Section 21107 Of Article 3. Local Regulation From California Vehicle Code >> Division 11. >> Chapter 1. >> Article 3.

. The provisions of this code shall not prevent any city from adopting rules and regulations by ordinance or resolution, regulating vehicular traffic on privately owned and maintained roads located within the boundary of such city, except that no such ordinance or resolution shall be effective until signs giving notice thereof are posted on the roads affected. The provisions of this section shall not apply to any city in which there are publicly maintained city streets.