The use of any alley of the city for repairing or working upon automobiles or other vehicles or for the purpose of supplying gas, oil or air to automobiles or other motor vehicles is prohibited; and all persons are prohibited from placing or maintaining in any of the alleys of the city stations for the purpose of supplying gas, oil or air to automobiles and other motor vehicles or from placing or maintaining in any alley building material or any other obstruction of any kind. (Prior code § 4-4-6)