La. Roads, Bridges and Ferries § 48:1154
If such bridge shall be designated a part of the state highway system, by order of the director of highways approved by the board of highways, the department of highways may contract to construct any highways necessary to connect the bridge with the state highway system, including the approaches to such bridge, and to pay the cost of such connecting highway or highways and approaches out of the moneys in the state highway fund, and the department of highways may further contract that after such bridge shall be opened for traffic it will maintain and operate such bridge, subject to any covenants which may have been made by the authority with the holders of bonds issued by such authority to provide for the cost of construction of such bridge.
Said contract shall define the location and extent of the connecting highways and the approaches to such bridge with reasonable certainty and the determination so made in said contract shall be conclusive and binding upon the parties thereto, upon the state and upon all other persons; provided, however, that the state highway department and the Authority may, by amendment to such contract, provide for the construction of additional approaches and highway connections to such bridge, and for the payment of the cost of construction of such additional connecting highways and approaches, subject to any covenants which may have been made by the Authority with the holders of any of its outstanding bonds.
La. Roads, Bridges and Ferries § 48:1154