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

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.

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.

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

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

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

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

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.

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.

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.