 AASHTO is in the process of eliminating all intrastate U.S. Highways less than 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 serve more than one state and "substantially meet the current AASHTO design standards". A version of this policy has been in place since 1937.
