65 ILCS 5/11-58-2
The corporate authorities of such a municipality shall exercise the power conferred by this Division 58 by passing an ordinance which (1) shall set forth the estimated total sum required to pay the prescribed proportion of the total costs of grade separations, together with all interest charges, and all other costs incident and necessary to the levying and collecting of the tax and of the payment by the municipality of its proportion of the costs of grade separations, (2) shall describe the general plan and nature of the grade separations and set forth the railroads and the public streets, or other public places, to be affected thereby, and (3) shall provide for levying and collecting a direct annual tax for not exceeding 10 successive years, sufficient to create a fund to pay in annual installments, the total sum so estimated and set forth in the ordinance. However, this tax shall not exceed in any one year the rate of .50% of the value, as equalized or assessed by the Department of Revenue, of all the taxable property within the municipality. This tax shall be levied and collected with and in like manner as the general tax in the municipality and shall be known as the grade separation tax.
65 ILCS 5/11-58-2