The historic road associated with Pixar's Cars setting is Route 66.
Radiator Springs is presented as a once-thriving roadside town on the old U.S. highway, whose fortunes decline after Interstate 40 bypasses it. This story reflects the real history of communities along U.S. Route 66, which connected Chicago and Santa Monica and became an important symbol of American road travel.
The filmmakers researched Route 66 during development. John Lasseter and members of the creative team visited real towns and landmarks to capture the highway's landscapes, architecture, businesses, and changing fortunes. Elements of Radiator Springs draw on several locations rather than reproducing one exact town.
Route 66 was officially removed from the United States Highway System in 1985, but it remains famous through tourism, music, literature, and film. Cars helped introduce the road's history to a worldwide audience. The film's fictional town is therefore inspired by Route 66, not located on a real map as a single exact place.