List of United States Numbered Highways
United States Numbered Highways are components of a national system of highways that is administered by the American Association of State Highway and Transportation Officials (AASHTO) and the various state departments of transportation. These U.S. Numbered Highways were initially designated on November 11, 1926, and extend throughout the contiguous United States.
| United States Numbered Highway System | |
|---|---|
Map of the present U.S. Highway network | |
| System information | |
| Length | 157,724 mi (253,832 km) |
| Formed | November 11, 1926 |
| Highway names | |
| US Highways | U.S. Highway nn (US nn) U.S. Route nn (US nn) |
| System links | |
There are several U.S. Highways that exist entirely within one state. Since the current policy on numbering and designating US Highways was written in 1991, AASHTO has been in the process of eliminating all intrastate U.S. Highways under 300 miles (480 km) in length, "as rapidly as the State Highway Department and the Standing Committee on Highways of the American Association of State Highway and Transportation Officials can reach agreement with reference thereto"; new additions to the system must therefore serve more than one state.