Arizona State Route 80 Arizona State Route 80 State Route 80 (SR 80) is a roughly arc-shaped highway lying in southeastern Arizona that, with New Mexico's State Road 80, is a relic of the old U.S. Route 80, now truncated from San Diego to Dallas. This segment of old US 80 was not closely paralleled by Interstate 10, which lies to its north, and instead supplants the old and more direct (defunct in eastern Arizona) State Route 86. The route begins at an intersection with I-10 Bus. in Benson near an Amtrak station. The route heads south until it exits the city limit of
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