La. Roads, Bridges and Ferries § 48:1095
For a period of sixty days from the date of the adoption by the authority of a resolution authorizing the issuance of bonds hereunder, any persons in interest shall have the right to contest the legality of the resolution and the legality of the bond issue or the indenture authorized by any such resolution for any cause; after which time no one shall have any cause or right of action to contest the legality of said resolution or indenture or of the bonds authorized thereby for any cause whatsoever. If no suit, action or proceeding is begun contesting the validity of the bond issue within the sixty days herein prescribed, the authority to issue the bonds, the legality thereof and of all the provisions of the resolution authorizing the issuance of the bonds and of any indenture executed to secure the payment thereof, shall be conclusively presumed, and no court shall have authority to inquire into such matters.
Such bonds shall have all the qualities of negotiable instruments under the law merchant and the negotiable instruments law of the state of Louisiana.
La. Roads, Bridges and Ferries § 48:1095