Per hour of activity, motorists are 12% more likely to suffer traumatic brain damage than cyclists (pedestrians fare far worse than either). As near as I can tell, cycling is about the safest way to get around. Add in the life-lengthening fitness benefits, and one has to wonder why any rational person would choose any other means.

I do wonder why we don't require motorists to wear helmets, since their activity is so dangerous to their brains. We should at least require that minors wear approved helmets when they are in cars, just as they have to wear (much less effective) helmets when on bikes.