Cal. Pub. Util. Code § 7602

Section 7601 does not apply to any track, siding, spur, or other track owned by private persons for their own use, except when the track, siding, spur, or other track is operated regularly in connection with the line of a common carrier for certain periods, in which case Section 7601 does apply. Section 7601 does not apply to the placing of signboards in places where physical conditions of track will not permit.