It shall be unlawful for any vehicle to be parked, whether occupied or not, in any unmarked parking meter space when such space is parallel to a curb or roadway, in such a manner as to cause the front of the vehicle to extend more than three (3) feet in front of or not more than three (3) feet behind the parking meter designated for that space. (1978 L.M.C., ch. 7, § 2.)