In Pixar's Cars, what highway bypassed Radiator Springs and caused its decline?

In Pixar's Cars, Interstate 40 bypassed Radiator Springs and caused the town's decline. The film uses this fictional history to dramatize how modern highways diverted travelers away from older Route 66 communities.

Before the interstate was built, Radiator Springs benefited from traffic along Route 66. Sally Carrera explains that the town lost customers when drivers were redirected to a faster road. The change affected local businesses and left the community isolated from the travelers who once sustained it.

The setting reflects a real historical pattern. Interstate 40 replaced much of the long-distance role once served by Route 66 across the American Southwest. The real Route 66 was removed from the United States Highway System in 1985, although many surviving sections remain cultural and tourist landmarks.

The film sometimes leads viewers to answer Route 66 because it is the famous road associated with Radiator Springs. Route 66 is the road the town depends on; Interstate 40 is the bypass that causes its traffic loss.