I don't think that totally stacks up though. A decline in injuries at the time of the introduction of the laws is natural - there was a lot of campaigning and awareness at the time.
And ultimately a net decrease in head injuries doesn't mean that much when there are many other injuries with cycling generally being more dangerous.
I'm just a single data point but I stopped cycling in nz after they introduced the fines for being caught without a helmet. I've cycled daily in London for years now an it's a much safer place to cycle. My feeling is that's generally due to the awareness from having a lot of cyclists on the road. Whatever nz are trying to do with their foisting of rules upon people, it's not working.
And ultimately a net decrease in head injuries doesn't mean that much when there are many other injuries with cycling generally being more dangerous.
I'm just a single data point but I stopped cycling in nz after they introduced the fines for being caught without a helmet. I've cycled daily in London for years now an it's a much safer place to cycle. My feeling is that's generally due to the awareness from having a lot of cyclists on the road. Whatever nz are trying to do with their foisting of rules upon people, it's not working.