Cal. Vehicle Code § 34681

(a) For purposes of this division, “private carrier” means a not-for-hire motor carrier, as defined in Section 408, who transports passengers and is required to obtain a carrier identification number pursuant to Section 34507.5, including an organization that provides transportation services incidental to the operation of a youth camp that is either a nonprofit organization that qualifies for tax exemption under Section 501(c)(3) of the Internal Revenue Code or an organization that operates an organized camp, as defined in Section 18897 of the Health and Safety Code, serving youth 18 years of age or younger. (b) For purposes of this division, “private carrier” does not include either of the following: (1) The operator of an automobile rental business that uses vehicles owned or leased by that operator, without charge other than as may be included in the automobile rental charges, to carry its customers to or from its office or facility where rental vehicles are furnished or returned after the rental period. (2) The operator of a hotel, motel, or other place of temporary lodging that provides transportation service in vehicles owned or leased by that operator, without charge other than as may be included in the charges for lodging, between the lodging facility and an air, rail, water, or bus passenger terminal or between the lodging facility and any place of entertainment or commercial attraction, including, but not limited to, facilities providing snow skiing. Nothing in this subdivision authorizes the operator of a hotel, motel, or other place of temporary lodging to provide any round-trip sightseeing service without a permit, as required by subdivision (c) of Section 5384 of the Public Utilities Code.