Tenn. Code Ann. § 54-5-1304

With respect to a TODS sign, the department shall not enter into a contract for the procurement of signs or other goods or for contracts for services unless the contract is objectively and competitively bid, pursuant to former § 12-3-102(a)(8). The department shall not use the request for proposals (RFP) procedure in the contracting process. The signs shall be subject to the requirements of part 11 of this chapter.