State Route 78 (Arizona–New Mexico) State Route 78 (Arizona–New Mexico) Arizona State Route 78 (SR 78) and New Mexico State Road 78 (NM 78) are a pair of adjoining state highways located in eastern Arizona and western New Mexico linking U.S. Route 191 (US 191) and Arizona State Route 75 near Greenlee County Airport to US 180 northwest of Cliff, New Mexico. It is also known in its Arizona stretch as Mule Creek Road. The western terminus of SR 78 is located at a junction with US 191 and SR 75 at Three Way, Arizona near Greenlee County Airport. The highway heads northeast from this
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