From the Illinois Department of Transportation Facebook page:
TRAVEL ADVISORY: A combination of freezing rain, drizzle and sleet is expected to impact travel throughout today and during the overnight hours. Icy conditions will make driving treacherous. Motorists are advised to make preparations if they plan to be on the road. IDOT crews have been pretreating areas susceptible to icing, and more than 1,700 trucks are available to salt and treat roads. Please be safe!