In Pixar's Cars, the historic road celebrated through Radiator Springs is Route 66.
U.S. Route 66 was established in 1926 and connected Chicago with Santa Monica across roughly 2,448 miles. It became associated with migration, road trips, diners, motels, and small businesses before being removed from the United States Highway System in 1985.
Cars uses Radiator Springs to dramatize what happened to many Route 66 communities after interstate highways redirected traffic. The town's population and businesses decline when travelers no longer pass through its main street, while abandoned roads and roadside attractions preserve its earlier identity.
Pixar artists researched real Route 66 locations, including communities in Arizona, Oklahoma, and New Mexico. Radiator Springs is fictional, but its setting combines features from several real towns. Route 66 is therefore both a location reference and a major historical theme in the film.