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-   -   The University of Aalborg Study on Daytime Flashing Lights forBicycles. (http://www.cyclebanter.com/showthread.php?t=252197)

SMS March 19th 17 07:53 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
I know how some people dislike any statements that are based on actual
facts, but the data are pretty clear.

See: https://books.google.com.au/books?id=LvthAgAAQBAJ&pg=PA168

It was interesting that in the Odense study, conducted by Reelight,
Odense Cycle City and the University of Aalborg, accident rates went
down by 32% with the use of daytime lights, but a cyclist's "sense of
security" went up by 85%!

Did they ride more dangerously because of the huge increase in their
"sense of security" and still experience a 32% decline?! Another study
showed that safety equipment increases an individual's dangerous
behavior, so if we could find a way to encourage the use of proven
safety equipment without increasing risky behavior, we'd be able to
change that 32% to a much higher number.

While a 32% decline in accident rates is significant, the 85% increase
in the "sense of security" could lead to more cycling, which will
further reduce the percentage of accidents.

The purpose of this whole study was to convince the government to make
flashing lights legal, since in some backward European countries
flashing lights are not legal. While this change in the law could
increase sales of Reelight, it also benefits every other light
manufacturer that produces flashing lights, and the other manufacturer's
produce much brighter daytime lights.

Hopefully the results of this study will lead to dynamo light
manufacturers adding a flash mode to lights that they export to
countries where flashing lights are legal. It just needs to be one
zero-ohm resistor that is installed or removed on the PCB. These lights
almost certainly already have a micro-controller that can be programmed
to do flash mode.

The bottom line is that we can all agree that daytime flashing lights on
bicycles are a very good idea and that greatly increase safety and that
their use should be encouraged. Frank now owns one of Barry Beam's
Oculus lights, so he can now experience the increased safety and
increased sense of security of a daytime flashing light as well as
increased visibility at night.

Now I have to go cash my check from Reelight.

Jeff Liebermann March 19th 17 10:02 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 11:53:38 -0700, sms
wrote:

I know how some people dislike any statements that are based on actual
facts, but the data are pretty clear.

See: https://books.google.com.au/books?id=LvthAgAAQBAJ&pg=PA168

It was interesting that in the Odense study, conducted by Reelight,
Odense Cycle City and the University of Aalborg, accident rates went
down by 32% with the use of daytime lights, but a cyclist's "sense of
security" went up by 85%!


According to the above URL, it "reduced the number of crashed by more
than 30%". Presumably, accidents without an associated crash were not
counted. Also, the study was conducted in 2005 in Denmark, a country
there cycling is far more common than in the US. The accidents were
self-reported which usually means that if someone is guilty of doing
something stupid on their bicycle, they are unlikely to report the
incident. It's also possible that the situation may have changed in
the last 12 years such as newer models by Reelight.

I also don't like terms like "30% reduction". In order to make sense
of that, the actual accident rates need to be disclosed. For example,
out of population of 2000 participants, a reduction from 3 accidents
to 2 accidents is a 33% reduction, as is a reduction from 300
accidents to 200 accidents. The former is bad joke while the latter
is probably statistically significant. Which is it?

The only link I can find to the original study is listed on the
Wikipedia Bicycle Lighting page as footnote 8. However the links to
both the original Danish and English translation are broken. Also, I
would have expected to see a copy of the study on the Reelight web
pile, but couldn't find anything. Duz anyone have a copy or a
functional link?

Oddly, the Reelight FAQ doesn't quite agree with the study:
https://www.reelight.com/en/faq/
"The number of accidents is not higher when it is dark.
However, the risk of being involved in a road accident is
greater at night than during daylight hours. This is why
bicycle lights are so important."

Note that they have a backup function, that continues to flash when
the bicycle is stopped:
"The backup function needs to charge the first time it is in use.
You need to ride the bike for 5-10 minutes for it to charge
fully and so that it will flash for a few minutes after you stop."

Do it thyself flashing tail light:
https://dr2chase.wordpress.com/2013/12/23/lights-for-a-beater-bike/

We've also been here befo
https://groups.google.com/forum/#!topic/rec.bicycles.tech/X0rymhXTgGo

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

AMuzi March 19th 17 10:54 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 4:02 PM, Jeff Liebermann wrote:
On Sun, 19 Mar 2017 11:53:38 -0700, sms
wrote:

I know how some people dislike any statements that are based on actual
facts, but the data are pretty clear.

See: https://books.google.com.au/books?id=LvthAgAAQBAJ&pg=PA168

It was interesting that in the Odense study, conducted by Reelight,
Odense Cycle City and the University of Aalborg, accident rates went
down by 32% with the use of daytime lights, but a cyclist's "sense of
security" went up by 85%!


According to the above URL, it "reduced the number of crashed by more
than 30%". Presumably, accidents without an associated crash were not
counted. Also, the study was conducted in 2005 in Denmark, a country
there cycling is far more common than in the US. The accidents were
self-reported which usually means that if someone is guilty of doing
something stupid on their bicycle, they are unlikely to report the
incident. It's also possible that the situation may have changed in
the last 12 years such as newer models by Reelight.

I also don't like terms like "30% reduction". In order to make sense
of that, the actual accident rates need to be disclosed. For example,
out of population of 2000 participants, a reduction from 3 accidents
to 2 accidents is a 33% reduction, as is a reduction from 300
accidents to 200 accidents. The former is bad joke while the latter
is probably statistically significant. Which is it?

The only link I can find to the original study is listed on the
Wikipedia Bicycle Lighting page as footnote 8. However the links to
both the original Danish and English translation are broken. Also, I
would have expected to see a copy of the study on the Reelight web
pile, but couldn't find anything. Duz anyone have a copy or a
functional link?

Oddly, the Reelight FAQ doesn't quite agree with the study:
https://www.reelight.com/en/faq/
"The number of accidents is not higher when it is dark.
However, the risk of being involved in a road accident is
greater at night than during daylight hours. This is why
bicycle lights are so important."

Note that they have a backup function, that continues to flash when
the bicycle is stopped:
"The backup function needs to charge the first time it is in use.
You need to ride the bike for 5-10 minutes for it to charge
fully and so that it will flash for a few minutes after you stop."

Do it thyself flashing tail light:
https://dr2chase.wordpress.com/2013/12/23/lights-for-a-beater-bike/

We've also been here befo
https://groups.google.com/forum/#!topic/rec.bicycles.tech/X0rymhXTgGo

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


I read 'lights for beater'. Twice. Then did a page search
for coil, magnet, dynamo and battery. Found nothing. What
powers the lights?

Bonus question- What does the mirror do?

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



SMS March 19th 17 11:22 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

The only link I can find to the original study is listed on the
Wikipedia Bicycle Lighting page as footnote 8. However the links to
both the original Danish and English translation are broken. Also, I
would have expected to see a copy of the study on the Reelight web
pile, but couldn't find anything. Duz anyone have a copy or a
functional link?


It's not free.
http://www.sciencedirect.com/science/article/pii/S0001457512002606.

I'll check on Tuesday if our library or Public Works department has
access to this journal.


SMS March 19th 17 11:24 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies. The
fact that it isn't true doesn't matter to them. They will come up with
any excuse they can think of to try to ignore the data.


Jeff Liebermann March 20th 17 01:47 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 16:54:07 -0500, AMuzi wrote:

On 3/19/2017 4:02 PM, Jeff Liebermann wrote:
Do it thyself flashing tail light:
https://dr2chase.wordpress.com/2013/12/23/lights-for-a-beater-bike/


I read 'lights for beater'. Twice. Then did a page search
for coil, magnet, dynamo and battery. Found nothing. What
powers the lights?


The top photo of the bicycle shows a hub dynamo on the front wheel.
Directly under the photo is:
"Note that there’s no off switch and no way to disconnect
anything but the hub without wire clippers or a soldering iron."
So, I guess it's powered by the hub. Since there's no on/off switch,
it's also a daytime tail light.

Bonus question- What does the mirror do?


Go to:
https://www.flickr.com/photos/dr2chase/11425296075
and drag the mouse around the photo. The captions for the mirror say
"Acrylic mirror to keep light down towards the road" and "Aluminum
angle - mirror glued to top, lights glued to front, holes drilled for
zip-tie attachment to basket".

The rectangular stick jammed between the mirror and basket is labeled"
Vertical aiming adjustment".

The cylindrical contraption is labeled "Greinacher-ish rectifier and
voltage doubler in corked tube". Schematic? Nope.

Other labels around the tangle of Romex electrical wire are "white
wire to hub AC power", "white wire to taillight", and "Connection of
rectifier to headlights, headlights to taillights, and taillights to
rectifier".

It's now kinda, maybe, sorta, almost, somewhat clear. If you want a
hub powered tail light to light up the road, that is how it can be
done.

His flickr page also has his helmet mounted headlight and tail light
combination:
https://www.flickr.com/photos/dr2chase/with/11425296075/
Soon, everyone will be wearing an optical test bench glued to their
helmet.

Please remind me not to reference a do-it-thyself web page without
first carefully reading it.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Andre Jute[_2_] March 20th 17 01:49 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sunday, March 19, 2017 at 6:56:22 PM UTC, sms wrote:
Odense


My ancestor, Odin, who was worshiped as a god by the Anglo-Saxons until the coming of Christianity, lived on Odense, an island off the coast of Jutland, where the city of Odense, named for him, now stands. Of course he wasn't a god to start with. He was a warrior and a poet, but then all chiefs were warriors and were expected to be poets as well; in addition he was widely recognized as a moral philosopher and he had lots of really violent descendants, including Horsa and Hengist, who founded the British nation. They were Jutes, like Odin, but the Jutes were a small tribe, so the mass of Anglo-Saxon johnny-come-latelies just claimed them, and Odin, for their own history. The Encyclopedia Britannica, at least in the famous 11th edition which I use, got it right, but who listens to the Britannica except the truly well-educated, whose relatives probably wrote the relevant articles.

Andre Jute
It helps your posterity to have lots of really violent descendants

PS Don't ask: I don't know if Odin cycled before he became too dignified, being a god, to ride a bicycle like the other Jutes, now called Danes.

Frank Krygowski[_4_] March 20th 17 01:51 AM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 6:24 PM, sms wrote:
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies.


The remarks (generally about commission) arose because several of your
websites which touted dozens of products, and had at the bottom
statements something like "if you're going to buy one of these, please
start from this website so I get my commission."

And some of your web pages included a sort of brief resume in which you
bragged about doing "guerilla marketing" in bicycle forums.

Those statements seem to have been taken down now. But when they were
first discovered, there were links and quotes posted here.


--
- Frank Krygowski

Jeff Liebermann March 20th 17 02:08 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 15:24:31 -0700, sms
wrote:

On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies. The
fact that it isn't true doesn't matter to them. They will come up with
any excuse they can think of to try to ignore the data.


If you arrange with Reelight to send your persecutors some free sample
lights, they might be inclined to reconsider their position.

The problem here is that if you are repeatedly accused of some
dastardly crime against the cycling multitudes, such as accepting
payola from a vendor, the mere repetition of the accusation will
eventually cause it to become a truism. Anyone who searches the web
for bicycle lighting recommendations will eventually blunder across
those accusations. The casual reader is more likely to accept the
accusations at face value than to continue reading the subsequent
discussion material. You might consider writing a explanation, FAQ,
or manifesto on the topic, which you can reference in future
discussions on the topic.

Please have them ship the bribe, errr... evaluation sample, to the
address below.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

John B.[_3_] March 20th 17 02:30 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 11:53:38 -0700, sms
wrote:

I know how some people dislike any statements that are based on actual
facts, but the data are pretty clear.

See: https://books.google.com.au/books?id=LvthAgAAQBAJ&pg=PA168

It was interesting that in the Odense study, conducted by Reelight,
Odense Cycle City and the University of Aalborg, accident rates went
down by 32% with the use of daytime lights, but a cyclist's "sense of
security" went up by 85%!

Did they ride more dangerously because of the huge increase in their
"sense of security" and still experience a 32% decline?! Another study
showed that safety equipment increases an individual's dangerous
behavior, so if we could find a way to encourage the use of proven
safety equipment without increasing risky behavior, we'd be able to
change that 32% to a much higher number.

While a 32% decline in accident rates is significant, the 85% increase
in the "sense of security" could lead to more cycling, which will
further reduce the percentage of accidents.

The purpose of this whole study was to convince the government to make
flashing lights legal, since in some backward European countries
flashing lights are not legal. While this change in the law could
increase sales of Reelight, it also benefits every other light
manufacturer that produces flashing lights, and the other manufacturer's
produce much brighter daytime lights.

Hopefully the results of this study will lead to dynamo light
manufacturers adding a flash mode to lights that they export to
countries where flashing lights are legal. It just needs to be one
zero-ohm resistor that is installed or removed on the PCB. These lights
almost certainly already have a micro-controller that can be programmed
to do flash mode.

The bottom line is that we can all agree that daytime flashing lights on
bicycles are a very good idea and that greatly increase safety and that
their use should be encouraged. Frank now owns one of Barry Beam's
Oculus lights, so he can now experience the increased safety and
increased sense of security of a daytime flashing light as well as
increased visibility at night.

Now I have to go cash my check from Reelight.


I find your research somewhat less than complete. Or to put it another
way, you carefully extracted certain figures from the study and
ignored major portions.

Quite contrary to what you imply the simple addition of fixed daytime
lights was only part of a major program to improve safety in the city
of Odense which also included:

"Activities:

Salt on the streets instead of gravel (which gives more punctures)

Lanes for bikes where cars must give way

Lanes for bicylists where they don't have to stop for red light but
can continue

Lending of bicycle trailers for kids

Lending of powered bicycles

Lending of tandem bikes

The police exchanging fines for driving without light, to bicycle
lights

The Cyclist of the year award

Exhibition for Better Bikes and possibility of having the bike checked
(to get ready for the summer biking season)

Campaign: We are biking to work distribution of badges to people
participating in the campaign

Providing drinking water and bicycle pumps several places in Odense

Cycle barometers (speed and amount of cyclists passing each day)"

And Amazingly, it worked.

"According to the police the annual number of
personal injuries amongst cyclists due to accidents involving more
than one party fell by 19 per cent in the Municipality of Odense from
the base years 1996-1997 to the period 1999-2002, when the Cycle City
project was being implemented, and by 20 per cent up to the year 2002.
Thus the project achieved its objective of reducing the number of
cyclists killed or injured in accidents involving more than one party
by 20 per cent by the end of 2002 as against the base years 1996-
1997.

The trend of personal injuries amongst cyclists due to accidents
involving more than one party followed the general trend. As there has
been a significant increase in the volume of bicycle traffic in the
Municipality of Odense in comparison to the trend in general, the
risks of cycling in Odense have thus fallen more in Odense than other
large Danish cities."

The moral of this little story is that there is a danger in quoting
sources. Some rotten, no good, SOB, might read them.

--
Cheers,

John B.


SMS March 20th 17 02:47 AM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 6:08 PM, Jeff Liebermann wrote:

snip

Please have them ship the bribe, errr... evaluation sample, to the
address below.


When I had the first web site that looked at many different folding
bikes I was getting free bicycles. But that didn't affect my evaluations
and I listed the pros and cons of each model in what I believed was an
honest way.

Sorry, I have no free lights to send out to anyone, and no one has sent
me any lights for free either.


SMS March 20th 17 02:54 AM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 6:30 PM, John B. wrote:

snip

The moral of this little story is that there is a danger in quoting
sources. Some rotten, no good, SOB, might read them.


Except that the Odense study compared two control groups. One with the
daytime lights, one without them. So each group had the benefit or
non-benefit of the various other changes you cited.

It was nothing like the bogus helmet "studies" we've seen in the past
where cycling rates have risen and fallen based on factors unrelated to
helmets--when cycling rates fell, it was due solely to helmet laws. When
cycling rates rose, they should have risen as fast as the population
went up. Of course you can look at China where there are no helmet laws
and where cycling rates have plunged due to other factors (private car
ownership, and a boom in subway construction).


Jeff Liebermann March 20th 17 04:18 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 18:54:54 -0700, sms
wrote:

When
cycling rates rose, they should have risen as fast as the population
went up.


Nope. If nothing changed except the population, the cycling rate
should remain constant because it's based on a percentage of that
population. Of course, everything else also changes, so it's unlikely
to be a constant rate.

"Nighttime Cycling: Accidents, Lights, and Laws in Europe"
http://www.beezodogsplace.com/wp-content/uploads/2014/10/huhn2013_Nighttime-Cycling-Accidents.pdf
"This suggests that the different rules have only a marginal
impact on the safety of bicycle traffic in the dark. Only a
small number of nighttime accidents can be clearly attributed
to the lack of lights: Other major risk factors are driving
or riding under the influence of alcohol, higher driving
speeds on empty roads at night and impaired night vision
especially in older drivers."

However, the article then blunders onward under:
"The importance of bike lights in accidents"
which makes me wonder if this is actually a contradiction between the
data collected, and the Abstract/Summary. Offhand, I would suspect
that this is one of those reports, where the data is owned by the
researcher, but the conclusions are owned by whomever funded the
study.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

John B.[_3_] March 20th 17 07:08 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sun, 19 Mar 2017 18:54:54 -0700, sms
wrote:

On 3/19/2017 6:30 PM, John B. wrote:

snip

The moral of this little story is that there is a danger in quoting
sources. Some rotten, no good, SOB, might read them.


Except that the Odense study compared two control groups. One with the
daytime lights, one without them. So each group had the benefit or
non-benefit of the various other changes you cited.


You really, really, should actually read the actually study.... who
was it that said something about engage the brain before activating
the voice?

Anyway, the actual study was not "One with daytime lights, one without
them" but between a permanently mounted and always on flashing light
and conventional bicycle lights. There was no indication of whether
the conventional bicycle lights were, or were not, used during the
daytime.

The results of the study was "The study contributed to a change in
Danish legislation whereby flashing bike lights became legal in 2005".

In short an always on, flashing, light, front and rear )that you can't
turn off (or forget to charge the batteries) is better than lights
that you can turn off or forget to charge.

The actual lights were the Reelight SL100 which is a permanently
mounted light mounted at the wheel axle level and powered by two
permanent magnets attached to the spokes.

Reelight states, "Reelight SL100 emits 29,000 mcd (microcandela, a
unit for measuring light) from the front light and 10,000 from the
rear light."

deleted
--
Cheers,

John B.


JBeattie March 20th 17 02:59 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sunday, March 19, 2017 at 5:51:25 PM UTC-7, Frank Krygowski wrote:
On 3/19/2017 6:24 PM, sms wrote:
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.

Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies.


The remarks (generally about commission) arose because several of your
websites which touted dozens of products, and had at the bottom
statements something like "if you're going to buy one of these, please
start from this website so I get my commission."

And some of your web pages included a sort of brief resume in which you
bragged about doing "guerilla marketing" in bicycle forums.

Those statements seem to have been taken down now. But when they were
first discovered, there were links and quotes posted here.


Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle

Don't ride in Auckland, even with a blinky.

-- Jay Beattie.

Jeff Liebermann March 20th 17 04:54 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 06:59:40 -0700 (PDT), jbeattie
wrote:

Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle
Don't ride in Auckland, even with a blinky.
-- Jay Beattie.


187 accidents among 162 participants in 6.4 years? The carnage in the
streets must be awful. I would expect all cyclists to be exterminated
within their expected lifetimes. If I ride for 64 years of my life, I
would expect to get hit about 10 times.

Maybe bicycle fashion is the problem?
https://www.google.com/search?q=dazzle+camouflage+bicycle+jacket&tbm=isch


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

SMS March 20th 17 06:08 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 11:08 PM, John B. wrote:

snip

We need a double-blind study of accident rates where they use 65,536
different combinations of front and rear lumens, flashing and steady,
battery and dynamo powered, performed in 128 different countries, over
ten years, in a variety of lighting conditions.

Until that study has been completed we can't be absolutely certain
whether or not an increase in conspicuity is beneficial to cyclists, so
it makes no sense for cyclists to make themselves more visible.

Let's get the UN to commission this study.


Frank Krygowski[_4_] March 20th 17 06:33 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 8:47 PM, Jeff Liebermann wrote:

Soon, everyone will be wearing an optical test bench glued to their
helmet.


Of course! Anything less would not be safe enough!


--
- Frank Krygowski

Frank Krygowski[_4_] March 20th 17 06:54 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 9:08 PM, Jeff Liebermann wrote:
On Sun, 19 Mar 2017 15:24:31 -0700, sms
wrote:

On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.

Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies. The
fact that it isn't true doesn't matter to them. They will come up with
any excuse they can think of to try to ignore the data.


If you arrange with Reelight to send your persecutors some free sample
lights, they might be inclined to reconsider their position.

The problem here is that if you are repeatedly accused of some
dastardly crime against the cycling multitudes, such as accepting
payola from a vendor, the mere repetition of the accusation will
eventually cause it to become a truism. Anyone who searches the web
for bicycle lighting recommendations will eventually blunder across
those accusations. The casual reader is more likely to accept the
accusations at face value than to continue reading the subsequent
discussion material. You might consider writing a explanation, FAQ,
or manifesto on the topic, which you can reference in future
discussions on the topic.


If Mr. Scharf were to do that, honesty would require including quotes of
his original statements saying something like "please start your
purchases from my website" and bragging about his "guerilla marketing to
all aspects of the bicycling community" - or whatever the precise
wording was. (I wish now I'd saved a copy.)

--
- Frank Krygowski

SMS March 20th 17 06:59 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/19/2017 8:18 PM, Jeff Liebermann wrote:
On Sun, 19 Mar 2017 18:54:54 -0700, sms
wrote:

When
cycling rates rose, they should have risen as fast as the population
went up.


Nope. If nothing changed except the population, the cycling rate
should remain constant because it's based on a percentage of that
population. Of course, everything else also changes, so it's unlikely
to be a constant rate.


Exactly. Demographics change. Roads change. Traffic changes. Bicycling
infrastructure changes. Mass-transit infrastructure changes. The economy
changes.

In Silicon Valley, the emergence of so many corporate bus systems has
reduced the number of cyclists combining a Caltrain commute with cycling
"the first and last mile" (or the first and last 5 miles). Get on an
Apple, Google, Yahoo, or Genentech bus near your home and there's no
need to deal with public transit, or the lack of public transit,
anymore. But there's been a tendency of the AHZs to blame any decline in
cycling on helmet laws, or helmet promotion, which of course has no
validity at all, it's just Trump-like "alternative facts."

Frank Krygowski[_4_] March 20th 17 07:01 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 1:08 PM, sms wrote:
On 3/19/2017 11:08 PM, John B. wrote:

snip

We need a double-blind study of accident rates where they use 65,536
different combinations of front and rear lumens, flashing and steady,
battery and dynamo powered, performed in 128 different countries, over
ten years, in a variety of lighting conditions.

Until that study has been completed we can't be absolutely certain
whether or not an increase in conspicuity is beneficial to cyclists, so
it makes no sense for cyclists to make themselves more visible.

Let's get the UN to commission this study.


I'd have thought you'd take on the project as a volunteer.

But you really should include those six foot (two meter) bicycle flags
on vertical poles as part of the study. I still don't understand why
the champion of "If it may possibly help" visibility doesn't use them.

Or even better, sell them via his websites. Your competition is killing
you!
http://www.swagbrokers.com/Fiberglas...Pole-181810804


--
- Frank Krygowski

Frank Krygowski[_4_] March 20th 17 07:27 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 1:59 PM, sms wrote:
On 3/19/2017 8:18 PM, Jeff Liebermann wrote:
On Sun, 19 Mar 2017 18:54:54 -0700, sms
wrote:

When
cycling rates rose, they should have risen as fast as the population
went up.


Nope. If nothing changed except the population, the cycling rate
should remain constant because it's based on a percentage of that
population. Of course, everything else also changes, so it's unlikely
to be a constant rate.


Exactly. Demographics change. Roads change. Traffic changes. Bicycling
infrastructure changes. Mass-transit infrastructure changes. The economy
changes.

In Silicon Valley, the emergence of so many corporate bus systems has
reduced the number of cyclists combining a Caltrain commute with cycling
"the first and last mile" (or the first and last 5 miles). Get on an
Apple, Google, Yahoo, or Genentech bus near your home and there's no
need to deal with public transit, or the lack of public transit,
anymore. But there's been a tendency of the AHZs to blame any decline in
cycling on helmet laws, or helmet promotion, which of course has no
validity at all, it's just Trump-like "alternative facts."


The fact that helmet laws dissuade riding has been best demonstrated by
Australian data, which showed a STEP drop in bike riding of over 30%
exactly when the helmet laws were enacted. It was not a gradual drop,
as would be expected from gradually changing demographics, traffic
conditions, etc. The sudden drop precisely aligned with the sudden
imposition of the helmet laws.

Furthermore, bike share systems have become extremely popular in recent
years. Some cities and nations have repealed mandatory helmets laws
because of their obvious deterrent effect on bike use. (Mexico City,
Tel Aviv, Anniston AL, Boznia-Hertzegovina, etc.) Very, very few cities
have attempted to implement bike share systems while enforcing helmet
laws, and those few efforts have been failures. (See Melbourne, Brisbane
and Seattle.)

And again, logic would indicate helmet mandates and promotion would have
to have some dissuading effect; the only question is the size of that
effect. Obviously, _some_ people will not ride if told they must wear a
helmet. _Some_ people will not ride if told bicycling is so dangerous
that protective headgear is necessary. How would those ever be
compensated by people who say "Oh, it's that dangerous? And I'm not
allowed to ride without that ugly hat? Great! Now I'm convinced to take
up bicycling!"

--
- Frank Krygowski

Sir Ridesalot March 20th 17 07:42 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Monday, March 20, 2017 at 2:27:30 PM UTC-4, Frank Krygowski wrote:
Snipped
And again, logic would indicate helmet mandates and promotion would have
to have some dissuading effect; the only question is the size of that
effect. Obviously, _some_ people will not ride if told they must wear a
helmet. _Some_ people will not ride if told bicycling is so dangerous
that protective headgear is necessary. How would those ever be
compensated by people who say "Oh, it's that dangerous? And I'm not
allowed to ride without that ugly hat? Great! Now I'm convinced to take
up bicycling!"

--
- Frank Krygowski


Amazing how almost every tpoic here eventually morphs into a helmet slugfest of for and against. ;)

As far as not riding because a law says you have to do something. Well a lot of people don't want to ride a bicycle with brakes either. A lot of people do not want to have to STOP at a stop sign or red light. In short, those who don't want to ride will ALWAYS find some excuse or the other.

BTW, on the weekend I rode through a small city that had some interesting signage. One sign onto a busy main road stated "NO LEFT TURNS - BICYCLES EXCEPTED" and another sign on a one way street said "ONE WAY STREET - BICYCLES EXCEPTED. Thus you have two cases where things that a drive wouldn't expect to see are permitted for bicycle riders and in my opinion that's not very safe for the bicycle rider.

Cheers

Frank Krygowski[_4_] March 20th 17 09:13 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 9:59 AM, jbeattie wrote:
On Sunday, March 19, 2017 at 5:51:25 PM UTC-7, Frank Krygowski wrote:
On 3/19/2017 6:24 PM, sms wrote:
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.

Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.

Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies.


The remarks (generally about commission) arose because several of your
websites which touted dozens of products, and had at the bottom
statements something like "if you're going to buy one of these, please
start from this website so I get my commission."

And some of your web pages included a sort of brief resume in which you
bragged about doing "guerilla marketing" in bicycle forums.

Those statements seem to have been taken down now. But when they were
first discovered, there were links and quotes posted here.


Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle

Don't ride in Auckland, even with a blinky.


Interesting study, with weird results. Seemed the group that was just
"occasionally conspicuous" had the lowest crash rate.

"The crash risk was similar across different patterns of using
conspicuity aids except that the ‘ occasionally conspicuous day & night’
group had a lower risk relative to others."

[The groups were these: " 'class one was termed ‘usually conspicuous day
& night’; class two was termed ‘often conspicuous during the day and do
not cycle in the dark’; class three was termed ‘occasionally conspicuous
day & night’; and class four was termed ‘rarely conspicuous during the
day but conspicuous in the dark’."]


And the authors also refer to some other studies with similarly
unexpected results. (Sorry, the footnote numbers won't appear here as
proper superscripts):

" ...this analysis used a composite measure of conspicuity and found no
significant association with the risk of crashes involving a motor
vehicle. Likewise in a previous cohort study involving bicycle commuters
in Portland, using lights in the dark or reflective materials _did not
predict the risk of traumatic events_ (defined as a cycling event
leading to injury). 16 A strong protective effect of fluorescent colours
observed in our earlier (cross-sectional) analysis 15 may be due to
failure to exclude cyclist only crashes.

"Our study is one of very few examining the effect of cyclist
conspicuity on incident crashes, but the design did not allow us to
account for behaviours of involved parties and road and traffic
conditions before the crash. Some case–control studies attempted to
address this issue by measuring cyclists’ acute behaviour including use
of conspicuity aids before a crash. A Canadian study observed that the
risk of collisions with a motor vehicle was _increased_ by wearing
fluorescent clothing but decreased by wearing white or coloured
clothing. 17 Likewise, a UK study reported an _increased_ risk of
collision or evasion crashes by using any item of fluorescent or
reflective material. 18 Additionally, a recent experiment in the UK
reported _little effect_ of fluorescent clothing on drivers’ overtaking
proximities. 32

"Overall, evidence for the effectiveness of conspicuity aids in reducing
bicycle crash risk remains equivocal. Some have argued that cyclists’
misconceptions about their conspicuity and subsequent risk compensation
could play a role in minimising potential benefits. In an Australian
study, cyclists overestimated their night-time visibility and occasional
cyclists were more likely than frequent cyclists to do so. 33,34 There
were also misjudgements on the conspicuity benefits of fluorescent vs.
retroreflective materials at night. If cyclists using conspicuity aids
are confident of being seen, they may be engaged in compensatory
behaviour changes, e.g. cycling in more dangerous circumstances. 18"

[I've underlined some phrases for emphasis.]

--
- Frank Krygowski

[email protected] March 20th 17 09:40 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Sunday, March 19, 2017 at 3:27:13 PM UTC-7, sms wrote:
On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.


Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies. The
fact that it isn't true doesn't matter to them. They will come up with
any excuse they can think of to try to ignore the data.


No worries, I do not think you are a paid shill - just deluded...............

Jeff showed himself to be extremely knowledgeable of statistics and noted the chief problem with the study. They did NOT show actual numbers because Reelights could not afford to shell out hundreds of thousands of free lights..

So this study was probably confined to perhaps a thousand and the change in accidents was in fact statistically irrelevant. So taken in pure percentages and presented as if it had meaning it makes for a good sales pitch and gives some undergraduate a paper to write.

SMS March 20th 17 10:26 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 1:40 PM, wrote:

No worries, I do not think you are a paid shill - just deluded..............


Gee, thanks.


Jeff showed himself to be extremely knowledgeable of statistics and noted the chief problem with the study. They did NOT show actual numbers because Reelights could not afford to shell out hundreds of thousands of free lights.

So this study was probably confined to perhaps a thousand and the change in accidents was in fact statistically irrelevant. So taken in pure percentages and presented as if it had meaning it makes for a good sales pitch and gives some undergraduate a paper to write.


Anytime someone doesn't like the results of a study they try to pick it
apart.


Frank Krygowski[_4_] March 20th 17 11:48 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 5:26 PM, sms wrote:
On 3/20/2017 1:40 PM, wrote:

No worries, I do not think you are a paid shill - just
deluded..............


Gee, thanks.


Jeff showed himself to be extremely knowledgeable of statistics and
noted the chief problem with the study. They did NOT show actual
numbers because Reelights could not afford to shell out hundreds of
thousands of free lights.

So this study was probably confined to perhaps a thousand and the
change in accidents was in fact statistically irrelevant. So taken in
pure percentages and presented as if it had meaning it makes for a
good sales pitch and gives some undergraduate a paper to write.


Anytime someone doesn't like the results of a study they try to pick it
apart.


So we should instead uncritically accept every promotional "study" that
comes down the pike?

Do you choose your toothpaste based on how much sexier it makes you?


--
- Frank Krygowski

Doug Landau March 21st 17 12:08 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 

Do you choose your toothpaste based on how much sexier it makes you?


Yes. Without question. See https://www.youtube.com/watch?v=uhD2GcXII3Q at 0:40

John B.[_3_] March 21st 17 03:42 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 10:08:00 -0700, sms
wrote:

On 3/19/2017 11:08 PM, John B. wrote:

snip

We need a double-blind study of accident rates where they use 65,536
different combinations of front and rear lumens, flashing and steady,
battery and dynamo powered, performed in 128 different countries, over
ten years, in a variety of lighting conditions.

Until that study has been completed we can't be absolutely certain
whether or not an increase in conspicuity is beneficial to cyclists, so
it makes no sense for cyclists to make themselves more visible.

Let's get the UN to commission this study.


I really like your style of rebuttal. First ignore what the other side
says since if included would demonstrate that you don't know what you
are talking about, and next make up some totally ridiculous proposal
and present it as what your opponent argued.

Beautiful work. I applaud you.

Unfortunately it does not conceal the fact that what you stated, "a
comparison of bike lights versus no bike lights", was not what the
Odense study tested, nor was it the results of the study.
--
Cheers,

John B.


John B.[_3_] March 21st 17 04:05 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 14:01:55 -0400, Frank Krygowski
wrote:

On 3/20/2017 1:08 PM, sms wrote:
On 3/19/2017 11:08 PM, John B. wrote:

snip

We need a double-blind study of accident rates where they use 65,536
different combinations of front and rear lumens, flashing and steady,
battery and dynamo powered, performed in 128 different countries, over
ten years, in a variety of lighting conditions.

Until that study has been completed we can't be absolutely certain
whether or not an increase in conspicuity is beneficial to cyclists, so
it makes no sense for cyclists to make themselves more visible.

Let's get the UN to commission this study.


I'd have thought you'd take on the project as a volunteer.

But you really should include those six foot (two meter) bicycle flags
on vertical poles as part of the study. I still don't understand why
the champion of "If it may possibly help" visibility doesn't use them.

Or even better, sell them via his websites. Your competition is killing
you!
http://www.swagbrokers.com/Fiberglas...Pole-181810804


The various countries I have visited all seem to have rules and
regulations that argue that a orange and white "checkerboard" flag
flown from vehicles operating on airfields is a good thing. I well
remember that when, as a young Airman stationed in Japan, one could
even ride one's personal motorbike on the airfield if flying such a
flag.

If a checkered flag will "fend off" a big Boeing bomber it should
prove equally effective in deterring a California SUV.

I believe that if the State of California should mandate that every
bicycle operated on the highways of the state must be equipped, and
display, a (lets be reasonable here) a 2 foot square (i.e. 4 square
feet) checkered flag it would immediately result in a substantial
decrease in annual bicycle "accidents" and fatalities.

If ridden at night the flag would obviously have to be illuminated in
some manner but that is just details.

--
Cheers,

John B.


John B.[_3_] March 21st 17 04:09 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 13:54:00 -0400, Frank Krygowski
wrote:

On 3/19/2017 9:08 PM, Jeff Liebermann wrote:
On Sun, 19 Mar 2017 15:24:31 -0700, sms
wrote:

On 3/19/2017 2:02 PM, Jeff Liebermann wrote:

Now I have to go cash my check from Reelight.

Such things are usually done by "loaning" you test samples of the
products, and then "forgetting" to recover them. In theory, you're
expected to declare the value of such samples as income for tax
purposes. Payments of cash or checks are rare unless you are hired as
a consultant.


Yes, but a couple of people in this group insist that the only reason I
favor good lights is because I am getting paid by light companies. The
fact that it isn't true doesn't matter to them. They will come up with
any excuse they can think of to try to ignore the data.


If you arrange with Reelight to send your persecutors some free sample
lights, they might be inclined to reconsider their position.

The problem here is that if you are repeatedly accused of some
dastardly crime against the cycling multitudes, such as accepting
payola from a vendor, the mere repetition of the accusation will
eventually cause it to become a truism. Anyone who searches the web
for bicycle lighting recommendations will eventually blunder across
those accusations. The casual reader is more likely to accept the
accusations at face value than to continue reading the subsequent
discussion material. You might consider writing a explanation, FAQ,
or manifesto on the topic, which you can reference in future
discussions on the topic.


If Mr. Scharf were to do that, honesty would require including quotes of
his original statements saying something like "please start your
purchases from my website" and bragging about his "guerilla marketing to
all aspects of the bicycling community" - or whatever the precise
wording was. (I wish now I'd saved a copy.)


guerilla ~ a member of an irregular armed force that fights by
sabotage and harassment.
--
Cheers,

John B.


John B.[_3_] March 21st 17 04:18 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 14:26:35 -0700, sms
wrote:

On 3/20/2017 1:40 PM, wrote:

No worries, I do not think you are a paid shill - just deluded..............


Gee, thanks.


Jeff showed himself to be extremely knowledgeable of statistics and noted the chief problem with the study. They did NOT show actual numbers because Reelights could not afford to shell out hundreds of thousands of free lights.

So this study was probably confined to perhaps a thousand and the change in accidents was in fact statistically irrelevant. So taken in pure percentages and presented as if it had meaning it makes for a good sales pitch and gives some undergraduate a paper to write.


Anytime someone doesn't like the results of a study they try to pick it
apart.


Actually not. The picking is aimed at those who seize on a study and
twist its meaning into something that suits themselves... or even tell
lies about the basis of the test, i.e., "bicycle lights versus no
bicycle lights" to justify their own arguments.

(guerilla ~ a member of an irregular armed force that fights by
sabotage and harassment).
--
Cheers,

John B.


Jeff Liebermann March 21st 17 07:06 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 14:26:35 -0700, sms
wrote:

Anytime someone doesn't like the results of a study they try to pick it
apart.


Actually, common practice is to first blame someone and then pick
apart the argument. However, I prefer to undermine the study and let
it collapse under its own weight.

If "pick it apart" is an unacceptable method of debating the merits of
a study, what would you consider to be an acceptable method for this
newsgroup? I could use propaganda, various logical fallacies,
anecdotal evidence, my personal feelings, or perhaps fabricate a
contradictory study. Methinks that "pick it apart" is the same as
breaking down the study into individual claims and seeing how each one
holds together under stress.

Perhaps it would be helpful if I explained how I analyze such studies.
I've done it in this newsgroup at least a dozen times, but have never
really explained how it's done. First, I find the original study.
This is the most difficult part because studies are now hidden behind
pay walls, revised continuously, and "edited for publication" in
different lengths and forms. Once I have the original study, I try to
determine who paid for it. That's because the conclusions and summary
of the study are owned by whomever paid for the study, while the
actual data and calculations are owned by the academics, scientists,
students, and statisticians that ran the study. Often these are
different or even in opposition. I then read the study in as much
detail as I have time available. That's when the differences between
the study and the web page announcing the study become apparent. In
medical studies and surveys, I've seen claims that are quite the
opposite of what the research shows, usually because the claims
support a product or remedy. From this point, my approach varies
depending on what I'm trying to demonstrate, prove, denounce, or
evaluate. Usually, pointing out inconsistencies, gross omissions, and
occasionally math errors is sufficient.

In this case, I have been unable to find the study in either the
original Danish or an English translation. Therefore, I have not read
the original and have had to work with a brief summary from some
unknown report or survey that apparently has been quoted and recycled
extensively. The best I could do is point out that the percentage
cited was meaningless without also disclosing the statistical
population (number of participants in the test). This is hardly "pick
it apart". So, I'll pick at it some more.

One problem with claiming that flashing tail lights reduce accidents
is that there just might not be any correlation between tail lights
and accidents at all. Just because two things correlate (follow the
same trends) does not mean that one causes the other. Some ludicrous
examples:
http://www.tylervigen.com/spurious-correlations
So, how does one prove that flashing tail lights actually cause a
reduction in accidents and that the 30% drop was not a coincidence?
Well, one way is play the record backwards. Instead of giving out
tail lights, find a group that has been using flashing tail lights for
some time and take away their tail lights. If accidents increase,
then there just might be a connection. Perhaps programming the tail
lights so that they flash at different rates under the assumption that
a faster flashing rate is more visible and therefore safer. I could
dream up a few more tests, but basically the idea is to do things that
test for a connection between flashing tail lights and accidents.

The other part of the problem is that it's very easy to demonstrate
that something is unsafe. All that's needed is one accident. However,
it's impossible prove that anything is safe because there will always
be accidents caused by coincidence or disconnected correlations.

Have I "picked apart" your one liner sufficiently?

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann March 21st 17 07:23 AM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Mon, 20 Mar 2017 16:13:39 -0400, Frank Krygowski
wrote:

On 3/20/2017 9:59 AM, jbeattie wrote:
Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle
Don't ride in Auckland, even with a blinky.


Interesting study, with weird results. Seemed the group that was just
"occasionally conspicuous" had the lowest crash rate.
(...)


I see one problem with the study. There's little correlation between
accident crash rate and being conspicuous. The problem that drives of
vehicles that hit bicyclists almost always proclaim that they didn't
see the bicyclist. That might be because the bicyclist was not easily
visible, but could also be because the driver wasn't paying attention,
was distracted, in desperate need of corrective vision, or was under
the influence of booze, drugs, or passengers. For these drivers no
amount of conspicuous clothing or flashing lights will improve their
driving.

That begs the question of what is the ratio of attentive drivers to
impaired losers? I don't know. If I arbitrarily assign a 50/50
distribution, then I'll probably find that the overwhelming majority
of bicycle crashes are caused by the impaired losers. That means that
visibility has little effect on the conscientious drivers, who will
probably be paying attention to their driving, and little effect on
the impaired losers, who will probably be immune to any improvements
in visibility.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Tosspot[_3_] March 21st 17 07:23 AM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 20/03/17 16:54, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 06:59:40 -0700 (PDT), jbeattie
wrote:

Check this out: https://academic.oup.com/eurpub/arti...enting-bicycle
Don't ride in Auckland, even with a blinky.
-- Jay Beattie.


187 accidents among 162 participants in 6.4 years? The carnage in the
streets must be awful. I would expect all cyclists to be exterminated
within their expected lifetimes. If I ride for 64 years of my life, I
would expect to get hit about 10 times.

Maybe bicycle fashion is the problem?
https://www.google.com/search?q=dazzle+camouflage+bicycle+jacket&tbm=isch


They won't hold off a New York SUV, but they may stop you getting
torpedoed by a German submarine :-)


https://en.wikipedia.org/wiki/Dazzle...1)_cropped.jpg

SMS March 21st 17 07:37 AM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/20/2017 11:06 PM, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 14:26:35 -0700, sms
wrote:

Anytime someone doesn't like the results of a study they try to pick it
apart.


Actually, common practice is to first blame someone and then pick
apart the argument. However, I prefer to undermine the study and let
it collapse under its own weight.

If "pick it apart" is an unacceptable method of debating the merits of
a study, what would you consider to be an acceptable method for this
newsgroup? I could use propaganda, various logical fallacies,
anecdotal evidence, my personal feelings, or perhaps fabricate a
contradictory study. Methinks that "pick it apart" is the same as
breaking down the study into individual claims and seeing how each one
holds together under stress.


There is a tendency to nitpick little things and then to declare the
entire study as worthless, when in fact, other than perhaps in drug
trials, there is just not going to be a "perfect study." Yet the goal of
the study was to determine if flashing lights were effective, and if so,
use the data to remove a ban on flashing lights. The company that was
involved in the study certainly had a vested interest in the outcome,
but they are only one of a multitude of companies that are benefiting
from the outcome.

Yet we used to often see studies that were almost completely bogus,
touted as proving something. I recall one study on cycling rates
following the imposition of an MHL where those doing the study decided
that they would simply not count a large group of cyclists that passed
by the counting location because they didn't think that they were normal
cycling traffic. That was a study to "prove" that MHLs caused a decrease
in cycling rates.

Yet the Odense study was actually pretty good as far as these things go,
with two control groups so factors other than the presence or absence of
lights cancelled out. And while it was only a 32% reduction in accident
rates, the fact that 85% cyclists "felt safer" is also a positive
outcome if it leads to higher cycling rates. Part of the reason that
cycling rates trend up following the passing of an MHL is probably the
same reason--"oh, if I wear a helmet then I'll be safe."



[email protected] March 21st 17 03:24 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Monday, March 20, 2017 at 2:29:18 PM UTC-7, sms wrote:
On 3/20/2017 1:40 PM, wrote:

No worries, I do not think you are a paid shill - just deluded...............


Gee, thanks.


Jeff showed himself to be extremely knowledgeable of statistics and noted the chief problem with the study. They did NOT show actual numbers because Reelights could not afford to shell out hundreds of thousands of free lights.

So this study was probably confined to perhaps a thousand and the change in accidents was in fact statistically irrelevant. So taken in pure percentages and presented as if it had meaning it makes for a good sales pitch and gives some undergraduate a paper to write.


Anytime someone doesn't like the results of a study they try to pick it
apart.


If they did not want it picked apart they only had to provide the actual numbers. And they didn't. Why do you suppose that was?

AMuzi March 21st 17 03:27 PM

The University of Aalborg Study on Daytime Flashing Lights forBicycles.
 
On 3/21/2017 1:06 AM, Jeff Liebermann wrote:
On Mon, 20 Mar 2017 14:26:35 -0700, sms
wrote:

Anytime someone doesn't like the results of a study they try to pick it
apart.


Actually, common practice is to first blame someone and then pick
apart the argument. However, I prefer to undermine the study and let
it collapse under its own weight.

If "pick it apart" is an unacceptable method of debating the merits of
a study, what would you consider to be an acceptable method for this
newsgroup? I could use propaganda, various logical fallacies,
anecdotal evidence, my personal feelings, or perhaps fabricate a
contradictory study. Methinks that "pick it apart" is the same as
breaking down the study into individual claims and seeing how each one
holds together under stress.

Perhaps it would be helpful if I explained how I analyze such studies.
I've done it in this newsgroup at least a dozen times, but have never
really explained how it's done. First, I find the original study.
This is the most difficult part because studies are now hidden behind
pay walls, revised continuously, and "edited for publication" in
different lengths and forms. Once I have the original study, I try to
determine who paid for it. That's because the conclusions and summary
of the study are owned by whomever paid for the study, while the
actual data and calculations are owned by the academics, scientists,
students, and statisticians that ran the study. Often these are
different or even in opposition. I then read the study in as much
detail as I have time available. That's when the differences between
the study and the web page announcing the study become apparent. In
medical studies and surveys, I've seen claims that are quite the
opposite of what the research shows, usually because the claims
support a product or remedy. From this point, my approach varies
depending on what I'm trying to demonstrate, prove, denounce, or
evaluate. Usually, pointing out inconsistencies, gross omissions, and
occasionally math errors is sufficient.

In this case, I have been unable to find the study in either the
original Danish or an English translation. Therefore, I have not read
the original and have had to work with a brief summary from some
unknown report or survey that apparently has been quoted and recycled
extensively. The best I could do is point out that the percentage
cited was meaningless without also disclosing the statistical
population (number of participants in the test). This is hardly "pick
it apart". So, I'll pick at it some more.

One problem with claiming that flashing tail lights reduce accidents
is that there just might not be any correlation between tail lights
and accidents at all. Just because two things correlate (follow the
same trends) does not mean that one causes the other. Some ludicrous
examples:
http://www.tylervigen.com/spurious-correlations
So, how does one prove that flashing tail lights actually cause a
reduction in accidents and that the 30% drop was not a coincidence?
Well, one way is play the record backwards. Instead of giving out
tail lights, find a group that has been using flashing tail lights for
some time and take away their tail lights. If accidents increase,
then there just might be a connection. Perhaps programming the tail
lights so that they flash at different rates under the assumption that
a faster flashing rate is more visible and therefore safer. I could
dream up a few more tests, but basically the idea is to do things that
test for a connection between flashing tail lights and accidents.

The other part of the problem is that it's very easy to demonstrate
that something is unsafe. All that's needed is one accident. However,
it's impossible prove that anything is safe because there will always
be accidents caused by coincidence or disconnected correlations.

Have I "picked apart" your one liner sufficiently?


I don't know but significance and meaning may vary.

Just read a newspaper headline about a "new drug found 70%
better than aspirin". Of 3600 people over 5 years there were
2.3% heart attacks in the daily aspirin group and 1.6% heart
attacks in the new new group.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971



[email protected] March 21st 17 03:31 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Monday, March 20, 2017 at 7:42:32 PM UTC-7, John B. wrote:

Unfortunately it does not conceal the fact that what you stated, "a
comparison of bike lights versus no bike lights", was not what the
Odense study tested, nor was it the results of the study.


But John, the whole point is that you have NO IDEA what they accomplished with a study that so obviously had such a small study group that they wouldn't even publish the size of it.

You know that in statistical analysis concerning small percentages of injuries and fatalities as bicycle accidents that the study size has to be gigantic to reveal any pertinent information. So why would you pretend differently?

[email protected] March 21st 17 03:34 PM

The University of Aalborg Study on Daytime Flashing Lights for Bicycles.
 
On Monday, March 20, 2017 at 8:05:55 PM UTC-7, John B. wrote:
On Mon, 20 Mar 2017 14:01:55 -0400, Frank Krygowski
wrote:

On 3/20/2017 1:08 PM, sms wrote:
On 3/19/2017 11:08 PM, John B. wrote:

snip

We need a double-blind study of accident rates where they use 65,536
different combinations of front and rear lumens, flashing and steady,
battery and dynamo powered, performed in 128 different countries, over
ten years, in a variety of lighting conditions.

Until that study has been completed we can't be absolutely certain
whether or not an increase in conspicuity is beneficial to cyclists, so
it makes no sense for cyclists to make themselves more visible.

Let's get the UN to commission this study.


I'd have thought you'd take on the project as a volunteer.

But you really should include those six foot (two meter) bicycle flags
on vertical poles as part of the study. I still don't understand why
the champion of "If it may possibly help" visibility doesn't use them.

Or even better, sell them via his websites. Your competition is killing
you!
http://www.swagbrokers.com/Fiberglas...Pole-181810804


The various countries I have visited all seem to have rules and
regulations that argue that a orange and white "checkerboard" flag
flown from vehicles operating on airfields is a good thing. I well
remember that when, as a young Airman stationed in Japan, one could
even ride one's personal motorbike on the airfield if flying such a
flag.

If a checkered flag will "fend off" a big Boeing bomber it should
prove equally effective in deterring a California SUV.

I believe that if the State of California should mandate that every
bicycle operated on the highways of the state must be equipped, and
display, a (lets be reasonable here) a 2 foot square (i.e. 4 square
feet) checkered flag it would immediately result in a substantial
decrease in annual bicycle "accidents" and fatalities.

If ridden at night the flag would obviously have to be illuminated in
some manner but that is just details.


John, how old are you? I spent four years in the Air Force in five different states and three different countries and never heard of such a requirement. I then spent three years in commercial aviation and never heard of such a thing either.


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