Back in the 80's my husband was brainstorming. He said why don't we put strong magnets on car bumpers,also on road guard rails. He said the magnets would repel each other, would cause less serious accidents. Then we all laughed because we pictured everyone's metal garbage cans stuck on the car bumpers. ha ha. I was flying home in 1992 from FL, I met a gentleman that was sitting next to me, he was an inventor. He was on his way to Schwinn to introduce the bike manufactor magnets to stop bikes. I did notice that Schwinn is using magnets. I wish I could have remembered his name.