david143 wrote:So why isn't the government along with all interested parties agreeing on the usefulness, or at least working together to get the answers?
To some extent they are, but the answer is messier than most people want it to be. Of course, it's not just a UK issue, so it's not right to look to the UK government to solve it alone.
Research is mostly done by scientists, medics and road-safety specialists. Science collects evidence, rather than creating proof. It's quite normal for the evidence to be contradictory. What you look for, of course, is for the overwhelming weight of evidence to point in one direction.
In very broad terms, helmet studies are of two main types. Hospital studies look at the injuries suffered by cyclists coming through the doors, and compare them according to whether or not a helmet was worn. These studies tend to come out in favour of helmets. However, they suffer from the "problem" that cyclist head injuries are actually quite rare, making it difficult to get statistically-significant samples. A second issue is the nature of "head injuries", which can mean abrasions that are not in any way life-threatening.
The better studies also compare the severity of other injuries, in order to have some degree of confidence that the two groups actually suffered similar crashes. One early study, still much-cited, totally failed to do this, and turned out to be comparing rich, helmetted kids riding off-road with poor, unhelmetted ones playing on the streets. Guess which group wasn't at risk from cars...
Population studies look at casualty rates across populations before and after helmets became widespread or compulsory. In broad terms, these fail to show any noticeable benefit from helmets. Some analyses show that trends worsened when helmets were worn. One method used is to compare trends in pedestrians and cyclists, which can be shown to tend to behave similarly - until helmets are introduced for cyclists, when things tend to get comparatively worse for the riders. These studies suffer from the problem that you have to adjust for changing cyclist numbers and mileage in order to figure out whether a drop was caused by reduced risk or reduced exposure. There is a lack of really robust figures for numbers and mileage, making the calculations imprecise.
In the face of this contradiction, most people revert to "common sense", which you can certainly respect when it means deciding individually to wear a helmet. However, it doesn't seem such a secure basis for talking of compulsion, given the above. Remember that reversals in road-safety policy have happened before; we used to make roads wider and straighter to improve safety, but now we are making them narrower and trickier again for the same reason. No-one thought it desirable to wait for the evidence, you see...
In particular, since the one effect of helmet promotion that does seem to be demonstrable is large falls in levels of cycling, promotion/compulsion on dubious grounds seems unwise. Add that to the tendency for everyone to focus on helmets to the exclusion of more important measures, and you have real problems. How often do you hear "Had he had cycle training?" when someone has a bike accident? No, it's always helmets, even when it wasn't the head that got hurt
The falls in cycling levels happen, of course, because people aren't daft. If you tell them they need a helmet to go cycling, they hear "Cycling is dangerous", and don't bother. That definitely increases their risk substantially on average, since the life expectancy benefits of cycling outweigh the risks by about 20:1, and whether you wear a helmet doesn't obviously make much difference to this either way.
Sorry for the essay
)
