Police said the crash happened in the Woodlawn neighborhood's 6600 block of South Kimbark Avenue just before 4 p.m.
A 38-year-old man was driving eastbound on 66th Street when a Ford Fusion, driving on the same street and in the same direction, struck his vehicle, police said. The Ford's driver then got out and opened fire on the victim, striking him in his leg.
The shooter then fled on foot. The victim was transported to the University of Chicago Medical Center in good condition.
There is no one in custody and area detectives are investigating. Police said they believe the shooting was a case of road rage.
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