Watch the incredible moment a motorist leaps into a moving car after the driver has a seizure.

This is the incredible moment a motorist jumped into a moving car to stop it after the driver had a seizure at the wheel.

The incident was captured on a Dixon police dashcam in Illinois. The police car had started to follow behind a blue Volkswagen Passat, which was being driven very slowly and began to dangerously veer onto the wrong side of the road.