I think everyone agrees that riding is always safer with a helmet. But here’s a (the?) argument for making helmets optional:
1. If helmets are optional, then more people will cycle.
2. And there will initially be more cycling casualties
But with more people cycling:
3. Drivers will learn to share the road better, and
4. Demand will rise for better cycling infrastructure
So after a while:
5. There will be fewer cycling casualties
6. People generally will be healthier
7. Better environment, stronger local communities, etc etc.
This all seems right. (Notice that this argument obviously doesn’t apply to motorcycles or car seatbelts or other superficially similar issues.)
The controversial part is that in point 2, casualties increase, then in point 5 they go down again. Will they go down significantly in the long run? And is it worth a short-term increase to see a long-term reduction?
This seems a lot like a trolley problem to me. If we change the law and people die, it feels as if the law change killed those people. Even if the law change saved more people than it killed, it’s hard to do this kind of accounting with people’s lives.