[knowtheory]

For fucks sake, no. This is a meme that will not die.

Howie's evidence (as nice a guy as he is) is based on a single study by a professor at the University of Bath. (And there's a PLOS One paper which disputes his conclusions too which is worth reading: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna... )

There is no compelling evidence to recommend that you shouldn't wear a bike helmet and PLENTY of very solid evidence why wearing helmets have very important and life altering effects on the outcome of serious head trauma.

If you are cycling, wear a bike helmet.

[xxgreg]

He also cites an Australian study, which concludes risk of head injury per million hours travelled: Cyclist 0.41, Pedestrian 0.80, Motor vehicle occupant 0.46, Motorcyclist 7.66.

So if you want to be consistent you should update your comment to:

If you are cycling or driving wear a helmet.

[knowtheory]

Okay, how's this :P

Cars have other safety equipment that make them unlike bicycles. These include airbags, seatbelts, crumple zones and the like.

If you are a driving, you should employ those safety devices when you do so.

[xxgreg]

Ok that leaves pedestrians, who have twice as many head injury's per km. Most likely due to being hit by cars - perhaps cars should have airbags on the outside too...

[Erwin]

Volvo does have such a pedestrian airbag: https://www.youtube.com/watch?v=X2Aw4eZoijk

Apparently that model has scored the highest Euro NCAP crash test as of 2012 (the NCAP tests tests both damage to drive AND pedestrians).