The crash happened on 95th Street near the Harlem Avenue entrance ramp, Oak Lawn police said.
Police said one vehicle was involved in the crash. The driver, a 35-year-old man, was transported to Christ Hospital, where he died.
The Cook County Medical Examiner's Office later identified the driver as Edwin Espinoza. He was a probationary officer.
The Oak Lawn Police Traffic Unit is investigating the crash.
Further information was not immediately available.