Sts. & Hy. Code, § 30778

(a) The annual tolls and revenues of the San Francisco-Oakland Bay Bridge, or so much thereof as may be necessary, after provision for the payment in full of all annual costs of operation, insurance, and other expenses of the San Francisco-Oakland Bay Bridge, and after payment or provision for payment in full of all of the costs of any project involving the San Mateo-Hayward Bridge, shall be pledged and used to finance and pay for the cost of the construction of additional highway crossings across San Francisco Bay as provided below, and for such other purposes as may be authorized by law, including, but not limited to, payment of the principal of, and interest and premiums, if any, on, and provision for security of, the revenue bonds of the commission issued pursuant to this article and the California Toll Bridge Authority Act (Chapter 1 (commencing with Section 30000)).

(b) Bonds for the construction of additional highway crossings across San Francisco Bay may be authorized and issued by the commission. In the event the commission shall be authorized to refund any and all bonds issued for the construction of other toll bridges or toll highway crossings of San Francisco Bay and the rivers and streams tributary thereto in the Counties of Alameda, Contra Costa, Marin, Napa, San Mateo, Santa Clara, Solano, and Sonoma and the City and County of San Francisco, then and in that event the commission is authorized to issue all of the bonds to be issued for the additional highway crossings over San Francisco Bay and the refunding bonds in a single authorization, and to pledge to the payment of the principal of, and interest on, all of the bonds and any provisions for the further security thereof, including reserve fund or sinking fund payments or otherwise, all of the revenues of all of the bridges of San Francisco Bay and the rivers and streams tributary thereto, including the San Francisco-Oakland Bay Bridge, the San Mateo-Hayward Bridge, the Dumbarton Bridge, the Carquinez Strait Bridges, the Benicia-Martinez Bridge, the Antioch Bridge, and the Richmond-San Rafael Bridge, or any thereof as may be determined by the commission, together with revenues of the additional crossings to be constructed across San Francisco Bay.