(a) No person shall stand or park a truck, trailer or semitrailer at any time upon a roadway in front of or alongside property which is used for residential purposes, except in the case of a disabled vehicle or for loading or unloading purposes.
(b) No person shall stand or park upon any street any commercial trailer which is detached from its tractor or other means of locomotion, except for the minimum period required for loading or unloading. (1972 Code 452.13)