Evolution of the Interstate Highway system in Idaho

The federal system of interstate highways has done more to shape the face of America than any other public works project in history. Indeed, it is hard to imagine a United States without its ubiquitous double-stranded concrete ribbons stretching through the plains, over the mountains and from sea to shining sea.

The year 2006 marks the 50th anniversary for the system that so many Americans use so often that they take if for granted. For example, the majority of Idaho residents who live close to a major city use Interstate 15, 90 or 84 for their daily commute. Outside of the metropolitan areas, these superhighways serve as a vital link between rural towns; a 75-mph zoom zone that dramatically shortens the time between destinations.

Although our interstates safely carry passenger and commercial freight traffic, they were designed primarily for U.S. Armed Forces as presidents Franklin D. Roosevelt and, especially, Dwight D. Eisenhower, recognized a critical need to move troops and supplies quickly from one end of America to the other.

“It is a military highway,” said Keith Green, a retired State Chief Engineer whose career in Idaho transportation began one sweaty summer day in 1957 as he helped build the interstate near Jerome. “One of the things that determined the height of the overpasses was the size of the missile that was expected to be towed underneath it.”

Because of its geographic location, perched on the western edge of the northern Rocky Mountains, Idaho’s interstate was built more as a network of crossroads than a destination in itself. But without the construction of Intestates 84, 90 and 15 in the last half of the 20th Century, America’s inland and coastal Northwest would remain mostly isolated from the rest of the country.

The first vision of a national superhighway goes back to Franklin D. Roosevelt, who contemplated a network of six roads – three running east-west and three from north to south – that would connect the major regions of the country. However, America’s intense involvement in World War II kept the latter Roosevelt Administration focused on foreign shores rather than our own backyard. Later, Eisenhower, who was part of an early convoy of military vehicles across the country, picked up his predecessor’s vision and expanded it multiple times.

As the Interstate was in its early planning stages, engineers followed the routes of the early western settlers who came through Idaho on the Oregon Trail. These hardy souls with their wagons and livestock by necessity took the path of least resistance over the often harsh conditions they found on the western plains, mountains and high deserts.

To fully understand the logic behind Idaho’s 611 miles of interstate highways, we must first widen our perspective to take in the entire western United States. Interstate 15 north of Salt Lake City is the only major connection between the United States and Canada between Seattle and western Minnesota. Similarly, the Interstate 86/84 route that cuts a swath diagonally between Salt Lake City and Seattle is the only direct route from the interior to the Northwest coast. Without these routes, traffic would have to swing far north to Helena, Montana, or as far south as Sacramento before drivers could set a straight course for the great Northwest port cities.

Boise, the capital city, is located on one of the Oregon Trail routes, and was thus lucky enough to find itself on the main east-west route through the southern part of the state. But the needs of the nation did not require a north-south route, a situation that bedevils transportation planners and politicians until the present day.

But as imperfect as Idaho’s internal systems of interstate roads may be for Idaho itself, without the construction of Interstates 84, 90 and 15, America’s northern Rockies and coastal Northwest would remain mostly isolated from the rest of the country.

Pre-World War II
The initial idea for a network of superhighways began with Franklin D. Roosevelt whoenvisioned a network of six toll superhighways that would link America. Toward this goal, Congress passed the Federal-Aid Highway Act in 1938, which reads in part:

“The Chief of the Bureau of Public Roads is hereby directed to investigate and make a report of his findings and recommend feasibility of building, and cost of, super highways not exceeding three in number, running in a general direction from the eastern to the western portion of the United States, and not exceeding three in number, running from the northern to the southern portion of the United States, including the feasibility of a toll system on such roads…”

The act resulted in a two-part report; the first of which asserted that there was not enough transcontinental traffic to support a network of toll superhighways. Some routes could be self-supporting as toll roads, but most highways in a national toll network would not.

The second part of the report, named "A Master Plan for Free Highway Development," recommended a 26,700-mile non-toll interregional highway network. The inter-regional highways would follow existing roads wherever possible (thereby preserving the investment in earlier stages of improvement). More than two lanes of traffic would be provided where traffic exceeded 2,000 vehicles per day, while access would be limited where entering vehicles would harm the freedom of movement of the main stream of traffic.

In 1939, Roosevelt recommended that Congress authorize a special system of inter-regional highways, with all necessary connections through and around cities. The highway should meet the needs of the national defense and anticipate the growing needs of future peacetime traffic. The transportation concept was on a scale that had not been contemplated since the Roman Empire, nearly 2000 years before.

But political winds were against Roosevelt. His opponents considered the plan to be “another ascent into the stratosphere of New Deal jitterbug economics,” as one critic put it. And although reaction to the recommendation among the nation’s highway building community was positive, the timing for such a project was bad. America was just starting to eke its way out of the Great Depression, yet all of Europe was at war and our country was being pressed hard to join the fight.

Although the time was not yet ripe, Roosevelt already wasthinking about the post-war period. He feared resumption of the Depression if American soldiers returned from the war and were unable to find jobs. A major highway program could be part of the answer.

In Idaho in the mid 1930s, the state was still emerging from a transportation system very much like the scenes depicted in Hollywood westerns. In 1934, with about 5,000 miles of roads throughout the state, only about one-third were paved or oiled. Another third was made of crushed rock while the final third were essentially unimproved wagon trails.
Although the Great Depression suppressed the flow of goods and services across the nation, the Roosevelt administration viewed road-building projects as a way to put paychecks into the economy and at the same time improve America’s transportation infrastructure.

In 1935 and 1936, road construction boomed to $11.3 million, with projects accounting for about 735 miles; along with a program to replace unsafe or outdated timber bridges with modern steel and concrete structures. In the following two years (1937-1938), road construction nearly doubled again, with orders for more than 1,100 new or reconstructed miles of paved or oiled roads; plus 43 new bridges.

Until 1938, there were no markings on Idaho roads to keep traffic separated. That year, the state hired two crews to paint yellow centerlines on hard-surface highways and had begun to install directional road signs in some locations. Of course, from the very beginning, the posting of highways signs brought inevitable vandalism. According to Idaho’s Highway History, 1863-1975, published by the Idaho Transportation Department, only two signs remained undamaged on a 54-mile stretch of U.S. 93 near Shosone after the first three months of their installation. During those three months, one sign was hit by 22 rifle or handgun shots and at least one shotgun blast.

The War Years
As World War II loomed over the next decade, Idaho found itself with a wealth of minerals important to the nation’s war making ability. Tungsten, mercury, copper, lead and phosphates lay in Idaho mines waiting for extraction and transportation to the military-industrial machine.

The Defense Highway Act of 1941 authorized the construction of access roads and strategic network construction. In 1944, Congress passed the Federal Aid Highway Act:

“There shall be designated within the continental United States a National System of Interstate Highways, not exceeding 40,000 miles in total extent so located as to connect by routes, as direct as practicable, the principal metropolitan areas, cities, and industrial centers, to serve the National Defense, and to connect at suitable border points with routes of continental importance in the Dominion of Canada and the Republic of Mexico.”

Within this limitation, the routes were established on maps; but without a national funding program or a commitment from Congress to actually build the roads, the plan stood idle for the next 12 years, until a World War II general and war hero became President of the United States.

“Our unity as a nation is sustained by free communication of thought and by easy transportation of people and goods. The ceaseless flow of information throughout the republic is matched by individual and commercial movement over a vast system of interconnected highways crisscrossing the country and joining at our national borders with friendly neighbors to the north and south.

“Together, the united forces of our communication and transportation systems are dynamic elements in the very name we bear - United States. Without them, we would be a mere alliance of many separate parts.” -- President Dwight D. Eisenhower, 1955, in a message to Congress about the importance of the Interstate Highway System.

During the dawning years of his military career, future president Dwight D. Eisenhower helped lead a military expedition across the United States in 1919, in part to test the Army’s ability to traverse its home ground.

According to a history by Richard F. Weingroff, the convoy took 62 days to travel from Washington, D.C. to San Francisco, experiencing “mechanical difficulties; vehicles stuck in mud or sand; trucks and other equipment crashing through wooden bridges; roads as slippery as ice or dusty or the consistency of `gumbo;’ extremes of weather from desert heat to Rocky Mountain freezing; and, for the soldiers, worst of all, speeches, speeches, and more speeches in every town along the way.”

Eisenhower, who would later lead U.S. forces to victory in Europe, grasped the genius of Germany’s national highway system, the Autobahn, a system of divided highways made for moving military and industrial goods quickly and efficiently. Ike liked it so much he decided America must have one of its own.

1950s and 1960s: The Dream Begins
During his State of the Union address in 1954, Eisenhower made clear that he was ready to turn his attention to the nation's highway problems. He considered it important to "protect the vital interest of every citizen in a safe and adequate highway system."

That year, Congress authorized $175 million for the interstate system in a shared project with the state. The law required states using the federal money to match 40 percent of the projects with their own funding. As he signed the bill on May 6, Eisenhower said it was an “effective forward step,” but he knew the federal government would have to sweeten the offer if states were to truly buy into his vision.

The president commissioned a National Highways Advisory Committee, filled with captains of industry, finance and labor organizations. The members included Steve Bechtel of Bechtel Corporation, Sloan Colt of Bankers' Trust Company, Bill Roberts of Allis-Chalmers Manufacturing Company, and Dave Beck of the International Brotherhood of Teamsters. The group was led by Gen. Lucius D. Clay, an engineer and a long-time associate and advisor to the president. At the time, Clay was chairman of the board of the Continental Can Company.

After months of study and hearings, the committee estimated the nation’s total highway needs to be $101 billion. A conference of state governors' report earlier that year had indicated that the federal share of total needs should be about 30 percent, including the federal share of the cost of the interstate system. The Bureau of Public Roads estimated that the cost of modernizing the designated 37,698 miles in 10 years would be $23 billion.

The committee made a rough estimate of $4 billion for the urban roads that had not yet been designated. This figure, $27 billion, was accepted by all parties as the goal of any plan for financing the interstate highways. Because the interstate system "is preponderantly national in scope and function," the report recommended that the federal government pay most of the cost of its construction. The state and local share would be about $2 billion.

To finance the system, the Clay Committee proposed creation of a Federal Highway Corporation that would issue bonds worth $25 billion. Revenue from gas taxes would be dedicated to retiring the bonds over 30 years. Because traffic would continue to increase during that period, revenue would also go up, and a hike in the gas tax would not be necessary.

Eisenhower sent the Clay Committee's report to Congress on Feb. 22, 1955. In his transmittal letter, he acknowledged the "varieties of proposals which must be resolved into a national highway pattern," and he wrote that the Clay Committee's proposal would "provide a solid foundation for a sound program."

Competing legislation to move the interstate system forward jangled around Congress for more than a year. In the early summer of 1956, a conference committee eventually hammered out a compromise that became the $25 billion Federal-Aid Highway Act.

The interstate system was expanded, but only by about 1,000 miles to about 41,000 miles, to be constructed between 1957 and 1969. The law called for uniform interstate design standards to accommodate anticipated traffic flows in 1975. The design standards were set to ensure uniformity, control access, and eliminate intersections between interstate and railroad crossings.

In the 1957 act, two-lane segments were allowed on the most lightly traveled sections, some of which were located in Idaho. In subsequent years, all parts of the interstate highway system were required to be at least four lanes wide.

Eisenhower signed the law on June 29 at Walter Reed Army Medical Center while recovering from an intestinal ailment. There was no ceremony, but White House Press Secretary James C. Hagerty told the press that the president was “highly pleased." Secretary of Commerce Sinclair Weeks immediately announced the allocation of $1.1 billion to the states for the first year of what he called "the greatest public works program in the history of the world."

Meanwhile in Idaho
In November of 1956, the Idaho Department of Highways was reaching out to the motoring public for support. The department published an informational booklet, Idaho Interstate Highway System: What, Why and How. With a distinct canary cover, the 28-page publication offered a keen and concise overview of the federal plan and how it would impact Idahoans.

“Travel via the Interstate highway will save time because of the reduction in travel distance and higher sustained operating speeds made possible by the elimination of left turns, intersections at grade and traffic signals,” the booklet proclaims.

Accompanied by a cover letter addressed to “Dear Mr. Highway User,” the booklet portrayed the future of Idaho’s interstate system with uncanny accuracy, down to artist’s conceptions of what “diamond” and “trumpet” rural intersections would look like in rural Idaho.

Clearly, the Department of Highways was attempting garner public support for the project.

“For the first time in 25 years you will have a highway system matched to the capacity of your modern automobile. You will get the full benefit from the large investment you have in our modern means of transportation,” the booklet continued.

At times, the authors resorted to hard-sell tactics:

“When you and your family go for a drive on the Interstate System our chances of being in an accident will drop by two-thirds. ... You may be one of the 4,000 people who will not die in an auto accident each year after the Interstate System is completed.”

Idaho’s Interstate plan covered 611 miles through the state on four specific routes. The network would serve 17 of the state’s 44 counties. However, three of the four routes, and the vast majority of the mileage, was planned to run through southern Idaho.