The highway featured in Pixar's Cars as the route toward Radiator Springs is Route 66.
The historic U.S. Route 66 strongly influenced the film's setting, characters, and story. Once connecting Chicago and Los Angeles, the road became famous for roadside businesses, motels, gas stations, and small communities. Interstate highways later diverted much of its traffic, leaving many towns economically isolated.
Cars turns that history into the story of Radiator Springs, a community bypassed by a new interstate. Lightning McQueen initially sees the town as an inconvenience, but its residents show him the cultural and human value of places overlooked by faster transportation routes.
U.S. Route 66 was officially removed from the United States Highway System in 1985, although historic sections remain popular tourist destinations. Route 66 is not the same as California's Pacific Coast Highway or U.S. Route 101, which are also well-known American roads.