The driver in the first car said he thought he had been hit by bullets while driving northbound. No one was hurt.
Police say the suspect, Kevin Houlihan, was found on a railroad overpass. He is charged with trespassing and illegal consumption of alcohol by a minor.
Rock debris was discovered on the roadway and investigators learned the rocks were being thrown from an overpass about 1/8 of a mile north of Lawrence Avenue, according to Illinois State Police District Chicago Trooper Ivan Bukaczyk.
Additional units, including Chicago police officers who went as a precaution, went to the scene and placed an 18-year-old man into custody, but preliminary information indicated several people were seen fleeing the scene, according to Bukaczyk.
The Sun-Times Media Wire contributed to this report.