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The University of Aalborg Study on Daytime Flashing Lights forBicycles.



 
 
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  #61  
Old March 22nd 17, 05:38 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,569
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Wed, 22 Mar 2017 14:34:03 +0700, John B.
wrote:

I think he had a six cell mag-light clamped on his
bike, but as I didn't stop to talk with him I can't be sure. But it
sure was bright.

But I don't see six cell mag-lights being suggested for bicycles :-)


No problem:
http://www.learnbydestroying.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Ads
  #62  
Old March 22nd 17, 05:55 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,346
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Tuesday, March 21, 2017 at 8:25:43 AM UTC-7, sms wrote:
On 3/21/2017 7:24 AM, wrote:
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?


The numbers are almost certainly there--if you pay for the full study. A
lot of studies are like that. They publish a summary for free, but you
have to pay for the full study. I guess that the thought is that it
would be organizations with a budget for which a few hundred dollars (or
in this case about $40) would not be a big deal.

But in countries where flashing lights are already legal and widely
used, and the benefits well-established, why would anyone pay anything
just to get the raw data?

Yesterday it was cloudy here. I was driving in the morning. Gray cars in
gray conditions don't stand out. But you see cyclists with DRLs coming a
mile away (literally), long before you see any bright clothing. I doubt
if anyone here really believes that on bicycles DRLs (flashing or
steady) are not effective. Just look at motorcycles which have been
required to have a DRL for decades (at least in most states). But an
Australian study stated that using a low beam headlight as a DRL was not
optimal, "Headlights waste energy when used as DRLs because, on low
beam, they are designed to direct most light below the horizontal and
away from the eyes of other road users." In the U.S. the effectiveness
of motorcycle DRLs is estimated at only a 13% reduction in crashes.
However this was before modulated DRLs started to be used.

https://www-nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0178-w.pdf


No offense but what leads you to believe that if you're so far away you can't see bright clothing that you need to be seen with a flashing light?
  #63  
Old March 22nd 17, 06:12 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,346
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Tuesday, March 21, 2017 at 8:25:43 AM UTC-7, sms wrote:
On 3/21/2017 7:24 AM, wrote:
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?


The numbers are almost certainly there--if you pay for the full study. A
lot of studies are like that. They publish a summary for free, but you
have to pay for the full study. I guess that the thought is that it
would be organizations with a budget for which a few hundred dollars (or
in this case about $40) would not be a big deal.

But in countries where flashing lights are already legal and widely
used, and the benefits well-established, why would anyone pay anything
just to get the raw data?

Yesterday it was cloudy here. I was driving in the morning. Gray cars in
gray conditions don't stand out. But you see cyclists with DRLs coming a
mile away (literally), long before you see any bright clothing. I doubt
if anyone here really believes that on bicycles DRLs (flashing or
steady) are not effective. Just look at motorcycles which have been
required to have a DRL for decades (at least in most states). But an
Australian study stated that using a low beam headlight as a DRL was not
optimal, "Headlights waste energy when used as DRLs because, on low
beam, they are designed to direct most light below the horizontal and
away from the eyes of other road users." In the U.S. the effectiveness
of motorcycle DRLs is estimated at only a 13% reduction in crashes.
However this was before modulated DRLs started to be used.

https://www-nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0178-w.pdf


The only hard numbers I can find for bicyclist deaths is 117 in Norway in 2015. So in Sweden with Zero Vision is couldn't be more than half of that.

One other number that I discovered was Norway had 2.2 fatalities per 100,000 inhabitants.

This would have a test group of .044 deaths. For a ten year test that would STILL give you a death rate of only a half person for the test group.

So can you explain to me how you could get ANY serious statistics from that?
  #64  
Old March 22nd 17, 09:51 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 7,996
Default The University of Aalborg Study on Daytime Flashing Lights forBicycles.

On 3/22/2017 7:25 AM, jbeattie wrote:

snip

However, it is amazing to me that a little flea-watt light makes such a dramatic difference.


True. Just think how much of a difference a more powerful light would make.

  #65  
Old March 22nd 17, 09:55 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 7,996
Default The University of Aalborg Study on Daytime Flashing Lights forBicycles.

On 3/22/2017 9:38 AM, Jeff Liebermann wrote:
On Wed, 22 Mar 2017 14:34:03 +0700, John B.
wrote:

I think he had a six cell mag-light clamped on his
bike, but as I didn't stop to talk with him I can't be sure. But it
sure was bright.

But I don't see six cell mag-lights being suggested for bicycles :-)


No problem:
http://www.learnbydestroying.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html


You've been posting the link to that photo for years.

At least order one of these: https://www.amazon.com/dp/B000AO3H24 or
build one of these http://nordicgroup.us/s78/images/IMG_0303.JPG.

Bungie cords are unacceptable.



  #66  
Old March 23rd 17, 02:38 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,549
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Wed, 22 Mar 2017 08:51:58 -0700, Jeff Liebermann
wrote:

On Wed, 22 Mar 2017 14:56:40 +0700, John B.
wrote:

There is some information available, although not much. Reelight
apparently donated some 2,000 fore and aft flashing permanently
mounted and, essentially, always on lights for the study. The study
was in Denmark where I would guess that all, or nearly all, bicycles
are equipped with conventional lights as I have read that if one is
caught riding after dark the fine is a rather substantial amount -
perhaps a week's pay if my figures were correct, and in fact in one of
the reports it was stated that the test was between bicycles with a
permanently mounted and always on flashing light and bicycles equipped
with "conventional bicycle lights"


So, the participants were expected to REMOVE their conventional
lighting system and replace it with a Reelight model? Or did they
leave both of them connected?


Nope. the Reelight SL-100's mount on the axle or skewer end and are
powered by two magnets attached to the spokes. If there were
conventional lights installed there is no need to remove them. The SL
100 is stated to: emit 29,000 mcd (microcandela's ( a unit for
measuring light) from the front light and 10,000 from the rear light.

Note: the SL100's can be bought as a set with a white front light and
a red rear

See:
https://www.reelight.com/en/products...t-front-light/
https://www.reelight.com/en/faq/

The results of the study was stated to be that the law covering
bicycle lighting was changed to allow flashing lights to be used.


That's probably true, as it provides a sales incentive. It also
explains why they ran the test in Denmark, where bicycles are very
common. I doubt that the Danish rule makers would accept a similar
study performed in another country as the basis for changing their
rules.

As an aside I might also mention that a good friend (now deceased)
owned a company that did financial analysis and the majority of the
studies he did were for companies that were investigating the
possibility of entering a specific market.

Surveys were a major factor in many, maybe most, of his market studies
and I remember him once stating he "could design a survey to prove
anything that the client required".


Agreed. I used to work in the advertising and market research sector.
I've also been involved in writing "customer satisfaction" surveys.
Most such surveys have nothing to do with the alleged topic. It's not
unusual to ask questions about unrelated products, buying habits,
driving habits, spending habits, mileage traveled, discretionary cash
available, etc. For example, the survey could be structured asking
indirectly if you bicycle commute, would you consider buying an
ADDITIONAL tail light for your machine(s). Here's one way how it's
done:

[Q] If this daytime flashing light saved your life, would you
consider purchasing one for all your bicycles?

Notice that the question assumes that the flashing light works and
will save lives. That would be followed by a few similar questions,
all assuming that the device works and saves lives. The last question
would be:

[Q] Do you believe the world would be a better place if everyone used
daytime flashing lights on their bicycles?

Most participants will automatically say yes because that's the
expected and "correct" answer. Then, the marketing people can say
"Almost everyone who took the survey would probably purchase a daytime
flashing bicycle light and will recommend it to all their friends".
Never mind that there's a big difference between "used" and "buy" and
that the entire survey assumes that the device works as expected.

Hint: Such survey questions are invariably answered by participants
in top down order. The first few questions involve the greatest
amount of considered thought by the participant. By the time they get
down to the last few questions, they are tired, bored, in a hurry, and
not really thinking clearly. Their resistance to suggestion is then
at its lowest. So, the really important questions are asked last.


Years ago I found a book in a used book shop that purported to be a
study on Thai social customs. It was quite obviously someone's
dissertation, although hopefully not for a PhD degree.

The author had never visited Thailand prior to the survey. He could
not speak the language and depended on a translator. He knew nothing
about the Buddhist religion as practiced in Thailand and the village
he surveyed had been used in a number of previous surveys.

He asked questions such as "If someone steals your water buffalo what
would you do?" The answer he used in his analysis was, "Nothing. The
thief probably needs it more that I do."

Another question was, "If you discovered that your wife was sleeping
with another man what would you do?" The answer, "I would forgive
her."

Now based on Buddhist morality these are nearly perfect answers but
based on the years I have lived in the country the real answers would
have been:

"I would get my shotgun and shoot that thieving SOB" and "I'd beat her
until she couldn't walk and take her back to her mother and get the
Sin Sod (bride price) back."

As the dissertation was published it is probable that it was
acceptable to the school but I've always wondered what sort of a grade
it resulted in?

(As an aside, I also wonder how much of U.S. foreign policy is based
on similar information :-)
--
Cheers,

John B.

  #67  
Old March 23rd 17, 02:48 AM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 9,022
Default The University of Aalborg Study on Daytime Flashing Lights forBicycles.

On 3/22/2017 8:38 PM, John B. wrote:
On Wed, 22 Mar 2017 08:51:58 -0700, Jeff Liebermann
wrote:

On Wed, 22 Mar 2017 14:56:40 +0700, John B.
wrote:

There is some information available, although not much. Reelight
apparently donated some 2,000 fore and aft flashing permanently
mounted and, essentially, always on lights for the study. The study
was in Denmark where I would guess that all, or nearly all, bicycles
are equipped with conventional lights as I have read that if one is
caught riding after dark the fine is a rather substantial amount -
perhaps a week's pay if my figures were correct, and in fact in one of
the reports it was stated that the test was between bicycles with a
permanently mounted and always on flashing light and bicycles equipped
with "conventional bicycle lights"


So, the participants were expected to REMOVE their conventional
lighting system and replace it with a Reelight model? Or did they
leave both of them connected?


Nope. the Reelight SL-100's mount on the axle or skewer end and are
powered by two magnets attached to the spokes. If there were
conventional lights installed there is no need to remove them. The SL
100 is stated to: emit 29,000 mcd (microcandela's ( a unit for
measuring light) from the front light and 10,000 from the rear light.

Note: the SL100's can be bought as a set with a white front light and
a red rear

See:
https://www.reelight.com/en/products...t-front-light/
https://www.reelight.com/en/faq/

The results of the study was stated to be that the law covering
bicycle lighting was changed to allow flashing lights to be used.


That's probably true, as it provides a sales incentive. It also
explains why they ran the test in Denmark, where bicycles are very
common. I doubt that the Danish rule makers would accept a similar
study performed in another country as the basis for changing their
rules.

As an aside I might also mention that a good friend (now deceased)
owned a company that did financial analysis and the majority of the
studies he did were for companies that were investigating the
possibility of entering a specific market.

Surveys were a major factor in many, maybe most, of his market studies
and I remember him once stating he "could design a survey to prove
anything that the client required".


Agreed. I used to work in the advertising and market research sector.
I've also been involved in writing "customer satisfaction" surveys.
Most such surveys have nothing to do with the alleged topic. It's not
unusual to ask questions about unrelated products, buying habits,
driving habits, spending habits, mileage traveled, discretionary cash
available, etc. For example, the survey could be structured asking
indirectly if you bicycle commute, would you consider buying an
ADDITIONAL tail light for your machine(s). Here's one way how it's
done:

[Q] If this daytime flashing light saved your life, would you
consider purchasing one for all your bicycles?

Notice that the question assumes that the flashing light works and
will save lives. That would be followed by a few similar questions,
all assuming that the device works and saves lives. The last question
would be:

[Q] Do you believe the world would be a better place if everyone used
daytime flashing lights on their bicycles?

Most participants will automatically say yes because that's the
expected and "correct" answer. Then, the marketing people can say
"Almost everyone who took the survey would probably purchase a daytime
flashing bicycle light and will recommend it to all their friends".
Never mind that there's a big difference between "used" and "buy" and
that the entire survey assumes that the device works as expected.

Hint: Such survey questions are invariably answered by participants
in top down order. The first few questions involve the greatest
amount of considered thought by the participant. By the time they get
down to the last few questions, they are tired, bored, in a hurry, and
not really thinking clearly. Their resistance to suggestion is then
at its lowest. So, the really important questions are asked last.


Years ago I found a book in a used book shop that purported to be a
study on Thai social customs. It was quite obviously someone's
dissertation, although hopefully not for a PhD degree.

The author had never visited Thailand prior to the survey. He could
not speak the language and depended on a translator. He knew nothing
about the Buddhist religion as practiced in Thailand and the village
he surveyed had been used in a number of previous surveys.

He asked questions such as "If someone steals your water buffalo what
would you do?" The answer he used in his analysis was, "Nothing. The
thief probably needs it more that I do."

Another question was, "If you discovered that your wife was sleeping
with another man what would you do?" The answer, "I would forgive
her."

Now based on Buddhist morality these are nearly perfect answers but
based on the years I have lived in the country the real answers would
have been:

"I would get my shotgun and shoot that thieving SOB" and "I'd beat her
until she couldn't walk and take her back to her mother and get the
Sin Sod (bride price) back."

As the dissertation was published it is probable that it was
acceptable to the school but I've always wondered what sort of a grade
it resulted in?

(As an aside, I also wonder how much of U.S. foreign policy is based
on similar information :-)
--
Cheers,

John B.


Easy question. All of it, of course.

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


  #68  
Old March 23rd 17, 02:49 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 3,549
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Wed, 22 Mar 2017 09:38:05 -0700, Jeff Liebermann
wrote:

On Wed, 22 Mar 2017 14:34:03 +0700, John B.
wrote:

I think he had a six cell mag-light clamped on his
bike, but as I didn't stop to talk with him I can't be sure. But it
sure was bright.

But I don't see six cell mag-lights being suggested for bicycles :-)


No problem:
http://www.learnbydestroying.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html


But that is a tiny little 4 cell light. Get the Real Man's 6 cell and
see how that works :-)
--
Cheers,

John B.

  #69  
Old March 23rd 17, 03:46 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,569
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Wed, 22 Mar 2017 13:55:00 -0700, sms
wrote:

On 3/22/2017 9:38 AM, Jeff Liebermann wrote:
On Wed, 22 Mar 2017 14:34:03 +0700, John B.
wrote:

I think he had a six cell mag-light clamped on his
bike, but as I didn't stop to talk with him I can't be sure. But it
sure was bright.

But I don't see six cell mag-lights being suggested for bicycles :-)


No problem:
http://www.learnbydestroying.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html


You've been posting the link to that photo for years.


The EXIF info for the picture (click the little camera icon to the
upper right of the photo) says Jan 2011. So, that would be about 6
years. To avoid complaints about posting repetitious links, I change
the URL from the original:
http://802.11junk.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html
When I wear out the new URL, I'll probably switch to:
http://802.11junk.com/jeffl/pics/bicycles/bicycle-flashlight.jpg
or:
http://www.LearnByDestroying.com/jeffl/pics/bicycles/bicycle-flashlight.jpg
When your patience with those links expire, I have a variety of other
domains available.

At least order one of these: https://www.amazon.com/dp/B000AO3H24 or
build one of these http://nordicgroup.us/s78/images/IMG_0303.JPG.


The Wald flashlight holder implies that the arrangement might be
permanent, which would not be the case. It's not very useful since
there is no way to adjust the flashlight position.

Your flashlight holder contrivance is clever and probably woth
considering because none of the infamous Santa Cruz bicycle component
thieves would consider removing it for resale. Were I to design and
build such a contrivance, it would be based on a DIN rail mounted
across the handlebars, with a variety of optional attachments
(flashlight, switching, charge controller, horn, bell, evidence
camera, smartphone, GPS, radar, ultrasonic vehicle passing distance
measure, paintball canon, etc).
https://www.google.com/search?tbm=isch&q=din+rail+mounting+clip
I already have most of the DIN rail parts and have just received some
of the cheap eBay flashlights. The plan is to attach 5 or 7
flashlights across the DIN rail, each aimed individually and powered
by 14500 or 18650 batteries. While there are theoretical arguments
that suggest that this approach might be a dumb idea, I want to see
for myself. If it works, I'll upgrade to a MegaLumen photon torpedo
system for the Kickstarter version.

Bungie cords are unacceptable.


Bungie cords were all I had available at the time. My regular
headlight was lost or stolen, and all I could find was my big heavy
Maglite. I use Bungie cords to secure my junk to the rear rack, so a
repurposed them as a flashlight mount. What it lacked in stability,
aiming accuracy, aesthetics, and sex appeal, the Bungie bicycle
headlight mount (patent pending) was quite adequate to safely
transport me across town after dark.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #70  
Old March 23rd 17, 03:58 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,569
Default The University of Aalborg Study on Daytime Flashing Lights for Bicycles.

On Thu, 23 Mar 2017 08:49:51 +0700, John B.
wrote:

On Wed, 22 Mar 2017 09:38:05 -0700, Jeff Liebermann
wrote:

On Wed, 22 Mar 2017 14:34:03 +0700, John B.
wrote:

I think he had a six cell mag-light clamped on his
bike, but as I didn't stop to talk with him I can't be sure. But it
sure was bright.

But I don't see six cell mag-lights being suggested for bicycles :-)


No problem:
http://www.learnbydestroying.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html


But that is a tiny little 4 cell light. Get the Real Man's 6 cell and
see how that works :-)


The 4D Maglite was all that I had available at the time. I would
probably have used a 6D Maglite, but all of mine need some work.
http://www.learnbydestroying.com/jeffl/crud/maglites.jpg
I'll probably end up donating these to a local thrift shop. There
were several large Maglites at their store available for sale for $6
and $8 that sat around without buyers for about 2 months. I got the
clue. Nobody wants them, even with the LED bulb conversion.

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




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