<P> The Dwight D. Eisenhower National System of Interstate and Defense Highways ( commonly known as the Interstate Highway System , Interstate Freeways , or simply the Interstate ) is a network of controlled - access highways that forms a part of the National Highway System of the United States . The system is named for President Dwight D. Eisenhower , who championed its formation . Construction was authorized by the Federal Aid Highway Act of 1956 , 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 2013 , it had a total length of 47,856 miles ( 77,017 km ) . As of 2013 , about one - quarter of all vehicle miles driven in the country use the Interstate system . In 2006 , the cost of construction was estimated at about $425 billion ( equivalent to $526 billion in 2016 ) . </P>
<P> The Dwight D. Eisenhower National System of Interstate and Defense Highways ( commonly known as the Interstate Highway System , Interstate Freeways , or simply the Interstate ) is a network of controlled - access highways that forms a part of the National Highway System of the United States . The system is named for President Dwight D. Eisenhower , who championed its formation . Construction was authorized by the Federal Aid Highway Act of 1956 , 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 2013 , it had a total length of 47,856 miles ( 77,017 km ) . As of 2013 , about one - quarter of all vehicle miles driven in the country use the Interstate system . In 2006 , the cost of construction was estimated at about $425 billion ( equivalent to $526 billion in 2016 ) . </P>
how many miles of interstate highways are there in the us
how many miles of interstate highways are there in the us
47,856 miles
47,856 miles