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Dangerous? Study: 77 to 1 benefit to risk
Many years ago, the eminent British researcher Mayer Hillman pegged the
benefit-to-risk ratio for cycling at 20:1 in favor of cycling. His estimate was based on calculations of years of life gained vs. years of life lost for society as a whole. That included, for example, pedestrians not killed by a car because the driver chose to cycle instead of drive. Last year de Hartog et.al. pegged the ratio at 9:1 in favor of cycling in the Netherlands, and 7:1 in Britain, this time for just the cyclists themselves. This did not account for things like fewer bystander deaths due to air pollution, for example. The latest paper gives even more optimistic estimates. A study of the urban cyclist use of Barcelona's bike sharing system pegged that ratio at 77 to 1 in favor of bicycling, for those replacing car trips with bike trips. A brief radio interview discussing this is at http://www.cycling-embassy.org.uk/au...-too-dangerous Warning: There is some slight mention of helmets - specifically, the statement that none of the people in the study wore them; and that they discourage riding. This is consistent with data from London's and Dublin's and Paris's bike share plans, with millions of users but no (or almost no) serious injuries. (And OTOH there's Melbourne's, which requires helmets and thus gets almost no use.) The paper's free to download at http://www.bmj.com/content/341/bmj.c5293.full.pdf Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? -- - Frank Krygowski |
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Dangerous? Study: 77 to 1 benefit to risk
On 8/5/2011 5:02 PM, Frank Krygowski wrote:
Many years ago, the eminent British researcher Mayer Hillman pegged the benefit-to-risk ratio for cycling at 20:1 in favor of cycling. His estimate was based on calculations of years of life gained vs. years of life lost for society as a whole. That included, for example, pedestrians not killed by a car because the driver chose to cycle instead of drive. Last year de Hartog et.al. pegged the ratio at 9:1 in favor of cycling in the Netherlands, and 7:1 in Britain, this time for just the cyclists themselves. This did not account for things like fewer bystander deaths due to air pollution, for example. The latest paper gives even more optimistic estimates. A study of the urban cyclist use of Barcelona's bike sharing system pegged that ratio at 77 to 1 in favor of bicycling, for those replacing car trips with bike trips. A brief radio interview discussing this is at http://www.cycling-embassy.org.uk/au...-too-dangerous Warning: There is some slight mention of helmets - specifically, the statement that none of the people in the study wore them; and that they discourage riding. This is consistent with data from London's and Dublin's and Paris's bike share plans, with millions of users but no (or almost no) serious injuries. (And OTOH there's Melbourne's, which requires helmets and thus gets almost no use.) The paper's free to download at http://www.bmj.com/content/341/bmj.c5293.full.pdf Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? Frank makes the mistake of thinking people value facts and proper statistical analyses over gut feelings and conventional "wisdom". -- Tºm Shermªn - 42.435731°N, 83.985007°W I am a vehicular cyclist. |
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Dangerous? Study: 77 to 1 benefit to risk
Frank Krygowski writes:
Many years ago, the eminent British researcher... snip Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? Safe enough for what? Safe enough to do? Don't we all do it? Or, by "stop worrying", do you mean safe enough to not bother trying to make it safer. |
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Dangerous? Study: 77 to 1 benefit to risk
Op 6-8-2011 0:02, Frank Krygowski schreef:
Many years ago, the eminent British researcher Mayer Hillman pegged the benefit-to-risk ratio for cycling at 20:1 in favor of cycling. His estimate was based on calculations of years of life gained vs. years of life lost for society as a whole. That included, for example, pedestrians not killed by a car because the driver chose to cycle instead of drive. Last year de Hartog et.al. pegged the ratio at 9:1 in favor of cycling in the Netherlands, and 7:1 in Britain, this time for just the cyclists themselves. This did not account for things like fewer bystander deaths due to air pollution, for example. The latest paper gives even more optimistic estimates. A study of the urban cyclist use of Barcelona's bike sharing system pegged that ratio at 77 to 1 in favor of bicycling, for those replacing car trips with bike trips. A brief radio interview discussing this is at http://www.cycling-embassy.org.uk/au...-too-dangerous Warning: There is some slight mention of helmets - specifically, the statement that none of the people in the study wore them; and that they discourage riding. This is consistent with data from London's and Dublin's and Paris's bike share plans, with millions of users but no (or almost no) serious injuries. (And OTOH there's Melbourne's, which requires helmets and thus gets almost no use.) The paper's free to download at http://www.bmj.com/content/341/bmj.c5293.full.pdf Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? What does 7:1 etc mean? What is benefit to risk ratio? Lou |
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Dangerous? Study: 77 to 1 benefit to risk
Dan wrote:
Frank writes: Many years ago, the eminent British researcher... snip Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? Safe enough for what? Safe enough to do? Don't we all do it? No, not for some definitions of "we." Or, by "stop worrying", do you mean safe enough to not bother trying to make it safer. Safe enough to dispense with the cries that "We need bike tracks and bike boxes and bike lanes and bike paths because ordinary roads are so dangerous." Safe enough to dispense with campaigns saying "Riding a bike without a helmet can kill you." Cyclists seem astonishingly willing to accept anti-bike propaganda, and to claim they would have died if not for their special hat, or special paint on the road. -- - Frank Krygowski |
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Dangerous? Study: 77 to 1 benefit to risk
Lou Holtman wrote:
What does 7:1 etc mean? What is benefit to risk ratio? The ratio is an estimate of the number of years of life gained for every year of life lost due to cycling. Obviously, it's an estimate, and one that's complicated to construct. But researchers have previously estimated the effects on longevity of various behaviors and environmental factors. This cycling research attempts to aggregate those effects as they relate to cycling, vs. not cycling (which typically means motoring). For example, one factor is breathing various concentrations of polluted air. (That applies to cyclists, motorists and bystanders - but "Danger! Danger!" people like Duane make noise about only the effect on cyclists.) Anyway, researchers can use measured data to estimate the amount of air pollution inhaled by cyclists and by motorists, and compute how many years of life are expected to be lost for each group. (That one's small, and worse for motorists, BTW.) They can also examine data on the health benefits of moderate exercise, and use that to estimate the number of years of life gained by regular cycling. That factor is quite large in favor of the cyclists. Finally, the big one in most people's minds: They can look at data on frequency of traffic crashes and see how likely a cyclist is to get killed or seriously injured while riding. They can work that into the computation as well. However, it turns out it's relatively tiny. Despite the fear mongering, loss of life while cycling is a very, very tiny risk. Again, Mayer Hillman's computations many years ago (around 1990, IIRC) put cycling's benefit:risk at 20:1. De Hartog's came out at 7:1 or 9:1 for different groups of cyclists. This latest comes out 77:1 - i.e. for each population year of life lost due to cycling-related factors, there are 77 years of life gained. Cycling is tremendously beneficial. The differences in these estimates are large, of course. But no matter which a person chooses, it shows that fears of cycling are unjustified, and that we don't need weird measures to reduce the mythical danger levels. -- - Frank Krygowski |
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Dangerous? Study: 77 to 1 benefit to risk
Lou Holtman wrote:
Op 6-8-2011 0:02, Frank Krygowski schreef: Many years ago, the eminent British researcher Mayer Hillman pegged the benefit-to-risk ratio for cycling at 20:1 in favor of cycling. His estimate was based on calculations of years of life gained vs. years of life lost for society as a whole. That included, for example, pedestrians not killed by a car because the driver chose to cycle instead of drive. Last year de Hartog et.al. pegged the ratio at 9:1 in favor of cycling in the Netherlands, and 7:1 in Britain, this time for just the cyclists themselves. This did not account for things like fewer bystander deaths due to air pollution, for example. The latest paper gives even more optimistic estimates. A study of the urban cyclist use of Barcelona's bike sharing system pegged that ratio at 77 to 1 in favor of bicycling, for those replacing car trips with bike trips. A brief radio interview discussing this is at http://www.cycling-embassy.org.uk/au...-too-dangerous Warning: There is some slight mention of helmets - specifically, the statement that none of the people in the study wore them; and that they discourage riding. This is consistent with data from London's and Dublin's and Paris's bike share plans, with millions of users but no (or almost no) serious injuries. (And OTOH there's Melbourne's, which requires helmets and thus gets almost no use.) The paper's free to download at http://www.bmj.com/content/341/bmj.c5293.full.pdf Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? What does 7:1 etc mean? What is benefit to risk ratio? It's a Bhutan thing. I'm 7x more satisfied than the texting putz trying to run over me. -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
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Dangerous? Study: 77 to 1 benefit to risk
Op 6-8-2011 17:45, Frank Krygowski schreef:
Lou Holtman wrote: What does 7:1 etc mean? What is benefit to risk ratio? The ratio is an estimate of the number of years of life gained for every year of life lost due to cycling. Obviously, it's an estimate, and one that's complicated to construct. But researchers have previously estimated the effects on longevity of various behaviors and environmental factors. This cycling research attempts to aggregate those effects as they relate to cycling, vs. not cycling (which typically means motoring). For example, one factor is breathing various concentrations of polluted air. (That applies to cyclists, motorists and bystanders - but "Danger! Danger!" people like Duane make noise about only the effect on cyclists.) Anyway, researchers can use measured data to estimate the amount of air pollution inhaled by cyclists and by motorists, and compute how many years of life are expected to be lost for each group. (That one's small, and worse for motorists, BTW.) They can also examine data on the health benefits of moderate exercise, and use that to estimate the number of years of life gained by regular cycling. That factor is quite large in favor of the cyclists. Finally, the big one in most people's minds: They can look at data on frequency of traffic crashes and see how likely a cyclist is to get killed or seriously injured while riding. They can work that into the computation as well. However, it turns out it's relatively tiny. Despite the fear mongering, loss of life while cycling is a very, very tiny risk. Again, Mayer Hillman's computations many years ago (around 1990, IIRC) put cycling's benefit:risk at 20:1. De Hartog's came out at 7:1 or 9:1 for different groups of cyclists. This latest comes out 77:1 - i.e. for each population year of life lost due to cycling-related factors, there are 77 years of life gained. Cycling is tremendously beneficial. The differences in these estimates are large, of course. But no matter which a person chooses, it shows that fears of cycling are unjustified, and that we don't need weird measures to reduce the mythical danger levels. Hmm, not very usefull those figures. I had a day off yesterday and did a ride during a weekday in working hours. It was a nice day and there were hordes of retired people on the road on their bikes. I didn't count them exactly but hell more than 50% were on E bikes. It's become a 'plague' here in the Neteherlands and boy they do dumb things on their bikes. They still think traffic is in the sixties. It was reported that accidents with older people are rapidly increasing the last 2 years. Go figure what only E bikes can do... Andre are you paying attention? Lou, has to watch cars and bloody E bikes these days. |
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Dangerous? Study: 77 to 1 benefit to risk
Frank Krygowski writes:
Dan wrote: Frank writes: Many years ago, the eminent British researcher... snip Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? Safe enough for what? Safe enough to do? Don't we all do it? No, not for some definitions of "we." Who is your audience for this post? Or, by "stop worrying", do you mean safe enough to not bother trying to make it safer. Safe enough to dispense with the cries that "We need bike tracks and bike boxes and bike lanes and bike paths because ordinary roads are so dangerous." Do I need to list links to this week's stories of bicyclists mown down like so much roadkill. Safe enough to dispense with campaigns saying "Riding a bike without a helmet can kill you." Who said that? To whom are you addressing this post? Cyclists seem astonishingly willing to accept anti-bike propaganda, and to claim they would have died if not for their special hat, or special paint on the road. Most of us are just in it to Ride Bike. I offer the benefit of my knowledge, opinions (such as they are ;-), perception and experience to those that seem to have an unrealistic perception, but I'm mostly just in it to Ride Bike. You go ahead on and make the world a better place - and go ahead and share information with us FWIW (and thanks for both); but give *us* some credit and spare us the lectures. |
#10
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Dangerous? Study: 77 to 1 benefit to risk
On 8/5/2011 9:16 PM, "T°m Sherm@n" wrote:
On 8/5/2011 5:02 PM, Frank Krygowski wrote: Many years ago, the eminent British researcher Mayer Hillman pegged the benefit-to-risk ratio for cycling at 20:1 in favor of cycling. His estimate was based on calculations of years of life gained vs. years of life lost for society as a whole. That included, for example, pedestrians not killed by a car because the driver chose to cycle instead of drive. Last year de Hartog et.al. pegged the ratio at 9:1 in favor of cycling in the Netherlands, and 7:1 in Britain, this time for just the cyclists themselves. This did not account for things like fewer bystander deaths due to air pollution, for example. The latest paper gives even more optimistic estimates. A study of the urban cyclist use of Barcelona's bike sharing system pegged that ratio at 77 to 1 in favor of bicycling, for those replacing car trips with bike trips. A brief radio interview discussing this is at http://www.cycling-embassy.org.uk/au...-too-dangerous Warning: There is some slight mention of helmets - specifically, the statement that none of the people in the study wore them; and that they discourage riding. This is consistent with data from London's and Dublin's and Paris's bike share plans, with millions of users but no (or almost no) serious injuries. (And OTOH there's Melbourne's, which requires helmets and thus gets almost no use.) I think any bike share program would be fatally handicapped with a mandatory helmet requirement. Boston just launched ours -- sans helmets, and it's off to a strong start. Hopefully these programs will reverse some of the helmet hysteria (as a side benefit). On the other hand, one serious accident could wreck things. The paper's free to download at http://www.bmj.com/content/341/bmj.c5293.full.pdf Really, how safe does cycling have to be, and by how much do its benefits have to exceed the tiny risk, before we say "Stop worrying. It's safe enough"? Frank makes the mistake of thinking people value facts and proper statistical analyses over gut feelings and conventional "wisdom". The problem is thinking in shades of gray -- something Frank has difficulty with, too. People do misjudge perception of safety with actual safety. Very few people are so rational to put complete faith in statistics, and only a few are aware of them. Still, some of our perceptions, while non-rational, are compelling. Some things, like auto traffic in close proximity, are not as dangerous as they seem, but that doesn't make them pleasant. I am only mildly interested in the prospect of an increase in cycling popularity. I think that an exchange of cars for bikes in dense urban areas would improve the quality of most cities, health-wise and aesthetically. I'm much more moved by aesthetics than health -- public or personal. Like it or not, the perception of safety plays a bigger role than actual statistical safety in most people's decision to bike, while convenience, comfort and social acceptability dwarf both concerns. Boston already leads the nation in walking. We've spent billions reversing some of the terrible urban planning decisions made in the 50's and 60's, which literally tore the city apart accommodating vehicular traffic. We have a reasonably good (by dismal US standards) public transportation infrastructure. Cycling is good on its own merits -- healthful (on balance), green, and all that, but I appreciate it most for it's aesthetics -- not just the wind in your hair freedom, but the freedom of mobility that comes from not being accompanied by a few cubic yards of steel, glass and plastic wherever you go. They may be necessary for suburban life, but ton and a half exoskeletons really detract from the urban experience. Hopefully, providing community bicycles will kick-start the cycling scene in Boston for the masses. Hopefully the nannies won't clutter things up with helmet requirements. |
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