The governing authority of any parish issuing its bonds under the provisions of this Sub-part shall impose rates for the use of any bridge sufficient to operate and maintain the bridge, pay the principal of and interest on the bonds, and provide an adequate fund for depreciation, improvements, and extensions. Subject to this requirement, the governing authority may fix and revise the tolls from time to time and charge and collect them.
Tolls shall be so fixed and adjusted, in respect of the aggregate of tolls from the bridge or bridges for which a single issue of bonds is issued, as to provide a fund sufficient, with other revenues of the bridge or bridges, if any, to pay:
(1) Any payments to reimburse the parish for losses of taxes, as provided by R.S. 48:882;
(2) The cost of maintaining and operating the bridge or bridges unless that cost is otherwise provided for; and
(3) The bonds and interest thereon as each becomes due.
These tolls are not subject to supervision or regulation by any state commission, board, bureau, or agency.