Originally Posted by
mr_pedro
...
The perceived deterrent is not so much the inconvenience of a helmet, but the message that cycling is dangerous. Especially if you want to promote helmet usage without it being mandatory, you only have the safety argument.
Possibly both of those. Whatever the reasons, after Australia imposed mandatory helmet laws, and then made them more stringent, we have some data about that. Some of the participation data is "limited and inconsistent" but nevertheless plausible data.
In a nutshell, cycling participation declined but total cyclist injuries and head injuries
increased. Fatalities decreased. We could argue about why and how, but here are the facts:
Pedal cyclist deaths and hospitalizations (Australian government)