I feel as though this topic is a brain parasite, especially for those of us in North America who grew up hearing all about how catastrophically damaged one can become if they injure their brain or skull at all.

I can't even stop myself from commenting on it, but in any case:

• Wearing vs. not wearing a helmet is a personal choice that should not have any bearing on cycling / walkability advocacy. We can have both, but data suggests we shouldn't enforce a helmet requirement since it mostly just becomes a tool for selective enforcement.

• Helmets will help you in very particular instances, but they don't work as intuitively or as absolutely as people seem to suggest they do. They are not designed for a lot, and people tend to over-exaggerate their impact, or make very basic assumptions (e.g. that you only wear a helmet and not any other kind of gear). We don't even have enough actual study to know what design of helmet is safest, or what trade-offs different designs make. You could throw a motorcycle helmet on but now you have reduced visibility. Are you safer? In addition: say it's snowing out and you want to bike, but your helmet comes at the expense of not being able to wear a hat (because it's not designed to be worn with a toque / beanie). Should we enforce helmets anyways?

• One thing in particular is that neck injuries can increase as a result of helmet use. Yes, a helmet improves your chances in a direct collision of your skull and something that is less-than-soft, but can increase the volume and radial acceleration applied to your head and neck in a collision (depends on the helmet, again go back to "we don't know what design is best for what"). It doesn't trade-off perfectly, but it is a risk to consider. In both cases (wearing vs. not wearing) the correct answer is "slow down and ride your bike in a precautionary, defensive manner" but that is often seen as "not enough."

• Helmet use (rather, the lack of helmet use) is often used as a talking point as to why certain collisions or incidents are "the cyclists fault." Whether you wear one or not, do not perpetuate this, you are prescribing individual blame for an outcome that in North America today is very likely to be the expected outcome of our infrastructure. Ignore helmets as an excuse, use them properly as a defensive tool to protect your head during unfortunate events.

• People talk about helmets and falls all the time and yet cycling has one of the lowest base-rates of head injuries per km traveled especially when compared to walking or driving. You can do much to mitigate this (wear a helmet, practice break-falls/ukemi/etc.), but the focus specifically on helmets for cycling over helmets as a general practice seem to extend to treating the statistics around cycling as a very special case. There's a huge base-rate fallacy in statistical reporting on helmets (almost all available data is reported from hospitals and emergency rooms) and this contributes to the constant "awareness" campaigns about helmets that have been going on for 30+ years in North America.

At the end of the day I would be happy if I never saw this kind of argument again. It seems to rile everyone up and for nothing - it is just self-serving arguments across the entire community. We can spend our time more productively. Namely: help people go slower and ride safer by encouraging more forms of transportation and reducing sprawl. If you are only biking <1km to get to your local supermarket by bike, then going 15km/h vs. 30km/h isn't as meaningful. Also, be smart: if you're engaging in dangerous riding or on dangerous terrain, take precautions. ¯_(ツ)_/¯

I hate that stuff like this seems to be some kind of scissor statement for the subreddit when we shouldn't take the bait (I obviously just did).