This reminds me of what a buddy and I used to do when my grandma was living with us back in the early 70's. We would take her wheelchair out to the road, and then we'd wait until we saw a car coming and I'd take off down the road in the wheelchair with my friend frantically chasing after me. I'd also lay it on its side in the ditch beside the road and lay beside it just to see cars slam on their brakes to see what was going on!