| United States Numbered Highway System | |
|---|---|
   | |
 Map of the present U.S. Highway network | |
| System information | |
| Length | 157,724 mi[a] (253,832 km) |
| Formed | November 11, 1926[1] |
| Highway names | |
| US Highways | U.S. Highway nn (US nn) U.S. Route nn (US nn) |
| System links | |
United States Numbered Highways are the components of a national system of highways administered by the American Association of State Highway and Transportation Officials (AASHTO), a nonprofit, nonpartisan association,[3] and the various state departments of transportation. These were initially designated on November 11, 1926, and extend throughout the contiguous United States.
There are several U.S. Highways that exist entirely within one state. Since the policy on numbering and designating US Highways was updated 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.[4]
- ^ Weingroff, Richard F. (April 7, 2011). "From Names to Numbers: The Origins of the US Numbered Highway System". Highway History. Federal Highway Administration. Retrieved June 10, 2011.
- ^ American Association of State Highway and Transportation Officials (1989). United States Numbered Highways (PDF) (1989 ed.). Washington, DC: American Association of State Highway and Transportation Officials. p. iv. OCLC 37586174. Archived from the original (PDF) on January 1, 2014. Retrieved September 17, 2016.
- ^ "About". AASHTO Association. American Association of State Highway and Transportation Officials. Retrieved October 21, 2024.
- ^ American Association of State Highway and Transportation Officials (January 2000) [retained from October 13, 1991]. "Establishment and Development of United States Numbered Highways" (PDF). AASHTO Transportation Policy Book. Washington, DC: American Association of State Highway and Transportation Officials. Archived from the original (PDF) on October 22, 2014. Retrieved January 16, 2014.
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