La. Roads, Bridges and Ferries § 48:1263
The state of Louisiana does pledge to and agree with the holders of the bonds issued pursuant to this Chapter, that the state will not limit or restrict the rights hereby vested in the authority to construct, reconstruct, maintain and operate any project as defined in this Chapter or to establish and collect such tolls or other charges as may be convenient or necessary to produce sufficient revenues to meet the expenses of maintenance and operation thereof and to fulfill the terms of any agreements made with the holders of bonds authorized by this Chapter or in any way impair the rights or remedies of the holders of such bonds until the bonds, together with interest thereon, are fully paid and discharged.
La. Roads, Bridges and Ferries § 48:1263