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The Dwight D. Eisenhower System of Interstate and Defense Highways
United States of America

America's Interstate highway is the world's most comprehensive system of roadways. It's vast scale, rapid development and subsequent advancements have changed the lives of everyone who travels its byways and receives goods shipped over its asphalt and concrete expanses.

Early super-highways, like the Pennsylvania Turnpike, sparked significant interest in the creation of a national highway system. But the onset of World War II and policy priorities of the post-war years held off significant progress on interstate construction until the mid-1950's.

Increase in military mobility was one early reason advocates used for the construction of the interstate. President Eisenhower also asserted that an interstate highway system would provide for safer, more efficient motoring, and encourage economic development. In 1956, he signed the Federal-Aid Highway Act, the largest public works project in history. It approved the construction of 41,000 miles of highway, serving nearly every major city in the United States. The system, later extended to 42,800 miles, was renamed in 1990 after the President who had helped launch the program: Dwight D. Eisenhower System of Interstate and Defense Highways.

The interstates were designed for safe, efficient operation. Because they are fully access controlled, all intersections are at different grades, with access via interchange ramps. Construction included more than 55,000 grade separation and other bridges. Curves were engineered for safe travel, and all interstate highways have at least four lanes (two in each direction). Conveniently spaced rest areas line the interstates. Furthermore, each interstate is designed to handle projected traffic loads expected 20 years after it was constructed.

The interstate system is a product of one of the most successful federal-state partnerships in history. The federal government provided 90 percent of the funds for the system, with revenue coming from federal excise taxes on highway user products, such as gasoline. The states, which built, own and operate the interstate highways, provided the remaining 10 percent.

The first complete interstate cost estimate, released in 1958, predicted the cost of construction would be $37.6 billion. Construction was expected to take 13 years. As mileage was added to the system, as inflation increased costs, and as environmental and social concerns, particularly in urban areas, increased the complexity of development, the interstate system exceeded its 13-year goal and expected cost. But by 1960, 10,000 miles had been constructed, and by 1980 more than 40,000 of the planned 42,800 miles were open to traffic. Today, the interstate system is essentially complete at an estimated cost of $130 billion, with at least 50 percent of the increase caused by inflation.

Conservative estimates calculate that the system has returned more than $6 in economic productivity for each $1 it cost to construct. In addition, reduced fatality numbers are attributed to use of the interstates, despite increases in automobile traffic. Some claims put the number of fatalities avoided as high as 187,000 during the 40-year lifetime of the system, while the number of injuries avoided quickly approached 12 million.

The interstate system has transformed America. In addition to being the workhorse of the American economy, it has helped unite the nation, provided the centerpiece of a transportation network that will ensure competitiveness in the international marketplace of the 21st Century, and enhanced the freedom of mobility that is essential to the American way of life.