70 ILCS 5/17.3
Any Metropolitan Airport Authority which, on the effective date of this amendatory Act of 1986, does not have a runway in excess of 5,100 feet shall, prior to the construction of a new runway or the extension of any existing runway to a length in excess of 5,100 feet, publish notice of such intent in a newspaper published within the Authority and having a general circulation within the Authority, for 3 successive weeks. The publication of the notice shall include a notice of (1) the specific number of voters required to sign a petition requesting that the question of the construction of a new runway or extension of an existing runway be submitted to the voters of the Authority; (2) the time within which the petition must be filed; and (3) the date of the prospective referendum. The secretary of the Board shall provide a petition form to any individual requesting one.
If within 30 days after publication of the last such notice no objection has been made, construction consistent with the notice may commence.
Objection may be made by filing a petition with the circuit court bearing the signatures of voters in the Authority equal in number to 10% or more of the registered voters in the Authority. If such an objection is made, the construction may not commence until the proposal is approved by a referendum held at the next election in accordance with the general election law. Such referendum shall be held in the entire territory of the Authority.
70 ILCS 5/17.3