In Pixar's Cars, what real-world highway inspires the road trip and setting?

In Pixar's Cars, U.S. Route 66 inspires the road trip and setting.

The film follows Lightning McQueen into Radiator Springs, a fictional town shaped by the history of U.S. Route 66. The highway once connected Chicago and Santa Monica and became famous as a major route for motorists traveling west. Its businesses, roadside attractions, and small towns later became symbols of classic American road travel.

Cars uses the decline of Route 66 to explain Radiator Springs's problems. When a faster interstate bypasses the town, travelers stop visiting, businesses close, and the population falls. The story turns that historical pattern into a character-driven setting where McQueen learns the value of places that cannot be measured only by speed or convenience.

Interstate 40 is important because it replaced much of Route 66's long-distance function in the Southwest, but it is not the road that primarily inspires the film. The correct subject is U.S. Route 66, also widely called the Mother Road.