Cal. PUC § 1031

(a) No passenger stage corporation shall operate or cause to be operated any passenger stage over any public highway in this state without first having obtained from the commission a certificate declaring that public convenience and necessity require such operation, but no such certificate shall be required of any passenger stage corporation as to the fixed termini between which, or the route over which, it was actually operating in good faith on July 29, 1927, in compliance with the provisions of Chapter 213, Statutes of 1917, nor shall any such certificate be required of any person or corporation who on January 1, 1927, was operating, or during the calendar year 1926 had operated a seasonal service of not less than three consecutive months’ duration, sightseeing buses on a continuous sightseeing trip with one terminus only. Any right, privilege, franchise, or permit held, owned, or obtained by any passenger stage corporation may be sold, assigned, leased, mortgaged, transferred, inherited, or otherwise encumbered as other property, only upon authorization by the commission.

(b) For purposes of this section, “public convenience and necessity,” as it affects applications for passenger stage corporation certificates, means that the applicant has met the criteria for issuance of a certificate specified in Section 1032.