Widespread freezing rain and drizzle are causing untreated roads, sidewalks, and driveways to become icy and slick.

Freezing rain and drizzle will create slick roads and hazardous travel conditions tonight across Chicagoland. A Winter Weather Advisory is in effect for the entire region until 6 a.m. Thursday. Warmer temperatures on Thursday will help melt any remaining ice by midday.

A powerful ice storm sweeping across the Midwest led to treacherous travel in Illinois and the Chicago area, with officials reporting slick roads across the region Wednesday night into Thursday morning.

A winter storm that brought snow, sleet and freezing rain to a large swath of the Midwest swept into the mid-Atlantic and Northeast on Thursday, causing treacherous travel conditions, prompting school delays and closures and potential power outages for millions of Americans.

"This lawsuit will put the spotlight on obstruction by state and local officials and their refusal to support the administration and compliance with the law," a DOJ official told The Post.

The U.S. Justice Department sued the state of Illinois and city of Chicago on Thursday, accusing the Democratic strongholds of unlawfully interfering with Republican President Donald Trump's crackdown on illegal immigration and seeking a court order blocking so-called sanctuary laws.