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I-15 Environmental Study
I-15 Environmental Study
Project FactsKey Number: 9000
Project Number: IM-0005(138)
The Idaho Transportation Department (ITD) is conducting an environmental study to evaluate interstate access and congestion issues in the northern Pocatello/Chubbuck area.
January Public HearingThe transportation department held a public hearing in January of this year to gather comment on a proposed new interchange and other improvements on I-15 and connecting roads.
Proposed improvements include a new interchange at milepost 73.4 near Siphon Road, a northbound collector-distributor road along I-15, extending Siphon Road east from Hiline Road to I-15 and continuing east and south to connect to Olympus Drive at its intersection with Chubbuck Road. The proposed improvements were identified during an Environmental Assessment. The proposed improvements and the No Action Alternative are evaluated in the Environmental Assessment.
Project Purpose and NeedThe purpose of the proposed action is to provide transportation system solutions to improve user operating conditions in the northern Pocatello/Chubbuck region while enhancing regional transportation system efficiency and safety.
The need for the project arises from limited access to the interstate for northbound and southbound motorists on I-15 north of I-86, along with the planned commercial and residential growth east/west of I-15 in the study area. Existing conditions have created congestion and safety concerns at current access points and future growth and development will only make the situation worse
Project BackgroundMotorists living north of I-86 in the northeastern Pocatello and northern Chubbuck areas currently have limited access to I-15. Traffic congestion, delays and safety concerns at current interstate interchanges are anticipated to get worse as growth and development continues in those areas.
A Major Investment Study (MIS) completed in 1995 and the recently completed Yellowstone Corridor Plan recommended developing an additional interchange on I-15. Ten congestion-relief concepts were evaluated in the MIS, including improvements to the Pocatello Creek and Clark Street Interchanges. Improvements to the Pocatello Creek Interchange and Clark Street Interchange have already been completed. The MIS also evaluated developing interchanges in the northern Pocatello/Chubbuck area.
Project DescriptionThe I-15 Environmental Study is evaluating interchange options on I-15 roughly bounded on the south by the WYE, and on the north by 2 1/2 Mile Road. The study area includes connecting roads and ramps at proposed interchange locations. As a requirement, local options not using I-15 are also being considered. The study has been ongoing since the summer of 2004.
What's Happened So FarProject officials met with the Bannock Planning Organization (BPO) Transportation Advisory Committee* and the Local Agency Input Group** in the summer of 2004 to identify issues that should be addressed in the study. Project engineers then analyzed 17 potential build concepts. Project officials then conducted a preliminary screening analysis. Concepts carried forward were those that best met transportation needs and addressed the issues identified. A No Build alternative is always included. (See inside of brochure for concepts.)
*The BPO Transportation Advisory Committee includes representatives from the City of Chubbuck, the City of Pocatello, Idaho State University and the Bannock Planning Organization.
**The Local Agency Input Group includes representatives from the City of Chubbuck, the City of Pocatello, the Shoshone-Bannock Tribe, the Bannock Planning Organization and the Bannock County Commissioners.Level 1 Screening (Preliminary) Project officials met with the Bannock Planning Organization (BPO) Transportation Advisory Committee and the Local Agency Input Group in the summer of 2004 to identify issues that should be addressed in the study. Project engineers investigated 17 potential “Build” Concepts. A preliminary screening analysis was conducted on the concepts. The “No Build” Concept and five “Build” Concepts that best met transportation needs were carried into the Level 2 Screening Process.
Level 2 Screening A Public Open House Meeting was held April 4, 2005 at Tyhee Elementary School in Chubbuck. The public was asked to provide input and identify project issues that needed to be addressed. The meeting was attended by 169 people who provided 50 written comments regarding the five “Build” Concepts carried forward from the Level 1 Screening.
A second Public Open House Meeting was held June 27, 2006 at the Portneuf District Library, in Chubbuck. The purpose of the meeting was to gather public input on the project’s Purpose and Need Statement, which alternative(s) should be carried forward in the environmental process and to identify any issues that may change the results of the Level 2 Screening Report. The meeting was attended by 52 people who provided 26 written comments on the project. The comments will help ITD narrow the number of comments carried forward in the environmental analysis and move toward selecting an alternative. Level 2 Screening documents:
Issues Identified• Limited access to I-15 north of the I-86/I-15 system interchange
• Existing access to I-15 north of the I-86/I-15 interchange requires out of direction travel which contributes to congestion on U.S. 91.
• The crash rates are higher than state averages along U.S. 91 between I-86 and Reservation Road.
• Long-range planning predicts that existing interstate access points will not accommodate current or projected growth.
Make CommentsThe Idaho Transportation Department values your input. Submit written comments using one of the forms below or contact for more information.
• Email Us please include your name and address
• Download a comment form (word doc)
ITD Project Manager
Compliance with Title VI of the Civil Rights ActThe Idaho Transportation Department (ITD) is committed to compliance with Title VI of the Civil Rights Act of 1964 and all related regulations and directives. ITD assures that no person shall on the grounds of race, color, national origin, gender, age, or disability be excluded from participation in, be denied the benefits of, or be otherwise subjected to discrimination under any ITD service, program, or activity. The department also assures that every effort will be made to prevent discrimination through the impacts of its programs, policies, and activities on minority and low-income populations. In addition, the department will take reasonable steps to provide meaningful access to services for persons with Limited English Proficiency.
Meetings/HearingsClick (+) to display/hide items
Environmental Assessment and Supporting Documents
Right-of-Way plan sheets
P.O. Box 7129
Boise, ID 83707-1129
Phone: (208) 334-8119
Fax: (208) 334-8563
TDD: (208) 334-4458