A person commits an offense if he stops, parks, or stands a truck-tractor, road tractor, trailer, semitrailer, pole trailer, bus, or any commercial motor vehicle upon a public street, alley, parkway, boulevard, or public place. This section shall not apply to street construction, maintenance, and repair equipment; trucks, equipment, trailers, and vehicles used by public service utility companies engaged in repairing or extending public service utilities; motor busses when taking on or discharging passengers at customary bus stops; other vehicles when actually parked at a designated loading zone, or where it is lawful to park a commercial motor vehicle for the purpose of accepting or delivering transportable goods; or a vehicle with a mechanical defect, making it unsafe to proceed further, in which event, it shall be lawful to stand or park the vehicle during the time necessary to make emergency repairs. (Ord. 14584)