La. Stat. tit. 33 § 3402
The owners of real estate abutting the street or alley to be improved shall pay two thirds of the entire cost of the improvement in proportion to the respective frontages of the abutting property owned by them and the municipality shall pay one third. Where a railway bed and track other than one municipally owned, occupies a portion of the street or alley, the owner shall pay in the proportion that the space occupied by its roadbed bears to the total area of the street or alley to be improved. In the event the railway bed and track is municipally owned, it shall be responsible only for the cost of the extra work made necessary by the presence of the track in the street or alley to be improved. In the event the space occupied by the railroad track is paved with a different material, the entire extra cost of the paving shall be borne by the owner.
If the owners of property abutting any street or alley, or any portion thereof one block or more in length, desire to initiate the construction of an improvement to the street, they may, by petition signed by more than one-half of the owners and representing more than one-half the assessed valuation of the property abutting the street, request the governing authority to construct the desired improvement, in which case the total cost of the improvement shall be apportioned as follows:
La. R.S. § 33:3402