(

a) The department may enter into financing agreements with the bank for the purpose of borrowing funds to finance or refinance the seismic retrofit project costs identified in paragraph (4) of subdivision (

a) of

Section 188.5. The bank may issue bonds for this purpose, pursuant to the authority granted to it under

Chapter 5 (commencing with

Section 63070) of Division of Title 6.7 of the Government Code, and deposit the proceeds from the bonds into the account. The amount of borrowing may be increased to fund necessary reserves, capitalized interest, interim bonds, including, but not limited to, commercial paper, costs of issuance, and administrative, financial, legal, and incidental services related to the bonds. The department shall pursue the most cost-effective and efficient financing plan for the bridge work identified in paragraph (4) of subdivision (

a) of

Section 188.5. (

b) To the extent provided in the governing documents, each of the bonds issued under this

section shall be payable from, and secured by, all or a portion of the toll surcharge revenue in the account and the assets in that account. (

c) Prior to the issuance of bonds payable from the toll surcharge, the bank shall confirm that bonds issued under

Chapter 4.3 (commencing with

Section 30950) shall not be impaired solely by action taken under this section, as evidenced by confirmation of the then existing ratings on these bonds, by the rating agencies then rating the bonds. This requirement shall not apply if the voters approve an increase in the toll rate pursuant to subdivision (

b) of

Section 30921.