The windshield on a white Toyota was shattered while driving on the Eisenhower Expressway near Pulaski Road Monday afternoon.
Less than four hours later, witnesses saw a group throwing rocks at cars on Interstate 57 near 151st Street. There was minor damage to one car. Five cars were damaged in the same area Sunday night.
On Saturday, several vehicles were hit with rocks on Interstate 55 between Pulaski and Kedzie.
The most serious situation unfolded last Wednesday when police shut down the Chicago Skyway for two hours. Two teenagers were charged in that case.
Police have not made any arrests in connection with the most recent rock-throwing incidents.