My worry is that making helmets mandatory will reduce the number of bike journeys as it adds friction.
I cycle a very large amount ever year and the number of accidents and near accidents is much larger than on the same number of km by car. This is kind of frustrating because I really enjoy biking and try to do as much of my mileage by bike as possible but the safety of it makes me wonder if I'm not playing some kind of lottery with 'very bad prizes'.
Helmet sits in the basket or hangs off the bars, takes ten second to put on so also not a deterrent.
The real deterrent is thinking “goddamn it’s 27 degrees out and my gloves are getting frayed my fingers are going to be cold”.