Amends the Illinois Highway Code. Provides that vegetation within the first 8 feet adjacent to the surface of a highway or road, or to the shoulder if there is one, may be mowed at any time, but not to a height of less than 4 inches. Provides that other vegetation within a right-of-way may be mowed up to 2 times between October 15 and April 1 and up to 2 times between July 1 and July 20, but not to a height of less than 12 inches. Provides that mowing at other times or at lower heights is not allowed unless authorized for necessary safety reasons: (i) by rule of the Department of Transportation; or (ii) after consultation with the Department and if not less restrictive than or in conflict with Department rules, by ordinance of the county, township, or road district having jurisdiction. Provides that the Department may also adopt rules: (i) for noxious weed control that causes minimal disruption of habitat; and (ii) that set conditions to allow for mowing, burning, or tilling to prepare the land for the establishment of a habitat consisting of native, low-maintenance, and permanent vegetative cover or for prairie vegetation management. Provides that weed control under the Code and under the Illinois Noxious Weed Law must be accomplished in compliance with the new provisions. Provides that a violation is a petty offense for the first offense and a Class B misdemeanor for a second or subsequent offense. Provides that, if an offense is not prosecuted by the State's Attorney, the Attorney General, or a special prosecutor appointed by the Attorney General, may bring the prosecution. Makes a corresponding change in the Illinois Noxious Weed Law. Effective immediately.