The grant of any such permit or the execution of any such contract by the California Transportation Commission shall not relieve any transportation company or corporation subject to the jurisdiction of the Public Utilities Commission from the duty of obtaining any certificate of public convenience and necessity for the conduct of a transportation service over any toll bridge or other highway crossing as required by law, or from the duty of complying with every lawful order, rule, or regulation of the Public Utilities Commission respecting such transportation service.
Ca. Sts. and High. Code § 30106