U.S. Route 66 in Arizona U.S. Route 66 in Arizona U.S. Route 66 (US 66, Route 66) covered as part of a former United States Numbered Highway in the state of Arizona. The highway ran from west to east, starting in Needles, California, through Kingman and Seligman to the New Mexico state line as part of the historic US 66 from Santa Monica, California, to Chicago, Illinois. The highway was decommissioned in 1985, although portions remain as State Route 66 (SR 66). In 1914 the road was designated National Old Trails Highway; in 1926 it was re-designated US 66 with the birth of the U.S.
Arizona State Route 79 agency, as of 2011 Arizona State Route 79 was the fastest road in the nation, with the fastest 5% of the vehicles using it clocked at an average speed of 88 miles per hour. SR 79 is the section of what was together U.S. Route 80 and U.S. Route 89. US 80 was removed from Arizona in 1989, and US 89 was removed from southern Arizona in 1992. The original SR 79 was designated in 1924 as part of the original state highways from Prescott to Jerome. By 1926, it extended northeast to Flagstaff. In 1941, this was redesignated as