Upon the approval of the general plan and cost estimate for any such project by the Department of Transportation, if required, the Board of Commissioners of the authority shall provide by ordinance for the acquisition or undertaking of such project, and for the issuance of bonds of the authority payable from taxes to pay the cost of such project to the authority or for costs with respect to rail facilities or related facilities as provided in Section 14.1. The ordinance shall prescribe all details of the bonds and shall state the time or times when bonds, and the interest thereon, shall become payable and the bonds shall be payable within not more than 20 years from the date thereof. Any authority may agree or contract to sell, issue or deliver bonds payable from taxes at such price and upon such terms as determined by the Board of Commissioners of the Authority and as will not cause the net effective interest rate to be paid by the Authority on the issue of which such bonds are a part to exceed the greater of (i) the maximum rate authorized by the Bond Authorization Act, as amended at the time of the making of the contract, or (ii) the greater of 9% per annum or 125% of the rate for the most recent date shown in the 20 G.O. Bonds Index of average municipal bond yields as published in the most recent edition of The Bond Buyer, published in New York, New York, (or any successor publication or index, or if such publication or index is no longer published, then any index of long term municipal tax-exempt bond yields then selected by the Board of Commissioners of the Authority), at the time the contract is made for such sale of the bonds. Subject to such limitation, the interest rate or rates on such bonds may be established by reference to an index or formula which may be implemented or administered by persons appointed or retained therefor by the Authority. A contract is made with respect to the sale of bonds when an Authority is contractually obligated to issue or deliver such bonds to a purchaser who is contractually obligated to purchase them, and, with respect to bonds bearing interest at a variable rate or subject to payment upon periodic demand or put or otherwise subject to remarketing by or for an Authority, a contract is made on each date of change in the variable rate or such demand, put or remarketing. The ordinance shall provide for the levy and collection of a direct annual tax upon all the taxable property within the corporate limits of such Authority, sufficient to meet the principal and interest of the bonds as same mature, which tax shall be in addition to and in excess of any other tax authorized to be levied by the Authority. The bonds may be issued in part under the authority of, and may be additionally secured as provided in, the Local Government Debt Reform Act. Proceeds of bonds issued with respect to rail facilities or related facilities shall be provided to, or expended by the Authority for the benefit of, the Rail Authority.
     A certified copy of the ordinance providing for the issuance of bonds authorized by this Section shall be filed with the county clerk of each county in which the authority or any portion thereof is situated and shall constitute the basis for the extension and collection of the tax necessary to pay the principal of and interest and premium, if any, upon the bonds issued under the ordinance as the same mature.
     The provisions of this amendatory Act of 1985 shall be cumulative and in addition to any powers or authority granted in any other laws of the State, and shall not be deemed to have repealed any provisions of existing laws. This amendatory Act of 1985 shall be construed as a grant of power to public corporations and shall not act as a limitation upon any sale of bonds authorized pursuant to any other law. This amendatory Act of 1985 shall not be construed as a limit upon any home rule unit of government.