La. Stat. tit. 45 § 324
Where railroads, tramroads, dirt or plank roads cross any highway, the corporation shall so construct the works as not to hinder, impede or obstruct its safe and convenient use. Wherever railroads, tramroads, dirt or plank roads shall be constructed or dug across any plantation or land in cultivation, or that may be cultivated the corporation shall so construct the work as not to hinder, impede or obstruct the drainage of the land. Should any railroad, tramroad, dirt or plank road cross any tide waters, lakes, inlets, rivers or streams, or other bodies of water, the company may erect for the sole and exclusive use of such railroad, tramroad, dirt or plank road, the bridges required for crossing, but such bridges shall be so constructed as not to obstruct or unnecessarily impede the navigation of said waters.
La. R.S. § 45:324