Interstate 10 in Arizona 2013. The remainder of the old US 80 section was rebuilt to interstate standards, with completion in 2014. East of Tucson, I‑10 parallels and in some cases overlies old US 80 to Benson, and was originally co-signed as US 80 and SR 86. The section of I-10 from Valencia Road to Rita Road was the first construction project in the state of Arizona funded by the Federal Aid Highway Act of 1956. Construction began in 1957 and was completed in 1960. From Benson, the Interstate follows the Southern Pacific mainline east through Willcox and Bowie to New Mexico, rather than
Interstate 40 in Arizona section of highway in Arizona. This section of the Interstate was complete in 1975. Construction of the $7.7 million bypass around Winslow began in 1977. I-40 was completed in Arizona in 1984, with the completion of a section in Williams. This was also the last section of US 66 to be bypassed by the Interstate, which led to it being decertified by the American Association of State Highway and Transportation Officials (AASHTO) the following year. 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