Study finds that wearing a cycle helmet may diminish ability to assess risk

[Mike Sales]

So this is all about stopping helmets being made compulsory because it might deter some people from cycling?

Isn't that exactly the same as saying we should reverse seatbelt laws because it puts some people off driving? It is isn't it? Yes it is.
Because if safety in numbers applied, then more cars on the road = safer roads.
Good logic.

For whatever reasons there some strong correlations around the use of helmets in various countries.
Some countries have low helmet wearing rates, low cycling injury rates and high cycling rates.
Others are the reverse. They have high wearing rates, high injury rates and low rates of cycling.
In some of these helmets have been made compulsory with no detectable effect on injury rates.
In Australia wearing rates went from about a third before the helmet law to close to 100%, with no detectable effect on the rate of cyclist casualties. There was a strong effect in reducing cycling rates, which is a home goal for public health in that obese country.
It has been observed that car accident rates decrease with traffic density. This is called Smeed's Law.
As motor traffic increases the rate of incidents per car decreases, though the rate of injuries per head of population increases.

[Wanlock Dod]

Because if safety in numbers applied, then more cars on the road = safer roads.

Seeds Law suggests that as the number of road users increases the risk to those road users declines, this is not the same as the number of accidents reducing because risk is a function of hazard and exposure.

[mjr]

Isn't that exactly the same as saying we should reverse seatbelt laws because it puts some people off driving? It is isn't it? Yes it is.

Do seatbelt laws deter drivers? It seems like they simply sit on top of the seatbelt (plugged in to stop the alarms) and carry on. So in that way, it seems different to cycle helmets, where there are surveys showing that some people don't cycle because they'd have to wear a helmet and many observations that cyclist numbers decrease when helmet promotion increases (one famous easily-found-online example with observations from Sweden and Denmark).

Because if safety in numbers applied, then more cars on the road = safer roads.
Good logic.

Trivially this can be shown to be true in the extreme case because if you put enough cars on the road, they all stop moving and very rarely kill anyone except by stuff like rarely randomly catching fire.

[poetd]

For whatever reasons there some strong correlations around the use of helmets in various countries.
Some countries have low helmet wearing rates, low cycling injury rates and high cycling rates.
Others are the reverse. They have high wearing rates, high injury rates and low rates of cycling.

But do those countries all have comparable cycling infrastructure?
Holland can't be compared to the UK, as most of their cycling infrastructure is a safe distance from other heavy traffic - so helmets or no - there's always going to be lower injury rates.
That's like arguing wearing a Holland football t-shirt is a safer form of body protection when cycling.

[Mike Sales]

For whatever reasons there some strong correlations around the use of helmets in various countries.
Some countries have low helmet wearing rates, low cycling injury rates and high cycling rates.
Others are the reverse. They have high wearing rates, high injury rates and low rates of cycling.

But do those countries all have comparable cycling infrastructure?
Holland can't be compared to the UK, as most of their cycling infrastructure is a safe distance from other heavy traffic - so helmets or no - there's always going to be lower injury rates.
That's like arguing wearing a Holland football t-shirt is a safer form of body protection when cycling.

Australia, which as I said has near 100% wearing, has more than twice our cycling head injury rate.
The Netherlands evidence certainly shows what works to keep cyclists safe.
The USA, South Africa and New Zealand all achieve much higher injury rates for cyclists than we do, in spite of much higher helmet wearing rates, and I don't think that can be put down to our extensive cycling facilities.

[Wanlock Dod]

Yet helmet wearers in The Netherlands have higher accident rates than those that don’t wear helmets.

[poetd]

Yet helmet wearers in The Netherlands have higher accident rates than those that don’t wear helmets.

So the "safety in numbers" effect of non helmet-wearing Dutchies is actually putting those who do chose to wear a helmet at risk?
That's the same principle applied is it not?

[Wanlock Dod]

Perhaps cyclists in The Netherlands that wear helmets take more risks than unhelmeted cyclists under similar circumstances.

[Mike Sales]

Yet helmet wearers in The Netherlands have higher accident rates than those that don’t wear helmets.

So the "safety in numbers" effect of non helmet-wearing Dutchies is actually putting those who do chose to wear a helmet at risk?
That's the same principle applied is it not?

It is not the only factor. That is simplistic. Racing cyclists wear helmets in the Netherlands (and Lycra) and perhaps they are young men inclined to take more risks than those who merely use bikes to get to work, school or the shops.

[Cugel]

One of the effects of cycle helmets is to deter people from cycling, which in turn reduces the safety of all people cycling through the safety in numbers principle.

So this is all about stopping helmets being made compulsory because it might deter some people from cycling?

Isn't that exactly the same as saying we should reverse seat belt laws because it puts some people off driving? It is isn't it? Yes it is.
Because if safety in numbers applied, then more cars on the road = safer roads.
Good logic.

Seat belts demonstrably do lessen the injury and death likely within a typical RTA - for the occupants of the car who are wearing the seat belts. However, they also make the driver take more risks. The risk-taking drivers will be more likely to be involved in an RTA. The others involved in an RTA, outside the car, will not have any protection from the seat belt, though.

Does the reduction of injury & death to drivers and passengers within cars outweigh the additional RTAs and their wider harm? What about when we add in the extra injuries and deaths caused to those outside the car (typically pedestrians and cyclists)? It would be interesting to see the statistics, should they be available.

Cugel

[Mike Sales]

Seat belts demonstrably do lessen the injury and death likely within a typical RTA - for the occupants of the car who are wearing the seat belts. However, they also make the driver take more risks. The risk-taking drivers will be more likely to be involved in an RTA. The others involved in an RTA, outside the car, will not have any protection from the seat belt, though.

Does the reduction of injury & death to drivers and passengers within cars outweigh the additional RTAs and their wider harm? What about when we add in the extra injuries and deaths caused to those outside the car (typically pedestrians and cyclists)? It would be interesting to see the statistics, should they be available.

Cugel

This question is thoroughly examined in John Adams's blog. You may be interested.

http://www.john-adams.co.uk/2013/03/24/the-biggest-lie/

[poetd]

It is not the only factor. That is simplistic. Racing cyclists wear helmets in the Netherlands (and Lycra) and perhaps they are young men inclined to take more risks than those who merely use bikes to get to work, school or the shops.

So it's not the helmet, it's the type of cyclist?
Controversial for these parts!

[Mike Sales]

It is not the only factor. That is simplistic. Racing cyclists wear helmets in the Netherlands (and Lycra) and perhaps they are young men inclined to take more risks than those who merely use bikes to get to work, school or the shops.

So it's not the helmet, it's the type of cyclist?
Controversial for these parts!

You persist in trying to reduce complex causation into simplistic conclusions. Why should it not be, in this case, that helmet wearing is a cause of risk taking and also a sign of being willing to take more risk? This is entirely consistent with risk homeostasis.
The focussing on helmets as an answer to the dangers cyclists face on the roads is a red herring. It is a diversion and an alibi for the chief cause of the danger, of which you are well aware. And the evidence is that helmets do not work in reducing that danger.

[Cugel]

The evidence is that helmets do not affect the rate of cyclist head injury in whole populations.
A hypothesis is that wearing a helmet affects a rider's assessment of risk. Since the risks in a situation undoubtedly affect behaviour, it seems likely that changing the perceived risk changes behaviour is a reasonable conclusion.
This experiment tries to catch that process happening.
You believe a helmet makes a significant difference but presumably believe that wearing does not affect your behaviour.
Would you ride without one? Because that is a gross change in behaviour.

I rode for many years and many miles without one as a young man. I'm not that young man any more, also there is vastly more traffic on the roads these days.
Would I ride without one now? Would depend on the journey and location. In city centre rush hour traffic? Probably not no to be honest.
It was only the fact that I saw NO-ONE wearing knee and elbow pads that put me off buying myself a pair.
I just want to get home from work alive. Thanks.

More traffic on the roads (and the associated increase in poor driving) might well mean the risk of being involved in an RTA with a car has gone up. But what makes you think a cycling helmet will offer any protection at all in such an event? The manufacturers of cycling helmets themselves will tell you that the cycling helmet offers no meaningful protection in an RTA. They will reduce the amount of mild head bump you feel when you fall off and hit your head on a flat surface at a very low speed.

As you will be taking more helmet-induced risks, you might fall off more often, of course.

I would like some hip pads now that I'm an oldescote of cyclist with bones more likely to snap than bend. The hip is the most vulnerable bit in a typical cycling fall, along with ankle, wrist, elbow, shoulder ... but not the head. I've banged all me bits in 60 years of cycling but never my head. A broken hip in an olescrote can kill.

But that cycling helmet will be of utility when you go up and down stairs, work in the garden or drive about in a car, where head injuries are far more likely. Mind, the helmet still only protects against a very low speed bang, not saving your life but rather saving you from a worse headache. Make sure you're wearing your seat belt. then; grab the stair rail firmly; hire another to do the garden!

Cugel

[poetd]

It is a diversion and an alibi for the chief cause of the danger, of which you are well aware. And the evidence is that helmets do not work in reducing that danger.

Agreed on the first point.
But then questionable lab studies don't prove that my choice to wear one in case of falls (I'm under no illusionment that it would do anything for me in a head-on collision with a HGV for instance) increases that danger.