Starting in the late 1930s, politicians debated and engineers studied the idea of linking Americas cities by a system of high-speed national highways with access limited to a few interchange points. The plan became a reality when President Dwight Eisenhower signed the Federal-Aid Highway Act of 1956. The federal government was to provide 90 percent of the fundingmostly from gasoline taxesand each state would provide the rest. Originally, Congress called for 41,000 miles of limited-access roads designed for speeds up to 70 miles per hour, to be completed by 1972.
Interstate Highway System and Turnpikes, American Automobile Association, 1959
Beginnings of the System
In 1938 Congress requested the Bureau of Public Roads to study the feasibility of a system of superhighways. Its 1939 report, Toll Roads and Free Roads, was the beginning of the concept for the Interstate Highway System. Throughout the 1940s additional studies addressed the way new highways would support defense and economic growth. The limited-access design of the Pennsylvania Turnpike, which opened in 1940, became a model for future superhighways.
Blue Mound Road, Wisconsins first divided highway, 1946
The first superhighways, like Wisconsins Blue Mound Road, were built in the 1920s and 1930s. Unlike the later interstates, travelers had direct access to businesses located along most of these highways.
Sign along Highway 40, now Interstate 70, St. Charles County, Missouri, 1956
With the influx of federal funding, states began planning and building new road projects. Motorists and truckers eagerly awaited the new highways.
Reworking the Landscape
The Interstate Highway System changed the American landscape. Workers cleared large swaths of land, demolished buildings, built bridges, and blasted through hills. The interstates would shape decisions made by individuals, governments, and businesses: roads dictated the location of housing developments, commercial buildings, factories, and truck terminals. Across the country, the interstates contributed to urban decline and suburban growth.
Interstate 10 southeast of Casa Grande, Arizona, 1967
Early highways provided access to residences and businesses along the roadside. The new interstates restricted access to a few interchanges to keep traffic moving. Some motels, restaurants, and gas stations relocated near the interchanges. Others, bypassed by the new road, went out of business.
Construction workers on bridge, New Mexico, 1967
Construction workers on bridge over Alamosa River, I-25, north of Truth or Consequences, New Mexico, 1967
Construction of East Portland Freeway (I-205) bridges over Tualatin River, Oregon, 1970
Earlier highways tended to follow the landscape. The new superhighways cut wide, straight swaths through the countryside, flattening hills and bridging valleys.