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

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.

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.

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.

=v= Good grief. Frank provided info for all of us to think
whatever the heck we want to think about it. You two reply
by slagging him for it?

=v= I'm aware that many people aren't swayed by facts and
a deeper understanding of statistics. That doesn't mean
these things should never be mentioned. Again, good grief.
Thank you, Frank,
_Jym_

On 8/7/2011 7:53 PM, Jym Dyer wrote:
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.

=v= Good grief. Frank provided info for all of us to think
whatever the heck we want to think about it. You two reply
by slagging him for it?

=v= I'm aware that many people aren't swayed by facts and
a deeper understanding of statistics. That doesn't mean
these things should never be mentioned. Again, good grief.
Thank you, Frank,
_Jym_

The information is rather old news, at least qualitatively. I have no
real interest in whether the benefit ratio is 77 to 1 or 1.1 to 1. I
don't think anyone disputes the likelihood that cycling provides a net
positive health benefit, there have been a slew of studies that claimed
this and, as far as I know, not a single one that claimed otherwise.

What you took out of context and apparently didn't get from the thread
was that Frank takes such data and spins it to conclude that anyone with
safety concerns is being a "fear monger". "Danger! Danger!" & all that.
That's essentially a straw man argument. The real question isn't what
the net health benefit is but whether cycling can't be easily made safer.

If he would just reference the article without editorializing about
helmets and/or facilities his posts would be fine.

Peter Cole wrote:
On 8/7/2011 7:53 PM, Jym Dyer wrote:


=v= Good grief. Frank provided info for all of us to think
whatever the heck we want to think about it. You two reply
by slagging him for it?

=v= I'm aware that many people aren't swayed by facts and
a deeper understanding of statistics. That doesn't mean
these things should never be mentioned. Again, good grief.
Thank you, Frank,
_Jym_

The information is rather old news, at least qualitatively. I have no
real interest in whether the benefit ratio is 77 to 1 or 1.1 to 1. I
don't think anyone disputes the likelihood that cycling provides a net
positive health benefit...

Then you are unaware of much propaganda, and much popular opinion.

... there have been a slew of studies that claimed
this and, as far as I know, not a single one that claimed otherwise.

And yet, I read and hear frequent complaints about the supposed dangers
of cycling. And fear of cycling is always among the top reasons people
say they don't cycle more.

Then there are the implicit statements of fear - like "We need barrier
separated bikeways for safety!" or "A bike path will give us a safe
place to ride, away from traffic."

What you took out of context and apparently didn't get from the thread
was that Frank takes such data and spins it to conclude that anyone with
safety concerns is being a "fear monger". "Danger! Danger!" & all that.
That's essentially a straw man argument.

What you just wrote was a straw man argument. "Fear monger" applies not
to "anyone with safety concerns." It applies to people who say things
like "Biking is really dangerous." We've gotten that with gusto from
certain posters - for example, Duane, who said "Yeah, but you don't know
how dangerous it is HERE in Montreal" (and who kill filed me when I put
up Montreal data showing he was wrong).

A person can have safety concerns without being a fear monger. Just
refrain from trying to convince others that they should share your fears.

The real question isn't what
the net health benefit is but whether cycling can't be easily made safer.

Ah yes. If _anything_ can be made safer, we _must_ work to make it
safer, no matter the costs, no matter the detriments. And of course,
the best way to make that happen is to tell people it's too dangerous.

There's no such thing as safe enough, you know!


--
- Frank Krygowski

On 8/7/2011 6:38 PM, Peter Cole wrote:

The information is rather old news, at least qualitatively. I have no
real interest in whether the benefit ratio is 77 to 1 or 1.1 to 1. I
don't think anyone disputes the likelihood that cycling provides a net
positive health benefit, there have been a slew of studies that claimed
this and, as far as I know, not a single one that claimed otherwise.

What is not only naive, but proven to be false, is the idea that if any
government body takes steps to increase bicycle safety by adding bicycle
facilities or by encouraging (or even compelling) the use of safety
equipment, that suddenly thousands of people will stop cycling and begin
driving everywhere, begin eating more junk food (rather than Power
Bars), become obese, and encounter all sorts of medical problems.

In fact we don't know what has caused both the increase in cycling,
increased use of helmets, and decreased level of injuries and
fatalities. It could be helmets, it could be better bicycle facilities,
it could be the price of gasoline, it could be health consciousness, it
could be weather changes, etc. Those in favor of mandatory helmet laws
will claim that it's helmets, those that favor more bicycle facilities
will claim that it's better facilities, and some will claim that cycling
levels would have went without any of these factors.

On 8/7/2011 6:53 PM, Jym Dyer wrote:
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.

=v= Good grief. Frank provided info for all of us to think
whatever the heck we want to think about it. You two reply
by slagging him for it?

If anyone thinks I am "slagging" Frank Krygowski, they have completely
missed the point.

=v= I'm aware that many people aren't swayed by facts and
a deeper understanding of statistics. That doesn't mean
these things should never be mentioned. Again, good grief.
Thank you, Frank,
_Jym_

Do not always be so literal.

--
Tºm Shermªn - 42.435731°N, 83.985007°W
I am a vehicular cyclist.

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.

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