Introduction
The supply chain in the United States depends in a great part on the movement of raw materials and finished goods from vendor to customer and finally to the consumer. The majority of products in the United States are moved by commercial vehicle along the 160,000 miles of the national highway system (NHS). Across the USA the NHS only accounts for four percent of the nationals roads but carries 75 percent of commercial vehicle movements. A subset of the NHS is the Interstate Highway System which includes 47,000 miles of freeways, highways and expressways, which only accounts for 1.1 percent of the roads in the US, but carries approximately 24 percent of the highway traffic.
How the Interstate Highway System Began
The Interstate Highway System began as part of the Federal-Aid Highway Act of 1944 which authorized the creation of a 40,000 mile highway system, but did not include any mechanism of how the creation of the highways was to be funded. Eight years later the Federal-Aid Highway Act of 1952 allocated $25 million to the project and Federal-Aid Highway Act of 1954 allocated $175 million. However it was the Federal-Aid Highway Act of 1956 which authorized the allocation of $25 billion for the construction of 41,000 miles of highways over the following twenty years. Ninety percent of the funds for the Interstate Highway System were supplied by the federal government, while individual states were required to fund the remaining ten percent.
The Influence of President Eisenhower
The architect of the Federal-Aid Highway Act was President Dwight Eisenhower who had seen the autobahn highway system in Germany during the war and believed the United States needed a highway system as a part of a wider national defense policy. However the concept of a national highway system was first described in a report for Congress called “Toll Roads and Free Roads” published in 1939. Congress had proposed a toll highway system, which would fund itself, but the report rejected this in favor of a toll-free highway system such as the one that was part of the 1956 Federal-Aid Highway Act.
President Eisenhower realized the dramatic size of the Interstate Highway System project could be a tremendous drain on the US economy and he required that the financing mechanism for the Interstate System be "self-liquidating” so that the project would not increase the US national debt. The initial budget for the twenty year highway project was $27 billion, ninety percent of which would be funded by the federal government. The estimated cost of the original project was calculated in 1991 to be approximately $129 billion.
Finishing The Project
Since the original project started there have been a number of extensions to the project and there is now 46,876 miles in the Interstate Highway System. With the extra miles and the time involved in completing the project some recent estimates have calculated the total expenditure has been as much as $425 billion allowing for inflation. Although the 1992 opening of the I-70 at Glenwood Canyon, Colorado was publicized nationwide as the final part of interstate highway system to be completed, that is actually incorrect. Officially the project has not been completed as there is still parts of the I-95 north of Philadelphia, Pennsylvania, and a part of the I-70 in Breezewood, Pennsylvania, that are unfinished.
Highway Numbering
The numbering of the interstate highways on the system has been the responsibility of the American Association of State Highway Officials (AASHO). The numbering of highways prior to the Interstate Highway project was administered by the AASHO and this model was used for the interstates, but in reverse. For example US Route 10 is in the North of the USA, while interstate 10 is in the South. With the mirroring scenario in place, the AASHO decided to omit Interstate 50 from the project as not to confuse drivers with US Route 50, as the two roads would be in similar locations across many states.
