California Code, Penal Code - PEN § 369g

(a) Any person who rides, drives, or propels any vehicle upon and along the track of any railroad through or over its private right-of-way, without the authorization of its superintendent or other officer in charge thereof, is guilty of a misdemeanor.

(b) Any person who rides, drives, or propels any vehicle upon and along the track of any railline owned or operated by a county transportation commission or transportation authority without the authorization of the commission or authority is guilty of a misdemeanor.