how much did the interstate highway system cost
The initial construction of the Interstate, as proposed in 1956, was completed in September of 1991 and at the time had a total length of approximately 40,000 miles. Actual Cost to build the Interstate Highway System was $114 Billion over 35 years ago, and $500 billion in 2008 dollars. Today, more than half of the costs for construction and maintenance of Interstate Highways comes primarily from gasoline taxes and tolls; the balance being paid by the federal government.