A cyclist rides a public hire "Boris Bike" in central London, November 2013.
LEON NEAL/AFP/Getty Images
A cyclist rides a public hire "Boris Bike" in central London, November 2013.

Story highlights

Some argue that cycling can lower risk of certain diseases - but at what cost?

Copenhagen, Amsterdam are bike-friendly cities, with extensive cycle routes

Studies show that safety improves in a city as the total number of cyclists increases

Northern Europe leading the way for city cycling infrastructure

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It was just another morning commute. That is, until a bus driver ran a red light, turned right, and drove straight into Ann-Doerthe Hass Jensen. The bus knocked the social worker off her bike, trapping her underneath, a wheel pinning down and crushing her left foot. It was a school bus heading to a Copenhagen kindergarten, and the children aboard were screaming. Ann was rushed to hospital in excruciating pain, every bone in her foot shattered.

In the six weeks of hospitalization that followed, part of Ann’s foot was amputated. Salvageable bones were wired back into place and skin grafts were taken from her thigh to replace the torn and missing flesh. “I’m pretty lucky,” says Ann. “People normally die when this happens.”

It was a year before she could walk again. During that year, she had to take a taxi to work every day. “I hated it,” she says. “Here, the taxi drivers are a menace, and I was really scared of accidents.” She also hated having to wait. Traveling by bike in Copenhagen is often the fastest way to get around, which is the top reason why Copenhageners cycle.

Ann’s physiotherapy was tricky. The missing portion of her foot is a crucial stepping point, and its absence affects her balance. But walking wasn’t the only part of her rehabilitation. In Copenhagen – where people own 5.2 bicycles for every car, over a third of residents pedal to work, school or college. So rehabilitation often literally means getting you back in the saddle. The City of Copenhagen helped Ann get a specially adapted Nihola cycle: a sturdy, stable three-wheeler that has allowed her to regain independent mobility.

In cities across the world, researchers, planners and policy makers are examining the many potential plus points of cycling. Increasing the proportion of people who cycle or walk, rather than drive, could not only reduce air pollution and greenhouse gas emissions, but also lower people’s risk of developing a number of diseases. But at what cost? To what extent does cycling in cities expose you to the risk of injury or death? What makes some cities so much safer and attractive for cyclists than others?

The drastically different design and policy approaches taken by large cities in Europe and North America provide some stark comparisons on cycling safety, equity and its impact on public health. To weigh up the risks and benefits of city cycling, and explore what can be learned where public health, urban design and transport engineering meet, I did what I had to do: I hopped on a bike.


Cycling smart, in Paris, France.
Cycling smart, in Paris, France.

In Paris, new bike lanes are pervasive. Though many of the streets are centuries old, sometimes cobbled, and claustrophobically narrow, bike lanes have been prominently marked. There are also some segregated cycle paths, often crazily disconnected – disappearing and appearing again in a seemingly random fashion. Skinny one-way streets might have bike lanes on the right, so you cycle with the direction of the traffic, or on the left, so you’re in the contraflow.

Oddly though, I didn’t feel unsafe cycling these narrow lanes. Many are marked 30 kph for cars. Having parked cars on the right of the bike lane, so they’re facing you, can be advantageous: it’s the passenger-side door that opens into bike traffic, so it’s less likely you’ll be struck than if it were the driver’s side exposed. And if you were to cycle into an open passenger door, you’re more likely to close it than open it further.

On some major streets, like Boulevard Saint-Michel, there are special lanes shared by bikes and buses. Though I felt less squeezed cycling in these wide lanes, where traffic was much lighter than the adjacent lanes for cars, I did feel a little intimidated about sharing the lane with buses. That said, the Parisian bus drivers gave me plenty of space, and didn’t behave aggressively. I did get a sense that traffic here has become accustomed to bicycles. There are some off-street cycle paths too. Zooming alongside the Seine on the elevated bike path, totally segregated from motorized traffic, was pure delight.

Velib’ bikes, from Paris’s bicycle-sharing system, were in use everywhere. I saw men in suits, teenagers, women in chic business attire, pensioners, and female university students riding side by side on the bikes. Posting celebrity Velib’ sightings on social media has apparently become something of a local pastime. The bikes are such a fixture that I saw one young man taking a break on a parked Velib’, feet on the handlebars, chatting on his mobile phone.

Read: Why bike is best for precious cargo

In the midst of Paris’s cycling revolution, it seemed fitting to meet Ari Rabl at Le Procope, a city restaurant where some of the leaders of the French Revolution gathered. With Audrey de Nazelle, a Lecturer at the Center for Environmental Policy at Imperial College London, Rabl, a consultant and retired senior scientist at the Centre Energetique et Procédes of the Ecole des Mines in Paris, has looked at the health benefits when people move from cars to walking or cycling.

Rabl explains that they found that the population-level costs due to fatal accidents are outweighed at least 10-fold by the health benefits of walking or cycling. Monetizing the costs and benefits, Rabl and de Nazelle estimated that for a driver who switches from driving to cycling for their 5 km commute, the overall health benefit from physical activity is worth about €1,300 ($1,795) per year. Of course, it’s important to point out that while fatal accidents might be reported as small “population-level costs” in public health studies, they have tragic, catastrophic costs for individuals and their loved ones.


City of cyclists. Copenhagen, Denmark
City of cyclists. Copenhagen, Denmark

Four days earlier, and some 1,000 or so kilometers north-east, I’m sitting in a conference room at the University of Copenhagen’s Department of Public Health, overlooking the picturesque Lakes area. Around the table are health researchers Astrid Ledgaard Holm, Henning Langberg and Henrik Bronnum-Hansen.

Ledgaard Holm, a doctoral student, has modeled the health impacts of increased cycling. Accounting for physical activity, exposure to accidents and air pollution, she and colleagues found that the overall burden of disease – including heart disease, stroke, type II diabetes, breast cancer, colon cancer, cardiopulmonary disease and lung cancer – was reduced in people who cycled. The positive health effects of increased cycling were more than a third larger than the potential loss of health from bicycle accidents and air pollution.

Other studies investigating the health impacts of cycling have found similar positive benefits, although the magnitude varies. In a different study based in Copenhagen, researchers analyzed data from over 13,000 women and 17,000 men to explore the impact of physical activity on mortality. Even after adjusting for other factors, such as physical activity in leisure time, they found that people who did not cycle to work experienced a 39% higher mortality rate than those who did. In other words, cycling improved longevity.

One of the most interesting insights the Danish researchers share is how they’ve discovered that many Danes don’t consider cycling exercise. “People here can easily be riding back and forth 5 km per day, and if you ask them on a questionnaire if they are physically active, they will say ‘No, I don’t do any exercise’,” says Holm. For many here, she says, it’s not a choice of activity, but your mode of transport.

Read: The laser light that could cut cyclist deaths

What’s immediately striking about cycling in Copenhagen is the incredible diversity of individuals on bicycles. Embedding myself in the morning rush-hour traffic on Norrebrogade, one of Copenhagen’s busiest cycle routes, I see a woman in a long flowing black jilbab pedaling a cargo bike with two small children in the basket. I see men of all ages in suits; women in dresses, high-heeled boots and smart coats, flowing garments protected from the spokes by metal skirt guards on the wheel hub. I see university students and children cycling to school; toddlers strapped into child seats on the front or back of mum or dad’s bike; and baskets of children pedaled along in sturdy Christiana or streamlined Bullit bikes. Some children ride the cycle paths independently. Others are shepherded by parents cycling alongside, who guide their charges with the occasional gentle hand on the back.

While cycling to interviews at the University of Copenhagen one morning, I happen upon a makeshift memorial on the side of the street. At the intersection of Store Kongensgade and Dronningens Tværgade in the city center, a stretch of tarmac the length of a body is adorned with fresh flowers and candle jars inscribed with handwritten notes. I discover later that it’s where a 20-year-old woman on her bike was struck and killed several weeks earlier by a tourist bus making a right-hand turn.

Decades after streets were first painted with white crosses to mark fallen cyclists, cycling accidents, although rare, are still not taken lightly here. Only one Copenhagen cyclist was killed in 2012, and no year from 1998 to 2012 has seen more than seven cyclists killed in the city, according to Statistics Denmark. These figures are quite something in a city where the population cycles an estimated 1.27 million km every day. The risk associated with being a cyclist in Copenhagen “has dropped by more than 70% over the last 15 years” according to Niels Torslov, the City of Copenhagen’s traffic director. “And it’s a very strong story about finding the right measures, and designing a road space in a way that protects the users, especially those cycling.”

The use of cycling helmets is growing among Copenhageners, noticeably more than in Amsterdam, where helmet wearing is still very much an exception. At the time of her accident, in 2006, Ann-Doerthe Hass Jensen was wearing a helmet, though clearly, as she says herself, a helmet protects your head but not your feet. She says that working at Copenhagen’s Center for Rehabilitation of Brain Injury, as she does, makes you fanatical about helmets. “There is no way I would not have a helmet on,” she says.

After several days of exploring Copenhagen by bike, I meet Ann at the Center, where she leads me outside to see her specially adapted tricycle. Her sense of pride is palpable. It takes her between 30 and 40 minutes to make the trip from home to work. “The first few times I got back on a bike again, it was hard. Really, really hard,” she says. “There was a lot of crying.” Now, though, there is no stopping her.

In her first year of recovery, Ann’s rehabilitation team felt she needed to re-establish both the freedom of mobility and the quality of life that her bicycle had previously allowed. It wasn’t easy. Beyond the physical challenges of getting Ann back in the saddle, there was another hurdle: her enormous fear. “I had to work with a psychologist… because I was scared like hell,” she says. Using cognitive therapy, she and her psychologist worked through the entire experience, going over the incident report in excruciating detail. Pushing through that fear was tough. “It wasn’t my perception that was off that day. It was somebody who actually did something wrong. And it took me a while to get my confidence again,” she says. Ann’s fear was not unreasonable. Her experience wasn’t just “an accident.” It was the action of a negligent driver, whose license was revoked when the case came to court two years later.


Cycling in the shadow of a London bus.
Cycling in the shadow of a London bus.

Research shows that perceived safety – how safe you feel – is at least as critical as measured safety to the willingness of citizens to hop on a bike. For me, of all the cities I cycled in, London was the most terrifying.

Cyclists were prevalent in the center of the city, and what immediately struck me, beyond the dense, fast-moving traffic they were attempting to navigate, was the rapid speed they were cycling at. In impromptu interviews with cyclists stopped at traffic lights, I asked one woman why she cycled. Her answer: “I hate the Tube [London’s underground train system], it’s really unhealthy and sweaty and overcrowded.” Asked if she felt safe cycling, she said, “No. That’s the honest answer.” But her sentiments weren’t shared by everyone I asked. A student who had just moved to London said, “It’s about five to 10 years ahead of New York,” adding that she felt quite safe cycling on London’s cycle superhighways.

I, on the other hand, did not. I spent some time watching cyclists crossing the Southwark Bridge section of one of the cycle superhighways. Riding along CS7’s blue painted bike lane on a Boris Bike (the nickname for bikes in London’s cycle hire scheme, introduced in 2010 under Mayor Boris Johnson) largely unseparated from mixed, fast-moving traffic, made me anxious and uneasy. What’s more, I suffer from asthma, making me a bit of a human canary for air pollution. After the noticeably clean air of Copenhagen, the polluted air of London made for labored breathing.

London is beginning to make progress on provisions for cyclists, and there are good sections of the growing infrastructure, but I saw plenty of room for improvement. On both sides of Southwark Bridge, which crosses the river Thames, the short, separated span of blue bike lane, protected by a concrete barrier, fed straight into a bus stop. This forced cyclists to choose between two unappealing options: wait like a sitting duck behind the bus while it stops, or pull out into traffic to overtake, and risk being in one of the bus’s many blind spots when it pulls out from the curb. Peter Wright is the delivery planner for cycling at Transport for London (TfL), the local government body chaired by Johnson. Wright explains that bus-stop bypasses are planned, “to try and avoid conflict so that cyclists don’t have to come out into general traffic.” A similar hazard was delivery vehicles parked in bike lanes, a common sight in London and Paris.

In November 2013, when asked about the spate of cycling deaths, Johnson told the Guardian that if cyclists did not follow the rules, “there’s no amount of traffic engineering that we invest in that is going to save people’s lives.” Growing evidence suggests that statement is untenable, not to mention that it blames the victim. I requested an interview with Johnson. His press office did not reply.

To be fair, though, London’s Mayor – a cyclist himself – is making gradual progress. In 2013, TfL announced its Safe Streets for London plan, which aims to reduce the number of people killed or seriously injured by 40% by 2020. Ben Plowden from TfL Surface Transport said: “In 2015, we will be spending £145 million ($240 million) a year on cycling, or roughly £18 ($30) a head, up with the best in Germany and almost on a par with the Netherlands. This represents around 2% of TfL’s overall expenditure and is roughly proportionate to the current 2% mode share of cycling.” He added that cycle spending would total £913m ($1.5 billion) during the next 10 years, more than treble previously planned levels.

Safety in numbers

Annual fatalities per 10,000 bike commuters

Annual fatalities per 10,000 bike commuters

  • Copenhagen 0.3
  • Amsterdam 0.4
  • Vancouver 0.9
  • Toronto 1.3
  • Portland 1.9
  • Montréal 2.0

    Annual fatalities per 100,000 daily cyclists

  • Paris 8.2
  • London 11.0
  • New York 37.6.
  • (All 2010 except Paris, London and New York, 2009)
  • (Source: "City Cycling," John Pucher, Ralph Buehler, 2012)
  • It is not completely clear how and why accident rates change as the number of cyclists varies, but a “safety in numbers” effect seems to occur: safety improves in a city as the total number of cyclists increases. This effect has been seen in studies in Denmark, the Netherlands, 14 other European countries, Australia and 68 cities in California.

    “It is likely that causation runs in both directions: safer cycling encourages more cycling, and more cycling encourages greater safety,” writes John Pucher, Professor of Urban Planning at Rutgers University, in his recent book “City Cycling.” Motorist behavior probably contributes to this phenomenon. In places like Copenhagen – where four out of five individuals have access to a bicycle – most drivers are also cyclists, and so are accustomed to sharing public space with bicycles.

    It can be difficult to compare safety between cities because of the lack of consistency in data collection and because of the need to frame injuries and deaths within the context of “exposure” – the overall numbers of trips, total distance or time spent cycling. Under-reporting of cycling crashes is also a well-documented problem. Nevertheless, Pucher’s 2012 book written with Ralph Buehler, “City Cycling,” listed figures for annual fatalities per 10,000 daily cyclists (see sidebar).

    Unless you are traveling at breakneck speed, though, there is nothing inherently dangerous about cycling – it’s the environment you’re in that creates danger. Ian Roberts, professor in the Nutrition and Public Health Intervention Research Unit at the London School of Hygiene and Tropical Medicine, began his career as a pediatric trauma doctor. “I saw lots of children hit by cars,” he says, “and it really is awful.” He describes these deaths as “kinetic energy disease” – a reference to the idea of mismatched masses in motion. When one of those masses is protected by metal casing, but the other isn’t, it’s clear who is more likely to be hurt.

    One of the trends Roberts has puzzled over is the long-term decline in the death rates of British pedestrians, despite an increase in motorization. “Road safety people would point to it as an example of how roads are getting safer. But I was a little bit skeptical… because [the] volume of kinetic energy on the road was going up.”

    An alternative hypothesis was that in industrialized countries, there were fewer people walking, something investigated in research he conducted while working in New Zealand. “Over the years it became obvious that people were walking and cycling less than ever before in the history of humans on the planet,” says Roberts. “The world was not getting safer, it was getting more hostile, and people were voting with their feet by getting out of the way.”

    “Vehicular cycling”

    Vehicular cycling in Buenos Aires, Argentina.
    Vehicular cycling in Buenos Aires, Argentina.

    In North America in the 1970s, cyclists – or at least the most vocal advocacy groups purporting to represent them – did not want to get out of the way. So-called vehicular cycling was emerging, a philosophy that has influenced transport policy in both North America and Britain. Fathered by Californian industrial engineer and cycling activist John Forester, vehicular cycling encourages cyclists to travel on the road in mixed traffic. On his website, Forester writes: “Vehicular cycling, so named because you are acting as the driver of a vehicle, just as the traffic laws require, is faster and more enjoyable, so that the plain joy of cycling overrides the annoyance of even heavy traffic.”