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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.



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