[taeric]

In my phone now, so not digging hard. Last time this came up there were quite a few studies linked.

I'll note that the one you referenced is not really that interesting. Trying to get individual behavior out of it may work, but it is the population wide metrics that were telling.

And this is absolutely no different than cars. Your gut is probably that we require seatbelts. But school buses are a glaring omission from that is. Public transit, in general. Even works on boating. When taking a ferry, just a boat, we do not require active vest usage.

Would they make you safer? Probably yes in both cases. Is it the needle mover in population wide metrics? Getting people out of an individual's vehicle and into a community one is seen as more important for safety. Similar logic seems to apply to bikes. Get people out of cars and onto bikes. Whatever increase in danger you may see in lax helmet laws could be offset by them not being in a car.