Certain restrictions against parking on public streets do not apply to garbage trucks collecting trash. These vehicles must have flashing hazard lights that are activated when stopping or stationary, and they must be clearly viewable from 200 feet in each direction while stopped. Special lighting also is required in accordance with rules promulgated by the state Department of Safety. T.C.A. § 55-8-158,T.C.A. § 55-8-160.