For the purpose of providing part or all of the money to be used, with or without any grants or other money that may become available, the issuance and sale of revenue bonds of the state in the total principal sum of not to exceed $500,000,000 is authorized to acquire, construct, equip, and install the additions, improvements, extensions, and facilities authorized in Alaska Stat. § 37.15.720 and 37.15.730. The principal of and interest on these bonds are paid out of and secured by the gross revenue derived by the state from the ownership, use, and operation of the toll facilities, and out of any other revenue or money that the state legislature may provide exclusive of any state tax or license. Bonds may not be issued to assist in the acquisition, financing, or operation of projects without prior approval from the legislature.