Cal. Sts. & High. Code § 31235

After all bonds issued pursuant to this chapter for the construction of the toll tunnel have been fully redeemed and paid, the authority may continue to collect tolls and other revenues for the use of such toll tunnel for the purpose of reimbursing the state for any expenditures which have been made by it in connection with the toll tunnel and for the purpose of repayment to any city, county, district, or political subdivision of the state of any amount the authority has agreed to repay for money, rights-of-way, labor, materials, or other property advanced or contributed for the acquisition or construction of the toll tunnel.