Two people were killed in as many crashes on I-80 southwest of Chicago; the third person was killed in a crash on the Eisenhower Expressway in Chicago.
Officials say they think drivers were caught off guard.
"The guys behind me spun out as well and before you knew it, there was probably six or seven cars involved in the pileup," driver John Periaswamy said.
There were three fatalities in all, including one on the Eisenhower Expressway at about 6 a.m. Friday. An inbound box truck rear-ended a pickup stopped on the shoulder at Cicero. One person was killed.
The Illinois Department of Transportation, which is responsible for area expressways except the toll roads said it deployed a quarter of its road-salting fleet just before midnight, doubled that by 2:30 am "The temperatures last night were very cold and the melting power of the salt certainly diminished the colder the temperatures get. Also, salt doesn't tend to activate as well in the light traffic conditions as is the case at 2, 3 in the morning," Guy Tridgell, IDOT, said.
Illinois State Police say weather conditions led to two deaths just before 2 a.m. on westbound I-80. Near Joliet, 29-year-old Theresa Lang died when her car swerved off the road, flipped and hit a tree. Further east, another 29-year-old Andres Pita-Jamon of Chicago lost his life when his car spun out and was hit by a semi-truck.
"We are reminding people that we are in the winter driving season and conditions can change very quickly. And they need to slow down and increase the distance and give themselves extra time on their trip to make sure they arrive safely," Guy Tridgell said.
In the city, drivers dealt with a mess on the Ohio Street feeder ramp into downtown, where several vehicles spun out in the morning rush causing a minor accidents and major delays.
The Chicago Transit Authority had some delays in the middle of the morning commute. But, officials say they were not weather-related.
"We had a couple of things that were a real concern and opposed to operating trains in a condition where we thought there might be dangerous or hazardous condition that would have resulted by proceeding, we stop and get our bearings and diagnose and correct and restore the service," Peter Ousley, CTA chief operating officer, said.