I got to see one of these real time yesterday. A tow truck towing a car on a dolly lost his load. The car and the dolly rolled across the front of my truck, down into a ditch, smashing the car into a power pole, it was awesome!! I was flashing my headlights at the traffic coming from the other direction because I could see it all unfolding. The tow truck driver hops out of his rig and just stares at it with the stupidest look on his face....hilarious!