Williams, Arizona, was the last community on Historic Route 66 to be bypassed by Interstate 40.
The final Interstate 40 bypass around Williams opened on October 13, 1984. Lawsuits and local opposition delayed construction, allowing the city to remain on the active Route 66 corridor longer than other Arizona communities.
The bypass marked the end of Route 66’s practical role as the main through highway in Williams. Interstate traffic no longer passed directly through the historic downtown, while the old road became a heritage and tourism route.
Williams is also known as a gateway to Grand Canyon National Park and retains a prominent historic downtown associated with Route 66. The city’s final bypass is often treated as a symbolic endpoint of the highway’s replacement by the Interstate system.