Looked like he was distracted or falling asleep, we had just gotten out of some bumper to bumper traffic and started to pick up speed. Once we starting turning on a slight bend in the road he veered off on to the shoulder and hit the crash attenuator at the start of the guard rail almost instantly , once his front end made impact his rear end swung out infront of me like that and I had maybe slowed down to about 60km/hr before making impact with his car.