Tenn. Code Ann. § 55-7-208: Twin trailer trucks

(a) Notwithstanding any law to the contrary, twin trailer trucks conforming to § 55-7-201 shall be permitted to operate on the interstate system and other federal-aid highways designated by the commissioner of transportation. Within the limitations as provided in this chapter, any such twin trailer truck may use and must confine itself to the shortest reasonable route to and from the interstate system, other designated highways, and terminals; or in the case of household goods carriers, to and from points of loading and unloading; or, where these twin trailers are manufactured or assembled within the state, from the place of manufacture or assembly, to the highways upon which the truck is permitted to operate by this chapter. Access to facilities in interchange areas adjoining these highways for food, fuel, repairs and rest shall not be denied.

(b) The state department, county or municipal agency or department having present authority to designate uses of roads and highways within its jurisdiction has the authority to establish certain reasonable routes over which twin trailer trucks subject to the restrictions in subsection (a) must travel on the highways within the jurisdictional boundaries and control of that county or municipality in the interest of public safety, bearing in mind the need for safe, efficient interstate transportation. The state department, county or municipal agency or department having the authority to designate reasonable routes shall also consider maintenance cost of the routes and safety of the motoring public before designating the routes.