605 ILCS 5/9-111

The highway authorities shall annually, at the proper season, to prevent the spread of noxious weeds as defined in the "Illinois Noxious Weed Law", approved August 17, 1971, as amended, destroy or cause to be destroyed, all such noxious weeds growing upon public highways under their respective jurisdictions. The highway authorities shall seasonably mow or manage all weeds and other vegetation growing along the highways under their respective jurisdictions.

Any highway officer failing to comply with the provisions of this Section shall be guilty of a petty offense and shall be liable to a fine of not less than $10 nor more than $25 for each season in which he neglects such requirements.