Do the health benefits of cycling outweigh the safety risks?

A recent spate of cycling accidents in Montreal and Winnipeg begs the question

by Julia Belluz

Photo by helter-skelter/Flickr

The Statement:  “To be sure, cycling provides good exercise, but there are safer ways to get it. [...] Second, bike riding here is not as environmentally virtuous as it’s cracked up to be.”—Montreal Gazette, 08/11/2011

This Gazette story was prompted by a series of five very sad cycling fatalities in Montreal this year, “an unusually high death toll,” the writer lamented, before going on to list myriad downsides related to cycling in the urban environment. The Winnipeg Free Press published a similarly disturbing article, which noted that in the last 18 months, 29 people have died on Winnipeg streets in car crashes, and 18 of them were pedestrians or cyclists. The Winnipeg Free Press article’s message was as clear and pedantic as its title: “Walking, cycling can be deadly.”

Ontario doctors have likewise called for safer cycling. They note that while biking is good exercise, the government needs to invest in cycling infrastructure, such as purpose-built bike lanes, to make commuting on two wheels safer. The provincial NDP in Ontario offered another (seemingly unlikely and impossible to enforce) solution to the problem of cars and bikes mingling dangerously on the road: they suggested changing the Highway Traffic Act so motorists can be fined for crossing a one-metre buffer with cyclists.

But what is the evidence behind these proposed cycling policies? And if cycling is as dangerous as these news articles purport, do the health benefits of cycling outweigh the risks? Or should people refrain from biking on city streets altogether?

I looked at a myth-busting evidence review produced for the Canadian National Collaborating Centre for Environmental Health. First, the good news: people who choose “active transport” (walking and cycling to get around) are, on average, more fit and less overweight and obese than motor-vehicle users. As well, all-cause mortality, disease-specific mortality, and cardiovascular risk are lower in this group. Exercise for transportation is also found to be sustained more consistently throughout a person’s life than other workouts, such as gym regimes.

Now, the bad news: people who choose active transport face higher risks of fatality or injury per distance travelled than people who use cars, buses, or rail, according to the review. A 2003 study published in the American Journal of Public Health found that the fatality risks per distance travelled for U.S. pedestrians and cyclists are 23 and 12 times higher, respectively, than for drivers. A study that looked at injury rates for Norwegian pedestrians and cyclists per distance travelled found they were 4 and 7.5 times higher, respectively, than for those who travelled by car.

There is no Canadian data on the absolute risk of injury and fatality for cyclists, but there are a few things we know about how bike accidents happen here. Transport Canada, which tracks crashes between cyclists and road motor vehicles, reported that 64 per cent of these deaths occurred on urban roads, and the peak time for crashes was afternoons and evenings. Bicyclists also make up the smallest percentage of road fatalities compared to other road users. For example, people who died while biking in 2009 made up 1.9 per cent of fatalities on the road (compared to 53.1 per cent for drivers, 19.5 per cent for passengers, and 13.9 per cent for pedestrians).

Of the risk to Canadians, Kay Teschke, a professor of public health at the University of British Columbia who studies cycling in cities, told Science-ish, “The fatality rates are about the same for cyclists and pedestrians, though the numbers of pedestrians killed is much higher, because more people walk. Of course, the numbers of motor-vehicle fatalities is much higher than either cycling or walking.” She concluded: “The safest mode of transport by far is transit—like buses or subways —there’s no question about it.”

So what would make cyclists safer: bike lanes or a one-metre buffer? Teschke noted that the evidence shows purpose-built bike lanes seem to be the way to go. “One of the interesting features that has been found in North American cities where European-style separated bike lanes are being installed is that this is not only lowering cyclist crashes, but also pedestrian and motor vehicle crashes.” She also pointed to European centres where bike-specific infrastructure is ubiquitous and cycling injury rates are much lower than in the United States. (See this comparison of American, Dutch, and German cyclists, which shows Americans are twice as likely to get killed as Germans and over 3 times as likely as the Dutch per kilometer and per trip cycled.)

Other studies from Europe indicate there are large net benefits of cycling. A 2010 review in Environmental Health Perspectives looked at cycling in the Netherlands—with its extensive cycling networks—and found that, “on average, the estimated health benefits of cycling were substantially larger than the risks relative to car driving.” A recent review published in the British Medical Journal, which looked at the risks and benefits to health of travel by bicycle, came to similarly positive conclusions. “The health benefits of physical activity from cycling using the bicycle sharing scheme (Bicing) in Barcleona, Spain, were large compared with the risks from inhalation of air pollutants and road traffic accidents.” One of the study authors told Science-ish, “Our findings are applicable to other cities, although the risk benefit ratio may change depending on the level of pollution between cities, as well as the risk of traffic accident. But the benefit of physical activity will remain constant.”

So, here in Canada, to cycle or not to cycle? Teschke said, “I think getting exercise is a major problem in North America, and though we have higher [injury and fatality] risks from cycling than in Europe, we have higher risks from obesity, as well. So, in North America, while the risks are greater, the benefits are greater as well.”

It’s important to note, too, that there is a well-documented “safety in numbers” effect for pedestrians and cyclists, meaning that as more people get on their bikes or walk to work in a city, the safer these methods of transport become. “In the Netherlands, which has some of the highest cycling rates in the world (almost 30% of all trips are by bicycle) the injury risk for cyclists is 1.1 cyclists injured per 10 million km cycled. In comparison, in the UK and the U.S. only about 1% of trips are made by bicycle, and the risk is 3.6 and 37.5 cyclists injured per 10 million km cycled,” the 2010 evidence review stated.

Teschke is hopeful that as more awareness is raised in Canada about the benefits of cycling and the need for biking infrastructure, the roads will be safer places for motorists on two wheels.

In fact, already, the number of fatalities for cyclists has been decreasing. In 2010, Transport Canada reported that “bicyclists accounted for about 2 per cent of traffic fatalities, with an average of 60 bicyclists being killed each year in collisions with motor vehicles.” This was a 2 per cent decrease from the 1996-2001 period. Similarly, this summer, the Canadian Institute for Health Information put out a press release that said while “the annual number of cycling injury hospitalizations remained relatively stable between 2001–2002 and 2009–2010, the number of cycling-related head injuries decreased significantly, from 907 to 665, over the same period.”

By now you may be wondering: what about that ubiquitous bicycle appendage, the helmet. Is it safer to wear one? Stephen Walter, a professor in clinical epidemiology and biostatistics at McMaster University, told Science-ish, “Some people argue they increase risk because their use may encourage riskier behaviour by riders and drivers.” But he added: “Conditional on being in an accident, I know I would rather be wearing one than not. If you’re going to bike, wear a helmet.”

Science-ish is a joint project of Maclean’s, The Medical Post, and the McMaster Health Forum. Julia Belluz is the associate editor at The Medical Post. Got a tip? Seen something that’s Science-ish? Message her at julia.belluz@medicalpost.rogers.com or on Twitter @juliaoftoronto




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Do the health benefits of cycling outweigh the safety risks?

  1. There are also the mental health benefits (difficult though they are to measure) of outdoor exercise. Anecdotally, I know that when I cycle to work my mood is improved throughout the day, I’m more productive and focused then I when I’m forced (due to icy conditions) to take the bus instead.

    • Are you sure you don’t have the causation reversed? That is, when you have to take the bus your mood sucks and you’re not as productive (because you know you’ll have to get on that bus later again..)

      • 6. Half dozen. Whatever.

      • Or possibly endorphins.  Which can be used to fill up half-empty glasses if you have one…

  2. Luckily I live in Ottawa where we have lots of good cycling trails. No way would I ever cycle on the road. Haven’t in a decade. Won’t ever again. You’re taking your life into your hands. Bicycles on streets made for cars just doesn’t work. I wish it were different. But it isn’t. It is way too dangerous. 

    • I’ve lived in Ottawa for over 30 years and since arriving have ridden for recreation and transport, virtually hundreds of thousands of kilometres on the roads. The roads are dangerous for dangerous cyclists. Bike paths however offer a false sense of security. A cyclist was killed in Montreal last week coming off a bike path. One was killed in Ottawa last year, also coming off a bike path. 

      • Oh the memories….Old Ottawa East to Tunney’s Pasture for work every day….what a rush, lol!!!

        No helmet laws but every bike had a license plate and most cyclists seemed more aware of what they were doing…..the good old days.

  3. I am in Guelph, and I really enjoy riding bicycle around town in summers. There are a few bike lanes on major streets but I mainly prefer side roads and bike trails and I can easily get around town.

    Also, riding bike after a few beers is awesome but I don’t know if there are any health benefits.

    Read about this other day. Sounds devilish.

    Daily Telegraph:
     
    Let me introduce you to bisin. No, not a herd of cattle (spelling, guys!). This is a magic ingredient, that will, it is claimed keep food “fresh” for months, years even.

    Never heard of it? You’re not the only one. It’s a substance so new that it doesn’t even have a Wikipedia page ….

    It has antibacterial properties, preventing  meat, dairy products and eggs from decomposing, although it won’t stop fruit and vegetables rotting. And it’s likely to appear in foods on the shelf in the next three years.

    http://blogs.telegraph.co.uk/culture/xantheclay/100055442/bisin-might-make-burgers-that-never-go-off-but-it-doesnt-make-them-fresh/

  4. “what about that ubiquitous bicycle appendage, the helmet”   This has been the hot topic on the radio talk shows for the past few weeks.

    Social engineering by the WHO starting back in the late ’80′s as they maintain it saves health care costs.  People were calling in saying we shouldn’t have to pay for a cyclists medical costs if they weren’t wearing a helmet – with that kind of thinking, let’s slap a fine on everyone who lights up a cigarette!!

    I’ve cycled in Sweden, Denmark and the Netherlands.   You see very few helmets, but, they have the right bike friendly infrastructure plus few vehicles in their city centres.  More vehicles = more accidents, pretty simple math.   I would also suggest that many cyclists here should be forced to do an I.Q. test on basic rules of the road before getting on a bike, lol!!

    Wearing a helmet should be a personal choice and being able to fine you if you don’t is wrong.  The overall net health benefit is the important statistic.

    See how many fat people you can spot.
    http://www.youtube.com/watch?v=n-AbPav5E5M&feature=related

    • Le_o, I used to feel the same way about people wearing helmuts skiing until Natasha Richardson wiped out on the bunny hill, hit her head and died.  It occured to me then…..”what is the risk and what is the benefit of wearing a helmut while enjoying these activities?”  At worst, people look like geeks, at best, a helmut will prevent a brain injury or perhaps a bleed leading to death. 
      These cities should have bike paths just like Calgary does.  If people are being hit coming off the bike paths, why is that?  Are there lights needed?  A friend of mine who bikes explained to me that he doesn’t like to ride too close to parked cars because he afraid someone will open a door suddenly and he will be injured seriously.  I understand that.  As I driver,  I find it difficult when they are so close to my passenger door.  Bike paths seem like the best alternative.

  5. The article in the Gazette finished with the comment that Montreal should stop romanticizing cycling.

    The author is right. Cycling used to be the domain mostly of bike clubs and they always demanded from uninitiated cyclists a reasonable level of road skills before encouraging them to venture into traffic. Dutch school-aged kids are trained to a basic level of competency since there’s no escaping some trips in traffic even in the Netherlands.

    Not so in North America. Mindless promotion of cycling as something that is ”chic” that anyone can do without training is leading to the kind of tragedies being experienced in all urban centres.

  6. If we take all the cyclists off the roadways, how many fatalities will there be? Now, let’s try it without the cars.

    It’s obvious which would produce a greater safety benefit, but we would never consider doing it, so why pretend that safety is “driving” (can’t help myself, sorry) decision making either by individuals making transportation choices, or planners and policy makers?

    Let’s face it we tolerate about 100 fatalities from crashes per million population annually as if there is nothing we can do about it, regardless of cycling.

    And, on the question of helmets … if they offer such great protection, why aren’t car drivers and passengers wearing them? They face a significant risk of head injury from high speed crashes on freeways and highways.

    • Are you serious?  You are comparing being in a 2 ton vehicle complete with safety belts & airbags to stradling a 2 pound bicycle with no safety features and hurling through the air when you are hit by the said 2 ton vehicle.  If you should hit a tree or another immobile object, the helmet MIGHT provide you with some protection.  Otherwise you are looking at serious brain injury or death.  Wearing a helmut in a car would be redundant.  Wearing a helmut on a bike with help you if you have a small wipe out and hit your head on a rock.  Have you ever heard of Natasha Richardson?  If not, google her.

  7. What is it with these articles about biking risk and injecting the “exercise benefits” of using a bicycle? They need to remain on-topic and discuss the actual risk of injury. Not ramble on about how fat most Americans are and how much they would benefit from exercising. It is, bluntly put, entirely irrelevant. Not everyone is a lazy pig who wouldn’t get exercise unless they rode their bike every day. Many of us already get the exercise we need in other forms and just want to know about the risks of biking.

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