All private driveways crossing the sidewalk space (except on unpaved streets where specifications as to mix and type of construction shall prevail where the driveway crosses the sidewalk space only) must be constructed of stone, brick, asphalt or concrete from the curbline to the lot line, and must be placed at a grade to be fixed by the City Engineer according to specifications furnished by the Superintendent of Public Works.
(1979 Code Sec. 13.16.030)