605 ILCS 5/7-101
Streets and alleys, including bridges and other structures, which are or will become part of the municipal street system may be laid out, established, constructed, reconstructed, altered, widened, relocated, improved, maintained, repaired and vacated by the respective municipalities in the manner provided in the Illinois Municipal Code, as heretofore or hereafter amended; provided that the Department and counties may locate and extend State and county highways into or through a municipality in the manner provided in this Code. In addition to the powers granted to municipalities by the Illinois Municipal Code, municipalities have powers granted and duties imposed by this Code.
A municipality 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 its county's boundaries unless such construction, reconstruction, improvement, widening, relocation, repair, alteration, or maintenance is part of the municipal street system, in an adjacent municipality, or 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 5/7-101