, 4) development of recommendations for possible improvements and 5) development of recommendations and guidelines for inlay and overlay design procedures. Two back-calculation p0rograms (MODULUS 4.0 AND EVERCALC 3.3) were used to determine and analyze pavement layer moduli for twelve road sections in Idaho. Both programs are generally acceptable for use in a three-layer system, however MODULUS 4.0 may be preferred since it is faster. The thickness of the pavement layers should be input as accurately as possible. Better results were observed for thicker pavements where the surface layer thickness is greater than 4 inches. The presence of a CTB layer will generally affect the accuracy of results. A number of recommendations are made for the use of back-calculation software.
Abstract  Final Report
RP 112(A) Determining the Feasibility of Using Video Imaging Techniques to Collect Transportation Data. Ashfaq Ali Khan & Michael Kyte, (1993).
  • RP 112(A) Final

    This report presents the findings of a study to 1) detect oversize vehicles at ports-of-entry and 2) collect traffic data on congested freeways and arterials. The results from this project indicate that it is possible to measure truck height, length, width and freeway volumes. Future work for measuring these parameters by using autoscope can be improved by considering the parameters of camera alignment, site geometry, and future improvements in the autoscope system for each case if applicable. The study included developing and testing alternative video imaging techniques and software processing capabilities.
Abstract  Final Report
RP 111(D) Forecasting Travel Demand on Idaho Highways. Michael Kyte, (1993).
  • RP 111(D)

    The purpose of this report is to present a methodology which was developed for forecasting future traffic volumes on Idaho highways. The traffic forecasting model forecasts total traffic, commercial traffic and truck weight or ESALS. These forecasts would be used by ITD traffic, materials and pavement engineers; highway designers; and planners in evaluating various projects and improvements. Time series analysis methods can be used to forecast future traffic volumes when a good historical database exists. Such a data base is available to the Idaho Transportation Department through the data generated by the Automatic Traffic Recorder stations located throughout the state. This report describes the process that can be used to develop time series models using the SAS software. Forecasts prepared for both total traffic and truck traffic using time series models show that this method has considerable merit. Forecast errors are reasonable and compare favorably with other methods. It is recommended that ITD implement the use of this technique on a trial basis.
Abstract  Final Report
RP 111(C) Development of a Methodology to Determine Appropriate Traffic Control for Intersections. Michael Kyte, Wade Allen, Sharon Feeley, Leroy Slemmer & Travis Hopkins, (1992).
  • RP 111(C)

    This report presents the results of a research project designed to develop a methodology that would allow a traffic engineer to determine for a range of traffic flow and geometric conditions, the most efficient traffic control strategy for a given intersection. Three basic kinds of control strategies were considered: signal control, two-way stop control and all-way stop control. Vehicle delay has been selected as the appropriate measure of effectiveness for this study. The report 1) summarizes how warrants and other guidelines are now used to select the appropriate kind of intersection control, 2) describes the methods available to calculate delay for various kinds of intersection control using several simulation models, 3) describes the results of simulation of single-lane and multi-lane approach intersections, and 4) presents the development of a methodology to determine control based on the results of the simulations. Simulation models for signal control, all-way stop control (AWSC) and two-way stop control (TWSC) were used to produce delay estimates. For single lane approach intersections, when approach volumes exceed 300 vph, signal control yields minimum subject approach and intersection delay. When major street volumes are less then 500 vph, AWSC yields minimum delay.
Abstract  Final Report
RP 111(B) Performance Life of Asphalt Concrete Overlays Governed by Fatigue Cracking Variables. Robert P. Lottman & Stephen Breje, (1991).
  • RP 111B

    In this study, a procedure is developed and the results are shown for a mechanistic approach to the prediction of fatigue cracking in asphalt concrete overlays. Results indicate that the performance life is mainly proportional to overlay thickness and to lack of cracking and faulting of the existing asphalt concrete surface. Implication is that a good correlation is needed between cracking condition of the existing asphalt concrete surface and its "slab-modulus" analog for computer program overlay strain calculation. This can be an objective of a pavement management program. the soil modulus was found to have a small effect for the range of site variables and for the incremental overlay cracking procedure used. The estimated fatigue cracking performance lives (total ESAL) are approximately 7 times those lives corresponding to the method of spontaneous fatigue cracking up through the overlay when the bottom-most overlay cracks. This indicates that the total ESAL's predicted by the procedure in this study should not require the use of a "field factor" multiplication constant that has been conventionally used in the past. Numerical examples are shown for selecting overlay thickness to resist fatigue cracking which incorporate site variables, varying ESAL rates and different design years.
Abstract  Final Report
RP 110(D) Subgrade Resilient Modulus for Idaho Pavements. James H. Hardcastle, (1992).
  • RP 110(D)

    This report documents a method for estimating seasonal values of resilient moduli of subgrade soils proposed for use with the 1986 AASHTO flexible pavement design guide. The method consists of applying a series of adjustment coefficients to a "reference resilient modulus," defined as the most probable resilient modulus measured on a soil compacted to 100 percent of the AASHTO T-99 maximum dry weight at optimum water content with a bulk stress of 10 psi. Reference resilient moduli are provided from a literature review for twelve soil classes as a function of grain sizes and soil plasticity.
Abstract  Final Report
RP 110(C) Benefit Cost Analysis of Winter Maintenance Levels of the Idaho Transportation Department. Donald F. Haber. & Umesh S. Limaye, (1990).
  • RP 110C

    This study is submitted as a phase 1 of an applied cooperative research project commissioned by ITD to analyze benefits and costs associated with the winter maintenance activities. The objective of the research is to formulate a model, based on historic data, to predict costs and benefits associated with winter maintenance. The model could then be used as a tool for setting winter maintenance standards. Cost is affected by steady-state and transient factors. A steady state model and 6 transient models – 1 for each district were formulated to predict winter maintenance cost using multiple regression analysis. Although no quantitative model could be formulated to express fatalities and injuries because o f insufficient data, it was statistically shown that injury rate on road sections decreased with an increase in the level of winter maintenance. Benefits related to delay time, comfort and conve4nience were quantified using the stochastic simulation. A computer program was developed for use of a PC type computer to illustrate the simulation of benefits and prediction of costs associated with changes in winter maintenance levels for any specified road section.
Abstract  Final Report
RP 110(B) Capacity and Delay Characteristics of Two-Way Stop-Controlled Intersections. Michael Kyte; Chris Clemow & Naseer Mahfood, (1991).
  • RP 110B

    This report has four objectives: 1) present a data base for TWSC intersections to be used to investigate factors influencing delay and capacity, 2) identify factors that affect delay and capacity at TWSC intersections, 3) develop a set of practical equations and data for the traffic engineer, and 4) suggest areas for further research that will lead to specific models or procedures to estimate the delay and capacity of TWSC intersections. Traffic flow, delay and geometric data were collected at nine TWSC intersections in the Pacific Northwest encompassing 13 hours of intersection operation. Nearly 2000 accepted and rejected gaps were recorded. Common characteristics included: four approach legs, single lane approaches and 25 mph speed limits on the major street. Several factors were identified that may influence delay and capacity at TWSC intersections: time waiting in queue, time waiting at the stop line, flow rate on the conflicting approaches, length of time vehicle has been delayed, the major street flow rate, and the directional movement of the delayed vehicle. Equations for forecasting minor street capacity and delay have been developed that can be used by the traffic engineer to study the performance at TWSC intersections. Data for gaps has also been summarized.
Abstract  Final Report
RP 110(A) A Procedure to Calculate the Economic Benefit of Increased Pavement Life that Results from Port-of-Entry Operation. Shaun Parkinson; John Finnie; Dennis Horn & Robert Lottman, (1990).
  • RP 110A

    A calculation procedure has been developed to determine the economic benefit of increased pavement life that results from operation of a port of entry. It uses Weigh-in-Motion data and the AASHTO ESAL tables to evaluate the percentage of overloaded trucks and their equivalent ratio. These values are used to calculate a reduction of pavement life. The cost of reduced pavement life is based on construction and rehabilitation costs of a typical asphalt highway section with an assumed life of 36 years.
Abstract  Final Report
RP 109(D) Pavement Deflection Data at the Long-Term Monitoring Sites in Idaho for Structural Performance. Sunil Sharma; Robert P. Lottman & Scott R. Ward, (1989).
  • RP 109D

    This final report presents the results of an evaluation of the Dynaflect deflections measured on asphalt concrete pavements at the Long Term Monitoring sites in Idaho. A Brief discussion of cross-slab deflections for Portland cement concrete pavements is also presented. An attempt was made to seek possible correlation between deflections and surface cracking. Details about the methodology, a discussion of the results, and conclusions and recommendations for future research are provided.
Abstract  Final Report
RP 109(C) Determination of a Model to Predict Winter Maintenance Personnel Levels. Donald F. Haber; M. Maloney & D. Horn, (1989).
  • RP 109C

    The purpose of this report is to provide the Idaho Transpiration Department with a model - a tool - which will help it make winter storm personnel staffing decisions which will maximize limited resources in a manner viewed by all personnel as having been made as fairly and objectively as possible. The previously used formula for assigning personnel to the various foreman areas addressed the number of lane-miles per person for four different types of terrain and four different levels of service. The subjective nature of the terrain type resulted in perceived inequities. The objective of the research was to identify the primary factors which influence the personnel requirements during peak storm oddts throughout the state and use these factors to model the personnel needs of each foreman area. Multiple regression analysis was the principle technique used. A model was developed and recommendations made on the review process that should be followed before the model is accepted and implemented.
Abstract  Final Report  Addendum
RP 109(B) Estimating Capacity and Delay at a Single-Lane Approach All-Way Stop-Controlled Intersection. Michael Kyte & Joseph Marek, (1989).
  • RP 109B

    The purpose of this report is to present the results of a study of single-lane approach all-way stop-controlled intersections. Data have been collected for nearly twenty-five hours of operation for eight sites in Idaho, Oregon and Washington. Estimates of capacity and of the nature of the delay-flow rate relationships have been made for the eight sites. A methodology for analyzing operational performance is proposed. This study is part of a larger effort in which data have been collected for twenty-three all-way stop-controlled intersections in Idaho, Oregon, Washington, Iowa, Colorado, and Texas. In the next phase of this study, the effects of non-standard conditions (number of approach lanes, pedestrians, heavy vehicles, etc.) will be considered.
Abstract  Final Report
RP 109(A) STBLIN - An Interactive Data Preparation Program for Slope Stability Program – STABL. Sunil Sharma, (1988).
  • RP 109A

    The purpose of this report is to serve as a reference manual providing a brief background to the STBLIN program as well as a guide to the structure and hierarchy of numerous menus and tables within the program. The program, STBLIN, has been developed to facilitate the data preparation phase required for using the slope stability program, STABL. The program is intended for use on an IBM-PC, or nearly compatible, suitably equipped for generating screen graphics. The program uses a suite of menus and data tables to guide the potential user through the many options offered by the STABL program. The approach offered by using the program STBLIN should minimize user error.
Abstract  Final Report
RP 105 Full Scale Experimental Investigation of the Structural Response of the Bonners Ferry Bridge. Donald F. Haber & Dale C. Perry, (1987).
  • RP 105

    The purpose of this report is to present results of an experimental investigation of the structural response of the new Bonners Ferry Bridge. The research study for this bridge project was undertaken because of the unique design which incorporated for the first time the use of post-tensioned steel plate girders. The objectives of the study were three-fold: 1) prior to construction, compute anticipated axial and bending stresses in various members for several stages of loading as well as design, assemble, calibrate and test the monitoring system; 2) during construction, monitor the girder post-tension stresses and tendon force at the stressing of the tendons and record field data for each stage of construction; and 3) after construction, record field data for test truck, compile data and compare results from field study with predicted responses from finite element techniques.
Abstract  Final Report
RP 102 Selection and Evaluation of Methods and Treatments for Acceptable Fatigue Life of Moisture-Susceptible Dense-Graded Asphalt Concrete: Southern Idaho Aggregates. Robert P. Lottman, (1983).
  • RP 102

    This report presents the results of a study to determine the long term fatigue loading on selected, treated and untreated asphalt mix design. The objective of the study was to evaluate four aggregate sources in southern Idaho from the basis of moisture damage susceptibility when the aggregate is incorporated into dense-graded asphalt concrete mixes. Field cores and performance information from four representative pavements were used with the laboratory test information obtained from laboratory specimens. Laboratory mechanical indicator tests that were used to reflect the moisture damage susceptibility were: splitting tensile strength, resilient modulus and repeated stress diametrical fatigue. These tests were performed on dry, vacuum saturated and accelerated conditioned laboratory specimens and cores. Three of the four aggregate source mixes were evaluated both in untreated and treated conditions. Pavement lives were predicted by two calculation methods using both the spitting tensile strength ratios and the fatigue lines.
Abstract  Final Report
RP 101 Evaluation of Idaho's First Sulphur Extended Asphalt (SEA) Pavement, Demonstration Project No. 54. E. K. Montgomery, (1982).
  • RP 101

    A 17.6 mile surfacing project was recently completed on Idaho State Route 14 near Elk City. The project consisted of experimental Sulfur Extended Asphalt (SEA) pavement and conventional asphalt cement (AC) pavement. This report covers the design and construction features of the experimental paving material and makes comparisons between SEA and conventional paving materials. Mix design was based upon the Hveem method for both AC and SEA mixes. Lab recommendations were 6.0% AC for the conventional mix and 7.3% SEA binder for the experimental mix. Construction of both pavement types utilized the same equipment. No significant differences in the two materials were noted. The SEA pavement was more susceptible to tenderness than the AC pavement and compaction had to be performed at a lower temperature. This project incorporated use of solid sulphur and sulphur-melter since the haul distances made it impractical to import molten sulphur. Although the capacity of the equipment was not adequate, the process of on-site melting proved to be a workable method of producing SEA mix.
Abstract  Initial Report
RP 99(3) Evaluation of the Impacts of Increasing Truck Weights on Two Pilot Project Routes in Idaho. Richard Nielsen, Fouad Bayomy, Michael Kyle, Melissa Lines, (1999).
  • RP 99(3)

    In 1998 the Idaho legislature amended Idaho Code 49-1001 to allow higher weight trucks to operate on two pilot project routes in Idaho. Currently, the maximum gross vehicle weight (GVW) allowed in Idaho is 105,500 lbs. This amendment allows trucks to operate at gross weights up to 129,000 pounds. The Idaho Transportation Department (ITD) desired an independent analysis, evaluation, and report on the impacts of this legislation on Idaho's bridges, pavement, and traffic safety and operations. ITD requested that the University of Idaho's National Institute for Advanced Transportation Technology (NIATT) conduct this evaluation.
    A direct measurement of the physical impacts of the higher weight trucks has not been possible during the first year of this project. Changes to pavement and bridge structures are not measurable over such a short period of time, and the number of trips by higher weight trucks is not currently a significant portion of the overall truck traffic stream.
    Therefore, this scoping study accomplishes 3 limited tasks: it oulines current and predicted truck traffic on the two pilot routes, and it provides an examination of the effects of this shift on pavement, bridges, and traffic safety and operations. It also identifies key concerns and areas requiring more investigation.
Abstract  Final Report
RP 99(2) Evaluation of the Impacts of Reducing Truck Speeds on Interstate Highways in Idaho, Phase III. Michael Dixon, (2000).
  • RP 99(2)

    The 1998 Idaho Legislature passed legislation that lowered the speed limit for a certain class of trucks operating on interstate highways. The speed limit change results in a differential of ten miles per hour between passenger cars and trucks with five or more axles weighing more than 26,000 pounds. Since uniformity in traffic speeds is an important factor in highway safety, speed differentials may reduce the safety of the highway. This study examines speed measurements taken at seventeen locations on interstate highways in Idaho, as well as crash statistics along these same highways, taken both before and after the change in truck speed limits. These measurements provide the information needed to make an assessment regarding the effect of the speed limit change. Following is a summary of the key findings of this study:
    • Passenger car speeds increased: mean speeds increased by 0.85 mph and 85th percentile speeds increased by 0.8 mph. Though this change is statistically significant, one cannot come to a definite conclusion regarding this, as the difference between the speeds is less than 1 mph.
    • Truck speeds declined slightly: mean speeds dropped by 1.0 mph, while 85th percentile speeds declined by 2.5 mph. While these changes are small, they are statistically significant and indicate that the travel speed of the faster trucks has decreased.
    • Speed differentials between trucks and passenger cars increased from 5.5 mph to 7.4 mph. Again, while this change is small, it is statistically significant.
    • The proportion of trucks violating the speed limit increased significantly from about 10 to 20 percent before the speed limit change to between 60 and 75 percent after the change.
    • The standard deviation of vehicle speeds including all vehicles did not increase, indicating that the overall uniformity in vehicle speeds remained unchanged.
    • Crash data did not increase as a result of the speed limit change.
    While the potential for a decrease in safety exists because of the speed limit differential, data collected show that a significant change in the safety level has not occurred. The passenger car-truck speed differential increased slightly. But the standard deviation in vehicle speeds has not increased. And, while the crash data is limited, there is no evidence of an increase in crashes involving trucks. The Idaho Transportation Department should continue to monitor the effects of the speed limit change, using both speed measurements and crash data.
Abstract  Interim Report  Final Report
RP 99 Effects of I-90 Construction Activities on Spawning Success of Kokanee (Oncorhynchus Nerka) in Coeur d'Alene Lake. David H. Bennett & Peter F. Hassemer, (1982).
  • RP 99

    The purpose of this study was to examine the effects of adding additional fill material to the Wolf Lodge Bay area of Coeur d'Alene Lake, compare spawning success of Kokanee salmon with other areas and based on these results, make recommendations on how to build spawning habitat for Kokanee salmon. Four study sites were established, one site was at the newly created construction site, one at an older highway fill, and two additional sites in areas unaltered by highway construction activities. At each of the study sites, underwater photographs were taken during the peak of the spawning season. Also, embryos were planted in the substrate at the various sites to quantify survival rates. Results of water quality analyses of interstitial water samples were compared among sites. Utilization of newly placed highway fills was similar to that in other areas surveyed. At all sites, Kokanee manifested preference for substrate with a range of median particle size from 21-90 mm of relatively homogeneous composition. Survival rates were similar between newly placed and older highway fills and greater than unaltered areas. No adverse water quality conditions could be attributed to the new and old highway fills. These results suggest that alterations to the shoreline of Coeur d'Alene Lake by highway construction activities have enhance survival of Kokanee embryos.
Abstract  Final Report
RP 97 Review and Modification of Resilient Modulus Test Procedures and Apparatus. James H. Hardcastle, (1981).
  • RP 97

    The purpose of this study was to evaluate the current procedures and equipment to perform resilient modulus tests on all types of flexible pavement materials. Specific results of this study will include improved practical procedures for test specimen preparation and conditioning, loading equipment designs, reliable test specimen response measurement and data recording systems. This second interim report briefly describes the work completed on the project during the period of 1 September 1980 and 30 June 1981. It covers 10 test equipment development, 2) test equipment and procedures evaluation, and 3) development of a comparative test plan. This report also contains an updated summary of the responses to the survey questionnaire on current resilient modulus testing practices. The emphasis of this report is on resilient modulus testing of subgrade soils.
Abstract  Final Report
RP 96 Polymer Concrete Bridge Deck Overlay near Murtaugh, Idaho. (1982).
  • RP 96

    This final report covers the evaluation and construction of a Polymer Concrete Bridge Deck Overlay. The users manual (FHWA RD-75-501) provided by Oregon gives information complete enough to design and estimate the work required for a type "A" and "B" deck treatment. Standard bridge deck finishing equipment equipped with heavy vibrators is capable of finishing and compacting polymer concrete overlays. Mixing equipment is not developed to handle the polymer materials. Mortar mixers having less than a yard capacity can handle the mixing. The Daffin mobile mixer mixes the material well but the liquid set time versus the mix set time problem has not been solved. The polymer materials are not performing as desired. The bonding to the deck is not adequate. Environmental changes are causing the damage. The Type "B" treatment did not provide a waterproof layer. Laboratory tests of the two layer system show water penetrates the system.
Abstract  Final Report
RP 95 Field Evaluation of the PAT Weigh-in-Motion System. Patrick Shannon, Ph.D. & Alon F. Stanley, (1986).
  • RP 95

    A reliable system for accurate weighing of trucks at highway speeds offers attractive potential for statistical data gathering, screening trucks for weight enforcement, and more efficient use of Port-of-Entry facilities and personnel. In a series of field trials from 1981 to 1983, ITD tested and evaluated the German made PAT Weigh-in-Motion system by recording data collected at highway speeds and comparing these data with static weights and measurements taken on the same trucks at the Bliss Port-of-Entry. Rigorous statistical analyses were conducted on data from the two major studies. While these studies did identify the more important operating variables, none of the statistical relationships demonstrated the precision necessary to use the models for predictive purposes. Operating at highway speeds, the PAT system evaluated in this project did not provide individual axle weights and spacing of sufficient accuracy to serve as direct substitutes for POE static weights and measurements. The results of these studies should provide useful information regarding the limitations and possible application of Weigh-in-Motion technology.
Abstract  Final Report
RP 94 A Calculator Program to Estimate Truck Coasting Speeds for Designing Gravel Arrester Beds. Alon F. Stanley, (1978).
  • RP 94

    This project was undertaken to provide an improved method for selecting the locations, lengths, and grades of gravel beds for stopping runaway trucks safely. A convenient program has been developed for use on desk calculators having proram storage of about 250 steps or more. It can be used to predict the speed of a coasting truck as it travels along a grade of varying steepness. Surface drag can be chosen to represent either pavement or a bed of loose gravel.
Abstract  Final Report
RP 88 Reducing Corrosion of Reinforcing Steel in Concrete Bridge Decks. J. L. Cosho, (1980).
  • RP 88

    The corrosion of reinforcing in concrete bridge decks and other structural members containing chloride ions (from deicing salts) results in the cracking and spalling of the surface concrete and the eventual destruction of the concrete. In this study, concrete block specimens, containing reinforcing steel, were exposed in the laboratory to solutions of 5% NaCl in water containing various other salts to determine if any corrosion inhibiting action could be detected. The salts investigated were calcium hydroxide, sodium carbonate, sodium silicate and calcium nitrate. Calcium hydroxide (hydrated lime) solutions showed little inhibiting effect, 1% sodium carbonate solutions tended to increase the rate of corrosion, while 10% sodium carbonate showed some inhibiting effect but is probably not practical because of its caustic nature. However, the sodium silicate and calcium nitrate solutions showed results that justify further study and field testing.
Abstract  Final Report
RP 87 Effects of Idaho Aggregate Gradation on Asphalt Paving Mix. Tri Buu, (1980).
  • RP 87

    This study is to investigate the effects of Idaho aggregate gradation on paving mix design. Four Idaho sources of aggregate were chosen for the study. For each source, three different gradations were made and subjected to the Hveem test. A general trend for the effects of the aggregate gradation on asphalt mix designs was not found. It appeared that gradation of each source had its own effect on the asphalt paving mix. It is found that for Source El-8, gradation does not have much effect on mix design. With Source Bk-117, gradation of 1/2" aggregate should be kept close to the lower limit of the gradation guide, the one that contains more coarse aggregate. Aggregate gradation from Source Ad-56 also should contain more coarse aggregate and this source is good for use in pavement under heavy traffic. Three-quarter aggregate from Source TF-25 also should be kept close to the lower limit of the gradation guide.
Abstract  Final Report
RP 83 V 2 Supporting Data for Value Engineering Study of Shoulder Maintenance. James W. Hill, E. M. Harding, Clyde Gillespie, D. R. Greene & Alon F. Stanley, (1977).
  • RP 83 Volume 2

    This report is the result of a value engineering study of foreslope (shoulder) maintenance in the Idaho Division of Highways. The work was done by a study team made up of the Research Supervisor, one District Engineer, two District Maintenance Engineers and the Associate Materials Engineer I. Concurrent Studies of shoulder maintenance were made in Arizona, Iowa, and West Virginia, and one coordination meeting was held in each of the four States during the study period. The entire project was sponsored by the Federal Highway Administration. Estimated cost savings approaching 50% were identified in connection with foreslope reshaping for the idealized case where obstructions such as delineators and signposts could be removed. Estimated cost savings of up to 26% were identified in the foreslope reshaping operation without removal of foreslope obstructions. A final report combining the results of all four State studies will be prepared by the Research Section under a contract with FHWA.
Abstract  Final Report
RP 83 V 1 Value Engineering Study of Shoulder Maintenance. Alon F. Stanley, (1977).
  • RP 83 Volume 1

    This report is the result of a value engineering study of foreslope (shoulder) maintenance in the Idaho Division of Highways. The work was done by a study team made up of the Research Supervisor, one District Engineer, two District Maintenance Engineers and the Associate Materials Engineer I. Concurrent Studies of shoulder maintenance were made in Arizona, Iowa, and West Virginia, and one coordination meeting was held in each of the four States during the study period. The entire project was sponsored by the Federal Highway Administration. Estimated cost savings approaching 50% were identified in connection with foreslope reshaping for the idealized case where obstructions such as delineators and signposts could be removed. Estimated cost savings of up to 26% were identified in the foreslope reshaping operation without removal of foreslope obstructions. A final report combining the results of all four State studies will be prepared by the Research Section under a contract with FHWA.
Abstract  Final Report
RP 82 Field Test of Sinmast Deep Conservation. Alon F. Stanley, (1977).
  • RP 82

    Sinmast Deep Conservation was a solvent cutback epoxy product sold as a penetrating sealer for Portland cement concrete. The product was initially applied to a seven year old structure in Boise in the Fall of 1975. A field evaluation was made in July of 1977. It was found that minor delaminated spots that had existed at the time of treatment had grown, resulting in surface spalling. The observed sealer penetration was in the order of 1/16 inch. The report recommends that this type of product not be specified as a one-time treatment for long-term concrete bridge deck protection unless the depth to which it penetrates can be greatly increased.
Abstract  Final Report
RP 81 Interim Predicting Moisture-Induced Damage to Asphaltic Concrete - Field Evaluation Phase. Robert P. Lottman, (1976).
  • RP 81 Interim

    This interim report presents the findings of the first 24 months of the following 60-month pavement evaluation study. A test system, developed in NCHRP 4-8(3) for the prediction of moisture damage in dense-graded asphalt concrete pavement, has been applied to laboratory specimens representing eight mixes from recently build pavements by the following participating highway agencies: Arizona, Colorado, FHWA 10, Georgia, Idaho, Montana and Virginia. The agencies are also testing cores obtained periodically from test sections of their pavements for purposes of matching the accumulated pavement moisture damage to the moisture damage predicted by the test system.
    The pavement test sections represent a large range of predicted moisture damage as well as a wide range of climate and precipitation. Periodic core tests have shown an increase of retained ratios of tensile strength and resilient moduli (diametral) due to aging and moisture and temperature effects. While it is still too early to assess the accuracy of the test system prediction, the increasing moisture damage is evident with stripping beginning in some of the moisture susceptible mixes. Final matching and evaluation will occur at the end of 60 months (July 1981).
Abstract  Report  Conference
RP 80 Pavement Width Standards for Rural Two-Lane Highways. Patrick Shannon & Alon F. Stanley, (1976).
  • RP 80

    This report was prepared for the Pacific Northwest Regional Commission and summarizes statistical and economic investigations of traffic accident records from selected Idaho and Washington rural two-lane highways. The primary area of concern is the relationship among construction cost, maintenance cost, and accident costs as related to paved width. Results are compared with the minimum paved widths currently specified by the Idaho Division of Highways. The only configuration of interest is full width roadway paving, or paving that covers both driving lane and shoulder. Structural section of the shoulder is assumed to be the same as that of the travel lane. In this report, the term "shoulder" refers to the roadway immediately to the right of the driving lane when looking in the direction of travel. The shoulder is bounded on the right by the intersection of the roadway plane and the side slope Plane.
Abstract  Final Report
RP 79 Maximum Probable Earthquake Acceleration on Bedrock in the State of Idaho. Roger W. Greensfelder, (1976).
  • RP 79

    This report presents the results of a study of earthquake risk predictions on a regional scale in Idaho. In order to make accurate deterministic predictions of earthquakes, one would need detailed knowledge of the mechanical properties of crustal rocks, strain rates throughout the crust and upper mantle, location of faults and fracture systems, and pore pressure of water. Without this data, earthquake risk prediction on a regional scale generally assumes a random distribution of seismicity; however, in some areas mapped faults would control the geographic distribution of the larger, more destructive quakes. Therefore, a synthesis of both geologic and seismologic data was necessary to provide a realistic prediction of future seismicity and attendant ground motion in Idaho. A hybrid method was used wherein earthquake risk in the vicinity of active faults is derived in a semi-deterministic manner, while in other areas it is derived assuming a completely random distribution of seismicity. The report contains several drawings and has been in great demand by surrounding states, agencies and firms.
Abstract  Final Report
RP 78 Progress 3 Progress Report of Roadway Revegetation Studies for the Mullan Line West Section of Interstate I-90. Stephen B. Monsen, (1975).
  • RP 78 Progress 3

    This is a series of three reports that developed planting procedures for revegetation of the Lookout Pass segment of I-90.
Abstract  Final Report
RP 78 Progress 2 Progress Report of Roadway Revegetation Studies for the Mullan Line West Section of Interstate I-90. Stephen B. Monsen, (1974).
  • RP 78 Progress 2

    This is a series of three reports that developed planting procedures for revegetation of the Lookout Pass segment of I-90.
Abstract  Final Report
RP 78 Progress 1 Progress Report of Roadway Revegetation Studies for the Mullan Line West Section of Interstate I-90. Stephen B. Monsen, (1972).
  • RP 78 Progress 1

    This is a series of three reports that developed planting procedures for revegetation of the Lookout Pass segment of I-90.
Abstract  Progress Report
RP 76 Practical Laboratory Measurement and Application of Stiffness or Resilient Properties of Soils and Granular Bases for Idaho Flexible Pavement Design Procedures. Robert P. Lottman, (1976).
  • RP 76

    This report covers background testing, soil specimen preparation, testing and resilient modulus determination, application or resilient modulus to flexible pavement thickness design and recommendations.
Abstract  Final Report  Manual
RP 74 In-Situ Determination of Chloride Content of Portland Cement Concrete in Bridge Decks. J. R. Rhodes, N. C. Carino, R. D. Sieberg, J. Stout & M. C. Taylor, (1977).
  • RP 74

    The objective of the two-phase program is to develop a gauge and corresponding test method for rapid, local, in situ determinations of the total chloride ion concentration in P.C.C. bridge decks or other reinforced concrete members at the level of the outermost mat of reinforcing steel, with a sensitivity of 100 ppm Cl or better. In Phase I a literature search and paper study confirmed that X-ray fluorescence, thermal neutron activation and thermal neutron-prompt gamma analysis were the only promising techniques.
    Experimental investigations showed that the following methods were feasible for analysis of samples taken from drill holes; energy dispersive XRF with Si(Li) spectrometer and 55Fe source; non-dispersive XRF with proportional counter, balanced filters and 55Fe source; thermal neutral activation with NaI(Tl) spectrometer and 252Cf source.
    A dual measurement method, employing both the prompt gamma and activation techniques, was shown to be feasible for nondestructive monitoring of chloride content at a specified depth or depth region below the surface with a sensitivity of 100 ppm or better, independently of the chloride content in the surface layers. With a properly designed gauge and test method several such measurements per hour would be feasible, on bridge decks. The same instrumentation could be used for rapid in-situ sample analysis.
    Design and performance data were obtained to facilitate the development of field instruments of each type.
Abstract  Final Report
RP 73 Regional Deer-Vehicle Accident Research. Dale Reed, Thomas N. Woodard & Thomas D. I. Beck, (1979).
  • RP 73

    This was a pooled fund project that Idaho joined. The purpose of this study was to evaluate and test the effectiveness of methods, devices or structures related to reducing the number of deer-vehicle accidents. Consistent with this purpose was the need to locate and examine potentially critical deer-vehicle accident areas and recommend methods or structures which could have reduced these accidents. In addition, the effects of the methods recommended and investigation of deer response to various experimental structures was conducted.
Abstract  Final Report
RP 72 Bark Mulch Trials. J. E. Rinard, (1981).
  • RP 72

    This report presents the findings of a series of bark mulch trials conducted in cooperation with the Pullman Soil Conservation Service Plant Materials Center. The study had two objectives: 1) finding a beneficial use of an abundant waste product of the Pacific Northwest lumber industry and 2) finding an alternative to conventional mulches because of the increasing cost and occasional shortages of grain straw and grass hay mulches. It was found that the depth variation allowable for obtaining the most successful establishment of plant growth, as determined by plant count, is from 1/4 inch to 3/4 of an inch. Bark depths greater than one inch prevented erosion while depths of 1/4 inch permitted small amounts. It was found that cedar bark increased the ground cover while spruce bark decreased the ground cover in comparison to straw and silvafiber. It was recommended that the use of cedar bark be permitted as a mulch on construction maintenance seeding projects.
Abstract  Final Report
RP 72 Interim Bark Mulch Trials Summary Status Report. A. F. Stanley, (1979).
  • RP 72 Interim

    This report presents the findings of a series of bark mulch trials conducted in cooperation with the Pullman Soil Conservation Service Plant Materials Center. The study had two objectives: 1) finding a beneficial use of an abundant waste product of the Pacific Northwest lumber industry and 2) finding an alternative to conventional mulches because of the increasing cost and occasional shortages of grain straw and grass hay mulches. It was found that bark depths of less than 1/2" had to be maintained to allow seedlings to survive. Bark depths greater than one inch prevented erosion.
Abstract  Final Report
RP 71 Cathodic Protection of Bridge Decks. William A. Sylvies, Dick Sanchez & J. L. Cosho, (1977).
  • RP 71

    This report presents the results of a three phase study initiated to see if aluminum, magnesium and galvanized metals would work for sacrificial protection of reinforcing steel in concrete subjected to de-icing salts. The first phase of testing concluded that aluminum worked best as a sacrificial anode while magnesium is not suitable for use as an anode because it reacts much too rapidly and forms excessive amounts of corrosion product.. During the second phase, sheet zinc and aluminum were further tested for sacrificial protection. A steel wire anode with impressed voltage was also tested. Aluminum continued to provide more protection than zinc and also seems to deteriorate at a slower rate. Impressed current seems to provide excellent protection. Based on this study, a field trial of an aluminum sacrificial anode protection system was initiated. During Phase III, impressed current cathode protection of steel in concrete was tested. Different anodes of graphite and conductive epoxy coated copper wires were used. Test specimens upon which impressed current Cathodic protection was used showed less corrosion on the steel than the control specimen. Graphite is unaffected by Corrosion when used as the anode. Copper wire with conductive coating, when used as the anode, is subject to corrosion and possible breakage if the coating is open in any spot.
Abstract  Final Report
RP 70 Asphalt Pavement Mixture Performance Evaluation. James M. Howard, (1974).
  • RP 70

    The State of Idaho has many miles of Interstate that are showing signs of premature pavement distress. This distress is evidenced by extensive pavement cracking. The purpose of this research project was to determine the conditions that were contributing to cracking. The study was confined to the southeastern section of the State. Roadway cores were taken and physical properties of recovered cores were determined. Project construction history as well as current national research activities relevant to the study was reviewed. Stripping aggregates and improper asphalt selections were considered the primary factors causing the premature cracking. Selection of asphalt based on its temperature susceptibility is recommended. Since the mechanics and cure for stripping, which simply is a bond failure between the asphalt and aggregate, is still a point of conjecture and until the time that a more definitive answer is available, continued emphasis should be placed on seal coats, permeable bases and low pavement air voids. These are proven steps that can minimize damage to pavements from water induced stripping.
Abstract  Final Report
RP 69 A Continuing Skid Resistance Inventory. L. M. Hatch, (1972).
  • RP 69

    This report documents an inventory of skid resistance measurements on the highway system during 1972 using a locked wheel trailer. Areas tested included those sections receiving a new surface, either by maintenance or construction, since the 1971 inventory and specific locations requested by the Districts to recheck previous tests at high frequency accident locations and special test sections. It is recommended that a skid resistance testing program include the testing of new surfaces soon after they are completed. This will establish a base from which to monitor deterioration of skid resistance with time.
Abstract  Final Report
RP 66 Earthwork Compaction Control by Percent Air Void. (1972).
  • RP 66

    The Department of Highways has used the Proctor method of earthwork compaction control almost continually since its introduction by R. R. Proctor. The percent air-voids concept of compaction control could expedite testing procedures and solve problems long associated with present test methods. The air voids method was tested alongside 4 earthwork projects. Test results indicated that this new method could be implemented if moisture controls were adopted.
Abstract  Final Report
RP 64 Field Study of Seal Coats. Boyd Rood, (1974).
  • RP 64

    This report documents the findings of an investigation made to determine and establish the control parameters which will ensure successful seal coats. During 1972, records of all construction conditions which might affect the performance of seal coats were kept for all projects. Following construction, weather conditions were monitored for several months and observations of the seal coats were made. All relevant parameters were analyzed to try to relate seal coat performance to conditions. Generally, it was found that contract projects were subjected to tighter controls than those done by maintenance personnel. Guidelines for obtaining successful seal coats were established.
Abstract  Final Report
RP 63 Idaho Commercial Truck Registration Study. Ken Casavant & Eric Jessup, (2004).
  • RP 63

    The state of Idaho has experienced significant structural changes in both process and implementation of the commercial truck registration system as a result of the case settlement between the American Trucking Association and the state in 1999. The overall purpose of this report is to extend and finalize the evaluation in the Idaho Weight Distance Conversion Study, initiated by Dr. James Jones for the National Institute for Advanced Transportation Technology (NIATT), and to undertake the following:
    • Analyze and compare Idaho Transportation Department’s former and current truck tax system;
    • Examine and analyze the impacts of the new truck tax structure on intra-and inter-state truck operations;
    • Document and analyze the economic and administrative impacts of the new tax system on affected taxpayers;
    • Recommend appropriate tax structure options and directions for Idaho;
    • Summarize findings in a report to the NIATT; and
    • Deliver verbal reports to the Idaho Transportation Board and the Idaho State Legislature.
Abstract  Final Report
RP 62 Asphalt Quality Evaluation. A. F. Stanley, (1976).
  • RP 62

    The project described in this report was undertaken to document and compare property variations of all grades of asphalt from all sources used by the Department and to evaluate the significance of these properties in pavement performance. The testing program can be divided into two phases: asphalt testing and asphaltic concrete testing. In both phases, parallel testing was done at two different temperatures to indicate the effect of environmental temperature. Similarly, parallel testing was done using fresh asphalt and artificially aged asphalt. Considerable differences in temperature susceptibility exist among asphalts which have been supplied for road construction in Idaho. Aggregate source can have a strong effect on instantaneous resilient modulus of asphalt concrete at 77F or 39F. Results of this project suggest the problem aggregates may be those which are moisture susceptible also. Asphalt source does not exert a statistically significant effect on moisture susceptibility of asphaltic concrete at 390F or 77F, at least within the range of sources commonly used in Idaho. Moisture can cause large decreases in both tensile strength and instantaneous resilient modulus of asphaltic concrete made with moisture susceptible aggregate.
Abstract  Final Report
RP 60 A Report on a Static and Dynamic Pile Test in Pocatello, Idaho. G. G. Goble & Frank Rausche, (1971).
  • RP 60

    The work presented in this report is a part of a larger research activity on dynamic pile behavior at Case Western Reserve University. Most of this work has been sponsored by the Ohio Department of Highways in cooperation with the Federal Highway Administration. In order to increase the amount of data available, the cooperation of other highway departments has been sought in making available, for dynamic testing, piles on which static load tests were to be conducted. This study was conducted to determine a method of calculating a pile's bearing capacity using dynamic data.
Abstract  Final Report
RP 59 An Inventory of the Skid Resistance of Idaho Highways. L. M. Hatch & L. F. Erickson, (1972).
  • RP 59

    By agreement with the National Highway Safety Commission, through the Idaho Traffic Safety Commission, the Department purchased a skid test trailer and made an inventory of skid resistance of all highways on the State system. The purposes of the project are 1) to obtain and maintain an inventory of skid resistance of the state highway system, 2) to check skid resistance of locations of frequent accidents, especially where skidding is reported to be a factor, 3) investigate the variability of skid resistance with speed for different pavement surfaces and 4) monitor loss of skid resistance of new pavements due to traffic wear. This report documents the results of the inventory, indicating the frequency of occurrence of each skid number for each pavement type for each District has been published.
Abstract  Final Report
RP 58 An Investigation of the Transverse Distribution of Live Loads on a Post-tensioned Concrete Spread Box-girder Type Bridge. Donald F. Haber & David E. Rice, (1972).
  • RP 58

    The overall purpose of this investigation was to determine the experimental transverse live load distribution on a spread box-girder type bridge and to compare the results with similar studies of other bridges of this type. The test structure consists of five cast-in-place and post-tensioned trapezoidal box girders, a composite cast-in-place reinforce concrete deck slap and reinforced concrete curbs. All of the tests were conducted with one series of gauges. The bridge mid-span was selected as the gauge section for determination of the transverse live load distribution. Gauges were also located along the longitudinal centerlines of the bottom surfaces of the girders to determine the location of the maximum bottom fiber stresses. One gauge was also imbedded in the concrete approximately 1 and 1/2 inches from the bottom of each girder at its mid-span. Stresses were applied to the structure with trucks loaded to H-20 and H-20-S16 capacities. Strains and deflections were recorded electronically. The data in this report is based on the crawl run strain responses. Using this data and computer programs, AASHO design requirements were checked. Conclusions were reached and recommendations made.
Abstract  Final Report
RP 57 Comparative Retroreflectivity of Glass Beads in Traffic Marking Paint. Roger L. Hopt, (1971).
  • RP 57

    This report presents the results of a study initiated to compare float type beads at different application rates with non-floatation type at different graduations and application rates. Comparison was made of both durability and reflectance. It was found that float type beads have significantly better reflectance than the non-floating beads during the first few months of service. However, as the effective life of the paint and glass is reached, they have almost identical reflective qualities. On concrete and plantmix pavements, the non-floating beads had slightly increased reflectivity throughout the first test period as the paint wore off the top of the glass. Decreased reflectivity from exposure to traffic was noted during the following periods.
Abstract  Final Report
RP 56 The Use of Kerosene as a Deslicking Agent. Gary Hazen & L. M. Hatch, (1969).
  • RP 56

    This report presents the results of a study conducted by District personnel to evaluate the use of kerosene to deslick areas where flushing or bleeding is a factor. It was found that this method does give immediate relief, but the area may lose its skid resistance during the warm, high traffic volume summer months.
Abstract  Final Report
RP 55 Effects of Aluminum Pipe on Pumped Concrete. L. F. Erickson, (1969).
  • RP 55

    The purpose of this project was to verify that pumping concrete through aluminum pipe for an extended distance will reduce the strength of the concrete due to abraded aluminum reacting with the cement in the concrete. A concrete slab was constructed at Challis using as near as possible the exact mix proportions used in a bridge deck that had failed to achieve design strength. The test results presented in this report appear to support the contention that the aluminum reaction was the cause of the failure.
Abstract  Final Report
RP 54 Determination of the Effect of Environmental Temperatures on Compaction of Asphaltic Pavements. Gene Wortham & L. F. Erickson, (1970).
  • RP 54

    This report presents the results of a project initiated to determine the effect of the base and air temperatures on the temperature, compaction and air voids of plantmix pavements of different thicknesses. The objective was to determine the realistic ambient temperatures for laydown of asphaltic concrete mixtures. It was found that a thin lift loses heat much faster than a thick lift and therefore is less dense and has much higher air voids upon completion of rolling. The bottom of a thick lift loses heat faster than either the top or middle of the lift and has more air voids.
Abstract  Final Report
RP 53 Phase I Geology and Highway Location Considerations in the Orofino - Kamiah - Nezperce Areas, Idaho. Michael C. Curtis, (1970).
  • RP 53 Phase I

    This field study and subsequent laboratory examination were directed toward determining the geologic feasibility of constructing a new road between NezPerce and the floor of the Clearwater River canyon.
Abstract  Thesis
RP 52 Settlement Study Conducted on 50-Foot High Granular Approach Embankment - F-FG-3022(16) East Connector to Boise. Walter V. Jones & Thomas R. Markland, (1971).
  • RP 52

    This report documents a settlement study of a 50-foot high gravel approach embankment constructed over a silt and gravel foundation. Six settlement platforms were constructed by State forces and were installed under the project contract by the contractor. Embankment settlement was monitored during and for some time following construction. It was concluded that the settlement of this embankment came from foundation settlement. Actual settlement was equal to the calculated settlement. Monitoring devices were not sensitive enough and the reading schedule not often enough to detect compression within the gravel embankment. Settlement occurred primarily during the first month and was essentially complete within four months. Sub-excavation was effective in reducing settlement.
Abstract  Final Report
RP 51 Pavement Evaluation: R-Value and Pavement Deflections - Phase I Report. Walter V. Jones, (1971).
  • RP 51

    In recognition of an existing problem in soils testing, a cooperative research program was conducted in 1967 by Washington, Oregon, Montana and Idaho State Highway Departments and the Bureau of Public Roads Regions 8 and 9 as well as their Washington D.C. laboratory. The investigation was designed to compare resistance values (R-values) obtained by each agency following their own testing procedures. Idaho's method resulted In R-values that averaged about 30 % higher than the other agencies. This raised a concern that Idaho's R-value tests were not adequately simulating poorest anticipated field conditions. This report describes a comprehensive evaluation of the R-value test procedure, presents test results, and denotes conclusions and recommendations.
Abstract  Final Report
RP 50 (2) Development of Microstation Tool to Compute Circuit Requirements and Lighting Design Elements. Michael Kyte, (1999).
  • RP 50(2)

    ITD is interested in developing 2 new software tools to improve the efficiency of the highway lighting and signalization design process. ITD currently performs lighting/signalization design with the MicroStation CADD design program plus 2 specialized software tools. These tools each have disadvantages.
Abstract  Final Report
RP 50 A Study of Littering along Idaho's Highways. Leland M. Hand, (1969).
  • RP 50

    The purpose of this study was to determine, not only the volume, but the type of litter being strewn along the highways. It is the purpose of the sponsoring organization to use this information to conduct programs of education for the people of America to reduce the scattering of litter wherever they travel.
    It is the purpose of this report to show the vast volume of litter which is accumulating along the major highways of Idaho. Although the test sample is small, the results are quite significant.
Abstract  Final Report
RP 48 Skid Resistance Testing of Idaho Highways. (1968).
  • RP 48

    Skid testing of Idaho highway pavements was conducted July 1 to July 18, 1968 using the Bureau of Public Road's skid trailer. Most major routes of the state were tested bringing forcibly to the attention of those concerned that Idaho does have some very slippery spots on highway pavements. Most of these are of short length. It is quite evident from these tests that Idaho's aggregates are not "polishing aggregates"; the slipperiness is due to loss of chips or to flushing asphalt. Even though the Portland cement concrete pavements did not produce extremely low skid numbers, the average of all tests was slightly lower than the average for the plantmix or chip seal pavements.
Abstract  Final Report
RP 47 Phase II The Moisture Mechanism that Causes Asphalt Stripping in Asphaltic Pavement Mixtures. Phase II, Robert P. Lottman & Dennis L. Johnson, (1969).
  • RP 47 Phase II

    The purpose of this project was to identify the moisture mechanism responsible for stripping in plantmix pavements. The ability of the asphalt binder to strip or detach from mineral aggregates in water-saturated asphaltic mixtures is a problem in many areas of the country. The objective of Phase II of the current research is to formulate the stripping mechanism as occurring in Idaho pavements using test results obtained in the laboratory and observations made in the field. Two aggregate sources were used to formulate the mechanism, one used in a paving project which later showed stripping failure and a second potentially non-stripping. Four asphalts marketed in Idaho were used with the two aggregates. The overall mechanism is reported and two possible analytical approaches are outlined.
Abstract  Final Report
RP 47 Phase I The Moisture Mechanism that Causes Asphalt Stripping in Asphaltic Pavement Mixtures, Phase I. Robert P. Lottman, (1968).
  • RP 47 Phase I

    The purpose of this project was to identify the moisture mechanism responsible for stripping in plantmix pavements. The ability of the asphalt binder to strip or detach from mineral aggregates in water-saturated asphaltic mixtures is a problem in many areas of the country. This report of Phase I consists of the results from preliminary testing of asphaltic mixtures from three Idaho projects. Conclusions were reached concerning the processes and causes of stripping. It was found that the use of compacted mixture specimens rather than loose asphalt-aggregate mixtures is a more direct approach because it more closely simulates field conditions. The results of the tests performed strongly suggest that internal tensile stresses occurring at the asphalt-aggregate interface greatly accelerate the stripping failure. Cyclic pore water pressures developed during the "dynamic tests" and static pressures developed during permeability testing have magnitudes approaching the tensile or adhesion strengths of the asphalt binders used in the mixtures. In most cases it was shown that mixture voids were proportional to the rate of stripping failure for a given mixture. However, it was also shown that voids are not an absolute parameter when considering different mixtures; permeability is more absolute. A decrease in permeability greatly increases the inhibition for stripping.
Abstract  Final Report
RP 46 Evaluation of Gilsabind. Leland M. Hatch, (1972).
  • RP 46

    This report documents the results of a series of test applications of Gilsabind, a trade name for a gilsonite product. It was intended to extend the life of pavements by sealing cracks, stopping raveling or rejuvenating the asphalt. The product was applied experimentally to several short sections of highway in Districts 1, 2 and 6. Very little, if any, effect was observed due to the Gilsabind.
Abstract  Final Report
RP 43 Evaluation Tests on Reclamite.
  • RP 43

    This report documents the results of a series of test applications of Reclamite, an emulsion of high quality petroleum oils and resins. It is designed to penetrate dry, weathered asphalt pavements, giving them new vitality and plasticity. The product was applied to test sites in Districts 2, 3, 4 and 5. Evaluation procedures at the sites included 1) visual observance of the application and penetration characteristics on various surfaces and 2) visual observance of the apparent change in surface characteristics after the application. An evaluation was also made of test cores in selected locations to determine the amount of penetration and any change in asphalt viscosity. Observations were made of these sites for several months with results varying from no effect at some sites to very effective in the healing of cracks at others.
Abstract  Final Report
RP 42 Evaluation of Asphalt Pavement Performance. Fred N. Finn, (1966).
  • RP 42

    This report presents the results of a comprehensive study of the level of performance achieved by selected in-service asphalt pavements with due consideration being given to all pertinent variables. The basic approach in the execution of this project has involved seven major steps, as follows: 1) discussions with Department personnel, 2) formulation of a suitable condition survey procedure, 3) field condition survey of representative pavements, 4) development of hypotheses as to mechanism for the types of distress observed, 5) evaluation of hypotheses using Department data obtained from constructions included in the field survey, suggestions for modifications in materials and construction requirements, and 7) recommendations for future research. Conclusions and recommendations relate to considerations dealing with: a) materials requirements and controls, b) structural design, c) construction procedures, d) maintenance procedures, and e) future research and special studies.
Abstract  Final Report
RP 39 Final Idaho Highway Maintenance Study: Part I - Maintenance, Part II - Highway Maintenance Classification, Part III – Field Maintenance Practices. R. D. Mason, C. W. Hathaway & G. W. Kennaly, (1968).
  • RP 39 Final

    The purpose of this project was to 1) determine how other states allocate money for maintenance and try to relate them to Idaho's past experience through computerized formulae and 2) to classify levels of maintenance and to study field maintenance operations as practiced by the Department. This study established for each major maintenance operation the standard and level of maintenance presently used by the majority of the Department's maintenance personnel. Of the eleven states that utilized a formula for allocation of maintenance funds, only six states sent formulae that could be programmed. It was indicated that the majority of states do not differentiate between the level of maintenance nor the standard of maintenance for different highway classifications. Results of the computerized formulae indicated that the allocation pr Idaho State Highway District should be in the same range, percentage wise, even though the formulae were based upon different criteria. The comparison of the results indicated that some inequities may exist in the present highway maintenance fund allocation system utilized by the Idaho Department of Highways.
Abstract  Final Report
RP 39 Progress Field Maintenance Practices of the Idaho Department of Highways. G. W. Kennaly, (1968).
  • RP 39 Progress

    The purpose of this investigation was to study field maintenance operations of the Idaho Department of Highways and to determine the variety of maintenance practices employed in performing each specific operation. The standards and levels of maintenance presently used for each major operation were also determined. A detailed questionnaire covering a variety of maintenance operations was used to obtain the data needed. Maintenance men responsible for the sections of highway selected for study were interviewed and their responses recorded. The 26,300 responses were compiled in statewide summaries of area foreman responses and maintenance men responses. The data analysis indicated that overall maintenance operations were performed in the same basic manner throughout the state and that no set basis was used in determining the standards and levels of maintenance. Even though a wide range of practices were reported for each operation, the number of responses comprising the extreme ends of the range was usually insignificant.
Abstract  Final Report
RP 38 Use of Insulation To Attenuate Frost Heaving. L. M. Hatch, (1969).
  • RP 38

    Frost heaves are known to be the result of ice segregation. In order for ice segregation to occur, one of the following factors must be present: 1) a frost susceptible soil, 2) freezing temperatures and 3) a source of water. This report documents the feasibility of reducing the effect of freezing temperatures by placing a layer of insulation between the pavement structure and the frost susceptible soil. Styrofoam HI, a product of the Dow Chemical Co. was used on a section of highway experiencing severe frost heaving. Three different thicknesses of insulation were installed at 1.5' depth and instrumented with thermisters and frost depth indicators (frost tubes). Daily high and low temperatures were recorded and freezing indices determined for the two years of the investigation. It was found that the insulation was effective in reducing frost heave.
Abstract  Final Report  Conference
RP 37 Use of Mineral Filler to Improve Poor Aggregate for Plant Mix Pavement: Phase I - Evaluation of Existing Test Procedures, Phase II - Development of a Standard Test. William A. Silvies, (1972).
  • RP 37

    Due to a serious shortage of suitable aggregate in several major areas of Idaho, poor aggregate must be upgraded by use of mineral filler for use in plantmix pavement. In Phase I of this study, three different mineral fillers (hydrated lime, Portland cement and limestone dust) in different combinations of fillers and asphalt contents were used in making specimens to be tested using aggregates from widely separated sources. These test results were compared with those from the same test using control specimens containing no mineral filler. In Phase II, a series of different combinations of tests were conducted on aggregates from five different poor sources. Analysis of all test results permitted the development of a proposed standard test procedure for the use of mineral filler to improve poor aggregate. A number of recommendations were made on appropriate tests and modifications to existing tests based upon the conclusions drawn from the study and past experience.
Abstract  Final Report
RP 37 Development Of A Standard Test Procedure For Use Of Mineral Fillers To Improve Marginal Aggregate (1967).
  • RP 37

    Due to a serious shortage of suitable aggregate in several major areas of Idaho, poor aggregate must be upgraded by use of mineral filler for use in plantmix pavement. In Phase I of this study, three different mineral fillers (hydrated lime, Portland cement and limestone dust) in different combinations of fillers and asphalt contents were used in making specimens to be tested using aggregates from widely separated sources. These test results were compared with those from the same test using control specimens containing no mineral filler. In Phase II, a series of different combinations of tests were conducted on aggregates from five different poor sources. Analysis of all test results permitted the development of a proposed standard test procedure for the use of mineral filler to improve poor aggregate. A number of recommendations were made on appropriate tests and modifications to existing tests based upon the conclusions drawn from the study and past experience.
Abstract  Thesis
RP 36 Phase III Studded Tire Pavement Wear Reduction and Repair: Phase 3. Milan Kruker & John C. Cook, (1973).
  • RP 36 Phase III

    This report documents a study of pavement damage from the use of stud equipped tires. The study was prompted by the anticipated increase in the use of studded tires. Literature was studied and tests were made to compare stopping distances for cars equipped with 1) tungsten carbide studs in all four tires, 2) wire inserts in all four tires, 3) plain tires, and 4) chains on the rear only. The advantages and disadvantages of studded tires are listed. It was concluded that studded tires are only useful if the driver exercises all normal cautions that are expected when driving under adverse weather conditions. Damage to pavements is significant depending on the volume of studded tire equipped vehicles, length of normal usage, amount of snow and ice covering the pavement, etc.
Abstract  Final Report
RP 36 Phase II Studded Tire Pavement Wear Reduction and Repair: Phase 2. Milan Kruker & John C. Cook, (1973).
  • RP 36 Phase II

    This report documents a study of pavement damage from the use of stud equipped tires. The study was prompted by the anticipated increase in the use of studded tires. Literature was studied and tests were made to compare stopping distances for cars equipped with 1) tungsten carbide studs in all four tires, 2) wire inserts in all four tires, 3) plain tires, and 4) chains on the rear only. The advantages and disadvantages of studded tires are listed. It was concluded that studded tires are only useful if the driver exercises all normal cautions that are expected when driving under adverse weather conditions. Damage to pavements is significant depending on the volume of studded tire equipped vehicles, length of normal usage, amount of snow and ice covering the pavement, etc.
Abstract  Final Report
RP 36 Phase I Studded Tire Pavement Wear Reduction & Repair. Milan Kruker & John C. Cook, (1972).
  • RP 36 Phase I

    This report documents a study of pavement damage from the use of stud equipped tires. The study was prompted by the anticipated increase in the use of studded tires. Literature was studied and tests were made to compare stopping distances for cars equipped with 1) tungsten carbide studs in all four tires, 2) wire inserts in all four tires, 3) plain tires, and 4) chains on the rear only. The advantages and disadvantages of studded tires are listed. It was concluded that studded tires are only useful if the driver exercises all normal cautions that are expected when driving under adverse weather conditions. Damage to pavements is significant depending on the volume of studded tire equipped vehicles, length of normal usage, amount of snow and ice covering the pavement, etc.
Abstract  Final Report
RP 36 Interim Pavement Damage From Use Of Stud Equipped Tires. (1966).
  • RP 36 Interim

    This report documents a study of pavement damage from the use of stud equipped tires. The study was prompted by the anticipated increase in the use of studded tires. Literature was studied and tests were made to compare stopping distances for cars equipped with 1) tungsten carbide studs in all four tires, 2) wire inserts in all four tires, 3) plain tires, and 4) chains on the rear only. The advantages and disadvantages of studded tires are listed. It was concluded that studded tires are only useful if the driver exercises all normal cautions that are expected when driving under adverse weather conditions. Damage to pavements is significant depending on the volume of studded tire equipped vehicles, length of normal usage, amount of snow and ice covering the pavement, etc.
Abstract  Final Report
RP 35 Highway Operations with Truck Trailer Double & Triple Units (1964).
  • RP 35

    The Idaho Motor Transport Association requested permission to operate doubles and triples between Boise and Pocatello and also Boise and Salt Lake to determine the operating costs and conditions using these units on Idaho highways. Overall length of these units ranged from 94' to 96' using 27' trailers for the triples and 40' trailers for the double units. The Highway Board authorized the Department to participate in the research to permit the observation of conditions affecting safe operation to obtain additional information on performance of large truck-trailer combinations climbing hills, etc. This report documents the types of trucks, loads carried and routes followed. Data reported includes axle weights and gross loads, weight - horsepower ratios, turning radii and off-tracking distances, fuel efficiency, average speed on test sections and slow speeds on hills, and traffic volumes encountered. Observations were made of impacts on highway operations and safety. As a result of this study, the Idaho Legislature authorized the Idaho Transportation Board to allow these units to operate on Idaho highways when and where they thought the conditions were suitable.
Abstract  Final Report
RP 34 Availability of Aggregates in Southern District II. Terry R. Howard, (1965).
  • RP 34

    A study was made of the availability of aggregate for the construction of highways in District IV (formerly District II). Some areas have an abundance of aggregate of questionable quality. Even this will require transportation to projects. Basalt rock from the extensive lava flows is available in abundance, but further investigation will be necessary to determine what processing may be necessary to make a material that will provide satisfactory service. Recommendations for further investigation of basalt and for obtaining comparative costs with shipping of aggregates from outlying areas are included. These recommendations also include suggestions for obtaining more complete knowledge of each geologic unit as a routine matter of materials source investigation.
Abstract  Final Report
RP 33 A Study Comparing the Sealing Resistance of Air-Entrained Concrete with Concrete Containing a Silicone Admixture. (1965).
  • RP 33

    This report documents a study of both the freeze-thaw resistance and compressive strength of air-entrained concrete compared with concrete containing Dow Corning 777 admixture under the severe weathering conditions of northern Idaho. Flexural and compressive strength as well as freeze-thaw specimens were taken for testing in the lab. A test slab was placed adjacent to a standard or control section for visual observation. The admixture resulted in no added freeze-thaw resistance, however, compressive and flexural strengths were increased.
Abstract  Final Report
RP 32 A Pilot Study of Maintenance Costs of Idaho Highways. William J. Parman, (1965).
  • RP 32

    This report documents the results of a pilot study to investigate the various factors that influence maintenance expenditures and to develop mathematical formulas to predict future maintenance costs. A further objective is to recommend areas of future research. The factors which were investigated to determine their influence on maintenance expenditures included climatic, environmental and highway characteristic data. Sections of highway were eliminated from the study due to insufficient weather data, poor mileage correlation between several data sources, inconsistency of the cost data for several years, and the planning of a practical route for field investigation. A linear regression analysis was made of snow-removal, travel way-routine repair , and the total of all routine regularly occurring expenditures. The regression analysis of snow removal and total routine maintenance expenditures were statistically significant and are therefore offered as valid explanations of these expenditures. Climatic data were the most important factors in explaining maintenance expenditures. The analysis of travel way-routine repair expenditures was statistically non-significant.
Abstract  Final Report
RP 31 Frost Heaves on State Highway 15. (1965).
  • RP 31

    This report documents an investigation of numerous typical frost heaves on State Highway 15 (Currently SH-55) during the late Spring of 1964. Borings were made in the heaved areas and in adjacent areas not evidently heaving. Cores were taken and examined for ice lensing and material in the cores was tested by the Central Laboratory. Efforts were made to determine the sources of water from drainage areas and to correlate drainage and heaving. It was evident that drainage affects the amount of heaving and that snow depths affect the ability to keep drainage channels open. In some cases, improvements are possible but in others it appears prohibitive in time and cost. It is recommended that efforts should be made to increase the depths of frost-free base and subbases to prevent or reduce surface distress from heaving. A number of other recommendations are also made.
Abstract  Final Report
RP 30 Development of a Simple Device for Predicting the Permissible Spring Axle Loading of Asphalt Pavements. (1965).
  • RP 30

    The measurement of pavement deflection can provide valuable information for predicting the load carrying capacity of asphalt pavements. The Benkleman Beam has been used by many Highway Departments to aid in the evaluation of flexible pavement performance. While extremely useful, it is large and cumbersome for use in frequent and numerous pavement deflection tests advocated in measuring the pavement condition during the spring breakup period. Phase I of this study consisted of the design and construction of 10, 30 and 48 inch curvature meters patterned after a Union of South Africa 10 inch device. These devices were then correlated with the Benkleman Beam. The 30 and 48 inch devices proved the easiest to use and correlated well with the Benkleman Beam. This next phase of this project will be the collection of field data from roadway test sections throughout the state. This data will be analyzed to determine if load limits may be placed on highways during spring breakup with deflection measurements serving as the criteria.
Abstract  Final Report
RP 28 Groundwater Movement in Landslides. Walter V. Jones & John J. Peebles, (1966).
  • RP 28

    This investigation was conducted to determine if tracer materials could be satisfactorily used to delineate the groundwater movement in or near active or potential landslide areas. An attempt was made to better evaluate field hydraulic conductivity so that the groundwater velocity and direction computed by Darcy's equation could be compared to the groundwater velocity and direction determined by the tracers. Laboratory experiments were conducted to identify the most effective chemical dye tracers. Fluorescein and pontacyl were most effective and were further tested at ten field sites. Other dyes were given limited field tests. Fluorescein and pontacyl were both effective in tracing ground water and at one site the movement was traced over 400 feet in 39 days. Conclusions were made that both fluorescein and pontacyl can be advantageously used to delineate groundwater movement in relation to landslides and that analysis of the samples by use of a fluorometer is necessary. Graphical presentation of the fluorometer readings is essential before definite conclusions can be made. It was also concluded that the auger-hole method of determining in-situ hydraulic conductivity can be utilized in certain landslide investigations as an aid in planning a tracer program.
RP 26 An Investigation of Nuclear Methods of Determining Moisture Contents and the Compacted Densities of soils and Aggregates. Fred Anderson & Jack Larsen, (1968).
  • RP 26

    This report contains the results of laboratory and field testing of a portable nuclear gauge for the measurement of in-place moisture content and density of earthen structures. Both laboratory and field evaluations have been directed toward determining a practical and accurate method of test operation for application to control and inspection. It was found that the nuclear method of testing gave comparable results with conventional testing while being less complicated, quicker, safe and reliable, and reducing much of the human error connected with moisture-density determinations. It was recommended that additional field testing be conducted on a construction project before a final decision was made on additional purchases of the equipment.
Abstract  Final Report
RP 24 (6) Asbestos Fiber as a Filler in a Plantmix Pavement. Gene R. Wortham & Leland M. Hatch, (1969).
  • RP 24 Number 6

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. It was extended and expanded to include the study of methods to prevent these occurrences. The use of asbestos fiber as an additive, or filler in plant mix pavement to improve performance became recognized as a possibility when reports of its superior performance in an asbestos mine haul road were received. A study was designed to determine if the addition of the asbestos fiber would increase the stability , durability and life of the pavement and reduce reflective cracking. The test section chosen was a located in a high volume section of US-30 between 11th Street and Capitol Blvd. on Front Street in Boise. From the results of laboratory testing on the mix and cores taken from the roadway, and from field observations of the test section, no definitive conclusions could be reported. However, reflective cracking was reduced in the section containing asbestos. The addition of asbestos to the mix required additional asphalt and thus decreased the air voids in the finished pavement, however, the finished pavement showed no flushing or bleeding. The addition of the asbestos to the asphalt mix increased the cost by approximately 30%.
Abstract  Final Report
RP 24 (6) Interim Asbestos Fiber as a Filler in a Plantmix Pavement. Gene R. Wortham & Leland M. Hatch, (1969).
  • RP 24 Number 6

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. It was extended and expanded to include the study of methods to prevent these occurrences. The use of asbestos fiber as an additive, or filler in plant mix pavement to improve performance became recognized as a possibility when reports of its superior performance in an asbestos mine haul road were received. A study was designed to determine if the addition of the asbestos fiber would increase the stability , durability and life of the pavement and reduce reflective cracking. The test section chosen was a located in a high volume section of US-30 between 11th Street and Capitol Blvd. on Front Street in Boise. From the results of laboratory testing on the mix and cores taken from the roadway, and from field observations of the test section, no definitive conclusions could be reported. However, reflective cracking was reduced in the section containing asbestos. The addition of asbestos to the mix required additional asphalt and thus decreased the air voids in the finished pavement, however, the finished pavement showed no flushing or bleeding. The addition of the asbestos to the asphalt mix increased the cost by approximately 30%.
Abstract  Interim Report
RP 24 (5) Non-destructive Testing and Compaction Control of Asphaltic Pavement Construction. Leland M. Hatch, Gene R. Wortham & Jon Schierman, (1969).
  • RP 24 Number 5

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. It was extended and expanded to include the study of methods to prevent these occurrences. For many years, highway departments cored pavements after construction to determine their density. This was too late to take any corrective action. This report covers research conducted in both 1965 and 1967 by the Idaho Department of Highways on different methods of non-destructive testing and also on alternative rolling sequences and compaction temperatures. Cores were taken to compare with the non-destructive test methods. Air flow tests were taken after breakdown, intermediate and final rolling. Water permeability and nuclear testing were done after final rolling only. Seven rolling patterns were evaluated. The air permeameter appeared more reliable than the water permeameter for this type of testing. More data is needed on the nuclear density gauge before its use can be justified. These conclusions are limited to thin lift projects. Two rolling patterns were recommended. It was also recommended that rolling be accomplished at as high of temperatures as possible.
Abstract  Final Report
RP 24 (4) Field Determination of the Areal Extent of Stripping in Idaho Pavements. Leland M. Hatch, (1969).
  • RP 24 Number 4

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. It was extended and expanded to include the study of methods to prevent these occurrences. The stripping of Asphalt from the aggregate within the plantmix pavements on many sections of Idaho highways is a problem of major proportions. A study by Materials Research and Development, Inc. entitled "Evaluation of Asphalt Pavement Performance" in Idaho identified stripping as one of the major factors causing the failure of asphalt pavements in Idaho. One of their recommendations was to immediately identify the full extent of asphalt-aggregate stripping on a statewide basis. This report concerns the project to identify the aerial extent of stripping statewide. The data appear to support the conclusion that stripping is not necessarily related to a particular type of aggregate, nor to a specific grade or source of asphalt. Pavements made of nearly every type of aggregate and all types and grades and many sources of asphalt were sampled and found to be stripping to some degree. It was recommended that research into the moisture mechanism which causes asphalt stripping in asphaltic concrete be continued and that use of lime or other anti-stripping agents be used where stripping is a problem.
Abstract  Final Report
RP 24 (3) Mixing Time Studies Using Ross Count Method. Larry Hippler, (1968).
  • RP 24 Number 3

    The Idaho Department of Highways Standard Specifications for Highway Construction, 1967 Edition, gives the Engineer the responsibility of determining mixing time for plantmix paving. Prior to 1967, the specifications required a minimum finish wet mixing time of 30 seconds for batch plants. Continuous plantmixing time was controlled by the output in lbs./sec. This output was not to greater than the dead weight capacity of the pugmill in pounds, divided by 30.
    In May 1968, mixing time studies were undertaken using the Ross Count Test Method. The purpose of these studies was to determine the mixing times being used by the plants throughout Idaho, to determine the effectiveness of the mixing using the Ross count criteria and to determine a minimum allowable mixing time using the same criteria.
Abstract  Final Report
RP 24 (2) Preliminary Analysis of Asphalt Pavement - Crack Investigation – Preliminary. (1966).
  • RP 24 Number 2

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. This report presents the findings of the case study conducted on State Highway 55 between Round Valley and Cascade. The north seven miles had a 0.8 ft. crushed rock base over 1.0 ft. of select borrow. The south seven miles had 0.5 ft of cement treated base over 1.0 ft. of select borrows. Both had 0.2 ft of plant mix. Within eight years, cracking had become serious in the southbound lanes on the CTB portion. It was concluded that a lack of uniformity of cement application and non-uniform mixing of the cement in the base as the primary cause of distress. A contributing factor may be the preponderance of heavy trucks in the southbound lane. It was also concluded that 0.5 ft. of cement treated base is not the equivalent of 0.8 ft. of crushed rock base under the conditions existing. It was recommended that in the future a pugmill be used for mixing the cement and aggregate rather than roadmixing. It was also recommended that more positive techniques be used to determine the proper amount of cement.
Abstract  Final Report
RP 24 (7) Laboratory Testing of Mineral Fiber Fillers for Asphalt Concrete. A. F. Stanley, (1975).
  • RP 24 Number 7

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. It was extended and expanded to include the study of methods to prevent these occurrences. A short testing program was undertaken to compare rock wool and two other types of glass fibers with asbestos as stabilizing fillers in asphalt paving. The fillers were compared on the basis of cost, Marshall stability, and tensile splitting strength. All three glass fiber fillers gave lower Marshall stabilities than unmodified plantmix, which had lower stability than asbestos filled mix.
Abstract  Final Report
RP 24 (1) V 4 Flexible Pavement Failures - Case Study No. 4: Round Valley to Cascade. (1966).
  • RP 24 Number 1 Volume 4

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. This report presents the findings of the case study conducted on State Highway 55 between Round Valley and Cascade. The north seven miles had a 0.8 ft. crushed rock base over 1.0 ft. of select borrow. The south seven miles had 0.5 ft of cement treated base over 1.0 ft. of select borrows. Both had 0.2 ft of plant mix. Within eight years, cracking had become serious in the southbound lanes on the CTB portion. It was concluded that a lack of uniformity of cement application and non-uniform mixing of the cement in the base as the primary cause of distress. A contributing factor may be the preponderance of heavy trucks in the southbound lane. It was also concluded that 0.5 ft. of cement treated base is not the equivalent of 0.8 ft. of crushed rock base under the conditions existing. It was recommended that in the future a pugmill be used for mixing the cement and aggregate rather than roadmixing. It was also recommended that more positive techniques be used to determine the proper amount of cement.
Abstract  Final Report
RP 24 (1) V 3 Flexible Pavement Failures - Case Study No. 3: Pocatello West to American Falls. (1965).
  • RP 24 Number 1 Volume 3

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. This report presents the findings of the case study conducted three projects on US-30 and I-86 from Pocatello west to American Falls. The I-86 project was the first stage of stage construction and was scheduled to receive a 0.4 ft. plant mix overlay in five years. One of the US-30 projects and the I-86 project exhibited structural failures at the time of the study, 11 years and four years after construction respectively. The second US-30 project showed little or no distress and was used as a comparison. Several test pits were dug on each of the three projects and Benkleman Beam measurements were made adjacent to each pit. The investigation revealed that the failure on the US-30 project could probably be attributed to substandard selected borrow subbase and to the fact that this material and the underlying soil were somewhat frost susceptible. It was determined that the failure on the interstate portion, which was not so extensive, could be attributed to the fact that it had reached its load carrying capacity before it received the plant mix paving.
Abstract  Final Report
RP 24 (1) V 2 Flexible Pavement Failures - Case Study No. 2: Jct. 20-26 at AEC to Idaho Falls (1964).
  • RP 24 Number 1 Volume 2

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. This report presents the findings of the case study conducted on US-20 from the junction with US-26 east toward Idaho Falls. Two years after construction of a plant mix overlay over a four year old BST, this project showed considerable block cracking with very little hexagonal cracking showing up. As the years progressed, the project exhibited some during spring breakup. After the sixth winter, pavement blowups were quite prevalent. Several test pits were dug and measurements of deflection were made with the Benkleman Beam. It was surmised from the available data that several factors contributed to the pavement failure, including 1) very cold winters with deep penetration of frost and 2) an asphalt that hardened greater than normal, causing an extremely brittle pavement more susceptible than normal to cracking at low temperatures.
Abstract  Final Report
RP 24 (1) V 1 Flexible Pavement Failures - Case Study No. 1: US 191 - Malad North & South. (1963).
  • RP 24 Number 1 Volume1

    This study was initiated to study the cause of cracking and general deterioration of recently constructed flexible pavements. This report presents the findings of the case study conducted on US-191 from the Utah State Line to a point approximately four mile north of the town of Malad. Four years after construction this project showed considerable transverse cracking with areas of block and map cracking. Several test pits were dug and measurements of deflection were made with the Benkleman Beam. It was determined that the aggregate exhibited excessive absorption of the asphalt and was the primary cause of the premature failure due to a brittle mix. It was recommended that steps be taken to develop a more suitable test to determine the percentage of asphalt absorbed by aggregates.
Abstract  Final Report
RP 21 Reconnaissance and Salvage of Archaeological Sites on Idaho Highways. L. F. Erickson, (1964).
  • RP 21

    This project was set up as a result of State and Federal laws providing for protection of historical or prehistoric ruins of any object of antiquity. This report describes the procedures and methods for administering archaeological reconnaissance and salvage through contract with the Idaho State University which were developed under this research project. It also summarizes the reconnaissance and salvage performed during the 18 month period covered by this report.
Abstract  Final Report
RP 20 An Evaluation of Flexible Pavement Design Methods. L. F. Erickson, (1964).
  • RP 20

    From 1957 to 1964, Idaho used the Resistance Value - Traffic Index method of Flexible Pavement Design as the primary design procedure. This procedure followed the basic California Department of Highways' procedure developed as a result of several test tracks and roads including the WASHO Test Road conducted at Malad during 1951 - 1953. Following the AASHO Road Test conducted in Illinois during the period of 1958 - 1963, the California Highway Department made a complete study of the results of the AASHO Road Test, the WASHO Road Test and other road tests. Based on these results and their own testing, California made a number of refinements to their design methods. This report compares the Idaho 1957 Design Method with the revised California method as published in Highway Research Board Record No. 13. Idaho loadometer data and traffic classification data were reviewed and used in this study to make a comparison with the design recommendations of the AASHO Committee on Design. In making this comparison, it was necessary to use the AASHO recommendations for the correlation between Soil Support Value as used in their design brochure and the Resistance value as reported by California. A proposed revision of the Idaho Design Method is presented, based on this study.
Abstract  Final Report
RP 16 Durability of Metal Pipe Culverts. Harry L. Day, (1965).
  • RP 16

    This investigation was made to determine the life of metal pipe installations, and to determine spelter and condition of the base metal, as well as gauge. In addition, the laboratory tested the soil for pH value and electrical resistivity. The investigation indicates a life expectancy in excess of 40 years except in a few areas. Soil in timbered areas and in pasture lands with excess soil moisture reduced the life expectancy to between 20 and 30 years. The test devised by the California Highway Department using soil pH and electrical resistivity appears to give a satisfactory estimate of service life, although few installations were old enough to verify the predicted life. Recommendations are made concerning criteria for design for service life and asphalt coating to extend service life.
Abstract  Final Report
RP 11 Quality Control. Gene R. Wortham & Robert D Haye, (1967).
  • RP 11

    The purpose of this project was to make a realistic appraisal of the Department's acceptance specifications for crushed mineral aggregate using statistical methods. Samples from two sources were tested for their 1) sampling variance, 2) testing variance and 3) material variance. A direct relationship was found between the sampling variance and sampling method. Samples obtained by means of an automatic sampling device produced lower and more uniform sampling variance than samples obtained manually. The splitting method used and the testing variance also showed a direct relationship. Samples which were cross split showed a lower testing variance than samples which were split only once.
Abstract  Final Report
RP 9 A Study of Pavement Serviceability with the Idaho Bumpometer. L. F. Erickson, (1963).
  • RP 9

    The purpose of this project was initially to construct a roughometer for measuring pavement roughness during construction while corrections were still possible, to mount this device in the trunk of a sedan, and to test it for adequacy. This report explains the design and function of the equipment and makes recommendations for its uses. It was found that general rideability of the pavement could best be determined at 50 mph unless the pavement was exceptionally rough. Then, 30 mph appeared more desirable.
Abstract  Final Report
RP 9 Initial Pavement Roughness Testing with the PCA Roadmeter. L. M. Hatch, (1971).
  • RP 9 Initial

    The Department purchased a PCA Roadmeter as an aid in making pavement condition survey to help Maintenance determine priorities for performing major surface maintenance and overlay projects and for testing the roughness of newly constructed pavements. The Department also obtained the use of the Bureau of Public Roads (BPR) Roughometer. Roads in southern Idaho were tested with both pieces of equipment and the results compared. After about a year's experience with the PCA Roadmeter, it was determined that 1) the roadmeter data differentiates sufficiently between smooth and rough surfaces to describe riding quality of the pavement, 2) the roadmeter is capable of good repeatability and 3) without correlation with the Chloe Profilometer or a roughometer that has been correlated with a Chloe, there is no benefit in making an attempt to derive a formula for a present serviceability rating (PSR).
Abstract  Final Report
RP 8 Field Experiment in Seal Coats. L. F. Erickson & Harry L. Day, (1963).
  • RP 8

    This report discusses various experimental seal coat projects constructed during the 1958 and 1959 seasons to test design methods and to compare many different types of asphalt and application rates. The degree of success achieved is reported.
Abstract  Conference  Final Report
RP 7 Field Control Of Asphalt Pavement Construction. (1967).
  • RP 7

    This research project was initiated to determine a test method which could be used for the compaction control of asphalt pavement construction.
    Test procedures and results are described for two nuclear density gages and an asphalt paving meter. The results indicate that both nuclear gages could be used for plant mix compaction control. The asphalt paving meter is not accurate enough for compaction control.
Abstract  Final Report
RP 6 Alkali Reactivity of Concrete Aggregates Used in Idaho. A. F. Stanley, (1975).
  • RP 6

    This report summarizes the history of a long-standing Idaho research project for which no previous formal report has been published. The object of the investigation was to determine the cause and possible remedy for the extensive progressive concrete disintegration that had taken place in highway structures since the mid 1930's. When the crazing and cracking were first noted, it was thought that the causes were improper construction, dirty aggregates, etc. Through observations and investigations, it was determined that the alkalis within the cement react with certain components of the aggregates forming a highly expansive silica jelly, which in turn causes cracking and subsequent disintegration. No laboratory work has been done since the early 1950's.
Abstract  Final Report
RP 5 Final Bear Ridge Base Stabilization Investigation. William A. Sylvies, (1976).
  • RP 5 Final

    Bear Ridge base stabilization Project S-4769(6) is located approximately eight miles south of Deary on S.H. 3 in Latah County. Winter climate in the area is severe and truck traffic consists mainly of heavy logging trucks, wood chip trucks and wheat trucks.
    An untreated base constructed on this roadway section in 1957 was to be used as a gravel surface with a roadmix surface to be added later. Extensive pot holes and weak spots developed in the base during the winter, however, and it was determined that the roadmix surface could not be placed on the existing base without risk of serious failure. Approval was thus obtained from the Federal Highway Administration to construct a 2.16 mile long stabilized base project to compare the effectiveness of hydrated lime, Portland cement, SS-1, emulsion asphalt, and a special road oil improving base stability and preventing further aggregate degradation.
Abstract  Final Report
RP 5 Interim A Progress Report on the Bear Ridge Investigation of Base Stabilization Using Degraded Aggregates. R. L. Helm, (1962).
  • RP 5 Interim

    This report contains the results of the tests performed under Research Project 5. A comparison of current results with the summarized results of previous tests is presented for the purpose of comparing the effect of various treatments on the rate of degregation. The comparisons revealed little major change in the quality of either the treated or untreated base material. It was substantiated by the good appearance of the highway. There was, however, an apparent small change in the plasticity of some of the fines. Stabilizing materials tested included Portland cement, hydrated lime, SS-1 emulsion and a special road oil.
Abstract  Final Report
RP 5 Planning and Financing Roads in Sparsely Settled Public Land States with Special Reference to Idaho. R.L. Helm, (1962).
  • RP 5

    This report deals mainly with what is termed the major public land states. These have been defined as the states in which public domain plus nontaxable Indian lands constitute more than 5 percent of the state’s area. The reason for this definition is that lands approximately thus defined constitute the basis for offsetting the existence of public land in states in funds required from states to match Federal aid for projects on Federal aid primary systems and Federal aid secondary system. Under this definition states having hitherto ordinarily been referred to as the 11 western states are included and also Alaska and South Dakota.
Abstract  Final Report  Article  Thesis
RP 4 Development of an Asphalt Pavement Air Permeameter and Evaluation of Its Use. N. C. Pyk, C. W. Hathaway & C. C. Warnick, (1965).
  • RP 4

    The purpose of this study was to establish a qualitative procedure for evaluating the need for sealing asphalt surfaces to prevent percolation of water through the pavement and to give the bitumen back its original properties. A pavement Permeameter was developed and data collected. The Permeameter and techniques developed appear to give reasonable and consistent results. Permeability appears to increase with the age of the pavement. There was little correlation between the opinions of highway engineers and measured permeability values with respect to the need for seal coating a specific section of highway.
Abstract  Final Report
RP 3 An Urban Sufficiency Rating Procedure for Idaho Highways. Robert P. Newell, (1965).
  • RP 3

    The purpose of this project was to formulate a sufficiency rating procedure specifically adapted to urban travel characteristics on the Idaho Highway system. A formula was given with the recommendation that additional studies be made. New formulas may be established which would isolate smaller variables, using the same data, and thus provide more accurate results.
Abstract  Final Report
RP 2 V 16 Land Economic Studies - Project 1381 (10) Case study No. 20. Blackfoot, Idaho Parcel 4.5 Severance Study. (1968).
  • RP 2 Volume 16

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 15 Land Economic Studies - Project I-15-1(19)61 (Case Study No. 19) Pocatello, ID Parcel 12, Severance Study. (1968).
  • RP 2 Volume 15

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 14 Land Economic Studies - Project F-1381(10) (Case Study No. 18) - Blackfoot, ID Parcel #4. (1968).
  • RP 2 Volume 14

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 13 Land Economic Studies - Project F-1381(10) (Case Study No. 17) - Blackfoot, ID Parcel 7 & 8 Severance Study. (1968).
  • RP 2 Volume 13

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 12 Land Economic Studies - Project F-1381(10) (Case Study No. 16) Blackfoot, ID Parcel #1 Severance Study (1968).
  • RP 2 Volume 12

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 11 Land Economic Studies - Project I-15-1(18)70 (Case Study No.15) - Pocatello, ID Parcel 6. (1967).
  • RP 2 Volume 11

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 10 Land Economic Studies - Project I-15-1(18)70 (Case Study No. 14) - Pocatello, Parcel 5 & 3/4's, Severance Study (1968).
  • RP 2 Volume 10

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 9 Land Economic Studies - Project I-15-1(18)70 (Case Study No. 13) - Pocatello Parcel 8, Severance Study. (1967).
  • RP 2 Volume 9

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 8 Land Economic Studies - Project I-15-1(18)70 (Case Study No. 12) - Pocatello, Parcel 6, Severance Study. (1967).
  • RP 2 Volume 8

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 7 Land Economic Studies - Project I-15-1(18)70 (Case Study No. 11) Pocatello, Parcel 5. (1967).
  • RP 2 Volume 7

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 6 Land Economic Studies - Project U-3021(22) (Case Study No. 10) - Boise, Parcel 8 & 9, Severance Study. (1967).
  • RP 2 Volume 6

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 5 Land Economic Studies - Project F-1032(20) (Case Study No. 9) - Pocatello, Idaho Parcel #1. (1965).
  • RP 2 Volume 5

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 4 Land Economic Studies - Project I-15-3(7)111 (Case Study No. 8) - Bingham County Line to Idaho Falls. Parcel C, (1965).
  • RP 2 Volume 4

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 3 Land Economic Studies - Project F-6471(17) (Case Study No. 7) Idaho Falls, Parcel 2 & 11, Severance Study. (1965).
  • RP 2 Volume 3

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 2 Land Economic Studies - Project I-15-3(3)117 (Case Studies 3-6 inclusive) Idaho Falls. Parcel D, (1965).
  • RP 2 Volume 2

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 1B Land Economic Studies - Project F-3022-8 (Case Studies 1-2) Sebree - Mt. Home Parcel 3. (1962).
  • RP 2 V 1B

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 2 V 1A Land Economic Studies – Studies of Right-of-Way Severance Damages. (1963).
  • RP 2 V 1A

    The objective of these studies is to determine the impact, if any, of highway construction and operation upon the value of remainders of certain parcels of abutting private property from which right-of-way was obtained. In most cases, it was found that the remainder had been sold for prices far in excess of the appraised valuation at the time of the right-of-way purchase; in fact, even far in excess of the projected appraisal.
Abstract  Final Report
RP 1 V 3 Some Problems of Planning and Financing Roads in Sparsely Settled Public-Land States with Special Reference to Idaho. Norman Nybroten, (1962).
  • RP 1 Volume 3

    An objective of this report is to present some effects of major elements of the present programs for highway financing and development in the major public-land states. These may be of some help in evaluating some possible alternatives in the program of Federal-aid in terms of maximizing the value of public lands in the nation's economy and also in the economies of the states primarily involved. It is concluded that financing and planning roads will have profound effects on resource uses far into the future. Although the major public-land states have special problems and interests due to their proximity to the public lands, the problem is national in scope. Extensive research is needed to properly assign the costs and benefits to different resource uses before the major costs are incurred.
Abstract  Final Report
RP 1 V 2 Value of Forest Highways in Idaho. N. Nybroten, W. H. Andrews, (1959).
  • RP 1 Volume 2

    The primary objective of this report is to present, quantitatively if feasible, such results of study that lead to a better evaluation of the services rendered, or might be rendered, by forest highways in Idaho. An effort was made to stress relevant factors and conditions peculiar to Idaho, giving added attention to those areas and conditions most affected by Forest Highways, either as they exist or as they might exist in an expanded program. An explanation of the financial and physical relationships of Forest Highways to the general highway program in Idaho is made. Factors of apparent economic importance, both production and consumption are presented.
Abstract  Final Report
RP 1 V 1 Value of Roads to and in Public Lands. N. Nybroten, H. W. Spiegel, M. E. Fletcher. (1958).
  • RP 1 Volume 1

    Because of the high percentage of publicly-owned land in the state, one of the major problems in determining benefits from a road system in the State of Idaho is to ascertain the value effects of roads to and in the public lands. The resources in these areas are extremely varied in amount, value and geography. Of those that might be more immediately measurable, it was deemed that timber would rate at or near the top. For that reason, the first report of the study emphasizes road effects on timber values. To determine some of the effects of roads on the value of standing timber, two different approaches to the problem were initiated. First, people who would be expected to have general information on the subject were consulted. Secondly, intensive studies were conducted in smaller areas where the most important variables affecting the issue are both more manageable and representative of general conditions.
Abstract  Final Report
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