Interstate 40 in Arizona

Interstate 40
Purple Heart Trail
I-40 highlighted in red
Route information
Maintained by ADOT
Length	359.11 mi[1] (577.93 km)
Existed	1960–present
NHS	Entire route
Major junctions
West end	I-40 at California state line
Major intersections	Future I-11 / US 93 in Kingman I-17 in Flagstaff US 180 from Flagstaff to Holbrook US 191 near Sanders
East end	I-40 at New Mexico state line
Location
Country	United States
State	Arizona
Counties	Mohave, Yavapai, Coconino, Navajo, Apache
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future Arizona State Highway System Interstate US State Proposed Former
← SR 30 → SR 50

Interstate 40 (I-40) is an east–west Interstate Highway that has a 359.11-mile (577.93 km) section in the US state of Arizona, connecting sections in California and New Mexico. The Interstate is also referred to as the Purple Heart Trail to honor those wounded in combat who have received the Purple Heart.^[2] 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 main highway connecting Phoenix and Las Vegas, Nevada) in Kingman and again approximately 22 miles (35 km) to the east and I-17 (the freeway linking Phoenix to northern Arizona) in Flagstaff.

For the majority of its routing through Arizona, I-40 follows the historic alignment of US 66. The lone exception is a stretch between Kingman and Ash Fork where US 66 took a more northerly, less direct route that is now State Route 66 (SR 66). Construction of I-40 was ongoing in the 1960s and 1970s and reached completion in 1984. With the completion of I-40 in 1984, the entire routing of US 66 had been bypassed by Interstate Highways which led to its decertification a year later in 1985.