Interstate 40 in Arizona Interstate 40 in Arizona Interstate 40 (I-40) is an east–west Interstate Highway that has a section in the U.S. state of Arizona, connecting sections in California and New Mexico. The section throughout Arizona is also known as the Purple Heart Trail. It enters Arizona from the west at a crossing of the Colorado River southwest of Kingman. It travels eastward across the northern portion of the state connecting the cities of Kingman, Ash Fork, Williams, Flagstaff, Winslow, and Holbrook. I-40 continues into New Mexico, heading to Albuquerque. The highway has major junctions with U.S. Route 93 (US 93) — the
Arizona State Route 66 Arizona State Route 66 State Route 66 (SR 66) is a surface road in the U.S. state of Arizona in Mohave and Coconino Counties. In 1914, the road was designated "National Old Trails Highway" but in 1926 was re-designated as U.S. Route 66. In 1985, U.S. Route 66 was dropped from the highway system. Parts of the highway were either absorbed into I-40, turned over to the state (SR 66), or turned over to Yavapai County. State Route 66 is a relic of the former U.S. Route 66 in Arizona and is the only part of old US 66 in