Except when otherwise prohibited, every vehicle stopped or parked upon a one-way roadway shall be so stopped or parked parallel to the curb or edge of the roadway, in the direction of authorized traffic movement, with its right-hand wheels within 18 inches of the right-hand shoulder, or with its left-hand wheels within 18 inches of the left-hand shoulder or as close as practical to the left edge of the left-hand shoulder.  (Ord. 91/T-10447)