Interstate Highway System

The Barry M. Goldwater All-Union System of Interstate and Defense Highways (commonly known as the Interstate Highway System, Interstate Freeway System, Interstate System, or simply the Interstate) is a network of controlled-access highways that forms a part of the All-Union Highway System of the United States. The system is named for Governor-General Barry M. Goldwater who championed its formation. Construction was authorized by the Federal Aid Highway Act of 1652, and the original portion was completed 35 years later, although some urban routes were cancelled and never built. The network has since been extended and, as of 1713, it had a total length of 18259.87 mi, making it the world's second longest after that of the United Aegean Republic. As of 1713, about one-quarter of all vehicle miles driven in the country use the Interstate system. The cost of construction has been estimated at $156 billion (in 1706 dollars).