No commercial vehicle or commercial trailer shall be parked out of doors between the hours of 8:00 p.m. and 6:00 a.m. in any residential zone or any lot or on the street adjoining the same and no more than one commercial vehicle shall be parked on any residential lot or on the street adjoining the same. No commercial vehicle or trailer shall be parked out of doors between the hours of 8:00 p.m. and 6:00 a.m. on any street located within both a commercial zone and a residential zone where the line dividing the zones from the residential zone bisects such street. A commercial vehicle including commercial trailers of 3/4 ton manufacturer's rated capacity or less, may be parked out of doors, provided however, that no more than one such vehicle shall be parked on any residential lot or street adjoining the same. Provisions of this section shall be administered and enforced by the Zoning Officer and the Director of Public Safety and their designees.