The accident happened at approximately 2:30 a.m. near the Ashland exit.
According to state police, the involved vehicles were an SUV and a coach bus rented out for a party. Authorities said the SUV might have sideswiped the bus, which was carrying more than 40 people. The SUV -- with four people inside-- reportedly rolled over.
"We were celebrating his birthday in remembrance of him, and somebody hit us," said bus rider Kenyata Bland.
"My head was just knocking wall to wall, and we were just moving. We were just flying all over the bus, flying. We were just tumbling all over the bus," bus rider Andrea Boyd said.
Two of the passengers inside the SUV, including one with an injured wrist, were among the nearly 20 people hurt.
State police say the driver of the SUV, 28-year-old Andy Taylor of Chicago, is charged with DUI, no insurance and improper lane change.
According to authorities, citations for the coach bus driver include no insurance and carrying too many people on the bus, which was supposed to ride 30 people.
The crash shut down the inbound side of the expressway for about an hour, but all lanes reopened later Tuesday morning.
All of those injured were transported to hospitals, but state police said none of the injuries was life-threatening. All were expected to be OK. The most serious injury was a broken leg.
Taylor was transported to Stroger Hospital after the accident but was released later. Authorities say they are not releasing his mug shot.