Tex. Transp. Code § 367.011
(b) The governing body of the municipality shall impose and collect pledged tolls and charges in an amount that will be at least sufficient, with any other pledged resource, to provide for the payment of:
(2) to the extent required by the ordinance authorizing issuance of the bonds:
Added by Acts 1999, 76th Leg., ch. 227, Sec. 25, eff. Sept. 1, 1999.