(a) An authority shall impose reasonable and nondiscriminatory fares, tolls, charges, rents, and other compensation for the use of the public transportation system sufficient to produce revenue, together with grants received by the authority, in an amount adequate to:
(1) pay all expenses necessary to operate and maintain the public transportation system;
(2) pay when due the principal of and interest on, and sinking fund and reserve fund payments agreed to be made with respect to, all bonds that are issued by the authority and payable wholly or partly from the revenue; and
(3) fulfill the terms of any other agreement with the holders of bonds described by Subdivision (2) or with a person acting on behalf of the bondholders.
(b) It is intended by this chapter that the compensation imposed under Subsection (a) not exceed the amounts necessary to produce revenue sufficient to meet the obligations of the authority under this chapter.

(c) Compensation for the use of the public transportation system may be set according to a zone system or to another classification that the authority determines to be reasonable.
(d) This section does not limit the state’s power to regulate fares, tolls, charges, or rents imposed by an authority or other compensation authorized under this section. The state agrees with holders of bonds issued under this chapter, however, not to alter the power given to an authority under this section to impose fares, tolls, charges, rents, and other compensation in amounts sufficient to comply with Subsection (a), or to impair the rights and remedies of an authority bondholder, or a person acting on behalf of a bondholder, until the bonds, interest on the bonds, interest on unpaid installments of interest, costs and expenses in connection with an action or proceeding by or on behalf of a bondholder, and other obligations of the authority in connection with the bonds are discharged.