By Public Health Expert 14/03/2017 13


By Prof Alistair Woodward, Auckland University

“It is too dangerous.” This is the reason given most commonly for not riding a bike on the road in New Zealand. In this blog, I summarise a paper we have just published quantifying the risk of cycling injury. We found it to be low compared to other activites that New Zealanders commonly engage in.

For example, riding a bike to a rugby game is roughly 500 times safer than playing the game. I conclude by examining why cycling is so marginalised (the bike is shunted, literally, to the side of the road), and how this might be changed.

“It is too dangerous” is the reason given most commonly for not riding a bike on the road in New Zealand (Legge and Landtroop, 2013). About half of New Zealand households own one or more bikes in good working condition, and most trips in the city are relatively short, but only 1-2% of those trips are made by bike (Ministry of Transport 2015).

In a study that was published last week we set out to determine how big the risk of injury due to cycle crashes actually is, and how it compares with injury risk of other common activities in New Zealand.

What should these comparisons be based on? Risk per hour, per kilometre, per head of population? We have used the notion of a “standard dose”. We were inspired by Prof David Nutt, an English physician and researcher. Nutt thought the regulation of psychotropic drugs should be in proportion to the damage these drugs caused, and he compared the probability of serious ill-effects per standard dose (what a user would commonly ingest) with the risk of injury during a typical day of horse-riding (Nutt 2009).

We proposed a standard dose of cycling might be a 30 minute trip, 3 times a week. This is rather more than the average cyclist in New Zealand presently spends on his or her bike, but fits with what national and local governments aspire to achieve in the near future (Auckland Transport, for instance, aims to triple the number of journeys by bike in the city in three years).

The comparison activities we selected were snow sports, do-it-yourself (DIY) activities in the home, rugby, horse riding and using quad bikes on farms. These were chosen on the basis that they are common, and there are data available on both person-time exposure, and the rates of injury. We used two injury outcomes. Injuries sufficient to cause the person affected to visit a hospital emergency department, and injuries that lead to a claim being made to the Accident Compensation Corporation (ACC).

We found the risk of injury while riding a bike is actually very small. Taking injuries that lead to claims to ACC, we found these occur roughly 9 times in every 100,000 short urban bike trips; the chance of receiving an injury sufficiently severe to cause a visit to the hospital was similar. If you rode a bike three times a week, most weeks, the chances are you would suffer one moderately severe injury every 70 years.

We estimate the risk of injury on a bike is similar to the risk associated with DIY activities in the home, more than a 100 times less than the risk of snow sports, and 500 times safer than playing rugby (see Figure 1, which uses a log scale).

Figure 1. Risk of injury sufficient to cause a visit to a hospital emergency department, or lead to a claim to ACC, per million typical exposures (such as a half hour bike ride, a game of rugby, half a day on the snow).

There are many assumptions and approximations in these results, so they should not be treated as precise measures. But the take home message, we suggest, is that riding a bike on New Zealand roads is not particularly dangerous (1 moderate injury in 70 years!), and indeed the risk is considerably less than that associated with some other common activities. (Many parents are reluctant to allow their children to ride to sports, but the bike trip is roughly 500 times safer than a game of rugby, for instance).

Risk is a construct – how the figures are presented affects the way they are perceived. The risk of injury per km travelled by cycle on New Zealand roads is higher than that for automobiles but the difference is reduced considerably if automobile casualties include those injured by cars as well as those injured in cars, and if travel on motorways is excluded (given that motorways are low risk environments, with no equivalent for bikes). For some sub-groups (eg, young men) the risk of injury in a car is greater than that when travelling by bike, yet bicycles are not seriously promoted as a means of reducing crash injuries among the young (Mindell et al 2012). The rate of a fatal injury per kilometre is higher for pedestrian travel than either cars or bikes (Shaw et al 2016), yet few people are put off walking by fear of traffic crash injury. Also, think of this – travelling by private motor car is an order of magnitude more dangerous, in terms of crash injuries, than going by public transport, but this is seldom used as an argument for more buses and trains. And why focus just on injury? If deaths from all causes are counted, cycling is a good deal healthier than driving in a car, as premature deaths avoided by extra physical activity (via reducing heart disease and cancer risk etc) exceed by roughly 20 to 1 cycling-related injury deaths (Lindsay et al, 2010).

So why does fear of injury deter so many people from getting around on a bike? We suggest the first point is that the probability of something happening is, on its own, a weak motivator. Statistical risk only makes sense when it is filtered and interpreted through personal perceptions and social frameworks. Daniel Kahneman won a Nobel Prize in Economics for his work on what he called the “psychophysics” of risky choices, which he suggests are conditioned strongly by expectations and framing (Kahneman and Tversky, 1984).

In the same vein, we argue that fear of riding a bike is primarily a consequence of living with a transport system that is dominated in every way by the motor car. The bicycle has literally been pushed to the margins (Figure 2) and the environment sends a powerful message, that such use of the road is unusual, different, and is not valued. The transport norm is reinforced in other ways. For example, cycling promotion campaigns with safety-oriented messages such as “Share the road” have, perhaps unwittingly, strengthened the social framing of cycling as an activity that is inherently dangerous.

cycling
Figure 2. Tamaki Drive, Auckland.

In the past the hostile conditions on New Zealand roads led to a vicious spiral. Car domination means fewer bikes, leading to greater fearfulness and increased resistance to road changes in favour of bikes. We need to turn this round.

The most powerful way to bring bikes back from the margin is to provide safe spaces for cyclists of all abilities to get to where they want to ride. Separated cycle ways are part of the fix, but not enough. There need to be changes on the road as well, such as slower vehicle speeds, better intersections, and wider shoulders to include cyclists. More people riding, and public spaces that celebrate two wheeled choices, will do two things – make cycling (even) safer, and reduce the fear of the bike.

References

Kahneman, D., Tversky, A., 1984. Choices, values, and frames. American Psychologist 39, 341-350

Legge N, Landtroop R., 2013. Auckland Transport Cycling Research. Auckland Transport. https://at.govt.nz/media/981846/AT-Active-Modes-Research-Report-June-2013.pdf

Lindsay G, McMillan A, Woodward A, 2010.  Moving urban trips from cars to bicycles: impact on health and emissions. ANZJPH, 35, 54-60.

Mindell, J.S., Leslie, D., Wardlaw, M., 2012. Exposure-based, ‘like-for-like’ assessment of road safety by travel mode using routine health data. PLoS One. 7, e50606.

Ministry of Transport, 2015. 25 years of New Zealand travel: New Zealand household travel 1989-2014. Wellington, New Zealand Government.

Nutt, D.J., 2009. Equasy – An overlooked addiction with implications for the current debate on drug harms. Journal of Psychopharmacology. 23, 3-5.

Shaw C, Russell M, van Sparrentak K, Merrett A, Clegg H, 2016. Benchmarking cycling and walking in six New Zealand cities. Pilot study 2015. New Zealand Centre for Sustainable Cities. University of Otago Wellington.


13 Responses to “Why do so many fear the bicycle?”

  • This is a really useful piece of research and the findings are very similar to the Near Miss Project report produced by researchers at the University of Westminster: http://www.nearmiss.bike/wp-content/uploads/2014/12/Nearmissreport-final-web-2.pdf. It also reinforces I point I remember you making in a previous blog about the Island Bay cycleway that accident stats are generally insensitive and partial, which makes them of limited value in planning and evaluation. I think that’s a key point for policy-makers to remember – crash stats are not necessarily a great indicator of where (and how) investment needs to be applied to generate cycling uptake. It would be great to see something like the Near Miss Project happening in New Zealand cities as well as better evaluation of projects like the Island Bay cycleway, which has now been operating for a year.

  • Interesting research. Thanks for sharing. It is in line with the reasons so many give to me for not cycling.

    One thing we have come to appreciate in behavioural economics (channeling Kahneman and Tversky) is also that people may be swayed by “attention arresting events”, even if these are low probability events. Cyclist deaths even if these are less likely than motorist deaths, do get a lot of media attention.

    There’s also an issue of using reported injuries or deaths as the metric for risk. Most of the ‘incidents’ I experience as a cyclist are non-collision. E.g. Just this morning a vehicle moved across into the cyclist lane I was riding in, just in front of me. Some of the reason cyclists don’t have higher reported injuries is not that cycling is necessarily ‘safe’. It’s more that many cyclists are good at avoiding accidents.

    Much of these could be dealt with by roads that better accommodated cyclists.

    Oddly, I’ve been seeing an upswing in cycling around here, and this may be due to it is more efficient for short trips with the congestion. The time-advantage of cars is eroding, and cyclists have less issues with finding car-park spaces…

  • o/t, but its interesting to note the figures for quad bikes. Would that data silence (or moderate) the current calls for significant controls and limits on the use of quad bikes?

  • Interesting report. But is it misleading? or missing key information. Mentioning cyclists use of roads is less than 2% of road users. Based on the 2016 terrible year for road deaths and great year for cyclists casualties , a cyclist is still more likely to be killed on a road at 2.45% over 2% usage. What is the death rate compared to snow boarders, horse riders or Rugby players per year ? . Again cyclist are more at risk. This report should not distract the reality of risks and need to separation of infrastructure. Ie bike lanes

  • Perhaps people fear a more widespread use of bikes because it is more difficult to use social media apps on a moving bicycle than in a moving car.

    • Could be 😀 … the number of cars I pass with motorists using their phones on their laps is not reassuring.

  • Fake report. But is it misleading? or missing key information. Mentioning cyclists use of roads is less than 2% of road users. Based on the 2016 terrible year for road deaths and great year for cyclists casualties , a cyclist is still more likely to be killed on a road at 2.45% over 2% usage. What is the death rate compared to snow boarders, horse riders or Rugby players per year ? . Again cyclist are more at risk. This report should not distract the reality of risks and need to separation of infrastructure. Ie bike lanes

    • John, claiming that this is a ‘fake report’ is just baseless. You can offer your thoughts on the study but if you are going to call it ‘fake’ you actually have to give some evidence of where the falsehoods lie. Or was your comment a fake comment?

    • Using just the estimated number of road users and death rates isn’t a good way to measure risk. There are important variables mentioned above that have to be taken into account.

  • There are other reasons for not biking (as a method of commuting) besides “fear”.
    For example, I didn’t bike to work today, because I’m going to the supermarket on the way home. Other days, I might need to go somewhere (pay a bill, whatever) during my lunch hour. And of course, the weather (besides just the rain); I’m asthmatic, so breathing hard in the cold air (as the seasons change) really hits me.
    I would LOVE to bike to work more than I do.
    On the plus side, due to the layout of the roads where I live/work, it takes me approximately the same time to bike to work as it does to drive.

    • Indeed, surveys show that various others factors deter cycling. Whether it too many hills, or the lack of shower and changing facilities at work, these all add up. The most popular deterrent though, remains the perceived risk.

      You probably do a lot more cycling than most ‘commuters’ anyway. I think one of the issue is the very low number of ‘commuting cyclists’ on roads. The base is so low that any rides are an improvement…

  • “The most powerful way to bring bikes back from the margin is to provide safe spaces for cyclists of all abilities to get to where they want to ride”

    That addresses perceived risk, which appears to be the major barrier. But it takes money and time, and some serious campaigning. Garry Moore in Christchurch and Fiona Campbell in Sydney spring to mind as examples of people who have (with help, obviously) made huge differences.

    http://www.nyc.gov/html/ia/gprb/downloads/pdf/Sydney_Cycle%20Strategy.pdf

    One comment I do make to people doing bicycle-related research is to be very careful with bike counts. From experience/unpublished research (http://www.moz.geek.nz/mozbike/bike-count-august-2001.html) I discovered that it’s actually very hard to do perimeter counts, and you miss a lot of cyclists if you don’t. Understating the number of cyclists because you insist that only people riding on major roads during rush hour “count” can lead to all sorts of problems.

  • This is a nice study, and confirms that cycling isn’t particularly risky. I venture to suggest though that that the current level of cycling is highly appropriate for the hostile cycling environment. Prof Woodward highlights himself just how stressful it is to constantly lookout for dooring, for cross traffic who don’t give way, and cope with the frank abuse. I personally stopped cycling for a (long) time after the 10th time I was run off the road by a bus. Grrr. I have started cycling now only because of the north western cycleway. Yay, 😎

    Finally, let now kid ourselves. There is still real risk of being crushed to death. The 2015 NZ transport report concluded “With 28.2 cyclists killed per billion kilometres travelled, New Zealand’s cyclist fatality rate is nearly three times that of the Netherlands and nearly doubles that of Denmark and Germany”.

    There are so many things that could be done, cheaply, effectively and without any impact on traffic capacity. If we can’t have separate cycleways everywhere, then the single biggest step to make cycling less unpleasant would be to reduce all non-motorway speed limits to 30 km/h. Physics rules!

    Alistair Jan Gunn.
    30 is enough