State police from the Mercer barracks say the trooper wasn't hurt in the incident just after 11 p.m. Monday. It happened in Worth Township, about 60 miles north of Pittsburgh.
The trooper reported seeing two people standing next to car parked on the overpass just before the windshield was smashed. The trooper gave chase but the vehicle on the overpass sped away.
Police say they found a fresh McDonald's Filet-O-Fish sandwich near where the cup hit the car.
Police on Wednesday tell The Associated Press they're still looking for the suspect.
