First proposed by former Governor Lamar Alexander as part of a system of Bicentennial Parkways, I-840 was constructed between 1991 and 2012. The highway was originally planned as an Interstate Highway, but was constructed entirely with state funds, and as a result was initially designated as a state route. In 2015, the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) approved TDOT's request to re-designate SR 840 as I-840 as part of its integration into the Interstate Highway System. On August 12, 2016, TDOT announced that the route had officially been renamed Interstate 840, and that re-signing work would begin.