Section 22507.8 of the Vehicle Code of the State, which provides that it shall be unlawful for any person to park or leave standing any vehicle in a stall or space designed for physically handicapped persons if, immediately adjacent to and visible from such stall or space, there is posted a sign consisting of a profile view of a wheelchair with an occupant in white on a bIue back-ground, unless the vehicle displays either one of the distinguishing license plates or a placard issued pursuant to Section 22511.5 or Section 9105 of said Vehicle Code, shall be operative on all off-street parking facilities owned or operated by the County, (§ 1, Ord. 927, eff. March 18, 1982)