(a) Where used in this section the following words and terms shall be given the following respective meanings:

(1) BONDS. Such term, without qualifying words or phrases, means bonds of the corporation issued under this article.

(2) CODE. The Code of Alabama, 1975.

(3) CORPORATION. Alabama Highway Finance Corporation, a public corporation and instrumentality of the State of Alabama that was organized and is existing under this article.

(4) GASOLINE TAX APPROPRIATION STATUTE. Section 40-17-359.

(5) HIGHWAY GASOLINE TAX.

a. The excise tax levied in subdivision (1) of subsection (a) of Section 40-17-325, exclusive of those portions of the tax in respect of aviation fuel and marine gasoline, as those terms are used in the section; and

b. The excise tax levied by Article 3 of Chapter 17 of Title 40, exclusive of that portion of the tax in respect of diesel fuel.

(6) NET GASOLINE TAX PROCEEDS. The entire proceeds from the highway gasoline tax less the cost of collection and less any refunds of the proceeds pursuant to the provisions of Chapter 17 of Title 40.

(7) STATE'S SHARE OF THE NET GASOLINE TAX PROCEEDS. The 45 percentum of the net gasoline tax proceeds allocated and appropriated for state highway purposes in subsection (c) of Section 40-17-359.

(b) For the purpose of providing funds to enable the corporation to pay at their respective maturities the principal of and interest on any bonds that may be issued by it under the provisions of this article and to accomplish the purposes and objects of its creation, there hereby is irrevocably pledged to the purpose and appropriated so much as may be necessary for the purpose of the following, subject, however, to the provisions, hereinafter set forth in this subsection, as to the rank of the pledges herein made:

(1) So much as may be necessary for such purpose of those portions of the motor vehicle license taxes and registration fees that are provided to be distributed to the state pursuant to the provisions of Division 1 of Article 5 of Chapter 12 of Title 40 as amended, remaining after the costs of collection thereof.

(2) To such extent and to such extent only as the revenues appropriated under subdivision (1) of this subsection may not be sufficient to pay at their respective maturities the principal of and interest on the bonds, so much as may be necessary for such purpose, when added to the amounts appropriated in subdivision (1) of this subsection, of the state's share of the net gasoline tax proceeds.

(3) To such extent and to such extent only as the revenues appropriated under subdivisions (1) and (2) of this subsection may not be sufficient to pay at their respective maturities the principal of and interest on the bonds, so much as may be necessary for such purpose, when added to the amounts appropriated in subdivisions (1) and (2) of this subsection, of the entire proceeds of the following excise taxes remaining after payment of the costs of collection thereof:

a. the excise tax levied by subdivision (2) of subsection (a) of Section 40-17-325 on distributors and storers of motor fuel, as therein defined; and

b. the excise tax levied by Article 3 of Chapter 17 of Title 40, exclusive of that portion of the tax in respect of gasoline.

The term "costs of collection," as used in this subdivision, shall mean that portion of the excise taxes referred to in this subdivision that may be appropriated by the Legislature to the Department of Revenue for its operating expenses.

(4) To such extent and to such extent only as the revenues appropriated under subdivisions (1), (2) and (3) of this subsection may not be sufficient to pay at their respective maturities the principal of and interest on the bonds, so much as may be necessary for such purpose, when added to the amounts appropriated in subdivisions (1), (2) and (3), of all that portion of the receipts from the inspection fee on certain petroleum products imposed by Division 1 of Article 5 of Chapter 17 of Title 8 that is required by the division to be deposited to the credit of the Public Road and Bridge Fund.

(5) To such extent and to such extent only as the revenues appropriated under subdivisions (1), (2), (3) and (4) of this subsection may not be sufficient to pay at their respective maturities the principal of and interest on the bonds, so much as may be necessary for such purpose, when added to the amounts appropriated in subdivisions (1), (2), (3) and (4), of the receipts from the fee in respect of identification markers on motor vehicles that is provided for in Section 40-17-150.

(c) All moneys hereby appropriated and pledged shall constitute a sinking fund for the purpose of paying the principal of and interest on the bonds. All pledges made by the corporation shall take precedence among themselves in the order of the adoption of the resolutions making such pledges, except as may be otherwise provided in such resolutions; provided; provided, however, that the appropriation and pledge of the state's share of the net gasoline tax proceeds shall be on parity with the pledge contained in Section 23-1-314 to secure obligations issued by the Alabama Federal Aid Highway Finance Authority.