The Illinois Department of Transportation, and any person acting on its behalf under a public-private agreement entered into in accordance with the Public-Private Agreements for the South Suburban Airport Act, is exempt from the permit requirements of this Act, provided that the Illinois Department of Transportation, or any such person, takes reasonable steps to comply with the provisions of this Act so long as compliance does not interfere with the design, development, operation, or maintenance of the South Suburban Airport or the exercise of their powers under the Public-Private Agreements for the South Suburban Airport Act.