The 1983 Tennessee state highway renumbering occurred when the Tennessee Department of Transportation (TDOT) took control of approximately 3,300 miles (5,300 km) of city and county maintained roads, designating them as state routes.
[3] In addition, a 1983 study conducted by TDOT found that a number of important roads were partially maintained by both the state and local governments.
[4] In May 1983, Tennessee Governor Lamar Alexander signed legislation which allowed for the state to assume control of 3,300 miles (5,300 km) of city and county maintained roads, and made an additional 11,500 miles (18,500 km) of rural roads eligible for state aid.
[5] TDOT took control of these roads on July 1, 1983, and incorporated them into the state route system.
[4] State routes were also divided into primary and secondary highways, with new primary shields unveiled to the public in November 1983;[8] secondary routes retained the inverted triangle shields, with the "Tenn" removed.