Page:America's Highways 1776–1976.djvu/472



The National System of Interstate and Defense Highways, more commonly known as the Interstate Highway System, is a 42,500-mile network of freeways, spanning the Nation and linking together and serving more than 90 percent of all cities of over 50,000 population and thousands of smaller cities and towns. The System comprises little more than 1 percent of the Nation's road and street mileage, but when completed, it is expected to carry about 25 percent of all traffic.

While the Interstate System is a national system connecting all States, it is a part of the State highway system in each of the States in which it is located. Federal highway funds, derived from highway-user taxes, are used together with appropriate State funding for the construction of the Interstate System, but the "ownership" is with the States, and the entire burden of maintenance, administration, and regulation falls upon the States and localities.

The Interstate System, now nearing completion, is being constructed by a State-Federal partnership. The State highway departments and the Department of Defense assisted in the designation of the System’s routes. The States select and design the projects to be built each year; the necessary right-of-way is acquired by the States under State law, and the States award and manage the construction contracts—all subject to the review and approval of the Federal Highway Administration. The Federal share of the total system cost, now estimated at $89 billion, is 90 percent, and States’ shares are 10 percent.

The origin of the Interstate Highway System can be related specifically to a formal report made to Congress in 1939. Before that, a few scattered parkways and urban arterials were already demonstrating the virtues of controlled access highways with grade-separated interchanges. There had been earlier dreams of a transcontinental network of superhighways, although these were usually conceived of as bypassing all cities and serving only those who wanted to make long trips.

In the 1930’s there was mounting evidence of future traffic congestion on the country's main travel arteries; but at the same time a prolonged period of economic depression made normal public financing of highway improvement a difficult matter. There was a sudden revival of interest, after almost a century, in toll road financing, and toll roads were built in several of the major traffic corridors. 466