Tennessee Code Title 54. Highways, Bridges and Ferries § 54-18-210

(a) Except utilities in highways at the time of the adoption of the official map, no public water facilities, sewer, or other public utility or improvement shall be constructed in any highway unless shown on the official map or as may be otherwise authorized in title 13, chapter 4, part 3, or the subdivision regulations of a municipality.

(b) Nothing contained in this section or in any other section of this chapter shall be construed to affect any right of a public utility otherwise acquired to cross over or under any highway with its facilities, whether or not the highway is on the official map.

(c) Nothing contained in this section shall be construed to affect any right of a public utility otherwise acquired to locate its facilities upon or along the highway in such a manner as not to interfere with the use or proposed use of the street or highway, whether or not the highway is on the official map.