Mannheim was closed in both directions Wednesday morning between Touhy and Howard in Des Plaines after a car slid under a semi.
The fire department and parademics extricated the driver of the car and transported the person to a nearby hospital. The driver's condition is not known.
It's also unknown how long Mannheim will be closed, a significant obstacle for holiday travelers headed to O'Hare Airport.
Southbound drivers are urged to take an alternate, moving over to River Road. About 217,000 people are expected to travel through O'Hare this Thanksgiving.