Va. Code § 33.2-1721
When the particular revenue bonds issued for any project and the interest thereon have been paid, or a sufficient amount has been provided for their payment and continues to be held for that purpose, the Board shall cease to charge tolls for the use of such project and thereafter such project shall be free; however, the Board may thereafter charge tolls for the use of any such project when tolls are required for maintaining, repairing, operating, improving, and reconstructing such project; when such tolls have been or are pledged by the Board to the payment of revenue bonds issued under the provisions of this chapter for another project on approval of the General Assembly; or when such tolls are designated by the Board to be deposited into the Transportation Trust Fund. However, any such pledge of tolls of a project to the payment of bonds issued for another project shall not be effective until the principal and interest of the bonds issued for the first mentioned project has been paid or provision made for their payment.
The provisions of this section shall also apply to tolls on projects constructed pursuant to (i) the Chesapeake Bay Bridge and Tunnel District and Commission established in Chapter 22 (§ 33.2-2200 et seq.) and (ii) the Richmond Metropolitan Transportation Authority established in Chapter 29 (§ 33.2-2900 et seq.), provided their governing bodies have acted as set forth in subdivision A 3 of § 33.2-1524.
Va. Code § 33.2-1721