20 ILCS 2705/2705-210
The Department has the power to develop, consolidate, and coordinate effective programs and activities for the advancement of driver education, for the facilitation of the movement of motor vehicle traffic, and for the protection and conservation of life and property on the streets and highways of this State and to advise, recommend, and consult with the several departments, divisions, boards, commissions, and other agencies of this State in regard to those programs and activities. The Department has the power to aid and assist the counties, cities, towns, and other political subdivisions of this State in the control of traffic and the prevention of traffic crashes . That aid and assistance to counties, cities, towns, and other political subdivisions of this State shall include assistance with regard to planning, traffic flow, light synchronizing, preferential lanes for carpools, and carpool parking allocations.
To further the prevention of crashes , the Department shall conduct a traffic study following the occurrence of any crash involving a pedestrian fatality that occurs at an intersection of a State highway. The study shall include, but not be limited to, consideration of alternative geometric design improvements, traffic control devices, and any other improvements that the Department deems necessary. The Department shall make the results of the study available to the public on its website.
20 ILCS 2705/2705-210