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 143 Interstate 10 and US 60 between the Mini Stack and the Broadway Curve, adding to additional traffic overload and safety issues at the interchange with SR 143/I-10/US 60. The speed limit on I-10 throughout the city of Phoenix is currently . Many other area freeways have limits of , notable exceptions being the Sky Harbor Expressway with , Arizona 51 south of Glendale Rd with 55 mph, and Interstate 17 with . Arizona State Route 143 Arizona State Route 143, also known as SR 143 and the Hohokam Expressway, is a north–south and access-controlled freeway in Maricopa County, Arizona, that