A space of not to exceed fifty feet is hereby reserved at the side of the street in front of any theater, auditorium, hotel having more than twenty-five sleeping rooms, or other buildings where large assemblages of people are being held, within which space, when clearly marked as such, no motor vehicle shall be left standing, parked, or stopped except in taking on or discharging passengers or freight, and then only for such length of time as is necessary for such purpose.