Sts. & Hy. Code, § 30503

The commission may enter into a binding agreement with any city, county, district, or political subdivision of the state to repay any money or the value of any rights-of-way, labor, materials, or other property advanced or contributed toward the expense of acquiring or constructing any toll bridge or other highway crossing, or the transportation facilities thereof or thereto, acquired or constructed pursuant to this chapter, but no repayment therefor shall be made until all obligations issued by the commission for the acquisition or construction of the toll bridge or other highway crossing, and the transportation facilities thereof or thereto, have been fully redeemed and paid, and then only out of the tolls and revenues received from the operation of the toll bridge or other highway crossing.