Cities fit for Cycling

I am extremely pleased to see that a national newspaper has given the safety of cyclists (and the inherent hostility of our present road network to them) the attention it so sorely deserves. I was even more amazed that it was none other than The Times who were behind this movement. The Cities fit for Cyclists campaign shows an understanding of the underlying issues, where it could have been all too easy to start talking about helmets or other such easy but ineffective measures. Needless to say, I encourage you all to sign up.

However, my joy at the issue of cyclist safety and the importance of infrastructure receiving such attention was dampened somewhat when I tried to encourage friends outside of cycling circles to sign up too. Surprisingly to me, the issue of 20 mph in residential areas appeared to be a bit of contentious one. The issue of children's freedom to play outside without motor traffic being a threat did not seem to be a significant persuader either, with the long history of children playing on the streets seeming to have been quickly forgotten by some. Inevitably, the issue that cycling, walking or public transport are not viable for every journey made by every person came up. Whilst true, it is my experience that this argument is often used to justify car use which, at least in the right road environment, could easily be made through walking or cycling. Walking, cycling and public transport are unlikely to be viable for every single journey made by every single person in the UK. This does not change the fact that they could be made viable for the vast majority of journeys made by the vast majority of people. To me, raising the limitations of our current public transport system is merely an acknowledgement of the need to invest in the expansion of our rail and bus services.

It didn't take long for the issue of the law-breaking behaviour of some cyclists to come up, despite its dubious relevance to the topic at hand. As a member of a vilified minority group, I am often expected to justify the behaviour of others within the same minority group, despite the fact that I have nothing to do with them. I acknowledged the bad behaviour of a minority of cyclists and gently pointed out the bad behaviour of (what I generously described as) a minority of motorists, including the red light jumping and pavement driving (both of which are regarded as reprehensible behaviour when cyclists do it but largely tolerated when motorists do it). The issue of motorist behaviour was mostly ignored.

The Times' Cities fit for Cyclists campaign is an enormous and welcome step in the right direction. However, the responses to my attempts at promoting of the campaign show that we need to keep plugging away at this issue to bring in further into the mainstream.

To its Logical Conclusion

I was stunned this week by some quotes from the Association of British Drivers which were featured in a post from As Easy As Riding A Bike. Whilst the criminal behaviour of motorists being rationalised by a motoring organisation is far from new, I found the sheer unashamed stupidity of what was being said really quite shocking.


"Because speed limits are set below the level at which the majority of drivers consider to be reasonable, you get a very high level of non-compliance. And you get a greater disparity of speeds – you get more frustration, [...] that will result in a large queue of drivers behind, who simply want to drive at what they consider to be normal speeds, and that leads to frustration, dangerous overtaking… "


A responsible drivers' organisation might suggest that a driver who gets so frustrated by having to drive within the law that they might attempt a manoeuvre which not only puts themselves in danger, but endangers the lives of innocent people might be better off not being allowed to drive at all, this is the ABD, and it is not an exaggeration to say that the ABD literally don't know the meaning of the word 'responsibility.' It is interesting to try to apply the ABD's logic to other areas:


Theft:


"Because the definition of theft is are set below the level at which thieves consider to be reasonable, you get a very high level of non-compliance. And you get a greater disparity of theft – you get more frustration, [...] as thieves try not to steal, and that leads to frustration, and when it gets released, events such as the August riots happen… "


Domestic Abuse:


"Because the definition of domestic abuse is are set below the level at which abusive partners consider to be reasonable, you get a very high level of non-compliance. And you get a greater disparity of beating – you get more frustration, [...] as abusive partners try not to beat their partners, and that leads to frustration, and when it gets released, it leads to serious injuries and even deaths… "


Road Safety:


"No, not lower speeds – lower speed limits. Because speed limits are set below the level at which the majority of drivers consider to be reasonable, you get a very high level of non-compliance. And you get a greater disparity of speeds – you get more frustration, because a small minority of drivers will obey the speed limit, even if they think it’s really silly, and that will result in a large queue of drivers behind, who simply want to drive at what they consider to be normal speeds, and that leads to frustration, dangerous overtaking… It also can lead to long queues of traffic, which prevent side road traffic from entering, or crossing, a main road. So you get these additional conflicts, even road rage, as a result. So if you have sensibly-set speed limits, which means set at the 85th percentile, which is the level that 85% of drivers wouldn’t exceed anyway, experience has shown – this goes back, certainly in the United States, to the late 1930s – that is the safest level at which to set speeds, speed limits, and you get the lowest casualty rates."


Oh wait, that one was real. The ABD goes on to use that brilliant debating tactic of pretending that something which is bullshit is actually backed by science (brilliantly debunked later in the original post). Their website actually displays this crap proudly on their homepage, but they have made it even more entertaining to read: 


"The ABD calls for the use of sensible speed limits that are based upon well established scientific road safety principles, not political correctness, emotive hysteria, or vociferous local activists."


Ahh yes, that well established scientific principle of 'Be safe: drive as fast as you want, wherever you want.' I really admire the balls they show by calling their made-up science 'well-established.' In fact is it so well established that it goes against everything that every bit of real road safety research and every road safety organisation in the whole world is saying. If that's not well established, I don't know what is! To make this statement of idiocy even more delicious, they included the Daily Mail's favourite phrase, 'political correctness' 
(They cleverly use the original meaning of the phrase, which is, 'Stuff what I done don't like').

Cycling is Safe

This one has been languishing in my drafts for quite some time, with both Vole O'Speed and As Easy As Riding A Bike sharing their own views on the issue in the meantime. Statistically speaking, cycling here in the UK appears to be surprisingly safe. Indeed, in the past I have focussed on this when talking to new and potential cyclists about their experiences of poor subjective safety. These statistics are also readily utilised by a vocal minority who  are ideologically opposed to the use of separation by mode for the prioritisation and protection of cyclists. As is often the case with statistics they only tell part of the story; whilst it appears at first that they show cycling to be a 'low-risk activity,' what they literally show is that the current sub-section of the population who choose to cycle are doing so relatively safely.

Like most other people who choose to cycle in the UK, when I cycle I do so in a hyper-aware state; I always expect the worst from other road users, I pre-emptively hover over the brakes when I see a car approaching a give-way line where I have clear priority and I plan my escape route for when that BMW makes a sudden turn without indicating. I am relatively fit, fast, I cycle in the optimal gear and I know precisely how much force I can put into the brakes before the wheel locks up. Put simply, the bar it set much higher for cyclists than it is for other road users because the road environment is inherently hostile for cycling. Most people who drive motorised vehicles, which are significantly wider, faster and heavier than bicycles, do not do so in a similar state of hyper-awareness. This is because there is simply no need; the vehicles and road environment have been designed in such a way that their operators are largely protected from the limitations of their own ability. The bar has been set rather too low for such inherently dangerous machines.

I have often thought that if some of the greatest minds of the 1950s were put together in a room and given  and nearly unlimited budget and the specific task of designing a road network to minimise the number of people choosing to cycle, without being permitted to explicitly make cycling illegal, the result would not be far off the current UK road network. The exceptional hostility for cycling which is designed into the UK road network is enough to prevent the vast majority of people from every wanting to cycle on it. The result is that those few who are willing to cycle on it are not at all representative of the general population; it is because this minority can cope with the road network as it currently exists that cycling appears to be a statistically safe activity.

In The Netherlands, cycling is statistically slightly safer than the UK. The difference is not as much as might be expected, which is often used as an excuse for opposing the construction of Netherlands-style dedicated cycle infrastructure in the UK. However, with a little context the safety statistics from The Netherlands start to appear much more impressive. By implementing road designs which are not inherently hostile to cycling, the section of the population choosing to cycle is much more representative of society as a whole. The majority of ordinary people, cycling without being in a hyper-aware state typical of UK cyclists manage to get around by bike and are still statistically more safe than the tiny minority of physically and mentally exceptional UK citizens who choose the bicycle. Next time there is a discussion about how safe cycling is, remember that in places such as the UK where cyclists are a tiny minority, the statistics don't tell you a great deal about how safe cycling is, only how safe cyclists are.

Pedestrian danger from cars versus cycles

Whenever cycling is discussed in the mainstream press, a common theme which often emerges in the comment thread following the story is the perceived danger cyclists pose to pedestrians. A good example of this is the comment thread under any of the stories published in The Grauniad Bike Blog. It is a truly impressive feat that the motoring lobby has managed to pull off; persuading pedestrians that it is cyclists, not motorists who pose the biggest threat to their safety. 

These comments are usually countered by comments from cyclists themselves, who are quick to point out the much, much greater risk posed to pedestrians by motorists. Usually, these comments consist of a series of suppositions which, whilst often perfectly plausible, are difficult to back up with actual documented evidence. These suppositions often include the following: Cyclists are less likely to be distracted on the road compared to motorists due to being aware of their increased vulnerability in the event of a collision, cyclists are more likely to notice pedestrians in their vicinity because their visibility is less impaired than that of someone sat in a car, cyclists are exposed to fewer distractions on a bike than motorists are in a car (generally bikes don't have radios/heaters/fans or passengers), the nature of cycling makes it less feasible to try to text/shave/apply make-up whilst cycling when compared to a motorist sat in a car. Please feel free to leave any other reasonable-sounding suppositions in the comments below.

Another argument given is that cyclists generally travel at lower speeds than motorists and that a bike & cyclist together are smaller and lighter than a car. Unlike the suppositions above, these things are either demonstrably true, or obviously self-evident. The figure at the top of the post shows a diagram of 70 metres of a 6 metre wide road with 1 metre pavements either side. The left lane shows a blue bar, graded in increasingly dark shades. The lightest section of this bar represents the space a 2 metre wide motor vehicle (such as those models favoured by pimps) travelling at 30 mph would travel through during a 3 second "Distraction period," during which its operator is not devoting their full attention to the road. The vehicle travels approximately 40 metres during the 3 second window where the driver is not paying attention, meaning the vehicle will cover an area of approximately 80 square metres. Any pedestrian (or other road user) present in this area at the time the driver takes their eyes off the road is at risk from the motor vehicle. At 40 mph (darker blue), the car will travel approximately 53 metres during this distraction period, covering an area of approximately 106 square metres. At 50 mph (darkest blue), the car will travel approximately 66 metres during the distraction period, covering an area of approximately 132 square metres. Speeds of up to 50 mph are still relatively common on urban roads, these speeds even being officially sanctioned on some roads.

The right lane shows a pink bar, graded in two shades of pink, representing the area which would be covered by a typical 0.6 metre wide utility bicycle travelling at 12 mph and 20 mph (light pink and darker pink respectively), during the same 3 second distraction window. At 12 mph (a fairly typical cycling speed for a utility cyclist) the cycle will travel approximately 15.8 metres during the same 3-second distraction period, covering an area of approximately 9.5 square metres. At 20 mph (the sprint speed recommended in Cyclecraft to enable cyclists to reasonably deal with our fundamentally cycling-hostile road network), the cycle will travel approximately 26.4 metres during the distraction period, covering an area of approximately 15.8 square metres. For a sense of scale, the black rectangle in the lower left corner is 1.7 metres by 0.6, representing the height and width of a relatively large human.

So there we have it, at a fairly common urban speed of 30 mph, a car will travel over an area more than five times greater than the area a cycle would cover at the relatively high speed of 20 mph during a three second period of operator distraction. At a typical cycling speed of 12 mph, a cycle will travel over an area which is over 8 times smaller than the car would at 30 mph. This representation is a bit of blunt instrument, It'd be great to see some research which takes into account the effects of vehicle mass, vehicle profile and some of the suppositions listed above too. As it is, I think it helps to hammer home the fact that it is of course the private motor vehicle which represents the greatest risk to the safety of pedestrians (and cyclists, and even other motorists). The reason people focus on the (much, much lower) risks posed to pedestrians by cyclists, is that the private motor vehicle is the sacred bull in society's china shop.

The propaganda deemed acceptable to show in schools

Years ago, when I was in high school, I remember that we were given numerous safety presentations. Sometimes these were about the railways (dare to step on the tracks and you WILL certainly be killed), sometimes about not flying kites near pylons and sometimes about the roads (such as the green cross code). The issue of responsibility was never discussed, interviews with children who had been maimed by cars were shown, although we were never told what happened to the motorist in the aftermath. The takeaway message from these videos was that when crossing the roads, the onus was very much on us to look out for cars and only cross when it was safe to do so. The wider issues of government-enshrined inequality between transport modes were never discussed, and the implication from the road safety propaganda we watched was that if we were hit by an adult in a car, it was our own stupid fault.

I have a little sister, who is currently in high school. In order to assess the state of "Road Safety" propaganda shown in schools nowadays, I decided to ask her what were the sort of things they showed her in school on the issue. I don't really talk to my sister about the issues I discuss here, she is quite young, like most people she doesn't cycle, and she doesn't generally give much thought to the issue of transport. By being careful in how I asked about it, this presented me with an opportunity to find out what the take-home message she (and by extension the average pupil in her age group) got from the propaganda. The conversation went something like this:

Me: Do they still show you those road safety videos in school nowadays?

Sis: Well, there was this one about a boy who got paralysed when crossing the road.

Me: Oh. Did they tell you what happened to the adult in the car who hit the boy?

Sis: No. It was the boy's fault because he was wearing dark clothes



So-called "Road safety" education programmes are generally funded by the fake road safety charities such as the Road Safety Foundation, RAC Foundation and the Road Safety Fund set-up by the AA, RAC and FIA. These education programmes have a very poor success record worldwide. Their main purpose is to counter the bad press the motoring lobby were receiving at the time they were founded due to the death-toll (particularly of children) caused by the actions of their members. It seems odd to me that this propaganda is welcomed by schools, but for example the tobacco and alcohol industries are not similarly indulged. At the very least the obvious conflict of interests should be recognised by the governments. Allowing the motoring lobby to set the agenda for how road safety is perceived by school children is a bit like allowing Anheuser-Busch InBev or British American tobacco to set the agenda for health education in schools. Perhaps all they need to do is set-up a cynical faux-charity foundation and they will be welcomed with open arms. 

The benefits afforded to the motor lobby and those whom it represents as a result of such education programmes are many. Firstly, it creates the image that the motoring lobbies care about, and are actively trying to reduce casualties. Secondly, by targeting the young and vulnerable, they are able to plant two very powerful ideas into the minds of the next generation; if a motorist hits a pedestrian (or any vulnerable road user, such as a cyclist), it is the victim who is at fault and that these activities are intrinsically dangerous compared to the perceived safety of the car.

Motorists benefit from this propaganda by the creation of a culture in which drivers are blameless for collisions involving their vehicle with more vulnerable road users. Additionally, this helps to prevent governments from reversing the creation of a road network favouring the use of the car for almost all journeys, high volumes of motor traffic and the high speeds attained by these vehicles.


The "Decade of Action on Road Safety" is a fine example of this. Fronted by Lewis Hamilton (Booked for speeding in UK, reckless driving in Australia) and Jenson Button (Booked for speeding in UK multiple times) and funded by the FIA, one of the biggest motoring lobbies and the world governing body of motorsport, it embodies our arse-about-face approach to road safety. It saddens me that an institution such as the United Nations would degrade itself by choosing to be associated with this pish. 


Those of you who have reproduced may wish to prevent your own children from being exposed to this blatant propaganda, or at least get through to them ahead of time. It might be fun for them to have an understanding of the forces at work behind the scenes of these campaigns, at least then they will be able to ask some awkward and disruptive questions in class.

Segregation Myths #2: Segregated Cycle Facilities are Dangerous

After writing my critique of Cyclecraft a few weeks ago, I noticed that a thread had cropped up on Cyclechat discussing the post. A common research article is cited by those who oppose introduction of Dutch-style cycle infrastructure in the UK is, Bicycle Track and Lanes: A Before and After Study, most commonly linked in the form of a summary report. This is often linked to as "proof" that segregated cycle facilities are dangerous, which in itself is rather unimportant, for reasons to be discussed later. Interestingly, very early on in the introduction, the author writes:

"Many studies of bicycle tracks have been undertaken in Northern Europe. A meta analysis of 11 studies shows a reduction of 4 percent in crashes, and the crash reduction is almost the same for pedestrians, bicyclists and motorists respectively."

The meta-analysis being referenced there is from, "The handbook of Road Safety Measures," by Rune Elvik. Meta-analyses are useful because they take a broader consensus from numerous studies, minimising the effect of any flaws or limitations in individual studies by looking for overall trends in the body of work as a whole. Picking a single piece of research which agrees with your own opinion whilst ignoring the wider consensus offered by the body of literature is called "Cherry-picking," and is generally frowned upon.

The study compares the numbers of cycle*-car and cycle-pedestrian crashes on roads with cycle tracks and with cycle lanes, to predicted crash figures based on figures for unaltered roads which have been altered to factor in the alteration to traffic volume and composition. The crash figures for junctions and straight road sections are treated separately, and the study finds that on roads with cycle tracks, cyclist crashes are decreased by 13% on straight sections, whilst at intersections they are increased by 24%. Overall, crashes involving cyclists increased by 10%.

This is the oft-cited percentage increase when discussing Dutch-style segregated cycle facilities with those who are vehemently opposed to them, and it is interesting to see how it is calculated; previously cyclist injuries at junctions had been measured as 353. After the installation of cycle tracks, the number of cyclist injuries at intersections was measured as 285, a reduction of 19% in absolute figures. However, the 24% increase figure is calculated from a predicted number of crashes figure for the after period, based on the changes to the traffic volume and mode composition, which predicted that at unmodified intersections with the same increase in cyclists, decrease in motorists and subject to pre-existing crash trends seen at the intersections which had been modified with cycle tracks, there should be 230 cyclist crashes. This is the figure which is used to generate the eye-catching 24% increase in crashes figure. The author of the paper also states that:

"The construction of bicycle tracks resulted in a 20 percent increase in [bicycle] traffic mileage and a 10 percent reduction in motor vehicle traffic mileage on those roads, where bicycle tracks have been constructed."

Taking intersections and straight sections together gives a figure of a 10% increase in crashes involving cyclists overall versus the predicted figures on un-altered junctions for the same traffic mode/volume composition (broadly speaking, a 10% reduction in motor traffic and a 20% increase in cycle traffic), a composition which is arguably only achievable where segregation is applied. The actual before and after numbers show a decrease in the absolute numbers of cyclist crashes of 29%. It is important to consider the effects of any pre-existing downward trend in crashes which could be contributing to this number, but also important to consider that this effect is seen contemporaneously with an increase in cyclists' mileage of 20% on these facilities.

"The bicycle facilities effects on traffic volumes are rather large. We do not know for sure whether these effects are a result of changes of route choice or transport mode choice or both. The magnitude of the changes in traffic volumes on the reconstituted streets, and the traffic volumes on parallel streets, however, do indicate that thousands of travellers in total must have changed their choice of transport mode. We do not know who have shifted mode - children, middle-ages or elderly, women or men, beginners or experienced, etc."

It is also interesting to note the large effect which the presence or absence of car parking restrictions on the adjacent road has on the number of collisions and injuries for cyclists and pedestrians which occur at intersections. Where parking restrictions were in place, there were more collisions due to the effect of motor vehicles parking on minor roads instead, resulting in more turning thus collisions.

At the beginning of this post, I stated that the safety effect of Dutch-style segregated cycle facilities is actually rather unimportant. Cycling, even on our hostile road network is actually a very low risk activity. A lot of people have invested a lot of time in trying to convey this message, that cycling is actually very safe, low risk and that the benefits from cycling hugely outweigh the risks a person is exposed to by cycling. It also featured as a common theme on the Cyclechat thread too, demonstrations of the statistically low risk which comes from in motor traffic and links to works such as the study discussed above (ignoring the wider consensus offered by the overall body of literature, which are even discussed in the introduction of this particular study).

Generally, the body of research shows that Dutch-style segregated infrastructure moderately decreases the risk to which cyclists are exposed, despite expanding the demographic itself from what is largely a small minority of experienced and vigilant hardcore cyclists under a vehicular approach, to include such disparate groups as teenagers chatting as they ride together or riding alone with earphones in, older people, parents with their children (either on their own bikes or on the parent's bike), children cycling to school without the need for supervisions and boozy revellers returning home from a pub or club by cycle. Despite the incredible broadening of the demographic, safety is still increased.

However, all of this is missing the point. Surprisingly, the main benefit and purpose of implementing Dutch-style segregated cycle infrastructure isn't just to reduce risk, it is to reduce fear. Increasing people's sense of subjective safety is a huge part of making the bicycle seem like an attractive and viable mode of transport to them. Another important factor is convenience. Both the need to feel safe whilst cycling, and the need for it to be convenient are provided where there are Dutch-style segregated facilities (and the extra options it opens up for reducing the speed, volume and permeability available to motorised traffic). All the statistics demonstrating the low-risk of vehicular cycling isn't going to change the average person's mind as long as it doesn't feel safe to them. People don't work that way

"Making these bicycle facilities must have contributed to benefits due to more physical activity, less air pollution, less traffic noise, less oil consumption, etc. [...] The positive benefits may well be much higher than the negative consequences caused by new safety problems." (My emphasis)

*In the study, numbers for cycles and mopeds limited to 30 km/h (which are legally permitted to use cycle tracks in Denmark) are bundled together. Make of this what you will.

Rune Elvik’s Bicycle Helmet Efficacy Review

A new review of helmet research has recently been published by Rune Elvik in Accident Analysis and Prevention. The paper can be found here, although it may be behind a paywall.

The way that more mainstream media outlets report science is often interesting. Monday’s Science article about a new drug molecule demonstrating a 15% reduction in tumour mass in a specific type of cancer in rats all too often becomes Tuesday’s Daily Mail article about a new miracle drug to cure cancer. Quite often, if a story doesn’t fit the news narrative*, it is quietly ignored altogether. In the UK, the standard line from the mainstream press is that cycling is an extreme sport, like rock-climbing or sky-diving, and anyone who doesn’t use a helmet is either partially or fully to blame if they are killed by a speeding and/or drunk driver. Unsurprisingly I have not seen this new research mentioned in the mainstream press.

Road.cc picked up on the article, and ran a surprisingly scientific piece on it, although they did fall into the usual media trap of adding “balance” to science reporting, by quoting pro-helmet Professor Alistair Woodward, head of the School of Population Health at the University of Auckland. I am glad they consulted a relevant researcher rather than a non-expert as is surprisingly common in science reporting (look out for interviews with homeopaths being added to “balance” reporting on non-placebo medicine articles**). However, Professor Alistair Woodward was quoted as saying;

“Whether they cause the neck to bend more than otherwise, I suppose it's possible. If there is an effect [on neck injuries], it's much smaller than the protective effect from head injuries.”

Despite the paper, a review article of the body of research on the effectiveness of helmets rather than an individual study, stating that,

“When the risk of injury to head, face or neck is viewed as a whole, bicycle helmets do provide a small protective effect. This effect is evident only in older studies. New studies, summarised by a random-effects model of analysis, indicate no net protective effect.”

In doing so, the article put the opinion of one pro-helmet man at the same level as an academic research review. It is hard to base too much on a single study, as there will be limitations in the design of any single study. This is why reviews of the existing literature such as this are a useful tool, they help to even out the limitations and biases of the individual studies. Sadly, because the review doesn’t fit nicely in the news narrative of “helmets are good,” it was felt necessary to include the opinion of one pro-helmet individual in an article about a review of the existing helmet literature.

The study was also picked up on by the New Zealand Herald (who interviewed Professor Alistair Woodward), who in the opening paragraph describe this review of the existing body of literature as “Contentious,” to immediately attempt to discredit the work, presumably because it doesn’t sit well with the existing news narrative. The pro-helmet bias in the NZ Herald piece continues, throughout, and culminates in the following bullet points at the end of the article:

“HEAD PROTECTION

* New research indicates wearing a helmet reduces the risk of head injury in a crash by 43 per cent.” [Neglecting to state the paper’s finding that the increased risk of neck injury brings the benefit of helmet wearing to a net of zero]

“* Previous research found the risk reduction was at least 60 per cent.

* The new findings are disputed.” [Because the NZ Herald went out to ask a pro-helmet individual to dispute the findings, and treating his opinion on the matter as having equal merit to the research to the contrary in the paper]

Bike Biz also ran a piece on the paper, largely based on the NZ Herald piece, focussing heavily on the opinions of Professor Alistair Woodward, and describing Elvik’s review of the existing body of literature as “controversial.”

The review focuses on the effects of helmet use on cyclists in the aftermath of a crash, finding there to be no overall net benefit to helmet wearing cyclists over non-helmet wearing cyclists in the aftermath of a crash. It would be interesting to see some quality research into risk compensation; whether the crash frequency and severity of helmet wearing cyclists is different from that of non-helmet wearing cyclists. I wouldn’t be surprised if the inclusion of such research into a review such as this wouldn’t bring the benefits of helmet wearing down from net zero benefit to a negative benefit to helmet wearers. However, this is just my opinion.

As I have stated previously, I see helmet wearing as a choice and I don’t have anything against anyone who choses to, or not to wear a helmet whilst cycling, walking, cooking or driving a car. It is perfectly reasonable to expect individuals to make decisions based on their own subjective fears, whilst simultaneously I’d prefer governments to make policy decisions based on objective risk. As a politician, Norman Baker’s recent defence of his choice to ride without a helmet is setting a good example rather than a bad one, by making an objective decision to not wear a helmet based on the minimal risk involved in cycling, he is portraying cycling as the safe, normal everyday activity it should be seen as.

* For more on the interesting peculiarities of mainstream news, I recommend Charlie Brooker’s entertaining and informative TV series Newswipe

** For more on the distortion and mis-reporting of science in the mainstream press (and more science-related stuff), I recommend Ben Goldacre’s entertaining Bad Science articles, ironically published in The Guardian

Risk Compensation Experience

I have written previously about the effects of risk compensation on road safety. A good example of this effect is the Munich Taxi experiment, where a fleet of taxis, half with ABS and half without were secretly monitored and the differences examined. It was found:

“Drivers of cabs with ABS made sharper turns in curves, were less accurate in their lane-holding behaviour, proceeded at a shorter forward sight distance, made more poorly adjusted merging manoeuvres and created more "traffic conflicts". This is a technical term for a situation in which one or more traffic participants have to take swift action to avoid a collision with another road user.[3] Finally, as compared with the non-ABS cabs, the ABS cabs were driven faster at one of the four measuring points along the route. All these differences were significant.”

In brief, the increased safety offered to the vehicle operators/occupants by the improved brakes was compensated for by an increase in risk-taking behaviour by the vehicle operators.

I currently operate a “fleet” of three bikes, all of which have different types and combinations of brakes:

The DL-1 has 70 mm Sturmey Archer drum brakes in both the front and rear wheels. These offer reasonable stopping power and supreme durability, requiring almost zero maintenance. Sturmey Archer drums offer good modulation, with light braking being easily controllable and hard braking available if you need it when you really squeeze the levers.

The Sturmey Archer drum brakes; front (top) and rear (bottom)

The Brompton has calliper brakes front and rear. These were presumably chosen because they offer reasonable stopping power and reasonable durability whilst minimising weight (which is an important consideration for a folding bike, unlike a full-sized transport bike). A peculiarity of the Brompton is that the rear brake seems to offer more stopping power than expected, whilst the front feels weaker than expected. The callipers offer similar stopping power and modulation to the Sturmey Archer drum brakes, but are exposed and thus require more maintenance.

The Brompton calliper brakes; front (left) and rear (right)

The Yuba Mundo has a more exotic brake configuration; a rear V-brake and a front 185 mm Avid Juicy hydraulic disc brake. This combination was chosen because the original front V-brake did not offer what I felt was appropriate stopping power or modulation for a loaded Yuba Mundo. The rear V-brake is adequate; offering a lot of stopping power but poor modulation, with a small amount of brake lever travel the brakes make the transition from doing hardly anything to slow the bike to locking up the rear wheel. The front disc brake offers an extreme level of stopping power, which is ideal when the bike is loaded. It also offers good modulation for when a small amount of braking is required. When the bike is unloaded/lightly loaded, it is able to stop incredibly quickly.

The Yuba Mundo front hydraulic disc brake (top) and rear V-brake (bottom)

Whilst I use all three bikes regularly, I rarely use different bikes in quick succession. A few weeks ago, I returned from a 30 km ride on the Yuba Mundo to pick up some wheel building parts which I dropped off at home. I had to pop back to work immediately afterwards and took the DL-1. When I approached the first set of traffic lights I experienced risk compensation first hand; after riding the lightly-loaded Yuba Mundo over a  few hours I had become accustomed to riding faster and braking later for a given set of road conditions, and I had to brake very hard on the DL-1 to stop in a space which the Yuba Mundo would have been able to stop in easily. This is why I worry when I hear about engineering-based safety enhancements such as ABS in cars, they improve the safety of the vehicle’s occupants but this is often at the expense of everyone outside of the vehicle.

Anecdotes and Evidence

The petition to block the proposed Cyclists (Protective Headgear) Bill in Northern Ireland has finally attracted some attention from the larger press outlets. With wider exposure comes the usual heated discussions over helmets in the comment threads. Many of you know my own stance on helmets, but I would not want to force anyone who wishes to cycle with a helmet to do so without one.

A helmet slpit along the vents, a common mode of failure. Image courtesy of cyclehelmets.org

One type of comment which comes up frequently on these comment threads follows the general form of “A helmet saved my/a friend's life.” This is not particularly surprising, during my own school days I remember being shown emotive video footage of an interview with a teenager who had survived being hit by a motorist whilst he was on his bike. He proudly showed the camera his helmet, split in two and with an unshakable conviction he stated that it had saved his life. In the years since this experience, the arse-about-face approach to road safety has continued to gain traction and find its way into online materials aimed at school-age children.

When listening to stories claiming a helmet saved someone’s life, it is important to remember that anecdotes aren’t the same as evidence. Consider the following:

With no control experiment, where all variables other than whether or not the rider was wearing a helmet left unchanged, it is impossible to state with any confidence whether or not the helmet had made a difference, or to appropriately quantify any difference it may have made.

The effects of risk compensation also need to be considered. For those who have been told and accepted the idea that a helmet will save their life, there will be an increase in their perceived safety which will have an effect on their behaviour. This also goes for the operators of motor vehicles, who will perceive a helmet-wearing cyclist as being less at risk from their vehicle. It is possible that the change in behaviour both on the part of the cyclist and the motorist caused by the effects of risk compensation were instrumental in leading to the collision. This effect has been studied with ABS in the Munich taxi experiment, and can also be seen in the increase in the severity and number of pedestrian and cyclist casualties following the introduction of compulsory seat-belt legislation, drivers felt safer with seat-belts and adjusted their behaviour to compensate for the reduced risk to them by driving faster and braking later. This resulted in decreased safety for those not travelling inside a car.

There are safety concerns attached to wearing a helmet, including increased risk of rotational brain injury which can be further exacerbated by the interaction between the air vents on a helmet and irregularities in the road surface leading to an increased risk of neck injuries. These effects are often dismissed due to the acceptance even amongst helmet advocates that there are limits to the protection a helmet can provide; if a helmet-wearing cyclist is injured in a collision, the injuries they sustain are uncritically regarded as being “less substantial than if they had been without a helmet,” when in fact they may have been exacerbated or even caused by the wearing of a helmet.

Plenty of cyclists survive collisions, accidents and other incidents despite not wearing a helmet. Unlike the sensational “Life-saving helmet,” stories we all see whenever there is a discussion regarding helmets, people who survive collisions, accidents and other incidents whilst not wearing a helmet rarely link their survival to the fact that they were not wearing a helmet.

It is human nature to find causal links between events which may in fact be unrelated. This is how we end up with things like lucky pants and ritualistic behaviour of athletes and sports-fans; people struggle to separate correlation from causality. For example, I have been involved in several minor incidents due to motorists over the years and survived each one of them. On every occasion I was wearing boxer shorts, but it would be foolish to state that my survival was definitely caused by the fact that I was wearing boxer shorts. At the very least I’d want to see the results from a control experiment where I was wearing budgie-smugglers in the same situations.