California Code, Vehicle Code - VEH § 23252

The chief of toll services, captains, lieutenants, and sergeants employed by the Department of Transportation shall have the powers and authority of peace officers as listed in Section 830.4 of the Penal Code while so employed on any vehicular crossing or as may be necessary to the performance of their duties while not upon such vehicular crossing. Captains, lieutenants, and sergeants so employed shall wear, while on duty, a uniform which shall be distinctly different from that of the California Highway Patrol, to be specified by the Director of Transportation.