620 ILCS 5/31
The Department may designate, design, and establish, expand or modify a State airport plan which will best serve the interests of the State, with due regard for the following factors; the present and future needs of foreign, inter-state and intra-state air commerce and air transportation; the present and future needs of foreign, inter-state and intra-state private flying; the existing and contemplated air navigation facilities, including those owned or controlled or to be owned or controlled by the Federal Government; the then current national airport plan and federal airways system; and the avoidance of unnecessary or unreasonable interference or conflict, on the part of airports, airport plans and restricted landing areas, with existing important or essential facilities, or buildings devoted to the public use. The Department may chart such State airport plan and arrange for publication and distribution of maps, charts, notices and bulletins relating thereto, as may be required in the public interest. To the extent practicable, the State airport plan shall be integrated with or supplementary to and coordinated in design and operation with the National airport plan and the Federal airways system, as the same may be revised from time to time. The State airport plan may include all types of air navigation facilities, whether publicly or privately owned, provided such facilities conform to federal safety standards.
620 ILCS 5/31