Without much fanfare, the Mother Road was removed from the U.S. Highway System. The end of Route 66 had been a long time coming, though. The new-fangled Interstate Highway System had taken its place and the old, crumbling road no longer had much purpose.

Route 66 was officially decertified on June 27, 1985, primarily because it had been rendered obsolete by the Interstate Highway System. Initiated by President Eisenhower in 1956, the new interstates (specifically I-40, I-44, and I-55) provided faster, safer, and more direct multi-lane routes that bypassed the winding, two-lane "Mother Road." As the final bypass was completed around Williams, Arizona, in 1984, the American Association of State Highway and Transportation Officials (AASHTO) removed the "66" designation from the federal map. Decertification was a blow to the small-town economies that relied on "Mother Road" traffic, leading many to become ghost towns. In 2026, the road lives on as a National Historic Trail, where travelers seek out the "ghosts" of mid-century Americana, but it no longer serves as a functional primary artery for cross-country commerce or high-speed travel.