Tennessee Code Title 55. Motor and Other Vehicles § 55-7-117

(a) Truck tractors and semitrailers, as defined in § 55-8-101, shall not use an engine compression braking device, unless the engine compression braking device is equipped with an operational, approved muffler.

(b) As used in this section, “approved muffler” means any muffler that complies with Federal Motor Carrier Safety Regulations on noise emissions, compiled in 49 CFR 325.1 et seq.

(c) A violation of this section is a Class C misdemeanor.

(d) Any local or municipal government may request that the department of transportation place signage within the local or municipal government's jurisdiction, to effectuate the purposes of this section within its jurisdiction. The erection of these signs shall be within the guidelines prescribed by the Manual on Uniform Traffic Control Devices. The department of transportation shall have the authority to develop appropriate signage, sign usage, and manufacture and installation guidelines regarding the signs. The local or municipal government shall remit to the department of transportation the cost of the manufacture and installation of the signs. The payment shall be made prior to any expenditure by the state for the manufacture or installation of the signs. The department shall return any unused portion of the estimated cost to the local or municipal government paying for the signs within thirty (30) days of the erection of the signs. If the local cost exceeds the estimated cost, an amount equal to the difference in such costs shall be remitted to the department within thirty (30) days of the local or municipal government receiving an itemized invoice of the actual cost from the department.

(e) The commissioner of transportation is authorized to promulgate rules and regulations to effectuate the purposes of this section. All rules and regulations shall be promulgated in accordance with the Uniform Administrative Procedures Act, compiled in title 4, chapter 5.