More and more supplemental routes in Missouri have their endpoints marked. Once an unusual practice, it appears to be more common. Route AA, otherwise known as Princeton Road, has its endpoint marked near 20th Street in Trenton. Route AA once was Business US 65, until the US 65 bypass was built around Trenton in the 1970s. At that time, the business-route designation was directed away from the downtown area, and along the old US 65 route, now called Oklahoma Avenue.