Call me crazy, but from what I've seen on TV, motorcycle crashes (in races on well built tracks that is), seem to result in much less injury than car crashes. From what I've typically seen, a motorcycle crash consists of the bike flipping over and over, and the rider just skidding along the track until he hits some grass, then sliding across that for a while, then hitting some hay bales. Usually, they get up right away, and try to get back on their bike, but find that the bike is unracable.