605 ILCS 5/2-220

The Department, after consultation with the Department of Natural Resources, shall, where appropriate, maintain in forested lands, rather than grasslands, Department-controlled property adjacent to and between divided lanes of State highways. In determining where such forestation is appropriate, the Department shall consider whether such forestation would:

(a) enhance the scenic quality of the highway;

(b) provide additional habitat for wildlife;

(c) result in a financial savings from reduced grassland maintenance;

(d) enhance air quality;

(e) serve as a deterrent to soil erosion;

(f) not hinder drivers' visibility or otherwise create a traffic hazard; and

(g) be fiscally prudent considering the availability of low cost or no cost nursery stock as provided by the Department of Natural Resources.