((a)) The use of the Golden Gate Bridge free of toll, provided for in , shall be granted upon the presentation and surrender at the toll lanes of an authorization certifying that the traffic in question is entitled to such right. Such authorization shall be issued and signed by any military or naval officer designated for such purpose in accordance with regulations which shall be prescribed by the Secretary of the Army and the Secretary of the Navy, respectively. The names and signatures of officers so designated shall be furnished to the Golden Gate Bridge and Highway District, and thereafter authorizations signed by them shall be accepted by such bridge and highway district as prima facie evidence of the facts stated therein.
((b)) Notwithstanding the provisions of subsection (a), such right to use the Golden Gate Bridge free of toll may be established by any other device or means which may be acceptable to the Golden Gate Bridge and Highway District; and the Secretary of the Army and the Golden Gate Bridge and Highway District, and the Secretary of the Navy and the Golden Gate Bridge and Highway District, may enter into any appropriate agreements to secure the effective, convenient, and just exercise of such right.