Cal. Public Utilities Code § 7817

Any street railroad corporation operating cars on the streets of cities or on the county roads within the State for the conveyance of passengers, propelled by means of wire ropes attached to stationary engines, or by electricity or compressed air, who runs, operates, or uses any car or dummy, unless each car and dummy, while in use, is fitted with a brake capable of bringing the car to a stop within a reasonable distance, and a suitable fender, or appliance placed in front or attached to the trucks of the dummy, or car, for the purpose of removing and clearing obstructions from the track, and preventing any obstacles, obstructions, or person on the track from getting under the dummy or car, and removing the same out of danger, and out of the way of the dummy or car, is guilty of a misdemeanor. Where the commission prescribes the fender or brake to be used, a compliance therewith constitutes a full compliance with this section.