State Route 84, also known as SR 84, is a 41-mile (66 km) east–west highway in south-central Arizona, with its western terminus at Exit 151 of Interstate 8 and its eastern signed terminus at its junction with State Route 387 and State Route 287 in Casa Grande. An unsigned section, which is mostly maintained by local governments, runs from the SR 287 and SR 387 junction southeast through Arizola and Eloy. East of Eloy, SR 84 is concurrent with the beginning 0.87 miles (1.40 km) of State Route 87 just north of Interstate 10 near Picacho.

Interstate 8 (I-8) is an Interstate Highway in the southwestern United States. It runs from the southern edge of Mission Bay at Sunset Cliffs Boulevard in San Diego, California, almost at the Pacific Ocean, to the junction with I-10, just southeast of Casa Grande, Arizona. In California, the freeway travels through the San Diego metropolitan area as the Ocean Beach Freeway and the Mission Valley Freeway before traversing the Cuyamaca Mountains and providing access through the Imperial Valley, including the city of El Centro. Crossing the Colorado River into Arizona, I-8 continues through the city of Yuma across the Sonoran Desert to Casa Grande, in between the cities of Phoenix and Tucson.