Cal. Veh. Code § 34503

It is the legislative intention in enacting this division that the rules and regulations adopted by the Department of the California Highway Patrol pursuant to this division shall apply uniformly throughout the State of California, and no state agency, city, city and county, county, or other political subdivision of this State, including, but not limited to, a chartered city, city and county, or county, shall adopt or enforce any ordinance or regulation which is inconsistent with the rules and regulations adopted by the department pursuant to this division.