The Growth of the Interstate Highway System

The Evolution of the Interstate is an animated map which allows you to view the construction of the U.S. Interstate Highway System from 1956 to 2017. The map starts in 1956, when the first 9,000 miles of highway are added to the map, and ends in 2017 with over 49,000 miles of highway.

As the Evolution of the Interstate progresses new highways are added to the map by their year of construction. A running total shows the number of miles of road added to the network. The map also occasionally zooms in on some of the most important stages in the construction of the Interstate Highway System.

The Interstate Highway System was championed by President Dwight D. Eisenhower and was first authorized by the Federal Aid Highway Act of 1956. A year earlier, in 1955, the General Location of National System of Interstate Highways, informally known as the Yellow Book, was published. This mapped out what was to become of the Interstate System. In 1956 the American Automobile Association published the National system of interstate and defense highways : as of June, 1958, a map of the planned interstate network.