(a) Parking on streets the pavement of which is twenty-six feet or less in width shall be restricted to one side thereof. No person shall park a vehicle at any time on that side of any such restricted street or part thereof designated by the Mayor as a no parking area, after signs are erected giving notice of such prohibition. In designating the area along the side of any such street in which there shall be no parking, the Mayor shall take into consideration the location of the fire hydrants and other conditions on or adjacent to such street or part thereof.