After the last 20pager...?
Was talking about this with the Mrs last night actually.
Its a VERY grey area, and basically there is no right or wrong...
My view is that ('scuze the potential for sounding like a H&S boffin
) the individual should assess the risk and the potential for harm, and does so systematically and evenly each time one throws ones leg over the saddle.
Mrs rides to work through traffic (and when I ride with her on my day off) = standard helmet wearing - high risk/high potential harm
I ride to my second job 1000yards at 7am and rarely see a car = i dont wear one - low risk/high potential harm
Me and Mrs ride through park and around the lake in the evening = we dont wear one - low risk/low potential harm
I go out for a lone ride to Clayton Vale or similar with friends = I do wear one - medium risk/high potential harm
What I do disagree with, is that while some people quite rightly argue that the standard crash test for helmet design and safety is somewhat lacking (vertical drop instead of in motion/rotational forces etc).... to then dismiss and refuse beligerantly* to wear a helemet on those grounds, or use the "I put my arms and hands out first" argument is just pain wrong
*not directly referencing anyone in particular, either in real life or on RB, just a generally observed attitude