Said bonds shall be signed by the Governor, the Comptroller and the Treasurer of the State of Louisiana, provided that the signatures of the Governor and Comptroller on said bonds may be printed, lithographed or engraved thereon. Any coupons attached to said bonds shall bear the facsimile signature of the Treasurer of the State of Louisiana. Said bonds are hereby declared to have the qualities of negotiable instruments under the law of Louisiana, and shall not be invalid for any irregularity or defect in the proceedings for the issuance and sale thereof, and shall be incontestable in the hands of bona fide purchasers or holders thereof.
No proceedings or approvals with respect to such bonds or the issuance and sale thereof shall be necessary except such as are contemplated by this Section.
If science or invention should reduce the use and consumption of gasoline, benzine, naphtha or other motor fuels to such an extent that the tax on such commodities should not be sufficient to retire the bonds issued under the authority of this Section, including the interest due thereon, then the Legislature shall have the authority to levy a tax upon any commodity, substance, appliance or paraphernalia, or to impose a license upon the right to sell or make use of such commodity, substance, appliance or paraphernalia, which may be sold or used to generate or supply motor fuel or other power for transportation; to levy such tax or license, or both, or such other taxes as may be necessary to pay said bonds and the interest thereon, and this authority shall in no wise affect the tax levied under the authority of the Constitution and statutes of the State upon gasoline, benzine, naphtha or other motor fuel as defined by law, or be subject to any limitation imposed by the Constitution.
In like manner, the one cent (1¢) gasoline tax levied under Article VI(A), of the Constitution, the use fuel tax, the tax on lubricating oil, and taxes for licenses on all motor vehicles and other vehicles shall continue to be levied so long as any bonds issued under authority of this Section are outstanding and the proceeds of such taxes subject to prior dedication, as aforesaid, shall be paid into the Long Range Highway Fund and applied as provided in this Section.
La. Const. A. § 6-23.1