Interstate Highway System Extension Act

Interstate Highway System Extension Act - Increases from 41,000 to 82,000 the number of miles authorized to be constructed under the National System of Interstate and Defense Highways.

Sets forth provisions governing the apportionment of funds between the States.

Authorizes appropriations of $1,500,000,000 for fiscal year 1973, and $4,500,000,000 for each fiscal year thereafter, to construct the Interstate System.