La. Roads, Bridges and Ferries § 48:1099
The exercise of the power granted by this Part will be in all respects for the benefit of the people of the state, for the increase of their commerce and prosperity, and for the improvement of their health and living conditions, and as the operation and maintenance of bridges and ferries by the authority will constitute the performance of essential governmental functions, the authority shall not be required to pay any taxes or assessments upon any bridge or ferry or any property acquired or used by the authority under the provisions of this Part, or upon the income therefrom, and any bridge or ferry or other property acquired or used by the authority under the provisions of this Part and the income therefrom, and the bonds issued under the provisions of this Part and the income therefrom shall be exempt from taxation by the state of Louisiana and by any parish, municipality or political subdivision of the state.
La. Roads, Bridges and Ferries § 48:1099