The injury rate has tripled since the helmet law.
By increasing the risk of accidents, helmets have made cycling more dangerous.
A recent study reveals a steady increase in cycling injuries in New South Wales (NSW), Australia, after the helmet law. Between 1991 and 2000, arm injuries doubled, while head injuries increased by 40%.
A 1996 cycling survey in Sydney revealed that cycling counts were 48% below 1991. According to the census, cycling in Sydney further decreased between 1996 and 2001.
After adjusting for the number of injuries per number of cyclist, the risk of injury is shown below:
A decade after the helmet law,
- the head injury rate almost tripled
- the arm injury rate quadrupled.
This indicates a quadrupling in the risk of accident.
Why did the injury rate triple?
How can the widespread wearing of a device that is supposed to protect the head result in almost a 3 time increase in the risk of head injury?
There are several reasons for this unexpected result.
Safety in numbers
Safety in numbers is a well-know phenomenon in safety, that resulted from observations that the fewer cyclists, the more dangerous cycling becomes. Research published in the Injury Prevention journal concluded:
“the behavior of motorists controls the likelihood of collisions with people walking and bicycling. It appears that motorists adjust their behavior in the presence of people walking and bicycling … A motorist is less likely to collide with a person walking and bicycling if more people walk or bicycle. Policies that increase the numbers of people walking and bicycling appear to be an effective route to improving the safety of people walking and bicycling.”
The “safety in numbers” effect has been measured. If cycling halves, the risk increases by 52%. The 48% decline in cycling observed corresponds to an increase in risk by 48%.
Degrading the bicycle helmet standard
Before the helmet law, Australia’s bicycle helmet standard required helmets to have hard shells. However, government research warned of deficiencies in the standard, as it failed to protect children, and failed to test for brain injury.
Instead of improving the standard based on recommendations from its own research, the government degraded Australia’s helmet standard to accommodate ”soft-shell helmets” providing little protection while increasing the risk of brain injury. Soft-shell helmets are more comfortable and facilitate compulsory helmet wearing.
By degrading the helmet standard, the government legitimized a piece of polystyrene generously called a “soft-shell helmet”. However, language cannot change the facts. Calling a piece of polystyrene a “helmet” doesn’t magically give it protective abilities. Still, it can fool people into believing that it provides far more protection than it really does.
By degrading the helmet standard, the government replaced useful helmets with dangerous devices providing minimal protection. This provided little more than the illusion of safety.
This is likely to have contributed to the increase in head injuries after the helmet law.
There is a well-known safety phenomenon called “risk compensation“, which resulted from observations that as people feel safer, they tend to take more risks:
“the law of unintended consequences is extraordinarily applicable when talking about safety innovations. Sometimes things intended to make us safer may not make any improvement at all to our overall safety”
Wearing a helmet can induce cyclists to take more risks, sometimes with severe consequences, as reported in the New York Times:
“the increased use of bike helmets may have had an unintended consequence: riders may feel an inflated sense of security and take more risks. …
The helmet he was wearing did not protect his neck; he was paralyzed from the neck down. …
”It didn’t cross my mind that this could happen,” said Philip, now 17. ”I definitely felt safe. I wouldn’t do something like that without a helmet.” ”
Risk compensation affects not only cyclists but also motorists who tend to be less careful around helmeted cyclists. As reported in a study published by the University of Bath in the UK:
“Bicyclists who wear protective helmets are more likely to be struck by passing vehicles”
Both the behaviour of helmeted cyclists and surrounding motorists increase the risk of accidents.
Even though the decline in cycling mostly occurred in the first few years following the helmet law, the risk of injury has kept rising afterwards. This coincided with helmet promotion campaigns launched in the mid 1990′s. Helmet promotion campaigns exaggerating the benefits of helmets have given cyclists a false sense of safety, increasing the risk of accidents.
Discouraging the safer cyclists
Following the helmet law, many cyclists who used a bicycle for transport, for example to cycle to the local shops, gave up cycling.
It is likely that transport cyclists have fewer injuries than sport cyclists, as they travel at lower speeds, and have no incentives to take risks. The increase in injuries after the helmet law can be partly explained by reduction in transport cycling.
However, the reduction in transport cycling cannot have quadrupled the injury rate. Even if sport cyclists had a risk of injury 4 times higher than transport cyclists, this could only result in a 50% increase in injury rate.
- The head injury rate almost tripled
- The arm injury rate quadrupled
The following factors explain the deterioration in safety after the helmet law:
- “safety in numbers”: the risk of accidents increased as there were fewer cyclists.
- The helmet standard had been degraded to include polystyrene “helmets” that provide little protection while increasing the risk of brain injury.
- “risk compensation”: cyclists wearing a helmet were lured into a false sense of safety, taking more risks, and having more accidents.
- The helmet law discouraged the safer cyclists.
The increase in the injury rate corresponds to an increase in risk for cyclists for the first 3 factors. However, the fourth factor cannot explain a quadrupling in injury rate. The helmet law is likely to have at least doubled the risk of injury.
But wait, the study authors claim the helmet law was a success!
Despite the large increase in head injuries, the study claims:
“the benefit of MHL to lowering head injuries”
How can the study authors make such a ridiculous claim?
- They ignored the decreased in cycling after the helmet law. Instead of using surveys that had counted the actual number of cyclists, they ASSUMED that cycling increased with population growth.
- The strong rise in injuries from the study’s main graph was ignored. How can the study authors have failed to notice this? This blindness to negative side-effects of the helmet law is reminiscent of a study affected by confirmation bias.
- The introduction of the helmet law occurred at the same time as other road safety measures, notably a crackdown on drink driving and lower speed limits. These measures lowered the speed of cycling accidents, thus reducing head injuries. However, the study authors attribute ALL the apparent relative reduction in head injuries relative to arm injuries to the helmet law, without taking into consideration other factors. This is a common mistake of failing to assess confounding factors.
- The study reports a reduction in head injuries since 2006. This coincides to a resurgence in cycling, with many of the new cyclists not wearing helmets. Head injury rates decreased while fewer cyclists wore helmets. Oblivious to this, the study attributes the reduction in injuries to spending on cycling infrastructure that occurred mostly in Sydney after 2009.
This “study” is like doing a cost benefit analysis while ignoring the costs and exaggerating the benefits.
This study was funded by a government who, struggling to justify its counterproductive policy, commissions “studies” to defend it. The bureaucrats quote this “study” as following:
“A recent study from the University of New South Wales showed that the initial benefits of the mandatory helmet laws have been maintained over time.”
Do they think we are complete fools?
This study did not fool a UK reporter:
As the fallout from Australia’s failed bike sharing schemes continues, it seems we haven’t seen the last of government-funded research showing that helmet laws are great actually, thanks very much.
The authors, Olivier, Walter and Grzebieta, previously published a paper in 2011 claiming to “end the debate about the effectiveness of cycle helmet legislation”, but which was severely criticised by fellow boffins
the government of NSW has commissioned research which (surprise!) finds the effect of their helmet law is massive and sustained, ignoring the uncomfortable fact that helmet wearing rates have actually fallen back significantly without any accompanying jump in head injuries.
The authors … include all types of minor flesh wounds, bruising etc. which you would certainly hope would be prevented by helmet use, rather than looking at a reduction of critical injury / death which is what public health policy should be worrying about, when the alternative is serious sedentary disease.
It’s generated some nice headlines and superficial reinforcement for the helmet law (which is probably what the government were really trying to commission).
Such a biased “study” helps bureaucrats keep their heads in the sand.
How does that serve the public?