“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.
If you are new to cycling (or at least to the politics surrounding cycling in the UK), you may be unaware of the two major schools of thought regarding cycling’s place as part of the wider transport spectrum; integration and segregation.
Integration is more commonly referred to as vehicular cycling. The ideal behind vehicular cycling is that bicycles are vehicles like any other, and that they belong on the road (with the exception of motorways). Segregation sees bicycle users as more vulnerable than other road users such as cars and buses, and strives for separate infrastructure to be provided for them (to varying degrees depending on the road environment). Most existing cycling campaigns focus on a vehicular approach to encouraging the uptake of cycling (CTC, LCC etc). Fewer campaigns focus on a segregation approach (The Cycling Embassy of Great Britain is the only one I can think of on a national level, Sustrans also believe in providing off-road facilities, but with a primarily recreational focus). I genuinely believe that campaigners from both schools of thought want to make conditions for cyclists better, and wish to encourage the uptake of cycling by more people.
The main focus of vehicular (integration) cycling campaigns are as follows:
Reducing (non-cycle) traffic volume
Reducing traffic speed
Improving driver behaviour through educational campaigns
Vehicular cycling training for cyclists
Reducing traffic volume is commonly done by either reducing road capacity, increasing the cost of driving or making driving less convenient. Reducing road capacity whilst maintaining the current vehicular cycling approach means reducing the capacity for cycles as well as cars, HGS and buses. This approach is not really feasible for a vehicular cycling approach because it will inevitably lead to greater conflict between cyclists and other road users. Making driving less convenient by instigating circuitous routes in dense urban locations is also going to make vehicular cycling less convenient. Increasing the cost of driving would reduce motor vehicle traffic and improve conditions for cyclists, but it is politically difficult to achieve any meaningful results from this policy.
Reducing traffic speed is commonly done by narrowing the carriageway (either with kerbs or with white lines). The white lines method of reducing traffic speed is how many of the UK’s existing awful cycle lanes were actually created; their primary purpose is traffic calming, the bicycle lane aspect is more of an afterthought. In a vehicular cycling approach, reducing the width of the carriageway is undesirable because it brings cyclists into conflict with other road users. Another option is to keep the road width but reduce the existing speed limit. The problem with this is that the width of the road has a psychological effect on drivers’ perceptions, making them feel safe to travel at higher speeds. Enforcement through speed cameras can help keep drivers in line with the lower speed limit, but they are costly, politically unpopular and drivers commonly flout the law during the stretches between speed cameras.
Improving driver behaviour through educational campaigns is difficult. New drivers can have their behaviour modified during the examination and licensing procedure. Existing drivers are hard to reach, due to the lack of regular re-examination of existing drivers at present. The main problem with this kind of educational campaign is that it requires the driver to consciously modify their behaviour, and to do so solely for the benefit of someone else (the cyclist), someone they don’t know.
Vehicular cycling training is beneficial to many, helping to equip them with the skills they need to survive on the roads as they presently are. It does seem like a counter-intuitive way to encourage cycling though, riding a bike is something which should be as easy as riding a bike. The very fact that vehicular cycling campaigns feel there is a need to train cyclists how to survive on the roads seems to underscore the fact that there is something very wrong with our roads as they are.
The main focus of segregation cycling campaigns are as follows:
Providing cyclists with dedicated safe, convenient and direct infrastructure
Reducing (non-cycle) traffic volume
Improving driver behaviour (such as speed) through infrastructure
Dedicated cycle infrastructure consisting of lanes separated from other traffic, providing direct and convenient routes has been shown to encourage mass uptake of cycling in other countries with a similar level of development to the UK (including The Netherlands and Denmark), including places with similar old town/city layouts as seen in the UK. The infrastructure is provided by re-allocating road space away from motorised traffic, which also has the benefit of encouraging cycling indirectly by deterring driving.
On smaller roads, or roads where separate cycle infrastructure cannot feasibly be provided, traffic volumes are reduced through the use of one-way streets with exemptions for cyclists, sending motorised traffic along inconvenient circuitous routes whilst still providing cyclists with a direct and convenient route through.
Driver behaviour is modified on an unconscious level through infrastructural changes. Narrow roads do not bring cyclists into conflict with other road users when they are provided with a separate lane, but still have the effect of slowing other traffic. This allows conditions for those on foot to be improved (by reducing motor traffic speed) without making cycling inconvenient or undesirable at the same time. Narrowing the width of the connections between side roads and main roads makes drivers turn into and out of side roads at a lower speed, reducing the possibility of conflict with cycle lanes as they cross side roads (with right of way given to the cycle road). There are many other small infrastructural tricks like this used in segregated cycling cultures.
Vehicular cycling used to be a successful strategy in the UK in the era before mass car ownership, because the conditions vehicular cycling campaigners now strive for were largely intact at the time. In the time since the era of mass car ownership began, only segregation has been demonstrated to be able to bring about mass cycling, as demonstrated in The Netherlands and Denmark.
If ideal vehicular cycling conditions could be produced, I do believe that many more people could be encouraged to cycle. However, I do not see any viable way that these conditions could be brought about; pricing people out of their cars without the subjective safety of cycling infrastructure as an alternative is not going to be at all popular politically. Generally, people don’t like feeling like they are being forced to do something.
Without being able to use inconvenient, circuitous routes or road capacity reduction to bring down (non-cycle) traffic volumes, and you can’t use carriageway width reduction to reduce speed, if you somehow still did manage to produce ideal conditions for vehicular cycling, you’d have also created ideal conditions for driving too.
And as has already been demonstrated by history, if you create ideal conditions for driving, you end up in the sort of mess we’re in now.