Department for Transport Research Report 30
From ChapmanCentral
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As a cyclist with a keen interest in safety issues I read the Department for Transport's Road Safety Research Report No 30, 2002 (RR30) (http://www.dft.gov.uk/stellent/groups/dft_rdsafety/documents/pdf/dft_rdsafety_pdf_507998.pdf) with some dismay.
My unhappiness stems not from the accuracy or otherwise of the report itself, although its acceptance without comment of figures which have since been publicly corrected is not a good sign, but from the fact that its stated limitations have clearly not been taken into account in the uses to which its conclusions have already been put.
The Project Brief states: "As part of its policy to improve the safety of pedal bicyclists DfT promotes the use of bicycle helmets, particularly amongst children. However, there is a wealth of published evidence both for and against promotion and compulsory use of bicycle helmets, and DfT requires an independent objective critique of the most up-to-date evidence on the efficacy of bicycle helmets. It is also important to have up-to-date information on legislative measures internationally and their impact on bicycling activity levels and safety." (my italics).
The report then goes on to consider the epidemiology of bicycle accidents without properly addressing the real concerns raised by studies of helmet promotion, including that in Australia. While the authors are surely justified in claiming that helmet promotion raises helmet use, this begs the question of whether this is an absolute good and ignores the question of whether a rise in helmet usage has actually resulted in any measurable reduction in cyclist injuries. I am not aware of any evidence showing that such a reduction has ever happened in any real cyclist population.
By addressing only part of the stated need the report reaches a questionable conclusion which it would be a mistake to use in the setting of publioc policy, as this is clearly outwith the applicable scope of its conclusions.
There is a more pressing issue: John Franklin, author of Cyclecraft and one of the most respected cycling experts in the UK, has identified significant technical shortcomings with the report itself. It would be normal for a scientific paper to undergo a process of peer review; in this case that has evidently not been possible. It would therefore be helpful to those seeking to form a balanced judgement if Franklin's comments could be linked n the website alongside the report. Failing that, the Department could of course submit the paper to peer review and publish it suitably amended when this process is completed. I urge you to ensure that the Department's reputation is not undermined by a failure to correct identified shortcomings in a Report which is published under its auspices.
Contents |
Discussion
The report focuses quite deliberately on the effect of cycle helmets once a crash has happened, excluding time-series and whole-population studies which indicate the overall effect of helmet promotion and compulsion. It is therefore clearly of no value in setting public policy which, by definition, affects whole populations. It may at best be viewed as an interesting sideline to the real debate: how to reduce casualty levels among cyclists.
In its conclusions RR30 references Unwin (1996) and his criteria for helmet compulsion:
- There must be a high level of scientific evidence that bicycle helmets are effective in reducing the rate of head injury to bicyclists.
- The benefits to society and others of mandatory bicycle helmets must be convincingly demonstrated, mandatory bicycle helmets cannot be justified simply to protect individual adult bicyclists.
- There must be widespread agreement, ideally by a large majority, that the potential benefits of compulsory bicycle helmets outweigh the infringement of personal liberty and other disbenefits.
- There must be good evidence to suggest that compulsory helmet wearing would not make the public health benefits of increased levels of bicycling significantly harder to obtain.
RR30 concludes that criterion 1 is now met, but this conclusion is undermined by credible peer-reviewed evidence which suggests the exact opposite. The key word is "rate:" evidence of numerical reduction in head injuries, where present, is generally accompanied by equal or greater reduction in cyclist numbers, thus the rate is not improved,and the overall situation is worsened. RR30 does not claim to establish the other three criteria.
Quality of the review
In Section 5 the authors review the situation in Victoria, Australia, and make the following observations: "While the increased rate of helmet wearing and reduced level of bicyclist casualties noted above is impressive, it is worth noting that it is possible that some of these changes were influenced by decreases in exposure. Following the introduction of the bicycle helmet law the estimated adult bicycling exposure increased marginally..."
In fact the measured (not estimated) level of adult cycling declined by nearly 30% in the year following compulsion, and remained suppressed a decade later according to other studies. The rate of adult head injuries remained steady in the two years following compulsion while other injuries rose and head injury rates in children rose by almost 60%. Far from an endorsement of helmet compulsion, this is an indicator for extreme caution.
If I, as a well-informed amateur, am able to spot this obvious flaw, surely there is a pressing need for the report to be peer-reviewed?
This is not the first time this issue has been raised. TRL report 286 raised the possibility that a major effect of helmet promotion is to deter cycling. It is noted that this requires further investigation. The need for such investigation, regarding the fundamental issue of the probability of a crash happening in the first place, is clearly more important than measures designed to mitigate the results once a crash has happened. Will the Department undertake to commission this vital research as a matter of urgency?
RR30 as a contribution to the debate
The authors state that:
- The pro-bicycle helmet group base their argument overwhelmingly on one major point: that there is scientific evidence that, in the event of a fall, helmets substantially reduce head injury.
- The anti-helmet group base their argument on a wider range of issues including: compulsory helmet wearing leads to a decline in bicycling, ‘risk compensation’ theory negates health gains, scientific studies are defective, the overall road environment needs to be improved.
- The way in which the debate has been conducted is unhelpful to those wishing to make a balanced judgement on the issue.
This misunderstands the nature of the debate. Those who are pro helmet are a relatively small, vocal and homogeneous group, generally led by doctors. There is no significant anti-helmet group, but the group which is anti compulsion (and by extension has profound reservations regarding promotion) is indeed broad and runs from the grass roots upwards. The range of concerns is naturally wide, but there is surprising uniformity on the issue of deterrent effect because such studies as have been published make this conclusion inescapable.
If "the way in which the debate is conducted is unhelpful to those wishing to make a balanced judgement on the issue, " it is probably because the two sides have not agreed on the issue in question. For the anti compulsion lobby the issue is reduction of cyclist injuries; for the pro compulsion lobby it is reduction of the severity of those injuries which do happen. As long as the means of achieving the latter is potentially inimical to the former, agreement is impossible.
Then again, perhaps the problem is how you define balance. Many have come to make what they perceive as a balanced judgement: balanced, that is, in that it weighs the evidence for helmets against the evidence agin them. If the result is inconclusive, surely that is indicative more of the complexity of the issue than any failure in the debate. Yes, broad-based research on bicycle helmets stubbornly refuses to confirm the findings of those concerned primarily with injury mitigation. Scientific method is awfully prone to dealing mortal blows to neat theories, and proving that the world is more complex than we would like it to be.
Those of us who are against helmet promotion and compulsion are, by and large, well-informed. We are also, for the most part, cyclists. It is in our own best interests to understand the issues, to judge the risks and benefits. Far from being anti-helmet, many of us wear helmets as a matter of course; few will allow their children to ride without helmets; and fewer still will challenge the right of others to forego the notional protection of a helmet should they so wish. We are all aware of the realities of risk compensation, a theory so blithely dismissed by the pro lobby, to the extent its being placed in quotes by the authors of RR30. If risk compensation does not exist, what, then, explains the observed rise in pedestrian, cyclist and rear-seat passenger fatalities following compulsory seat belt legislation in the UK? Given the availability of safety cages, crumple zones, ABS, airbags, high-performance tyres and road surfaces - surely driver fatalities in the UK should be, to all intents and purposes, a thing of the past?
Factors improving cyclist safety
There are three factors which are acknowledged to affect, above all other considerations, the safety of cyclists on the roads. They are, in no particular order, driver behaviour, rider behaviour and the number of cyclists using the roads.
Helmet promotion deters people from cycling on the roads, and by extension it encourages the use of more dangerous alternatives such as shared-use cycle paths. The policy of allowing only helmeted cyclists to be shown in official publications, will inevitably reinforce the inaccurate public perception of road cycling as a dangerous activity. I believe it will also make it impossible to show Steve Norris on his bike, since he is an avowed non helmet wearer. Finally, it is not supported by the acknowledged limitations of the report. I therefore ask the Department to drop any such policy, at least until research has been conducted which addresses the whole-population isssues of helmet promotion.
Helmet promotion has an insidious effect on motorist behaviour. It portrays the cyclist as one who is knowingly engaging in a dangerous activity, rather than one who is engaging in a safe activity which the behaviour of drivers may make dangerous. The largest cause of car vs. bicycle crashes is error by the driver of the car, and the most likely outcome is injury or worse to the cyclist. It should therefore be a matter of pressing concern to redress this balance by a mix of stronger penalties and better public information aimed at careless drivers. Instead we have the recent Think! campaign proposing defensive riding by users of powered two wheelers as a solution for inattentive car drivers. Helmet promotion comes out of the same bag: an unwillingness to deal with the problem at source, so shift the focus onto the victim. When will the Department bring forward a campaign addressing the behaviour of careless drivers?
There have been numerous incidents where drivers have caused the death of cyclists through bad driving and have attracted penalties so light as to amount to an endorsement of such behaviour. At what point will the long-promised review of driver sentencing be complete? And what mechanisms will be put in place to measure the effectiveness of thiese policies?
Cyclist behaviour, too, is subtly influenced by helmet wearing. One of the reasons why time-series and whole-population data are so important in assessing the effects of helmet promotion is that data based solely on injury rates after crashes fails to take into account the question of whether the wearing of helmets makes the crash more likely. There is no doubt that the most survivable crash is the one which doesn't happen in the first place. The mechanisms for increased accident rates among populations with high helmet-wearing rates are imperfectly understood, although there is strong evidence to support risk compensation. What research does the Department have in mind to address this important knowledge gap?
The majority of helmet promotion material focuses on the danger from cars, but cycle helmets are of very limited benefit in car v bike crashes, which almost invariably exceed their design parameters. Helmets give protection primarily in single vehicle accidents at speeds up to 12mph. This covers many of the situations where bikes are in use, but absolutely not the one which is purported to be the greatest concern. A cyclist hit by a car at speed is likely to suffer injuries to many parts of the body, and the impact speed is unlikely to be within the ability of the helmet to give meaningful protection. What action is the Department taking to ensure that cyclists are not misled as to the efficacy of helmets? And is the Department covered by Crown immunity if a cyclist should, through having been so misled in the past, suffer grievous injury?
There is a clear contradiction at present between talk of promoting cycle use, migrating journeys to benign modes and making the roads safe for all users, and policy and practice which shows reasonable understanding of the bicycle as a leisure item, includes some promotion of cycling as an alternative to the school run, and leaves the bulk of the dangers and inconveniences suffered by transportational cyclists either untouched or worsened. What action is the Department taking to ensure that policy decisions affecting cyclists are informed by experienced cyclists?
If the DfT is as serious as it claims about cyclist safety and promoting cycle use they should ensure that all departments in their literature show ordinary cyclists going about their ordinary lives wearing ordinary clothes. An unrelated publication which shows in the background a City gent on his Brompton, suited, with his briefcase on the carrier and his hair unperturbed by his stately progress, will have more positive effect than any photo shoot with smiling happy helmeted families riding mountain bikes on well-graded offroad paths - which ghettoisation of cycling is unlikely to result in significant reductions in the destructively sedentary lifestyle of the average Briton.
Personal perspective
As a year-round transportational cyclist I also offer below some of the things which would make my life safer - and which would address the concerns of those cyclists I know who are hovering on the brink of using their bikes for daily transportation:
- An effective campaign against competitive and aggressive driving. The thing which is most likely to lead to my death on the road is not the wearing or otherwise of a helmet but the driver whose journey is so urgent that they cannot bring themselves to wait for a safe place to overtake. For the most part, of course, their destination is the back of the traffic queue ahead, but this does not deter them from taking my life in their hands and overtaking dangerously. I encourage you to observe the behaviour of drivers towards cyclists at a typical traffic calming pinch point. These pinch points are almost invariably not narrow enough to actually reduce speed (this requires them to be too narrow for LGVs and buses), so drivers are accustomed to negotiating them without slowing. When they see a cyclist on approach to such an obstruction their reaction is quite often to try to pass before the obstacle. Since very few drivers realise that cyclists can easily be travelling at speeds of 25mph and more on a level road this judgement is often flawed. The result is that the car gets halfway past and cuts in to avoid the bollards. Perversely, those who have actually given the cycle sufficient space when passing cause more danger as they must cut in more sharply, and may well overshoot into the path of the bike. All of this, and the classic "left hook" where the driver overtakes the cyclist and immediately turns left, would be reduced if people drove more calmly -if the driver's first thought were not "how can I pass this slow-moving object" (bikes are rarely seen as vehicles) but "what is the safe way of negotiating this situation." Perversely, the focus on speeding as pretty much the only aspect of driver behaviour challenged by Government campaigns has resulted on an even greater determination to maintain the illusion of progress, at whatever cost to other road users. Campaigners against speed enforcement have validated the view that the driver's transient personal convenience is the overriding priority, and the driver may safely be left to judge the extent of his impact on other road users. Since few drivers even consider cyclists when making these judgements, the danger of this viewpoint is evident.
- A proper public information campaign on overtaking techniques, and including overtaking in the Driving Test. Overtaking is a most dangerous manoeuvre and is routinely handled extremely badly. The principle is simple: drop back, wait until there is a clear space ahead, check mirrors, accelerate and pass, and when well past pull in. The reality is that drivers overtaking cyclists will do one or more of the following: sit within a few inches of the cyclist's back wheel, look at the cyclist not the road ahead, pull out without signalling or checking mirrors, start to pass and only then look ahead to see that there's a car coming the other way, move left to avoid the oncoming vehicle (squeezing the cyclist) and pull in when the cyclist is out of their peripheral vision (typically when the car is about 1/3 of the way past). And of course the four drivers are following on the bumper of the overtaking vehicle will follow through despite the fact that by now they are on a blind bend with more traffic coming the other way, each one moving out a few inches less than the one in front. Rules 138-143 and 188 of the Highway Code appear on the face of it to be Terra Incognita to the average motorist. This must be remedied if transportational cycling is to become a more pleasant activity.
- Widely available expert training for adult cyclists. I know the CTC are working to promote adult cycle training, but we have been trying for over a year now to find any group locally who will run an open cycle training course which my wife, a relatively new cyclist, can attend. She rides to school with the children several times per week and would value some expert tuition. One would imagine that this is precisely the kind of thing which the Government would wish to support, but there is a near-complete absence of training. I would be prepared to run a course myself if there were a nationally accredited instructors' training system. There isn't. From this year I will be running National Cycling Proficiency training at the school where I am a governor - there is not training available for me in advance; it's a matter of "sitting with Nellie" and hoping that "Nellie," in this case fortunately a well respected local cyclist, is suitably expert.
This was written in 2003; the national standards for cycle training are now available and appear to have subtly altered thinking in the road safety establishment
See also
- The Bicycle Helmet Research Foundation has information on this topic: see http://www.cyclehelmets.org/mf.html?1067
- Critique of RR30 by Dorothy Robinson: http://www.cyclehelmets.org/papers/c2004.pdf
