Tucson is primarily served by I-10 and I-19. I-19 spilts off from I-10 in the southern part of Tucson, runs through southern Tucson (including an exit serving the historic Mission San Xavier) and the retirement community of Green Valley, and terminates in Nogales, in Santa Cruz County, at the international border with Mexico. Mileage signs have metric mileage figures in kilometers instead of standard miles.

State Route 210 (Barraza Aviation Parkway) is a limited-access parkway built in the early 1990's to connect downtown Tucson to the southeastern portion of the city. Few new limited-access roads are in the plans in Tucson due to strong community opposition to freeways.

As recently as 1959, many roads such as State Highway 87, the Beeline Highway between Phoenix and the small community of Payson in Gila County, were unpaved.

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