The State of Tennessee use to have "primary" and "secondary" highways. The primary highways were shielded by white rectancles with a picture of the state below the number. Tennessee's secondary highways were marked by black rectangles with white triangles on them. Noel Evans, Manager I in the Planning Division of the Tennessee Department of Transportation, stated that Section 1006 of the Intermodel Surface Transportation Effciency Act (ISTEA) of 1991 directed the development of a National Highway System (NHS) of roads. The approval of NHS in 1993 ended the previous Federal-Aid Primary and Federal Aid Secondary system of roads. The 2007 Tranportation Map from TDOT (Tennessee Department of Transportation) was the first map issued from the state that indicated that they were no longer using primary and secondary highways.
