605 ILCS 5/5-101.9
To exercise any other power and perform any other duty prescribed in this Code
A county shall not construct, reconstruct, improve, widen, relocate, repair, alter, or maintain a highway, road, street, alley, bridge, culvert, drainage structure, sidewalk, bicycle path, parking lot, driveway, or any other transportation-related facility that is outside of the county's boundaries unless such construction, reconstruction, improvement, widening, relocation, repair, alteration, or maintenance is part of the county highway system, is jointly performed with another county through the sharing of road equipment pursuant to an intergovernmental agreement, or is provided as necessary relief services following the occurrence of a disaster as defined by the Illinois Emergency Management Agency Act.
As used in this Section, "maintain" or "maintenance" does not include mowing, gravel reclamation, snow removal or the application of salt, sand, or any other substance applied for the purpose of improving the safety of vehicular or pedestrian traffic in response to the presence or prediction of ice or snow.
605 ILCS 5/5-101.9