Interstate Highway System

The Dwight D. Eisenhower National of and Defense Highways, commonly known as the , is a of controlled-access highways that forms part of the National in the .

of the original was proclaimed complete in 1992, despite deviations from the original 1956 plan and several stretches that did not fully conform with federal standards.

The cost of of the was approximately $114 billion (equivalent to $530 billion in 2019).

The has continued to expand and grow as additional federal funding has provided for new routes to be added, and the will grow into the future.

As of 2018, about one-quarter of all vehicle miles driven in the used the , which had a total length of 48,741 miles (78,441 km).