bike accident fatalities and google maps?

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Date: 21 Sep 2007 20:51:22
From: damyth
Subject: bike accident fatalities and google maps?

A recent spate of bike fatalities in the local area (Sand Hill Road
near Menlo Park/SLAC, CA) has me wondering. Is there a map or
database pinpointing locations of bike fatalities? This would be
incredibly helpful for people to find out where the most dangerous
roads to ride are, a geographical representation of frequency, and
maybe help people to avoid/improve those areas.

Some of you might point out it should be "obvious" where the most
dangerous areas are, but I ride that area often, but it never occurred
to me that so many fatalities have occurred there until someone
recently pointed it out.

Date: 01 Oct 2007 01:35:28
From: Mapmedia
Subject: Re: bike accident fatalities and google maps?

I know the City of Napa has bicycle safety data in their GIS, such as
points of accidents. These can be plotted on GE.

Date: 24 Sep 2007 14:07:19
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 24, 4:15 pm, Michael Press <rub...@pacbell.net > wrote:
> In article
> <1190647413.063501.86...@19g2000hsx.googlegroups.com>,
>
> frkry...@gmail.com wrote:
> > On Sep 23, 10:03 pm, Michael Press <rub...@pacbell.net> wrote:
> > >
> > > That is not what regression to the mean means.
>
> > That was meant as a brief remark, by way of illustration. I can write
> > a 500 word explanation of what it means, if you like. I was hoping
> > that wasn't necessary!
>
> Your loose speech was too loose.

Again, I was assuming people needed only the briefest reminder of what
it meant. Tech group, remember. Perhaps I was wrong.

> As a matter of fact, it was completely incorrect.

Sorry, I don't buy that. "Too trivial an example"? Perhaps. But not
incorrect.

> An essay on regression to the mean is not necessary.
> A simple example such as the classic one I presented
> is all that is called for.

The "classic" one you gave is probably the most common explanation of
the concept. But based on over 30 years of teaching technical
subjects, I know that it's valuable to have more than one
explanation. Saying one explanation is "all that is called for" is
the same as abandoning anybody who didn't understand that
explanation. Different people "get" things in different contexts.

- Frank Krygowski

Date: 25 Sep 2007 00:29:09
From: Michael Press
Subject: Re: bike accident fatalities and google maps?

In article
<1190668039.757318.315490@n39g2000hsh.googlegroups.com >
,
frkrygow@gmail.com wrote:

> On Sep 24, 4:15 pm, Michael Press <rub...@pacbell.net> wrote:
> > In article
> > <1190647413.063501.86...@19g2000hsx.googlegroups.com>,
> >
> > frkry...@gmail.com wrote:
> > > On Sep 23, 10:03 pm, Michael Press <rub...@pacbell.net> wrote:
> > > >
> > > > That is not what regression to the mean means.
> >
> > > That was meant as a brief remark, by way of illustration. I can write
> > > a 500 word explanation of what it means, if you like. I was hoping
> > > that wasn't necessary!
> >
> > Your loose speech was too loose.
>
> Again, I was assuming people needed only the briefest reminder of what
> it meant. Tech group, remember. Perhaps I was wrong.
>
> > As a matter of fact, it was completely incorrect.
>
> Sorry, I don't buy that. "Too trivial an example"? Perhaps. But not
> incorrect.

The example of meteorites does not exemplify regression to the mean.
Incorrect, completely incorrect. You wrote
> But it's probable that the observed effect is nothing more than what's
> called "regression to the mean." Loosely speaking, that means
> meteorites don't strike twice in the same place.* If nothing at all
> had been done, the odd coincidence that caused the blip would have
> vanished on its own.

Regression to the mean does not mean independent events.
They are not the same concept, or even similar, or related
by any mathematical theorems.

> > An essay on regression to the mean is not necessary.
> > A simple example such as the classic one I presented
> > is all that is called for.
>
> The "classic" one you gave is probably the most common explanation of
> the concept. But based on over 30 years of teaching technical
> subjects, I know that it's valuable to have more than one
> explanation. Saying one explanation is "all that is called for" is
> the same as abandoning anybody who didn't understand that
> explanation. Different people "get" things in different contexts.

"All that is called for" in this forum, in my message.
I left out these qualifications. Sorry.
Explain it further; plenty of people will benefit.
Two good references are

Korner, T.H., [1988]; _Fourier_Analysis_, Chapter 83,
Cambridge University Press.

Jaynes, E.T., [2003], Probabilty Theory, Chapter 7,
Cambridge University Press.

--
Michael Press

Date: 24 Sep 2007 11:53:12
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 24, 10:41 am, Ryan Cousineau <rcous...@sfu.ca > wrote:
> In article <1190602602.426518.287...@19g2000hsx.googlegroups.com>,
>
>
>
> damyth <mdk.10.dam...@spamgourmet.com> wrote:
> > On Sep 23, 6:51 pm, frkry...@gmail.com wrote:
> > > On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>
> > > > Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> > > > because they're convinced this is a futile exercise. It's interesting
> > > > that they take this position a priori, even before I found a web site
> > > > where I can map this out.
>
> > > FWIW, I'm convinced this is a futile exercise because I understand a
> > > fair amount about data collection and statistical data processing. I
> > > know that there are roughly only 750 to 800 bike fatalities a year all
> > > across the US, and I know that you're unlikely to get enough fatality
> > > data points on any given road or intersection to reach any
> > > statistically valid conclusions.
>
> [...]
>
>
>
> > > > I'd invite Carl and Frank to take a look at figures 5-7 in this report
> > > > so they can get a firsthand idea of what I'm talking
> > > > about:http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/safetyi
> > > > n...
>
> > > Some of the figures you reference plot injury data, rather than
> > > fatality data. I think that's a bit of improvement, because you've at
> > > least got a chance of getting enough data points to do something
> > > with. OTOH, that data still needs a denominator. That is, it needs
> > > to be reduced to "per cyclist" or "per mile ridden" data.
>
> > Yeah, keep minimizing the fact first figure shows fatalities. And in
> > the Google mashup I never said anything like "only fatalities should
> > be included." In fact I explicitly included an incident that was not
> > fatal (but could have been).
>
> > The only reason I started with fatalities in the Google mashup was
> > those reports were easy for me to come by.
>
> > > I'm currently reading _Death in the Streets_ by Robert Davis. (ISBN
> > > 0-948135-46-8). He points out that the dominance of the automobile
> > > has intimidated many cyclists and pedestrians off the roads. And he
> > > points out that the motoring-dominated "road safety" organizations
> > > don't acknowledge that fact. They look at any reduction in bike and
> > > ped fatalities as proof that they're doing things right.
>
> > > By that logic, a freeway is the safest possible place to walk, because
> > > freeways have close to zero pedestrian fatalities. Your proposed
> > > method is likely to make the same mistake, calling places where no
> > > cyclist ever rides "safe," and calling places where tons of cyclists
> > > ride "dangerous," even if they're safer per mile ridden.
>
> > Apparently you think everyone else is an idiot. You're the first
> > person who has thought of this and deserve a Nobel Prize.
>
> This paragraph strikes me as being of the Paulian "not even wrong"
> category:
>
> http://en.wikipedia.org/wiki/Not_even_wrong
>
Heh, thanks for the words of encouragement.

> BTW, I think that to the extent you can get good accident (not just
> fatality) stats for bicycles, you have a chance of creating a
> statistically meaningful map.
>
> But you'll still need to face the question of what your map will be
> measuring, and how to separate the popular roads from the dangerous ones.
>
Herein lies the fallacy that most people like Frank and Carl commit.
They think the map is supposed to "measure" something. It doesn't.
It's meant to be used as an analytical tool, to elicit relationships
that would not have been obvious otherwise by looking at some DOT
stats.

In my map, there have been 4 incidents on Sand Hill Road. 3 involved
both motor vehicles and bicycles, and the other one was bicycle only.
Carl and Frank would never have found out by looking at DOT stats that
all three motorized vehicle-bike incidents occurred on "extended
weekends," namely Independence Day, Memorial Day, and Christmas.

Once these relationships are clear, then one can discuss what
statistical models to use, and what's correlated and what's not. It's
inappropriate to say the map is useless, you'll never get any
meaningful statistics out of it, Frank has unconsciously chosen a
statistical model a priori.

Here are a few other links that shows Frank's reasoning to be false.
There are graduate schools of urban planning with departments that's
dedicated to studying such things:
http://www.bicyclinginfo.org/bc/about.cfm
http://www.metroplanorlando.com/site/upload/documents/Bicyclist_Crash_Study_OrlandoArea.pdf

> Otherwise, you'll end up with charts like those on pp. 18-19 of this
> report, and you'll think you've found something important:
>
> http://www.aaafoundation.org/pdf/bikeuse_PBA.pdf
>
> (for those who don't want to read it, the report shows that the
> Netherlands has a bicycle death rate of 17.7/million inhabitants, as
> opposed to 3.1/million in the US. Let's all contemplate the confounding
> variable. The report-writers are well aware of the confounding
> variables, and conclude (in concert with other data) that the
> Netherlands has a safer transportation infrastructure than the US)..
>
> --
> Ryan Cousineau rcous...@sfu.cahttp://www.wiredcola.com/
> "I don't want kids who are thinking about going into mathematics
> to think that they have to take drugs to succeed." -Paul Erdos

Date: 24 Sep 2007 19:43:17
From: Ryan Cousineau
Subject: Re: bike accident fatalities and google maps?

In article <1190659992.156025.306600@o80g2000hse.googlegroups.com >,
damyth <mdk.10.damyth@spamgourmet.com > wrote:

> On Sep 24, 10:41 am, Ryan Cousineau <rcous...@sfu.ca> wrote:
> > In article <1190602602.426518.287...@19g2000hsx.googlegroups.com>,
> >
> >
> >
> > damyth <mdk.10.dam...@spamgourmet.com> wrote:
> > > On Sep 23, 6:51 pm, frkry...@gmail.com wrote:
> > > > On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
> >
> > > > > Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> > > > > because they're convinced this is a futile exercise. It's
> > > > > interesting
> > > > > that they take this position a priori, even before I found a web site
> > > > > where I can map this out.
> >
> > > > FWIW, I'm convinced this is a futile exercise because I understand a
> > > > fair amount about data collection and statistical data processing. I
> > > > know that there are roughly only 750 to 800 bike fatalities a year all
> > > > across the US, and I know that you're unlikely to get enough fatality
> > > > data points on any given road or intersection to reach any
> > > > statistically valid conclusions.
> >
> > [...]
> >
> >
> >
> > > > > I'd invite Carl and Frank to take a look at figures 5-7 in this
> > > > > report
> > > > > so they can get a firsthand idea of what I'm talking
> > > > > about:http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/saf
> > > > > etyi
> > > > > n...
> >
> > > > Some of the figures you reference plot injury data, rather than
> > > > fatality data. I think that's a bit of improvement, because you've at
> > > > least got a chance of getting enough data points to do something
> > > > with. OTOH, that data still needs a denominator. That is, it needs
> > > > to be reduced to "per cyclist" or "per mile ridden" data.
> >
> > > Yeah, keep minimizing the fact first figure shows fatalities. And in
> > > the Google mashup I never said anything like "only fatalities should
> > > be included." In fact I explicitly included an incident that was not
> > > fatal (but could have been).
> >
> > > The only reason I started with fatalities in the Google mashup was
> > > those reports were easy for me to come by.
> >
> > > > I'm currently reading _Death in the Streets_ by Robert Davis. (ISBN
> > > > 0-948135-46-8). He points out that the dominance of the automobile
> > > > has intimidated many cyclists and pedestrians off the roads. And he
> > > > points out that the motoring-dominated "road safety" organizations
> > > > don't acknowledge that fact. They look at any reduction in bike and
> > > > ped fatalities as proof that they're doing things right.
> >
> > > > By that logic, a freeway is the safest possible place to walk, because
> > > > freeways have close to zero pedestrian fatalities. Your proposed
> > > > method is likely to make the same mistake, calling places where no
> > > > cyclist ever rides "safe," and calling places where tons of cyclists
> > > > ride "dangerous," even if they're safer per mile ridden.
> >
> > > Apparently you think everyone else is an idiot. You're the first
> > > person who has thought of this and deserve a Nobel Prize.
> >
> > This paragraph strikes me as being of the Paulian "not even wrong"
> > category:
> >
> > http://en.wikipedia.org/wiki/Not_even_wrong
> >
> Heh, thanks for the words of encouragement.
>
> > BTW, I think that to the extent you can get good accident (not just
> > fatality) stats for bicycles, you have a chance of creating a
> > statistically meaningful map.
> >
> > But you'll still need to face the question of what your map will be
> > measuring, and how to separate the popular roads from the dangerous ones.
> >
> Herein lies the fallacy that most people like Frank and Carl commit.
> They think the map is supposed to "measure" something. It doesn't.
> It's meant to be used as an analytical tool, to elicit relationships
> that would not have been obvious otherwise by looking at some DOT
> stats.

Well, I get the idea of using it as an exploratory, data-visualization
tool. That's worthy. But be wary of the conclusions it is likely to lead
you to. So far, it sounds like more of an art project than a data
analysis tool.

> In my map, there have been 4 incidents on Sand Hill Road. 3 involved
> both motor vehicles and bicycles, and the other one was bicycle only.
> Carl and Frank would never have found out by looking at DOT stats that
> all three motorized vehicle-bike incidents occurred on "extended
> weekends," namely Independence Day, Memorial Day, and Christmas.

Is that significant, or a coincidence?

> Once these relationships are clear, then one can discuss what
> statistical models to use, and what's correlated and what's not. It's
> inappropriate to say the map is useless, you'll never get any
> meaningful statistics out of it, Frank has unconsciously chosen a
> statistical model a priori.

Well, perhaps there's a misapprehension about what you're trying to do,
but the point is that fatalities, by themselves, and especially when
isolated by location, don't happen often enough to tell you much about
the streets where they happen.

Maybe this analogy will help, maybe not:

I give you a list of all the reported fatal shark attacks ever, with
their location pinpointed to the nearest 100m or so (I'm trying for an
equivalent of by-block location of accidents).

Given that information, I need you to tell me which beaches in Florida I
should avoid if I don't want to get attacked by a shark.

http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm

Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
there have been less than 500 fatal shark attacks recorded between 1580
and today.

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Date: 24 Sep 2007 15:44:02
From:
Subject: Re: bike accident fatalities and google maps?

On Mon, 24 Sep 2007 19:43:17 GMT, Ryan Cousineau <rcousine@sfu.ca >
wrote:

[snip]

>Maybe this analogy will help, maybe not:
>
>I give you a list of all the reported fatal shark attacks ever, with
>their location pinpointed to the nearest 100m or so (I'm trying for an
>equivalent of by-block location of accidents).
>
>Given that information, I need you to tell me which beaches in Florida I
>should avoid if I don't want to get attacked by a shark.
>
>http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm
>
>Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
>there have been less than 500 fatal shark attacks recorded between 1580
>and today.

Dear Ryan,

Well, sure, mapping _shark_ attacks is pointless for bicyclists.

But your whole argument falls apart like a well-chewed walnut when we
contemplate the rising red tide of _squirrel_ attacks!

Cheers,

Carl Fogel

Date: 25 Sep 2007 00:16:37
From: Ryan Cousineau
Subject: Re: bike accident fatalities and google maps?

In article <d5agf3pe67sfflip8afc3kcvl11c3t6eft@4ax.com >,
carlfogel@comcast.net wrote:

> On Mon, 24 Sep 2007 19:43:17 GMT, Ryan Cousineau <rcousine@sfu.ca>
> wrote:
>
> [snip]
>
> >Maybe this analogy will help, maybe not:
> >
> >I give you a list of all the reported fatal shark attacks ever, with
> >their location pinpointed to the nearest 100m or so (I'm trying for an
> >equivalent of by-block location of accidents).
> >
> >Given that information, I need you to tell me which beaches in Florida I
> >should avoid if I don't want to get attacked by a shark.
> >
> >http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm
> >
> >Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
> >there have been less than 500 fatal shark attacks recorded between 1580
> >and today.
>
> Dear Ryan,
>
> Well, sure, mapping _shark_ attacks is pointless for bicyclists.
>
> But your whole argument falls apart like a well-chewed walnut when we
> contemplate the rising red tide of _squirrel_ attacks!
>
> Cheers,
>
> Carl Fogel

Mm, yes! This discussion has completely neglected the Squirrel Question.
Quick, how many cyclists are killed every year by squirrels?

Hm. The figures are not obvious.

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Date: 24 Sep 2007 19:31:51
From: A Muzi
Subject: Re: bike accident fatalities and google maps?

>> Ryan Cousineau <rcousine@sfu.ca> wrote:
>> [snip]
>>> Maybe this analogy will help, maybe not:
>>> I give you a list of all the reported fatal shark attacks ever, with
>>> their location pinpointed to the nearest 100m or so (I'm trying for an
>>> equivalent of by-block location of accidents).
>>> Given that information, I need you to tell me which beaches in Florida I
>>> should avoid if I don't want to get attacked by a shark.
>>> http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm
>>> Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
>>> there have been less than 500 fatal shark attacks recorded between 1580
>>> and today.

> carlfogel@comcast.net wrote:
>> Well, sure, mapping _shark_ attacks is pointless for bicyclists.
>> But your whole argument falls apart like a well-chewed walnut when we
>> contemplate the rising red tide of _squirrel_ attacks!

Ryan Cousineau wrote:
> Mm, yes! This discussion has completely neglected the Squirrel Question.
> Quick, how many cyclists are killed every year by squirrels?
Hm. The figures are not obvious.

More than you may have intended! Recently, a rider with a snapped-off
fork, wrecked wheel and a neck brace told our service writer he had
"just missed a squirrel" until Tim showed him the blood and fur on the
broken edge of his carbon fork.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 25 Sep 2007 00:00:19
From: Michael Press
Subject: Re: bike accident fatalities and google maps?

In article <13fgllmk4jsb349@corp.supernews.com >,
A Muzi <am@yellowjersey.org > wrote:

> >> Ryan Cousineau <rcousine@sfu.ca> wrote:
> >> [snip]
> >>> Maybe this analogy will help, maybe not:
> >>> I give you a list of all the reported fatal shark attacks ever, with
> >>> their location pinpointed to the nearest 100m or so (I'm trying for an
> >>> equivalent of by-block location of accidents).
> >>> Given that information, I need you to tell me which beaches in Florida I
> >>> should avoid if I don't want to get attacked by a shark.
> >>> http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm
> >>> Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
> >>> there have been less than 500 fatal shark attacks recorded between 1580
> >>> and today.
>
> > carlfogel@comcast.net wrote:
> >> Well, sure, mapping _shark_ attacks is pointless for bicyclists.
> >> But your whole argument falls apart like a well-chewed walnut when we
> >> contemplate the rising red tide of _squirrel_ attacks!
>
> Ryan Cousineau wrote:
> > Mm, yes! This discussion has completely neglected the Squirrel Question.
> > Quick, how many cyclists are killed every year by squirrels?
> Hm. The figures are not obvious.
>
> More than you may have intended! Recently, a rider with a snapped-off
> fork, wrecked wheel and a neck brace told our service writer he had
> "just missed a squirrel" until Tim showed him the blood and fur on the
> broken edge of his carbon fork.

How many spokes?

--
Michael Press

Date: 25 Sep 2007 12:46:08
From: A Muzi
Subject: Re: bike accident fatalities and google maps?

>>>> Ryan Cousineau <rcousine@sfu.ca> wrote:
>>>> [snip]
>>>>> Maybe this analogy will help, maybe not:
>>>>> I give you a list of all the reported fatal shark attacks ever, with
>>>>> their location pinpointed to the nearest 100m or so (I'm trying for an
>>>>> equivalent of by-block location of accidents).
>>>>> Given that information, I need you to tell me which beaches in Florida I
>>>>> should avoid if I don't want to get attacked by a shark.
>>>>> http://www.flmnh.ufl.edu/fish/sharks/statistics/GAttack/World.htm
>>>>> Boy, the internet rocks, dunnit? Five minutes, and I can tell you that
>>>>> there have been less than 500 fatal shark attacks recorded between 1580
>>>>> and today.

>>> carlfogel@comcast.net wrote:
>>>> Well, sure, mapping _shark_ attacks is pointless for bicyclists.
>>>> But your whole argument falls apart like a well-chewed walnut when we
>>>> contemplate the rising red tide of _squirrel_ attacks!

>> Ryan Cousineau wrote:
>>> Mm, yes! This discussion has completely neglected the Squirrel Question.
>>> Quick, how many cyclists are killed every year by squirrels?
>> Hm. The figures are not obvious.

> A Muzi <am@yellowjersey.org> wrote:
>> More than you may have intended! Recently, a rider with a snapped-off
>> fork, wrecked wheel and a neck brace told our service writer he had
>> "just missed a squirrel" until Tim showed him the blood and fur on the
>> broken edge of his carbon fork.

Michael Press wrote:
> How many spokes?

Not enough.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 24 Sep 2007 15:40:59
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 10:56 pm, damyth <mdk.10.dam...@spamgourmet.com > wrote:
> On Sep 23, 6:51 pm, frkry...@gmail.com wrote:
>
> > On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>
> > > Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> > > because they're convinced this is a futile exercise. It's interesting
> > > that they take this position a priori, even before I found a web site
> > > where I can map this out.
>
> > FWIW, I'm convinced this is a futile exercise because I understand a
> > fair amount about data collection and statistical data processing. I
> > know that there are roughly only 750 to 800 bike fatalities a year all
> > across the US, and I know that you're unlikely to get enough fatality
> > data points on any given road or intersection to reach any
> > statistically valid conclusions.
>
> This is rich considering you don't have a proper understanding of
> regression to the mean.

??? Are you basing that only on Michael Press's statement, or do you
have a specific technical definition you'd like to give? If so, you
should give it so we can discuss.

> At the very minimum you failed to properly explain the concept.

I didn't realize that people would need a detailed explanation of the
concept. I thought it was more commonly understood, especially in a
"tech" group.

I can get as mathematical as you like, but the non-mathematical
explanation that I just gave in a previous post should suffice. (And
keep in mind "proper" explanations depend on the audience.)

> > I also know about confounding factors in data analysis. I know, for
> > example, that if a given road has twenty times the bike traffic of an
> > adjacent road, your general method is more likely to call that road
> > "dangerous," even if it's safer per mile cycled than the adjacent
> > one. More concisely, you at _least_ need to evaluate cycling traffic
> > at each location you post - and I'm pretty sure you won't have a way
> > to do that.
>
> Any fool who bikes the local roads around here knows Sand Hill Road is
> heavily used by bicyclists. It's about the only easy way to get from
> civilization to the cycling mecca that is Portola Valley. And that's
> one of the reasons I advised people from drawing hasty conclusions
> from the data.

Do you understand your problem, then? If it's the only way to cycle
to a very popular spot, and if it therefore gets almost all the
cycling traffic, of course it's going to get almost all the cycling
accidents!

If you intend to do something useful with your map, you need to find a
way to account for that. As I said, you need a denominator. You need
to show the frequency of accidents per mile cycled.

> Apparently you think everyone else is an idiot. You're the first
> person who has thought of this and deserve a Nobel Prize.

Sheesh!

Look, if you don't want people to comment on what you're doing, you
should keep it off the internet! If you want to hear only the
cheerful, supporting comments, you should keep it away from discussion
groups where people are known to discuss both pros and cons of ideas.

As I said, carry on, if you like. I'm willing to see what you come up
with. But it's smart to think about the possible shortcomings of a
project ahead of time. You don't want to spend lots of time doing
something that is ultimately judged to be not worth doing.

- Frank Krygowski

Date: 24 Sep 2007 15:23:33
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 10:03 pm, Michael Press <rub...@pacbell.net > wrote:
> In article
> <1190497975.006721.12...@w3g2000hsg.googlegroups.com>,
>
> frkry...@gmail.com wrote:
> > But it's probable that the observed effect is nothing more than what's
> > called "regression to the mean." Loosely speaking, that means
> > meteorites don't strike twice in the same place.*
>
> That is not what regression to the mean means.

That was meant as a brief remark, by way of illustration. I can write
a 500 word explanation of what it means, if you like. I was hoping
that wasn't necessary!

> Regression to the mean is better illustrated
> by the fact that taller than average parents
> have taller than average children, but the children
> tend to be shorter than the parents.

That's the classic explanation for the concept, largely (I think)
because that was the first context in which the concept was stated.
But it applies broadly to many situations. Again, if you read _Risk_
by John Adams, or if you read _Death in the Streets_ by Robert Davis,
you'll get a specific explanation of how it applies to "black
spots" (i.e. more dangerous locations) regarding traffic accidents.
And that's our topic in this thread.

> > If nothing at all
> > had been done, the odd coincidence that caused the blip would have
> > vanished on its own.

This is the practical side of the effect, as far as we're concerned.
In many locations, the presence of a cluster of accidents is due only
to random chance, not to physical features of the location. Even in
those locations where there are physical features that contribute to
danger, an element of chance is still present. Since the "chance"
effect goes up and down (i.e. it's random) a period of high accident
counts will tend to be followed by a period of lower accident counts,
even if no change is made.

Specifically, when the random effect is high, it does not tend to stay
high. If it did, it wouldn't be random. When the random effect is
low, it does not tend to stay low. In both cases, when it changes, it
tends to move toward the average value - the mean.

That's regression towards the mean.

- Frank Krygowski

Date: 24 Sep 2007 13:15:55
From: Michael Press
Subject: Re: bike accident fatalities and google maps?

In article
<1190647413.063501.86190@19g2000hsx.googlegroups.com >,
frkrygow@gmail.com wrote:

> On Sep 23, 10:03 pm, Michael Press <rub...@pacbell.net> wrote:
> > In article
> > <1190497975.006721.12...@w3g2000hsg.googlegroups.com>,
> >
> > frkry...@gmail.com wrote:
> > > But it's probable that the observed effect is nothing more than what's
> > > called "regression to the mean." Loosely speaking, that means
> > > meteorites don't strike twice in the same place.*
> >
> > That is not what regression to the mean means.
>
> That was meant as a brief remark, by way of illustration. I can write
> a 500 word explanation of what it means, if you like. I was hoping
> that wasn't necessary!

Your loose speech was too loose.
As a matter of fact, it was completely incorrect.
Regression to the mean is not the same as
or even similar to independent events.

An essay on regression to the mean is not necessary.
A simple example such as the classic one I presented
is all that is called for.

Neither is regression to the mean anything like
the common misconception that `random' chance
dictates that a string of reds at a roulette table
is followed by a compensating preponderance of blacks.

--
Michael Press

Date: 24 Sep 2007 13:49:14
From: datakoll
Subject: Re: bike accident fatalities and google maps?

yahoo's computer software is cycle oriented:

http://news.yahoo.com/s/afp/20070924/wl_uk_afp/britainqueuingoffbeat

Date: 24 Sep 2007 04:20:55
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 3:18 am, carlfo...@comcast.net wrote:
> On Sat, 22 Sep 2007 23:51:33 -0700, damyth
>
> <mdk.10.dam...@spamgourmet.com> wrote:
> >I invite all of you (including all you naysayers) to join me in
> >mapping out bicycle fatalities here:
> >http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>
> >_Anyone_ can make edits to this map. This is a wiki and google map
> >rolled in one. I started out with the San Francisco Bay Area because
> >this is where I happen to ride most, but there is no technical reason
> >why this can't include all contiguous 48 states.
>
> >It is well known that geographic information system (GIS) tools can
> >improve bicycle and pedestrian safety. Just google "GIS bicycle
> >safety." However, one should not make any hasty judgments regarding
> >the data.
>
> Dear D,
>
> It will be hard to make hasty judgements, given the scarcity of bike
> fatalities versus the geographical spread.
>
> Expect a single pedalcyclist fatality per year for San Francisco
> County--there's been 1 every year from 2002 to 2006:
>
> http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/C...
>
> Expect 0, or 1-5 deaths per year in all but one nearby county, judging
> by this map:
>
> http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6...
>
> For "safety", head north. The map shows that the ten north-most
> counties in California had 0 bike fatalities in 2006.
>
> Florida appears to be far more "dangerous," with half as many people
> as California, and the same number of deaths from 2002 to 2006.
>
> Cheers,
>
> Carl Fogel

Check out Fort Wayne, Indiana. 3 years ago Allen Co., which
encompasses Fort Wayne, had the highest per capita cyclist death rate
in the US. There were 5 cyclist deaths in one year with a population
of 300,000. Very sad! It has gotten somewhat better. During the last
two years there have been 2 deaths per year. Personally this year I
have had things thrown at me, had a car accelerate in an attempt to
hit me and had one motorist make a u-turn to come back and shout
obscenities at me for using a public roadway.

Ride Safe!

Date: 24 Sep 2007 14:38:33
From:
Subject: Re: bike accident fatalities and google maps?

On Mon, 24 Sep 2007 04:20:55 -0700, dwintin@verizon.net wrote:

>On Sep 23, 3:18 am, carlfo...@comcast.net wrote:
>> On Sat, 22 Sep 2007 23:51:33 -0700, damyth
>>
>> <mdk.10.dam...@spamgourmet.com> wrote:
>> >I invite all of you (including all you naysayers) to join me in
>> >mapping out bicycle fatalities here:
>> >http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>>
>> >_Anyone_ can make edits to this map. This is a wiki and google map
>> >rolled in one. I started out with the San Francisco Bay Area because
>> >this is where I happen to ride most, but there is no technical reason
>> >why this can't include all contiguous 48 states.
>>
>> >It is well known that geographic information system (GIS) tools can
>> >improve bicycle and pedestrian safety. Just google "GIS bicycle
>> >safety." However, one should not make any hasty judgments regarding
>> >the data.
>>
>> Dear D,
>>
>> It will be hard to make hasty judgements, given the scarcity of bike
>> fatalities versus the geographical spread.
>>
>> Expect a single pedalcyclist fatality per year for San Francisco
>> County--there's been 1 every year from 2002 to 2006:
>>
>> http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/C...
>>
>> Expect 0, or 1-5 deaths per year in all but one nearby county, judging
>> by this map:
>>
>> http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6...
>>
>> For "safety", head north. The map shows that the ten north-most
>> counties in California had 0 bike fatalities in 2006.
>>
>> Florida appears to be far more "dangerous," with half as many people
>> as California, and the same number of deaths from 2002 to 2006.
>>
>> Cheers,
>>
>> Carl Fogel
>
>Check out Fort Wayne, Indiana. 3 years ago Allen Co., which
>encompasses Fort Wayne, had the highest per capita cyclist death rate
>in the US. There were 5 cyclist deaths in one year with a population
>of 300,000. Very sad! It has gotten somewhat better. During the last
>two years there have been 2 deaths per year. Personally this year I
>have had things thrown at me, had a car accelerate in an attempt to
>hit me and had one motorist make a u-turn to come back and shout
>obscenities at me for using a public roadway.
>
>Ride Safe!

Dear D,

Unfortunately, _some_ county must always be the highest in anything.

As expected, the annual bike death rate did _not_ stay high. Instead,
it dropped 60%.

That's normal for random variation with extremely rare events in
extremely large samples. As Frank points out, if the rate stayed high
(or low) in a statistically significant fashion, it wouldn't be
random.

In true random distributions, clusters of events are normal--they're
not evenly distributed. It's hard not to look at clusters and think
that they _must_ mean something.

People who struggle to teach statistics usually point out that we
ignore the much larger clusters of non-events--empty spots aren't as
dramatic, even though they're just as random. Few of us would believe
that Pueblo, Colorado, is immensely safer for bicycles than Fort
Wayne, Indiana, just because there were no bicycle deaths here from
2002 to 2006.

Modern epidemiology is the study of rare events in huge populations.
The biggest problem is the tendency to squeeze meaning out of random
situations. As a rule of thumb, when a handful of events can affect
the statistical outcome, it's meaningless. A single bike death would
have raised or lowered the death rate 20% in the 5-death year, and 50%
in a 2-death year.

Compare it to a murder rate or the weather. If Fort Wayne had 2
murders some years, or 5 murders other years, would anyone except a
newspaper reporter desperate for a "story" think that it was any more
random than the number of snowstorms?

Or compare it to flipping coins. If you flip a coin a hundred times,
you're likely to end up fairly close to 50 heads and 50 tails. But if
you track the results for ten flips at a time, you're practically
guaranteed that 5-5 will be rare.

That is, Pascal's triangle shows this heads/tails distribution for
1,024 sets of 10 coin flips:

h/t h/t
10/0 9/1 8/2 7/3 6/4 5/5 4/6 3/7 2/8 1/9 0/10
1 10 45 120 210 252 210 120 45 10 1

With only 10 tosses, the 50-50 result appears only about 1 out of 4
times, 252 out of 1,024 trials. In other words, 75% of the time, you
can't flip a coin ten times and get five heads and five tails. About
35% of the time, you'll end up with lopsided 7-3 results or even
worse.

Drawing unsupportable conclusions from too small a sample for the rate
of occurrence is the most common mistake in statistics. Five bike
deaths in Fort Wayne with 300,000 people in a year may seem like a
huge sample and a dramatic result, but it's actually about as useless
as trying to study whether a coin lands heads or tails by flipping it
ten times.

A few minutes with a penny, a pencil, and a piece of paper usually
teaches people that either they have a magic coin or statistics are
trickier than they first thought. Try ten trials of ten tosses, count
how often you end up 5-5, and throw the penny in a fountain for luck.

Cheers,

Carl Fogel

Date: 23 Sep 2007 19:56:42
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 6:51 pm, frkry...@gmail.com wrote:
> On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>
>
>
> > Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> > because they're convinced this is a futile exercise. It's interesting
> > that they take this position a priori, even before I found a web site
> > where I can map this out.
>
> FWIW, I'm convinced this is a futile exercise because I understand a
> fair amount about data collection and statistical data processing. I
> know that there are roughly only 750 to 800 bike fatalities a year all
> across the US, and I know that you're unlikely to get enough fatality
> data points on any given road or intersection to reach any
> statistically valid conclusions.
>
This is rich considering you don't have a proper understanding of
regression to the mean. At the very minimum you failed to properly
explain the concept. And why arbitrarily set a time limit of one
year?

> I also know about confounding factors in data analysis. I know, for
> example, that if a given road has twenty times the bike traffic of an
> adjacent road, your general method is more likely to call that road
> "dangerous," even if it's safer per mile cycled than the adjacent
> one. More concisely, you at _least_ need to evaluate cycling traffic
> at each location you post - and I'm pretty sure you won't have a way
> to do that.
>
Any fool who bikes the local roads around here knows Sand Hill Road is
heavily used by bicyclists. It's about the only easy way to get from
civilization to the cycling mecca that is Portola Valley. And that's
one of the reasons I advised people from drawing hasty conclusions
from the data.

By the same token, Carl looks up DOT data, and concludes going north
is "safe" when he doesn't even understand the DOT numbers are
contrived.

> > I honestly don't whether this representation is helpful or not. Right
> > now I'm in the mode of "Let's see what this representation might
> > show."
>
> That's fine. I'm willing to let you work on it and report back from
> time to time! ;-)
>
> > Every responsible department of transportation would have
> > somebody doing this very same thing, it's just in this digital age we
> > can get more of the back story instead of some jumble of numbers that
> > doesn't relate to the real world.
>
> I'm not sure about your meaning in the first sentence of that
> paragraph. Did you mean "should have" instead of "would have"? In
> any case, I think it's unlikely that many resources would be devoted
> to this effort - for exactly the reasons Carl and I have enumerated.
> They know it will be futile, and wouldn't make much difference even if
> it succeeded. There are better ways to spend money.
>
And what citations do you use to support this claim of "futility?" I
at least provided a counterexample where the Metropolitan
Transportation Commission in California spent money on such analysis.

> > I'd invite Carl and Frank to take a look at figures 5-7 in this report
> > so they can get a firsthand idea of what I'm talking about:http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/safetyin...
>
> Some of the figures you reference plot injury data, rather than
> fatality data. I think that's a bit of improvement, because you've at
> least got a chance of getting enough data points to do something
> with. OTOH, that data still needs a denominator. That is, it needs
> to be reduced to "per cyclist" or "per mile ridden" data.
>
Yeah, keep minimizing the fact first figure shows fatalities. And in
the Google mashup I never said anything like "only fatalities should
be included." In fact I explicitly included an incident that was not
fatal (but could have been).

The only reason I started with fatalities in the Google mashup was
those reports were easy for me to come by.

> I'm currently reading _Death in the Streets_ by Robert Davis. (ISBN
> 0-948135-46-8). He points out that the dominance of the automobile
> has intimidated many cyclists and pedestrians off the roads. And he
> points out that the motoring-dominated "road safety" organizations
> don't acknowledge that fact. They look at any reduction in bike and
> ped fatalities as proof that they're doing things right.
>
> By that logic, a freeway is the safest possible place to walk, because
> freeways have close to zero pedestrian fatalities. Your proposed
> method is likely to make the same mistake, calling places where no
> cyclist ever rides "safe," and calling places where tons of cyclists
> ride "dangerous," even if they're safer per mile ridden.
>
Apparently you think everyone else is an idiot. You're the first
person who has thought of this and deserve a Nobel Prize.

> But carry on, if you like. I'm willing to see what you come up with.
>
> - Frank Krygowski

Date: 24 Sep 2007 17:41:17
From: Ryan Cousineau
Subject: Re: bike accident fatalities and google maps?

In article <1190602602.426518.287410@19g2000hsx.googlegroups.com >,
damyth <mdk.10.damyth@spamgourmet.com > wrote:

> On Sep 23, 6:51 pm, frkry...@gmail.com wrote:
> > On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
> >
> >
> >
> > > Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> > > because they're convinced this is a futile exercise. It's interesting
> > > that they take this position a priori, even before I found a web site
> > > where I can map this out.
> >
> > FWIW, I'm convinced this is a futile exercise because I understand a
> > fair amount about data collection and statistical data processing. I
> > know that there are roughly only 750 to 800 bike fatalities a year all
> > across the US, and I know that you're unlikely to get enough fatality
> > data points on any given road or intersection to reach any
> > statistically valid conclusions.

[...]

> > > I'd invite Carl and Frank to take a look at figures 5-7 in this report
> > > so they can get a firsthand idea of what I'm talking
> > > about:http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/safetyi
> > > n...
> >
> > Some of the figures you reference plot injury data, rather than
> > fatality data. I think that's a bit of improvement, because you've at
> > least got a chance of getting enough data points to do something
> > with. OTOH, that data still needs a denominator. That is, it needs
> > to be reduced to "per cyclist" or "per mile ridden" data.
> >
> Yeah, keep minimizing the fact first figure shows fatalities. And in
> the Google mashup I never said anything like "only fatalities should
> be included." In fact I explicitly included an incident that was not
> fatal (but could have been).
>
> The only reason I started with fatalities in the Google mashup was
> those reports were easy for me to come by.
>
> > I'm currently reading _Death in the Streets_ by Robert Davis. (ISBN
> > 0-948135-46-8). He points out that the dominance of the automobile
> > has intimidated many cyclists and pedestrians off the roads. And he
> > points out that the motoring-dominated "road safety" organizations
> > don't acknowledge that fact. They look at any reduction in bike and
> > ped fatalities as proof that they're doing things right.
> >
> > By that logic, a freeway is the safest possible place to walk, because
> > freeways have close to zero pedestrian fatalities. Your proposed
> > method is likely to make the same mistake, calling places where no
> > cyclist ever rides "safe," and calling places where tons of cyclists
> > ride "dangerous," even if they're safer per mile ridden.
> >
> Apparently you think everyone else is an idiot. You're the first
> person who has thought of this and deserve a Nobel Prize.

This paragraph strikes me as being of the Paulian "not even wrong"
category:

http://en.wikipedia.org/wiki/Not_even_wrong

BTW, I think that to the extent you can get good accident (not just
fatality) stats for bicycles, you have a chance of creating a
statistically meaningful map.

But you'll still need to face the question of what your map will be
measuring, and how to separate the popular roads from the dangerous ones.

Otherwise, you'll end up with charts like those on pp. 18-19 of this
report, and you'll think you've found something important:

http://www.aaafoundation.org/pdf/bikeuse_PBA.pdf

(for those who don't want to read it, the report shows that the
Netherlands has a bicycle death rate of 17.7/million inhabitants, as
opposed to 3.1/million in the US. Let's all contemplate the confounding
variable. The report-writers are well aware of the confounding
variables, and conclude (in concert with other data) that the
Netherlands has a safer transportation infrastructure than the US)..

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Date: 24 Sep 2007 01:51:25
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 8:45 pm, damyth <mdk.10.dam...@spamgourmet.com > wrote:
>
> Carl Fogel & Frank Krygowski have their biking shorts in a bunch
> because they're convinced this is a futile exercise. It's interesting
> that they take this position a priori, even before I found a web site
> where I can map this out.

FWIW, I'm convinced this is a futile exercise because I understand a
fair amount about data collection and statistical data processing. I
know that there are roughly only 750 to 800 bike fatalities a year all
across the US, and I know that you're unlikely to get enough fatality
data points on any given road or intersection to reach any
statistically valid conclusions.

I also know about confounding factors in data analysis. I know, for
example, that if a given road has twenty times the bike traffic of an
adjacent road, your general method is more likely to call that road
"dangerous," even if it's safer per mile cycled than the adjacent
one. More concisely, you at _least_ need to evaluate cycling traffic
at each location you post - and I'm pretty sure you won't have a way
to do that.

> I honestly don't whether this representation is helpful or not. Right
> now I'm in the mode of "Let's see what this representation might
> show."

That's fine. I'm willing to let you work on it and report back from
time to time! ;-)

> Every responsible department of transportation would have
> somebody doing this very same thing, it's just in this digital age we
> can get more of the back story instead of some jumble of numbers that
> doesn't relate to the real world.

I'm not sure about your meaning in the first sentence of that
paragraph. Did you mean "should have" instead of "would have"? In
any case, I think it's unlikely that many resources would be devoted
to this effort - for exactly the reasons Carl and I have enumerated.
They know it will be futile, and wouldn't make much difference even if
it succeeded. There are better ways to spend money.

> I'd invite Carl and Frank to take a look at figures 5-7 in this report
> so they can get a firsthand idea of what I'm talking about:http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/safetyin...

Some of the figures you reference plot injury data, rather than
fatality data. I think that's a bit of improvement, because you've at
least got a chance of getting enough data points to do something
with. OTOH, that data still needs a denominator. That is, it needs
to be reduced to "per cyclist" or "per mile ridden" data.

I'm currently reading _Death in the Streets_ by Robert Davis. (ISBN
0-948135-46-8). He points out that the dominance of the automobile
has intimidated many cyclists and pedestrians off the roads. And he
points out that the motoring-dominated "road safety" organizations
don't acknowledge that fact. They look at any reduction in bike and
ped fatalities as proof that they're doing things right.

By that logic, a freeway is the safest possible place to walk, because
freeways have close to zero pedestrian fatalities. Your proposed
method is likely to make the same mistake, calling places where no
cyclist ever rides "safe," and calling places where tons of cyclists
ride "dangerous," even if they're safer per mile ridden.

But carry on, if you like. I'm willing to see what you come up with.

- Frank Krygowski

Date: 23 Sep 2007 17:45:48
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 4:41 pm, "Mike Jacoubowsky" <mik...@ix.netcom.com > wrote:
> > Given fewer than a thousand bicycle fatalities per year, it is
> > extremely unlikely that a single intersection in the U.S. can be
> > identified as causing problems.
>
> It seems like an absurd use of data if we limit it to a binary choice-
> cyclist killed, or not. The devil is in the details, and unless we're in a
> situation where cyclists are generally killed on roads and not injured
> (which, thankfully, I believe not to be the case), more-meaningful
> conclusions and workarounds are likely to be had from analyzing deaths *and*
> injuries. This, I would think, should increase the sample size dramatically,
> and make judgments of individual roads far more relevant.
>
> Or am I missing something here? There's a chance I really don't understand
> the central point to this thread at all. That seems to happen to me with
> increasing frequency lately, and I'm not sure if it's me or rbt or a
> combination of the two. Guess the relevant meaningful statistic that might
> help here is that I'm 51.
>
> --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com
>
> <carlfo...@comcast.net> wrote in message
>
> news:7jqdf3t6iicvkc6reqva5f66tebjce7bst@4ax.com...
>
> > On Sun, 23 Sep 2007 15:32:03 -0700, damyth
> > <mdk.10.dam...@spamgourmet.com> wrote:
>
> > [snip]
>
> >>As Thomas Paine once said, "Lead, follow, or get out of my way."
>
> > Dear D,
>
> > Ah, the lemming war-cry!
>
> > :-)
>
> > More seriously, it's an exhortation for nothing more than motion, even
> > when movement is pointless or even counter-productive. The urge to
> > _do_ something is strong, but not necessarily useful.
>
> > "Don't just _do_ something, stand there!"
>
> > To be more specific, the most common cause of a fatal bicycle accident
> > is a car-bicycle collision.
>
> > If a specific intersection had more than the average number of biek
> > deaths, then an intersection could be identified as more dangerous
> > than average--providing that it had no more than average bike traffic
> > and that the excess was statistically significant.
>
> > Given fewer than a thousand bicycle fatalities per year, it is
> > extremely unlikely that a single intersection in the U.S. can be
> > identified as causing problems.
>
> > The same applies to any stretch of road.
>
> > Until you get up to geographical areas the size of counties, there
> > just isn't much difference, and even at that level it's not
> > significant.
>
> > Cheers,
>
> > Carl Fogel

According to the data I've collected let me be the first to urge you
to obtain a medical check up prior to attempting Old La Honda, Kings
Mountain, or Empire Grade. :)

Just kidding.

Carl Fogel & Frank Krygowski have their biking shorts in a bunch
because they're convinced this is a futile exercise. It's interesting
that they take this position a priori, even before I found a web site
where I can map this out. It's even more amusing to me that Carl
Fogel quotes us DOT statistics without understanding or addressing DOT
underlying assumptions.

I honestly don't whether this representation is helpful or not. Right
now I'm in the mode of "Let's see what this representation might
show." Every responsible department of transportation would have
somebody doing this very same thing, it's just in this digital age we
can get more of the back story instead of some jumble of numbers that
doesn't relate to the real world.

I'd invite Carl and Frank to take a look at figures 5-7 in this report
so they can get a firsthand idea of what I'm talking about:
http://mtc.ca.gov/library/2001_rtp/downloads/bike/final_plan/safetyindex.doc

Date: 24 Sep 2007 00:08:26
From: datakoll
Subject: Re: bike accident fatalities and google maps?

the auto accident maps combined with bike accident maps plus topo and
fed info give ACCIDENT POTENTIAL which is what urawl looking for, not
accident occurence per se.
CLEARLY, intersections or road segments evidencing high vehicle
accident rates are dangerous roads for bike riding.
Vehicle accident trouble areas should be available from County or
State.
Then yawl add bike accident reports dutifully sent in by the bike club
minions who are gentically involved in this process 24/7/365/you know
who they are right? That's the source otherwise the maps are outdated
like now or sooner.
There are several in Lee county where I moved from. Awareness of that
danger kept me from potential injury.
Once I came upon the scene of 3 burning car/truck/van piled on mating
fashion. Stopped for the light? Clearly dangerous. Eg, search
Okeechobee and Military Trail in West Palm Beach.

Date: 23 Sep 2007 15:32:03
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 7:38 am, frkry...@gmail.com wrote:
> On Sep 23, 2:51 am, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>
> > I invite all of you (including all you naysayers) to join me in
> > mapping out bicycle fatalities here:http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>
> > _Anyone_ can make edits to this map. This is a wiki and google map
> > rolled in one. I started out with the San Francisco Bay Area because
> > this is where I happen to ride most, but there is no technical reason
> > why this can't include all contiguous 48 states.
>
> > It is well known that geographic information system (GIS) tools can
> > improve bicycle and pedestrian safety. Just google "GIS bicycle
> > safety." However, one should not make any hasty judgments regarding
> > the data.
>
> I am pretty curious what you'll do with the information you get. Will
> you stay off a road if a cyclist had a heart attack while riding?
> (That's two of your fatalities.) What if the fatality was caused by a
> kid riding directly off a sidewalk into a turning truck? (That was
> the last fatality in our area.)
>
You'll notice I have explicitly refrained from drawing conclusions.
It's not as if I've tried to obscure the cause of death (in the
possible heart attack cases).

If you've ridden the area at all, you'd understand why heart attacks
may have occurred in those instances. They are STEEP, and at a very
minimum the elderly should not ride those roads without having a
proper medical to verify their tickers won't give out.

I've even included incidents such as a bicyclist who crossed train
tracks, and 8 year old kid drivers. Whether those data points should
be included or not, that's exactly why technology is useful. They
viewer chooses which data set is of interest.

> If, say, a two mile stretch of road has two fatalities in ten years,
> was that because the road is dangerous, or because of a combination of
> random bad luck and a very popular cycling route?
>
> And if you're at the east end of that two miles, and you need to get
> to the west end, how much of a mountain will you climb to avoid it?
>
I'm well aware of the pitfalls of cluster analysis.

Sand Hill Road has had three fatalities with the last 8 years, and an
additional one that could easily have been fatal. 3 of the 4
incidents involved female bicyclists. This is exactly the kind of
relationship one wants to elicit from this type of representation, and
a little data mining.

I've always thought of Sand Hill Road as not particularly dangerous,
although I consider it to be a "fast" road. Based on the information
I've gathered, you bet I'm going to be more situationally aware while
riding Sand Hill Road. Does it mean I'm going to stop or curtail
riding it? Of course not.

> It's going to be interesting to see how - and if - this progresses.
> Keep us posted.
>
Yeah, keep on snickering. The Google mashup presents the data from a
different perspective, it's really no different from a phase space
representation. People who mis-interpret the data or draw incorrect
conclusions are not my problem. At a very minimum, this will inform
bicyclists and drivers to be a bit more heedful of each other on Sand
Hill Road.

As Thomas Paine once said, "Lead, follow, or get out of my way."

> - Frank Krygowski

Date: 25 Sep 2007 01:08:03
From: datakoll
Subject: Re: bike accident fatalities and google maps?

just discovered hoover dike's gettin paved.
various blogs and papers mention the threat of

http://outdoortravels.com/biking_fl_overview_lake-okeechobee.html

swing around and head down to the keys with a north wind from Boone!

Date: 23 Sep 2007 16:52:54
From:
Subject: Re: bike accident fatalities and google maps?

On Sun, 23 Sep 2007 15:32:03 -0700, damyth
<mdk.10.damyth@spamgourmet.com > wrote:

[snip]

>As Thomas Paine once said, "Lead, follow, or get out of my way."

Dear D,

Ah, the lemming war-cry!

:-)

More seriously, it's an exhortation for nothing more than motion, even
when movement is pointless or even counter-productive. The urge to
_do_ something is strong, but not necessarily useful.

"Don't just _do_ something, stand there!"

To be more specific, the most common cause of a fatal bicycle accident
is a car-bicycle collision.

If a specific intersection had more than the average number of biek
deaths, then an intersection could be identified as more dangerous
than average--providing that it had no more than average bike traffic
and that the excess was statistically significant.

Given fewer than a thousand bicycle fatalities per year, it is
extremely unlikely that a single intersection in the U.S. can be
identified as causing problems.

The same applies to any stretch of road.

Until you get up to geographical areas the size of counties, there
just isn't much difference, and even at that level it's not
significant.

Cheers,

Carl Fogel

Date: 23 Sep 2007 19:51:25
From: A Muzi
Subject: Re: bike accident fatalities and google maps?

> damyth <mdk.10.damyth@spamgourmet.com> wrote:
> [snip]
>> As Thomas Paine once said, "Lead, follow, or get out of my way."

carlfogel@comcast.net wrote:
> Ah, the lemming war-cry!
> :-)
> More seriously, it's an exhortation for nothing more than motion, even
> when movement is pointless or even counter-productive. The urge to
> _do_ something is strong, but not necessarily useful.
> "Don't just _do_ something, stand there!"
-snip on-topic filler-

Anyone who listened to Emil Jones (Illinois State Senate president)
pontificating on 'leadership' and 'action' on the radio today already
knows those pitfalls.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Date: 24 Sep 2007 01:24:18
From: Kristian M Zoerhoff
Subject: Re: bike accident fatalities and google maps?

On 2007-09-24, A Muzi <am@yellowjersey.org > wrote:
>> damyth <mdk.10.damyth@spamgourmet.com> wrote:
>> [snip]
>>> As Thomas Paine once said, "Lead, follow, or get out of my way."
>
> carlfogel@comcast.net wrote:
>> Ah, the lemming war-cry!
>> :-)
>> More seriously, it's an exhortation for nothing more than motion, even
>> when movement is pointless or even counter-productive. The urge to
>> _do_ something is strong, but not necessarily useful.
>> "Don't just _do_ something, stand there!"
> -snip on-topic filler-
>
> Anyone who listened to Emil Jones (Illinois State Senate president)
> pontificating on 'leadership' and 'action' on the radio today already
> knows those pitfalls.

Given that he seems to be an expert on neither, I'm not surprised.

--

__o Kristian Zoerhoff
_'\(,_ kristian.zoerhoff@gmail.com
(_)/ (_)

Date: 23 Sep 2007 16:41:19
From: Mike Jacoubowsky
Subject: Re: bike accident fatalities and google maps?

> Given fewer than a thousand bicycle fatalities per year, it is
> extremely unlikely that a single intersection in the U.S. can be
> identified as causing problems.

It seems like an absurd use of data if we limit it to a binary choice-
cyclist killed, or not. The devil is in the details, and unless we're in a
situation where cyclists are generally killed on roads and not injured
(which, thankfully, I believe not to be the case), more-meaningful
conclusions and workarounds are likely to be had from analyzing deaths *and*
injuries. This, I would think, should increase the sample size dramatically,
and make judgments of individual roads far more relevant.

Or am I missing something here? There's a chance I really don't understand
the central point to this thread at all. That seems to happen to me with
increasing frequency lately, and I'm not sure if it's me or rbt or a
combination of the two. Guess the relevant meaningful statistic that might
help here is that I'm 51.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

<carlfogel@comcast.net > wrote in message
news:7jqdf3t6iicvkc6reqva5f66tebjce7bst@4ax.com...
> On Sun, 23 Sep 2007 15:32:03 -0700, damyth
> <mdk.10.damyth@spamgourmet.com> wrote:
>
> [snip]
>
>>As Thomas Paine once said, "Lead, follow, or get out of my way."
>
> Dear D,
>
> Ah, the lemming war-cry!
>
> :-)
>
> More seriously, it's an exhortation for nothing more than motion, even
> when movement is pointless or even counter-productive. The urge to
> _do_ something is strong, but not necessarily useful.
>
> "Don't just _do_ something, stand there!"
>
> To be more specific, the most common cause of a fatal bicycle accident
> is a car-bicycle collision.
>
> If a specific intersection had more than the average number of biek
> deaths, then an intersection could be identified as more dangerous
> than average--providing that it had no more than average bike traffic
> and that the excess was statistically significant.
>
> Given fewer than a thousand bicycle fatalities per year, it is
> extremely unlikely that a single intersection in the U.S. can be
> identified as causing problems.
>
> The same applies to any stretch of road.
>
> Until you get up to geographical areas the size of counties, there
> just isn't much difference, and even at that level it's not
> significant.
>
> Cheers,
>
> Carl Fogel

Date: 23 Sep 2007 15:49:56
From: Mike Jacoubowsky
Subject: Re: bike accident fatalities and google maps?

> Sand Hill Road has had three fatalities with the last 8 years, and an
> additional one that could easily have been fatal. 3 of the 4
> incidents involved female bicyclists. This is exactly the kind of
> relationship one wants to elicit from this type of representation, and
> a little data mining.

It's going to be tough filtering out "bad luck" as a contributing factor. I
can quickly come up with two which, I believe, have nothing whatsoever to do
with the actual safety of the road involved.

First would be the King's Mountain fatality some years ago, in which a guy
was riding up the hill, about 3/4 mile from the bottom (before the first
semi-hairpin where it crosses the creek). He was all the way at the right
side of the road, doing, by all accounts, absolutely nothing wrong. A car
coming in the opposite direction was heading down the hill (as the cyclist
was riding up) and managed to get his right wheels off the edge of the road,
where there was, at the time, a significant drop-off of perhaps 4 inches. To
get out of the rut the driver over-corrected, sending his car careening
across the road, taking out the cyclist and pinning him (the cyclist)
between the truck and a tree about 20 feet off the road (towards the creek).
What makes this "bad luck" to me is that the road is fairly lightly traveled
(especially at the time of day of the incident), and it in no way involved
the cyclist causing or even contributing to the accident. He was in the
exact wrong place at the wrong time, the odds of which boggle the mind.

Second would the be most-recent fatality on Sand Hill, which involved
someone I know hitting a traffic cone and managing to crash in exactly the
right manner to cause a fatal head injury. Given that there is nothing about
a traffic cone that's particular to Sand Hill Road (any more than any other
road), and the accident did not involve anyone other than the cyclist, and
that there were no road issues involved other than the cone (there were
witnesses), I think this again is something I'd have a tough time using to
say a given road is more dangerous than another.

For what it's worth, I extensively investigated the first incident I
mentioned. It rattled me greatly, given that it's a road I ride twice a
week, and also that, when we first heard about someone being involved in a
fatal accident on Kings Mtn, there was a good chance that it was one of our
employees, who was out riding that road that day. It wasn't, but I didn't
know that for several hours (during which I was unable to contact her and
thus concerned).

I think the real value of a database such as you're working on isn't to come
up with a list of roads that are statistically worse than others, but rather
a way to look at each road individually and think about ways that
improvements (on that particular road) might prevent future accidents and
fatalities. In other words, it would be great if we could look at one road
at a time (Sand Hill, for example) and identify all the issues and work to
make it a better road for cyclists. And then move on to the next one, and so
on. Which might be the same thing you have in mind?

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

"damyth" <mdk.10.damyth@spamgourmet.com > wrote in message
news:1190586723.717386.159700@o80g2000hse.googlegroups.com...
> On Sep 23, 7:38 am, frkry...@gmail.com wrote:
>> On Sep 23, 2:51 am, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>>
>> > I invite all of you (including all you naysayers) to join me in
>> > mapping out bicycle fatalities
>> > here:http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>>
>> > _Anyone_ can make edits to this map. This is a wiki and google map
>> > rolled in one. I started out with the San Francisco Bay Area because
>> > this is where I happen to ride most, but there is no technical reason
>> > why this can't include all contiguous 48 states.
>>
>> > It is well known that geographic information system (GIS) tools can
>> > improve bicycle and pedestrian safety. Just google "GIS bicycle
>> > safety." However, one should not make any hasty judgments regarding
>> > the data.
>>
>> I am pretty curious what you'll do with the information you get. Will
>> you stay off a road if a cyclist had a heart attack while riding?
>> (That's two of your fatalities.) What if the fatality was caused by a
>> kid riding directly off a sidewalk into a turning truck? (That was
>> the last fatality in our area.)
>>
> You'll notice I have explicitly refrained from drawing conclusions.
> It's not as if I've tried to obscure the cause of death (in the
> possible heart attack cases).
>
> If you've ridden the area at all, you'd understand why heart attacks
> may have occurred in those instances. They are STEEP, and at a very
> minimum the elderly should not ride those roads without having a
> proper medical to verify their tickers won't give out.
>
> I've even included incidents such as a bicyclist who crossed train
> tracks, and 8 year old kid drivers. Whether those data points should
> be included or not, that's exactly why technology is useful. They
> viewer chooses which data set is of interest.
>
>> If, say, a two mile stretch of road has two fatalities in ten years,
>> was that because the road is dangerous, or because of a combination of
>> random bad luck and a very popular cycling route?
>>
>> And if you're at the east end of that two miles, and you need to get
>> to the west end, how much of a mountain will you climb to avoid it?
>>
> I'm well aware of the pitfalls of cluster analysis.
>
> Sand Hill Road has had three fatalities with the last 8 years, and an
> additional one that could easily have been fatal. 3 of the 4
> incidents involved female bicyclists. This is exactly the kind of
> relationship one wants to elicit from this type of representation, and
> a little data mining.
>
> I've always thought of Sand Hill Road as not particularly dangerous,
> although I consider it to be a "fast" road. Based on the information
> I've gathered, you bet I'm going to be more situationally aware while
> riding Sand Hill Road. Does it mean I'm going to stop or curtail
> riding it? Of course not.
>
>> It's going to be interesting to see how - and if - this progresses.
>> Keep us posted.
>>
> Yeah, keep on snickering. The Google mashup presents the data from a
> different perspective, it's really no different from a phase space
> representation. People who mis-interpret the data or draw incorrect
> conclusions are not my problem. At a very minimum, this will inform
> bicyclists and drivers to be a bit more heedful of each other on Sand
> Hill Road.
>
> As Thomas Paine once said, "Lead, follow, or get out of my way."
>
>> - Frank Krygowski
>

Date: 23 Sep 2007 16:09:57
From: datakoll
Subject: Re: bike accident fatalities and google maps?

crunching numbers toward a reality is difficult. Cal's two number sets
with shifting county colors is ....
but North Cal is easy. No one lives in North Cal, roads are dangerous,
and there's no traffic, and no bicycles = relatively few bicycle
fatalities.
Like the Indian mortality in Manhattan 1865-1890.
>From a distance, we may comfortably ignore the North Cal data and
proceed on topo, road map, and federal stats (whom by the way became
the country's majority employeer)
Butbutbut in SF, we see a cluster. Why? well, we don't know but the
cluster is evidence that the area is relatively dangerous: otherwise
no cluster. Adding the cluster to topo, road map, and federal stats
and there's whatchucallur hard data.
Not only for the wannabe x country or x nurb rider but also the civic
do gooder.
Off course, if one needs military service to learn how to shower...?

Date: 23 Sep 2007 14:38:29
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 23, 2:51 am, damyth <mdk.10.dam...@spamgourmet.com > wrote:
> I invite all of you (including all you naysayers) to join me in
> mapping out bicycle fatalities here:http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>
> _Anyone_ can make edits to this map. This is a wiki and google map
> rolled in one. I started out with the San Francisco Bay Area because
> this is where I happen to ride most, but there is no technical reason
> why this can't include all contiguous 48 states.
>
> It is well known that geographic information system (GIS) tools can
> improve bicycle and pedestrian safety. Just google "GIS bicycle
> safety." However, one should not make any hasty judgments regarding
> the data.

I am pretty curious what you'll do with the information you get. Will
you stay off a road if a cyclist had a heart attack while riding?
(That's two of your fatalities.) What if the fatality was caused by a
kid riding directly off a sidewalk into a turning truck? (That was
the last fatality in our area.)

If, say, a two mile stretch of road has two fatalities in ten years,
was that because the road is dangerous, or because of a combination of
random bad luck and a very popular cycling route?

And if you're at the east end of that two miles, and you need to get
to the west end, how much of a mountain will you climb to avoid it?

It's going to be interesting to see how - and if - this progresses.
Keep us posted.

- Frank Krygowski

Date: 23 Sep 2007 12:29:56
From: datakoll
Subject: Re: bike accident fatalities and google maps?

Date: 22 Sep 2007 23:51:33
From: damyth
Subject: Re: bike accident fatalities and google maps?

I invite all of you (including all you naysayers) to join me in
mapping out bicycle fatalities here:
http://www.wikyblog.com/map/damyth/SFBayBikeFatal

_Anyone_ can make edits to this map. This is a wiki and google map
rolled in one. I started out with the San Francisco Bay Area because
this is where I happen to ride most, but there is no technical reason
why this can't include all contiguous 48 states.

It is well known that geographic information system (GIS) tools can
improve bicycle and pedestrian safety. Just google "GIS bicycle
safety." However, one should not make any hasty judgments regarding
the data.

Date: 23 Sep 2007 12:04:56
From: Wayne Pein
Subject: Re: bike accident fatalities and google maps?

damyth wrote:

> I invite all of you (including all you naysayers) to join me in
> mapping out bicycle fatalities here:
> http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>
> _Anyone_ can make edits to this map. This is a wiki and google map
> rolled in one. I started out with the San Francisco Bay Area because
> this is where I happen to ride most, but there is no technical reason
> why this can't include all contiguous 48 states.
>

How about the reason that's it's a useless waste of time?

Wayne

Date: 23 Sep 2007 01:18:50
From:
Subject: Re: bike accident fatalities and google maps?

On Sat, 22 Sep 2007 23:51:33 -0700, damyth
<mdk.10.damyth@spamgourmet.com > wrote:

>I invite all of you (including all you naysayers) to join me in
>mapping out bicycle fatalities here:
>http://www.wikyblog.com/map/damyth/SFBayBikeFatal
>
>_Anyone_ can make edits to this map. This is a wiki and google map
>rolled in one. I started out with the San Francisco Bay Area because
>this is where I happen to ride most, but there is no technical reason
>why this can't include all contiguous 48 states.
>
>It is well known that geographic information system (GIS) tools can
>improve bicycle and pedestrian safety. Just google "GIS bicycle
>safety." However, one should not make any hasty judgments regarding
>the data.

Dear D,

It will be hard to make hasty judgements, given the scarcity of bike
fatalities versus the geographical spread.

Expect a single pedalcyclist fatality per year for San Francisco
County--there's been 1 every year from 2002 to 2006:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/Counties/California_San%20Francisco%20County_2006.HTM

Expect 0, or 1-5 deaths per year in all but one nearby county, judging
by this map:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6_CA_2006.htm#CTY_MAPS9

For "safety", head north. The map shows that the ten north-most
counties in California had 0 bike fatalities in 2006.

Florida appears to be far more "dangerous," with half as many people
as California, and the same number of deaths from 2002 to 2006.

Cheers,

Carl Fogel

Date: 22 Sep 2007 23:47:57
From: datakoll
Subject: Re: bike accident fatalities and google maps?

http://biz.yahoo.com/brn/070914/22589.html?.v=1&.pf=family-home

Date: 22 Sep 2007 21:52:55
From:
Subject: Re: bike accident fatalities and google maps?

On Sep 21, 11:51 pm, damyth <mdk.10.dam...@spamgourmet.com > wrote:
> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.

As the discussion has showed, it's really unlikely you'll ever get
such a map. There are far too few bike fatalities to show anything
significant. It would be like asking for a map of meteorite strikes,
so you could carry a metal umbrella when you were in the area.

But about the "spate of bike fatalities": While some areas are
certainly more dangerous than others, it's probable that many, if not
most such "spates" are just random variation. IIRC, Portland Oregon
had such a spate in 2006, with (I think) five cyclist fatalities that
year. That doesn't mean Portland suddenly got very dangerous. In all
probability, it just means random chance played out that way.

One interesting consequence is that, in response to a spate of
accidents, the public often calls for officials to _do_ something.
And the officials often comply, to stay elected. And the success is
often immediate - as in, "Look, we made cyclists wear pink shirts, and
the fatalities dropped back to their previous value! Aren't we wise!"

But it's probable that the observed effect is nothing more than what's
called "regression to the mean." Loosely speaking, that means
meteorites don't strike twice in the same place.* If nothing at all
had been done, the odd coincidence that caused the blip would have
vanished on its own.

IIRC, the book _Risk_ by John Adams discusses many examples of this
phenomenon, regarding improvements to "black spots" on British roads.
He claimed evidence of a strong "regression to the mean" effect.

My approach would be: if there's one particular road that
_consistently_ generates injuries or fatalities, then yes, there's
probably something wrong there. Working to fix it or avoid it might
make sense. But most fatalities are going to be almost as random as
meteorite strikes - except, as Carl noted, for the influence of
alcohol.

So I'd say, don't drink and ride. I'd also ride competently, because
many car-bike crashes are apparently the cyclist's fault. Those will
markedly improve your already excellent odds.

But I don't think it's worth the time to search out specific fatality
data.

*Unfortunately for the proverb writers, lightning often does strike
twice in the same place.

- Frank Krygowski

Date: 24 Sep 2007 02:03:23
From: Michael Press
Subject: Re: bike accident fatalities and google maps?

In article
<1190497975.006721.12360@w3g2000hsg.googlegroups.com >,
frkrygow@gmail.com wrote:

> But it's probable that the observed effect is nothing more than what's
> called "regression to the mean." Loosely speaking, that means
> meteorites don't strike twice in the same place.*

That is not what regression to the mean means.

Flip a (fair) coin 30 times and get
HHTTTHTHTHTTTTTHHHHTTHTHTTHTH

The probability of getting the same sequence again in
30 tosses remains about 1 in a thousand million,
completely unaffected by the occurrence of that
sequence.

Regression to the mean is better illustrated
by the fact that taller than average parents
have taller than average children, but the children
tend to be shorter than the parents.

Shorter than average parents tend to have shorter
than average children, but the children tend
to be taller than their parents.

> If nothing at all
> had been done, the odd coincidence that caused the blip would have
> vanished on its own.

--
Michael Press

Date: 22 Sep 2007 20:21:11
From: datakoll
Subject: Re: bike accident fatalities and google maps?

No interactive stats on the holiday situation. I lived on the island,
traveled by bike, maybe holding the record for bicycle causeway
crossings at around 278.Rode every day.
Tourist businesses line Periwinkle From the right map or south side to
the point where you'll read Gulf Drive: confining parking spaces,
dense traffic, and a few cross streets.
Annnnddddd, scooter, bicycle rentals.
During the winter season, the frequency of cycle crashes over 2-3
miles was astounding coming upon one (1) good intersection or lot exit
crash every 5 days. Carnage!
No "can't afford batteries" or "I live around the corner" excuses
here:
Big rush, drunk, stoned, incompetent, no experienced, foolhardy,
blind, no reflexes. Awesome.
Another map category.

http://www.sanibelflorida.com/bybike.htm

the FOSSET PRIZE could have several participating categories: GPS
satellite tracking, video and audio, barefoot checkin
I'm not sure one could get away with an entry fee?
Wow! Imagine Big rush, drunk, stoned, incompetent, no experienced,
foolhardy, blind, no reflexes. Awesome. Crawling over the desert
mountains looking for $1,000,000.

bottoms up!

Date: 22 Sep 2007 14:55:41
From: Wayne Pein
Subject: Re: bike accident fatalities and google maps?

damyth wrote:

> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.
>

How do you know the bicyclists weren't at fault, meaning the roads are
not dangerous but dangerous riding resulted in the fatalaties?

Wayne

Date: 22 Sep 2007 23:14:36
From: Dennis Ferguson
Subject: Re: bike accident fatalities and google maps?

On 2007-09-22, Wayne Pein <wpein@nc.rr.com > wrote:
> damyth wrote:
>
>> A recent spate of bike fatalities in the local area (Sand Hill Road
>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>> database pinpointing locations of bike fatalities? This would be
>> incredibly helpful for people to find out where the most dangerous
>> roads to ride are, a geographical representation of frequency, and
>> maybe help people to avoid/improve those areas.
>>
>> Some of you might point out it should be "obvious" where the most
>> dangerous areas are, but I ride that area often, but it never occurred
>> to me that so many fatalities have occurred there until someone
>> recently pointed it out.
>>
>
> How do you know the bicyclists weren't at fault, meaning the roads are
> not dangerous but dangerous riding resulted in the fatalaties?

With respect to the two deaths I know about there this year, both
were experienced cyclists, riding during the day, who got hit by a
car from behind. One got hit on the shoulder (and the shoulder is
10 feet wide there, with good asphalt and usually clean) by an old
guy who came over the fog line to get him, the other I think got hit
on or near a freeway overpass by a driver who had an open container of
alcohol in the truck.

I don't think the cyclists did anything wrong. I also don't think
that road is particularly dangerous, though it seems a few dangerous
drivers use it.

Dennis Ferguson

Date: 22 Sep 2007 21:24:07
From: Wayne Pein
Subject: Re: bike accident fatalities and google maps?

Dennis Ferguson wrote:

> On 2007-09-22, Wayne Pein <wpein@nc.rr.com> wrote:
>

>>How do you know the bicyclists weren't at fault, meaning the roads are
>>not dangerous but dangerous riding resulted in the fatalaties?
>
>
> With respect to the two deaths I know about there this year, both
> were experienced cyclists, riding during the day, who got hit by a
> car from behind. One got hit on the shoulder (and the shoulder is
> 10 feet wide there, with good asphalt and usually clean) by an old
> guy who came over the fog line to get him, the other I think got hit
> on or near a freeway overpass by a driver who had an open container of
> alcohol in the truck.
>
> I don't think the cyclists did anything wrong. I also don't think
> that road is particularly dangerous, though it seems a few dangerous
> drivers use it.
>

I'd speculate that the very wide shoulder might have duped him into
thinking it a lane.

Wayne

Date: 22 Sep 2007 13:42:43
From:
Subject: Re: bike accident fatalities and google maps?

On Sat, 22 Sep 2007 14:55:41 -0400, Wayne Pein <wpein@nc.rr.com >
wrote:

>damyth wrote:
>
>> A recent spate of bike fatalities in the local area (Sand Hill Road
>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>> database pinpointing locations of bike fatalities? This would be
>> incredibly helpful for people to find out where the most dangerous
>> roads to ride are, a geographical representation of frequency, and
>> maybe help people to avoid/improve those areas.
>>
>> Some of you might point out it should be "obvious" where the most
>> dangerous areas are, but I ride that area often, but it never occurred
>> to me that so many fatalities have occurred there until someone
>> recently pointed it out.
>>
>
>How do you know the bicyclists weren't at fault, meaning the roads are
>not dangerous but dangerous riding resulted in the fatalaties?
>
>Wayne

Dear Wayne,

It's often overlooked, but bicycle deaths resemble auto fatalities in
that there's often an empty bottle in the background:

"Drinking alcohol and bicycling don?t mix well, say Johns Hopkins
researchers, whose study of 466 Maryland bicyclists found that a third
of fatally injured riders had elevated blood alcohol levels at the
time of their accident. In addition, a blood alcohol concentration of
0.08 grams per deciliter ? the legal level of drunkenness in most
states ? was found to increase the rider?s risk of fatal or serious
injury by 2,000 percent. . . ."

"Alcohol may play an even greater role than indicated by this study,
the researchers said, since the group did not look at bicycle injuries
occurring at night, when 56 percent of fatal bicycling injuries and 32
percent of serious bicycling injuries occur."

http://www.hopkinsmedicine.org/press/2001/FEBRUARY/010220.HTM

I don't recall any RBT anecdotes that involve drunk riders killing
themselves. Possibly they're all non-drinkers, like me, but there are
other plausible explanations.

Chee--

Er, that's just an expression, not a toast.

Carl Fogel

Date: 22 Sep 2007 10:42:16
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 21, 8:51 pm, damyth <mdk.10.dam...@spamgourmet.com > wrote:
> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.

Found via google:
http://kcbike.info/maps/crash/

And I thought we had it bad here in CA.

Date: 22 Sep 2007 13:10:35
From:
Subject: Re: bike accident fatalities and google maps?

On Sat, 22 Sep 2007 10:42:16 -0700, damyth
<mdk.10.damyth@spamgourmet.com > wrote:

>On Sep 21, 8:51 pm, damyth <mdk.10.dam...@spamgourmet.com> wrote:
>> A recent spate of bike fatalities in the local area (Sand Hill Road
>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>> database pinpointing locations of bike fatalities? This would be
>> incredibly helpful for people to find out where the most dangerous
>> roads to ride are, a geographical representation of frequency, and
>> maybe help people to avoid/improve those areas.
>>
>> Some of you might point out it should be "obvious" where the most
>> dangerous areas are, but I ride that area often, but it never occurred
>> to me that so many fatalities have occurred there until someone
>> recently pointed it out.
>
>Found via google:
>http://kcbike.info/maps/crash/
>
>And I thought we had it bad here in CA.

Dear D,

http://kcbike.info/maps/crash/

That map shows 32 bike fatalities in 16 years from 1991 to 2007, an
average of 2 per year, in the Kansas City, Missouri, area. Wikipedia
indicates a population of 2 million for that sprawling area:

http://en.wikipedia.org/wiki/Kansas_city

For 2006, that Kansas City map shows 5 bike fatalities:

http://kcbike.info/maps/crash/

For 2006, this database shows 7 bike fatalities for the whole _state_
of Missouri:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/29_MO/2006/29_MO_2006.htm

And 6 bike fatalities for the _whole_ state of Kansas in 2006:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/20_KS/2006/20_KS_2006.htm#CTY_MAPS9

Here's the pair of county-level 2006 maps for Kansas, showing that the
Kansas county on the Kansas side of the urban area (white counties at
jagged eastern border) didn't even show up in 2006--no fatalities:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/20_KS/2006/20_KS_2006.htm#CTY_MAPS9

(You can check this by clicking on the western red flags of the map
and looking at the date and state in the info balloon.)

Here's the pair of county-level 2006 maps for Missouri, showing that
the Kansas City area (green on west side of state) is in the _lower_
third of all counties for bike deaths / 100,000 population:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/29_MO/2006/29_MO_2006.htm#CTY_MAPS9

In other words, the Kansas City area is _below_ the national county
average in bike deaths per 100,000 population.

The two states that include that area had a total of 13 bike
fatalities in 2006. Missouri had 5.8 million people, Kansas 2.7
million, or 13 bike deaths among 8.5 million people.

http://en.wikipedia.org/wiki/Missouri#Demographics

http://en.wikipedia.org/wiki/Kansas#Demographics

Cheers,

Carl Fogel

Date: 22 Sep 2007 13:01:05
From: Matt O'Toole
Subject: Re: bike accident fatalities and google maps?

On Fri, 21 Sep 2007 20:51:22 -0700, damyth wrote:

> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.

This is the kind of thing the Bikeleague could be doing, but they're not
even smart enough to have a news blog with an RSS feed, and all the neato
possibilities with that. Email newsletters are *so* 12 years ago.

They're advertising for new board members.

Matt O.

Date: 22 Sep 2007 13:17:40
From:
Subject: Re: bike accident fatalities and google maps?

On Sat, 22 Sep 2007 13:01:05 -0400, Matt O'Toole
<mattotoole@letterboxes.org > wrote:

>On Fri, 21 Sep 2007 20:51:22 -0700, damyth wrote:
>
>> A recent spate of bike fatalities in the local area (Sand Hill Road
>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>> database pinpointing locations of bike fatalities? This would be
>> incredibly helpful for people to find out where the most dangerous
>> roads to ride are, a geographical representation of frequency, and
>> maybe help people to avoid/improve those areas.
>
>This is the kind of thing the Bikeleague could be doing, but they're not
>even smart enough to have a news blog with an RSS feed, and all the neato
>possibilities with that. Email newsletters are *so* 12 years ago.
>
>They're advertising for new board members.
>
>Matt O.

Dear Matt,

Use this database, select a state, scroll down to pedalcyclist
fatalities, note the statewide numbers, click on it, and look at the
county-level maps:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6_CA_2006.htm#CTY_MAPS9

That's California, probably the best-represented state on RBT. The
figures and the maps show why there's so little interest in tracking
bike deaths locally. Los Angeles County, for example, had 24
pedalcyclist fatalities in 2006:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/Counties/California_Los%20Angeles%20County_2006.HTM

That's 24 deaths in a county with 9.9 million people in 2006:

http://quickfacts.census.gov/qfd/states/06/06037.html

Cheers,

Carl Fogel

Date: 22 Sep 2007 23:01:38
From: Dennis Ferguson
Subject: Re: bike accident fatalities and google maps?

On 2007-09-22, carlfogel@comcast.net <carlfogel@comcast.net > wrote:
> On Sat, 22 Sep 2007 13:01:05 -0400, Matt O'Toole
><mattotoole@letterboxes.org> wrote:
>
>>On Fri, 21 Sep 2007 20:51:22 -0700, damyth wrote:
>>
>>> A recent spate of bike fatalities in the local area (Sand Hill Road
>>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>>> database pinpointing locations of bike fatalities? This would be
>>> incredibly helpful for people to find out where the most dangerous
>>> roads to ride are, a geographical representation of frequency, and
>>> maybe help people to avoid/improve those areas.
>>
>>This is the kind of thing the Bikeleague could be doing, but they're not
>>even smart enough to have a news blog with an RSS feed, and all the neato
>>possibilities with that. Email newsletters are *so* 12 years ago.
>>
>>They're advertising for new board members.
>>
> Use this database, select a state, scroll down to pedalcyclist
> fatalities, note the statewide numbers, click on it, and look at the
> county-level maps:
>
> http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6_CA_2006.htm#CTY_MAPS9
>
> That's California, probably the best-represented state on RBT. The
> figures and the maps show why there's so little interest in tracking
> bike deaths locally. Los Angeles County, for example, had 24
> pedalcyclist fatalities in 2006:

The county the location he's asking about is in is San Mateo, which must
have a population of close to 1 million and yet had 1 fatality in all of
2006. The 2 (or more? I only heard about 2) deaths on that one stretch of
road this year stand out in comparison, but the numbers are so small that
this seems like nothing more than random variation.

That particular road is fairly heavily travelled by bicycles since it
is part of one of the nicer lunchtime loops to ride as well as leading
to a couple of the better climbs into the coastal mountains. I don't
think the fact that a couple of cyclists got hit there says it is
necessarily dangerous, it just has a lot of cyclists to hit.

Dennis Ferguson

Date: 22 Sep 2007 16:37:49
From: datakoll
Subject: Re: bike accident fatalities and google maps?

a gift from above sent into 'my (their)groups'

alt . suicide . holiday

Date: 22 Sep 2007 16:09:57
From: datakoll
Subject: Re: bike accident fatalities and google maps?

On Sep 22, 10:39 am, datakoll <datak...@yahoo.com > wrote:
> On Sep 22, 10:17 am, datakoll <datak...@yahoo.com> wrote:
>
> > hmmm. I'm thinking a FOSSET PRIZE is a good way to break the tedium,
> > pawsibly a new reality TV 'show'
> > 1,000,000 for Fosset's head.

http://www.openroadjourney.com/?gclid=COnGocK5144CFQ0pgAodCAw45A

Date: 22 Sep 2007 15:27:27
From: datakoll
Subject: Re: bike accident fatalities and google maps?

google images is useful

http://images.google.com/imgres?imgurl=http://www.teresco.org/pics/signs/20020413/warning.jpg&imgrefurl=http://www.teresco.org/pics/signs/&h=480&w=640&sz=51&hl=en&start=4&sig2=K8P_mNNE9vuK4EDayoX9nA&um=1&tbnid=atJ9B00_U58KdM:&tbnh=103&tbnw=137&ei=qDP1RvLEO4uMebnEwI8O&prev=/images%3Fq%3Dgrand%2Barmy%2Bof%2Bthe%2Brepublic%2Bhighway%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3Dcom.microsoft:*:IE-SearchBox%26rlz%3D1I7GGLJ%26sa%3DN

Date: 22 Sep 2007 14:58:03
From: datakoll
Subject: Re: bike accident fatalities and google maps?

>
> like this?
>
> http://www.fhp.state.fl.us/traffic/

right! works good. if the area is known then tap Dixie to see what and
get...

http://www.fhp.state.fl.us/traffic/crs_h808.htm
tap any accident to get the Dixie map
then the solitary outback
that is a 'normal' outback fatality

WHERE'S THE ARCHIVE?

from a distance,with the satellite/hybrid, figuring riding on route
zero is possible PRIZE or no PRIZE

Date: 22 Sep 2007 14:39:45
From: datakoll
Subject: Re: bike accident fatalities and google maps?

On Sep 22, 10:17 am, datakoll <datak...@yahoo.com > wrote:
> hmmm. I'm thinking a FOSSET PRIZE is a good way to break the tedium,
> pawsibly a new reality TV 'show'
> 1,000,000 for Fosset's head.

like this?

http://www.fhp.state.fl.us/traffic/

California's road system is not one of the seven wonders: point A to B
is more West Side Highway when the asylum gets out for lunch.

Date: 22 Sep 2007 14:17:31
From: datakoll
Subject: Re: bike accident fatalities and google maps?

hmmm. I'm thinking a FOSSET PRIZE is a good way to break the tedium,
pawsibly a new reality TV 'show'
1,000,000 for Fosset's head.

Date: 21 Sep 2007 22:59:23
From: damyth
Subject: Re: bike accident fatalities and google maps?

On Sep 21, 10:20 pm, Chalo <chalo.col...@gmail.com > wrote:
> damyth wrote:
>
> > A recent spate of bike fatalities in the local area (Sand Hill Road
> > near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> > database pinpointing locations of bike fatalities? This would be
> > incredibly helpful for people to find out where the most dangerous
> > roads to ride are, a geographical representation of frequency, and
> > maybe help people to avoid/improve those areas.
>
> That sounds useful enough, and labor-intensive enough, to persuade
> someone to give you a grant for doing it. Google has opened their
> Maps database for such outside hacks, e.g. Bikely, Gmap-Pedometer,
> Frappr.
>
> Chalo

Heh, a site like bikefatalities.org, kind of like chicagocrime.org.
An effort like this would only be scalable and useful if this is a
community contributed project. A combination of a wiki + Google maps,
where anyone can add an entry on the map of verified incidents. I
haven't searched very hard, but I haven't yet found a public-editable
site that allows this. Frappr is more of a social networking site,
and only resolves to down to cities, which would be inadequate for
this purpose. As far as I know chicagocrime.org is not editable by
any random person (i.e. not everyone has write permission).

Date: 22 Sep 2007 05:20:16
From: Chalo
Subject: Re: bike accident fatalities and google maps?

damyth wrote:
>
> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.

That sounds useful enough, and labor-intensive enough, to persuade
someone to give you a grant for doing it. Google has opened their
Maps database for such outside hacks, e.g. Bikely, Gmap-Pedometer,
Frappr.

Chalo

Date: 22 Sep 2007 00:16:35
From:
Subject: Re: bike accident fatalities and google maps?

On Sat, 22 Sep 2007 05:20:16 -0000, Chalo <chalo.colina@gmail.com >
wrote:

>damyth wrote:
>>
>> A recent spate of bike fatalities in the local area (Sand Hill Road
>> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
>> database pinpointing locations of bike fatalities? This would be
>> incredibly helpful for people to find out where the most dangerous
>> roads to ride are, a geographical representation of frequency, and
>> maybe help people to avoid/improve those areas.
>
>That sounds useful enough, and labor-intensive enough, to persuade
>someone to give you a grant for doing it. Google has opened their
>Maps database for such outside hacks, e.g. Bikely, Gmap-Pedometer,
>Frappr.
>
>Chalo

Dear Chalo,

This database lets you select any county in any state, whole states,
and then see county-level maps and statistics for pedalcyclist deaths.

Here it's set to all of California, no county:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6_CA_2006.htm

If you scroll down, it shows 141 pedalcyclist deaths in California in
2006.

Click on "pedalcyclists," and it jumps you down to a county-by-county
colored map display:

http://www-nrd.nhtsa.dot.gov/departments/nrd-30/ncsa/STSI/6_CA/2006/6_CA_2006.htm#CTY_MAPS9

Obviously, some counties must be above average, others below average,
and--well, you get the idea.

Given only 141 fatalities, you'd be hard-pressed to avoid even a
county in California on the grounds that the whole county had more
than the average in bicycle fatalities.

The counties in white on the left-hand map had 0 bike fatalities in
2006.

The counties in light blue had 1-5 fatalities.

Dark blue means 6-15 fatalities for the whole county.

Green means Los An--er, 16 to 25 fatalities per county.

The right-hand map colors the counties according to deaths per 100,000
population compared to the U.S. national average.

You can also select earlier years back to 2002, but the obvious point
is that there just aren't enough bike fatalities to show much.

Cheers,

Carl Fogel

Date: 22 Sep 2007 00:30:45
From: Greens
Subject: Re: bike accident fatalities and google maps?

"damyth" <mdk.10.damyth@spamgourmet.com > wrote in message
news:1190433082.645445.215830@22g2000hsm.googlegroups.com...
>A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.
>

That sounds like a good idea to me. I think cyclists might avoid the most
dangerous places so they actually won't have that many fatalities, but the
places they can't avoid, the places that seem safe but aren't, those should
show up. There might even be something that can be done to fix them.

Date: 22 Sep 2007 04:25:17
From: Mike Jacoubowsky
Subject: Re: bike accident fatalities and google maps?

>A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.

You'll probably get a better response in the ba.bicycles newsgroup. Somebody
might have already done a map like that on their own. You might also check
out the western wheelers email list as well; go to www.westernwheelers.org
for info.

But as you've already figured out, Sand Hill has far more than its share. We
lost a customer just a month or so ago there. In her case there was no car
involved, but typically it seems the issue with roads like Sand Hill tends
to be drivers drifting off-line and into the shoulder area, or simply mowing
them down on the onramps to 280. The scary thing is that most of those
accidents are from behind the cyclist, and it's just not clear there's much
you (as a cyclist) can do about it. I'm not a fan of bots dots & rumble
strips, but there might be roads (and especially areas around onramps) where
they'd be a good idea.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

"damyth" <mdk.10.damyth@spamgourmet.com > wrote in message
news:1190433082.645445.215830@22g2000hsm.googlegroups.com...
>A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.
>

Date: 22 Sep 2007 04:24:41
From: Ryan Cousineau
Subject: Re: bike accident fatalities and google maps?

In article <1190433082.645445.215830@22g2000hsm.googlegroups.com >,
damyth <mdk.10.damyth@spamgourmet.com > wrote:

> A recent spate of bike fatalities in the local area (Sand Hill Road
> near Menlo Park/SLAC, CA) has me wondering. Is there a map or
> database pinpointing locations of bike fatalities? This would be
> incredibly helpful for people to find out where the most dangerous
> roads to ride are, a geographical representation of frequency, and
> maybe help people to avoid/improve those areas.
>
> Some of you might point out it should be "obvious" where the most
> dangerous areas are, but I ride that area often, but it never occurred
> to me that so many fatalities have occurred there until someone
> recently pointed it out.

One hazard of your mashup map is that you'll need a statistically
significant number of incidents before you can really comment on the
relative danger of various locales.

--
Ryan Cousineau rcousine@sfu.ca http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

Date: 22 Sep 2007 04:02:09
From: datakoll
Subject: Re: bike accident fatalities and google maps?

ask the county sheriff or representative for some counties keep public
statistics