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
Arizona State Route 68 trucks and recreational vehicles traveling between Arizona and Las Vegas, Nevada via US 93, due to the heavy vehicle restrictions over Hoover Dam. The detour was temporary and was removed in 2010, when the new bypass was completed south of the dam . SR 68 was a 2 lane highway and had a high grade going through the Black Mountains. The highway was expanded to 4 lanes in the mid-1990s and now has a smoother ride through the mountains. Arizona State Route 68 State Route 68, also known as SR 68, is an east–west highway in northwestern Arizona running from