visibility of DRL

On 05/04/2019 15.41, Sepp Ruf wrote:
Tosspot wrote:
On 05/04/2019 00.17, wrote:

In general flashlights are bad because there can be a *lot* of bleed
outside the designed boresight angle. I suffer from this a lot from
people coming the other way at night, but tbf, it is very variable, with
some flashlights having little bleed. How do I tell? The conical beam
shape is a dead giveaway. With respect to your test, not a bad idea.
My IQ-X doesn't even illuminate tail lights/reflectors, and still throws
a beam some 20ft down the road, and in an exact mirror of your test, I

20ft - are you so greatly enjoying seeing all of the beam? I'd suggest you
set it to at least 20 yards if you ride more than half as fast as Jay or Joerg.

fitted a flashlight to the handlebars to try and determine the angle at
which the same occurred. It required *my* light to be set far to far
down to be useful.

Steady 20kph (say 15mph), it isn't pitch dark but that's easily enough
to avoid pot holes, broken bottles etc. It might be a bit more, but I'd
say no more than 30. You got me thinking now, I'll have to dream up a
way of measuring it. I was guessing at lengths of 6ft of me.

Frank Krygowski wrote:
On 4/5/2019 7:11 PM, wrote:
On Fri, 5 Apr 2019 15:31:36 -0400, Frank Krygowski
wrote:

On 4/5/2019 2:50 PM, Joerg wrote:


Especially at night I had neighbors who passed me later say "Man, from
the distance I thought it was a cop so I tried to be on my best
behavior". Objective accomplished.

Similarly, I've had multiple people comment on how good my lights were.
On my nighttime route home from work, there were two different instances
where a motorist and a motorcyclist spontaneously complimented my lights
as we sat at a red light, saying they could see my lights "from way back
there." I've had pedestrians shout "nice lights" when I rode by. I had a
co-worker on a committee remark about seeing my "space-shipey" lights
when I rode by her house. I had a colleague from work stop me after he
drove by to ask "What's that super bright light down by your rear axle?"
(It was a reflector.)

I've had many motorists wait inordinately long for me to pass before
either making left turns across my path, or pulling out from stop signs
to my right. In all those cases, at least three cars would have had time
to make the same maneuver before I got to the intersection.

All the above is with lights that were powered by a 3 Watt dynamo,
and/or very ordinary reflectors. In almost all cases, the lights weren't
even LED. They were halogen bulbs.

A post rather reminiscent of Jorge and his story of how his bright
lights prevented motorists pulling out of parking into his path.

Which was my point. Joerg thinks this works only with eye scorchers.
Instead, it works with any good quality light. There's no need for overkill.


I was getting the occasional car pulling out when I just had a fairly
normal cheap light (day time) which clearly folks just hadn’t
noticed/looked, for other reasons I bought a nice front light, so I don’t
have to run two since it has a remote so can easily go from full to dip or
close enough.

But I have noticed that running it on low/dip during the day seems to have
stopped folks absent minded pulling out.

I do cross some fairly major roads so something to cut though is handy and
is zero cost essentially I also have some rear lights though blinding folks
is less of a issue with rear lights.

Roger Merriman

On 4/4/2019 4:17 PM, wrote:

snip

I've read you and others going on about lights that blind oncoming
riders but frankly I don't see how that happens if the light is aimed
to illuminate the road. I use a regular single cell (3.7 VDC)
flashlight with the normal "unsophisticated" round beam and if I aim
it to illuminate the road it does not shine in the eyes of oncoming
riders, in fact after reading your various posts about blinding lights
I tested my lights.

True, but there are people that don't properly aim their lights to
illuminate the road. On roads, even two lane residential roads, opposing
direction cyclists are at 20-24 feet apart (more if there are bike
lanes) and they aren't annoying opposing cyclists, but they may be
annoying apposing vehicles if the lights aren't aimed correctly. On
narrow multi-use trails, it is annoying to opposing direction cyclists
when an adequate light is improperly aimed.

Better bike lights use a lower-intensity modulated DRL to avoid annoying
oncoming traffic, what one manufacturer calls "breathing mode," and
similar to modulated motorcycle headlights where the headlight doesn't
turn all the way off. Most LED flashlights I've seen use only
full-intensity in flash mode. I picked up one of the lights with a
low-intensity modulated mode as a show sample at Interbike
https://www.aliexpress.com/item/Gaciron-V9D-1600-Bike-Front-Light-Waterproof-1600-Lumens-Rechargeable-5000mAh-Power-Bank-Flashlight-bicycle-accessories/32967401766.html.
An expensive light at $56, certainly more than a single cell flashlight,
but it has several advantages, including the low-intensity flash mode.
1600 lumens (in theory anyway).

Since multiple studies have shown a big benefit for DRLs, for cyclists
and motorcyclists more than for cars, it would be pretty foolish not to
use them, since you're going to have some sort of light no matter what.
They don't have to be expensive. Sadly, there aren't many flashing
dynamo powered lights available, this is the only one I've found
https://www.planetbike.com/store/blaze-dynamo-sl-bike-headlight.html.

As part of my discretionary budget as mayor, I ordered 1000 sets of USB
rechargeable front and rear lights to give away, and they were $2.50 per
set. If only 10% of them end up being used on a regular basis before
being broken or lost or stolen that's still good enough. The biggest
issue I see (or don't see) with cyclists is actually right after
daylight savings time starts and students are bicycling to school in the
dark with no lights. The situation improved a little this year because
the high schools moved from a 7:30 a.m. start time to an 8:00 a.m. start
time. We are also finally getting moving on an ambitious
bicycle-pedestrian plan, with a very big fruit company in town offering
some funding for it.

On 4/6/2019 4:22 AM, Roger Merriman wrote:

I was getting the occasional car pulling out when I just had a fairly
normal cheap light (day time) which clearly folks just hadn’t
noticed/looked, for other reasons I bought a nice front light, so I don’t
have to run two since it has a remote so can easily go from full to dip or
close enough.

But I have noticed that running it on low/dip during the day seems to have
stopped folks absent minded pulling out.

I do cross some fairly major roads so something to cut though is handy and
is zero cost essentially I also have some rear lights though blinding folks
is less of a issue with rear lights.

Exactly. The biggest change in driver behavior I've seen when using
adequate lights, both day and night, is a reduction in vehicles exiting
parking lots in front of me, or making right on red turns in front of
me. And as most of us that drive have also experienced, the "I just
didn't see you" excuse that vehicle drivers use, actually does have some
validity--you are MUCH more visible when you use an adequate light, both
day and night.

Since multiple studies have come to this conclusion regarding DRLs it
should not surprise anyone (well unless they abhor statistically
significant studies and research, and judging from the number of
climate-change deniers there are still some of these individuals around).

On 2019-04-05 17:54, wrote:
On Fri, 05 Apr 2019 16:55:22 -0700, Joerg
wrote:

On 2019-04-05 16:18, wrote:
On Fri, 05 Apr 2019 12:03:31 -0700, Joerg
wrote:

On 2019-04-04 17:18, Frank Krygowski wrote:
On 4/4/2019 6:01 PM, Joerg wrote:
On 2019-04-04 12:15, jbeattie wrote:
On Thursday, April 4, 2019 at 11:15:40 AM UTC-7, Joerg wrote:
On 2019-04-03 18:56, David Scheidt wrote:
From time to time, we have discussed the visibility of daytime
running lights. I commute on a bike with B&M Cyo, which I leave
on all the time, because I can't tell the difference if it's on
or off. I found myself on google street view on my ride home
last fall. I got passed by the car, and then passed it, and got
passed again. So I, and the bike, are in a bunch of pictures,
from the front and behind, over several blocks. This one gives a
good view of the headlight. It's more visible than I'd have
expected. This was about an hour before dark, and overcast
November day.

https://goo.gl/maps/NQURJ9dps3p


Not bad, for a StVZO light. However, I went virtually behind you in
the street view and it seems you need a better rear light. And as a
male toddler I wouldn't want to be seen sitting in that
rose-colored baby seat :-)

Really? https://tinyurl.com/y5v8pva3 He's more visible than the gray
Hyundai ahead of him. I would have absolutely no problem seeing him
if I were in a car or on a bike.


Next to the red car behind it, less visible:

https://goo.gl/maps/dNQBiRm4z672

Yes, because he chose a red jacket. If he chose yellow, he'd be better
off with the red car as background.

But then he might come upon a yellow car. Perhaps he should use green?

The obvious solution is to carry a full wardrobe of various colors and
quickly change jackets depending on traffic conditions.


No, just lights of motorcycle-grade brightness. Good enough.


Much more seriously: "less visible" than some theoretical maximum is not
necessarily a problem. A cyclist needs to be visible _enough_. And
despite the currently fashionable fear mongering, that does not require
any technology that wasn't common 20 years ago.

Good grief, Joerg, how did you survive riding 20 years ago??


Simple. Automotive technology is and was most of the time decades ahead
of bicycle technology, and so was I. Even 30+ years ago my bicycles had
a real electrical system including a rechargeable battery. At first a
small lead-acid battery, kind of heavy. Then NiCd and now LiIon. I
skipped the NiMH era. While my road bike still has the dynamo that used
to keep batteries charged I no longer use that dynamo. The LiIon pack is
good enough for 4h rides with the ship fully lit and I don't need DRL on
bike paths which, of course, I prefer. Meaning I can ride all day and
re-charge at home.

Why not go all the way and mount the radio and air conditioner. Think
of the luxury.


The radio transceiver is only needed on MTB rides way into the boonies.
My air conditioner is a cleaned-out yoghurt beker that gets dunked into
a creek and then poured over my T-shirt.

You can't be serious. You deliberately go riding in the "boonies"
where you say that you will be bored and need to listen to a radio?

Strange that. If I go in the "boonies" I find a lot of things to
watch, rabbets, squirrels, birds, and in emergencies I can even think
about what I am doing.


Has it ever occurred to you that riding to more interesting areas can
require passing through boring land? Never crossed a desert?

Look around in your car, somewhere near the center of the dashboard.
There is a device with a few buttons and usually a slot to stick
something in there. Why is it there?


A cop in Germany wanted to give me a ticket for "non-StVZO compliant
lights". Unfortunately for him I was able to prove foreign residency so
he had to let me _and_ the bright lights go.

Next upgrade, some day, is a 8V - 5V switchmode converter so I can plug
in USB stuff. Turns out my bike's MP3 player which has its own battery
only lasts 2h and then it would last all day. If another rider's cell
phone runs out of juice I could help them out as well.

It may take another 10-20 years until the bicyle industry figures this
out. Or maybe never.

Why in God's world would one want an MP3 player on a bicycle?


Because there are some utterly boring stretches out here. Even on the
MTB, like the singletrack through Malby Crossing:

https://goo.gl/maps/ctjwfurCRLw

But if they are boring just go another way.


Before making such statements take a look and suggest _which_ way. The
only alternative to this singletrack is currently White Rock Road and
that's outright dangerous for cyclists. I had to bail off once and so
did other cyclists. When Folsom Ranch is built out that's going to be
different because they are obligated to install class I bike paths but
that will take time.


... When I lived at Edwards
AFB I used to go "gold panning" on the central branch of the Yuba
river. The back roads there were likely built during the gold rush
days and there was a lot to see. We discovered an old, abandoned,
"Chinese" Cemetery one day, way up in the mountains.


We have that too here and then, of course, my MP3 player is off.


... Or a
cell phone that runs out of juice. If one wants to listen to music an
jabber on the telephone just stay at home enthroned on the sofa in the
"Front Room" with the TV on.


Ever heard of GPS and maps? That can suck a lot of battery juice. This
is a core reason why I have a smart phone.

Yup. I used a GPS to navigate when I had my boat. Works well.... but
of course there weren't any roads on the ocean.


There aren't any road either in many places where I ride my MTB.


I might add that I've driven all over the U.S., Japan, Malaysia,
Indonesia and Thailand without a GPS and roamed around the back woods
along the Yuba River in California and the logging roads in northern
Maine without a GPS and I can't remember getting lost :-)


I don't either but it's another ballgame if you have to arrive at a
certain place at an agreed upon time. Sometimes on the MTB I get to a
place and discover it's flooded, no more trail. It was there last week
but now it ain't. Then it is very practical to have something with
satellite view.

--
Regards, Joerg

http://www.analogconsultants.com/

On 2019-04-05 18:08, jbeattie wrote:
On Friday, April 5, 2019 at 4:49:00 PM UTC-7, Joerg wrote:
On 2019-04-05 16:08, wrote:
On Fri, 05 Apr 2019 11:50:30 -0700, Joerg
wrote:

On 2019-04-04 18:18, jbeattie wrote:
On Thursday, April 4, 2019 at 3:01:46 PM UTC-7, Joerg wrote:
On 2019-04-04 12:15, jbeattie wrote:
On Thursday, April 4, 2019 at 11:15:40 AM UTC-7, Joerg
wrote:
On 2019-04-03 18:56, David Scheidt wrote:
From time to time, we have discussed the visibility
of daytime running lights. I commute on a bike with
B&M Cyo, which I leave on all the time, because I
can't tell the difference if it's on or off. I found
myself on google street view on my ride home last
fall. I got passed by the car, and then passed it,
and got passed again. So I, and the bike, are in a
bunch of pictures, from the front and behind, over
several blocks. This one gives a good view of the
headlight. It's more visible than I'd have expected.
This was about an hour before dark, and overcast
November day.

https://goo.gl/maps/NQURJ9dps3p


Not bad, for a StVZO light. However, I went virtually
behind you in the street view and it seems you need a
better rear light. And as a male toddler I wouldn't
want to be seen sitting in that rose-colored baby seat
:-)

Really? https://tinyurl.com/y5v8pva3 He's more visible
than the gray Hyundai ahead of him. I would have
absolutely no problem seeing him if I were in a car or on
a bike.


Next to the red car behind it, less visible:

https://goo.gl/maps/dNQBiRm4z672

I am not talking about you or me seeing him. I am talking
about the slightly soused dude who is keeping an eye on his
smart phone.

What about the moth effect!
https://www.poconorecord.com/article...NEWS/207150316
What if the soused dude who is keeping an eye on his smart
phone has a seizure induced by the flasher! What if he is so
distracted, he wouldn't notice the second coming -- let alone
a retina burning blinky! Lions and tigers and bears, oh my!


Especially at night I had neighbors who passed me later say
"Man, from the distance I thought it was a cop so I tried to be
on my best behavior". Objective accomplished.

Interesting as I thought that cops in California had flashing
blue lights?


No, red and blue, with the red optically crowding out the blue. The
more distant, the more the red wins.

Older style:

https://www.youtube.com/watch?v=tLfi1RIomMs

Similar in New York:

https://www.youtube.com/watch?v=Zr_Wmg9GYeo

Thing is, when a slightly soused driver sees such a light pattern
in the distance he may not know for sure whether it is a cop but
will try to sit straight up and be on his best behavior. Because it
if is a cop and he gets pulled over that might cost the license and
$5-10k. That's what I want.

Right. Some wobbling tail lights on a bike are going to fool a drunk
into driving straight because, you know, when the real police are
around, drunks just snap out of it and stop being drunk. That's the
great thing about being drunk -- you can just stop it anytime you
want.


Several neighbors who passed me from behind told me that it looked like
police from the distance (not once they got closer, of course). Good
enough for me, which is why I kept this light and will continue using it.


BTW, it's not just color, its pattern.
https://www.youtube.com/watch?v=riLzUHIAIGk


In the distance it doesn't matter. All people see is a lot of red
flickering and that usually triggers teh instinct of letting off of the
accelerator pedal.

--
Regards, Joerg

http://www.analogconsultants.com/

On Saturday, April 6, 2019 at 7:27:31 AM UTC-7, sms wrote:
On 4/6/2019 4:22 AM, Roger Merriman wrote:

I was getting the occasional car pulling out when I just had a fairly
normal cheap light (day time) which clearly folks just hadn’t
noticed/looked, for other reasons I bought a nice front light, so I don’t
have to run two since it has a remote so can easily go from full to dip or
close enough.

But I have noticed that running it on low/dip during the day seems to have
stopped folks absent minded pulling out.

I do cross some fairly major roads so something to cut though is handy and
is zero cost essentially I also have some rear lights though blinding folks
is less of a issue with rear lights.

You would be surprised about rear lights. I've gotten stuck behind some cyclists with blinding flashers like airplane landing lights. But if one comments on the excessiveness of the light, the come back is just as we see here -- it is never enough because it is life and death.

Reflective clothing is FAR more effective. The uber-expensive Showers Pass torch jackets are like road flares. http://tinyurl.com/y62bvycz I think it was Endura or Sugoi that made reflective tights. My next door neighbor had a pair, and those things lit up and bobbed up and down with pedaling. I'd catch her on the way home from work and was amazed at how far away you could see her. I have a bunch of reflective tape on my commuter that is really brilliant. None of this is blinding to other riders.


Exactly. The biggest change in driver behavior I've seen when using
adequate lights, both day and night, is a reduction in vehicles exiting
parking lots in front of me, or making right on red turns in front of
me. And as most of us that drive have also experienced, the "I just
didn't see you" excuse that vehicle drivers use, actually does have some
validity--you are MUCH more visible when you use an adequate light, both
day and night.

I have a L&M Urban 800 with a pulse mode -- that I was pointing directly in the driver-side window of a motorist who had pulled across a cycle track. I was two feet from his window -- just over the radius of my wheel. He just sat there staring at his phone -- and then suddenly woke up, but I think it was the yelling. Absent actual feed back from drivers like, "oh, I was going to pull out, but I saw your light," there is no way of telling what motivates them.


Since multiple studies have come to this conclusion regarding DRLs it
should not surprise anyone (well unless they abhor statistically
significant studies and research, and judging from the number of
climate-change deniers there are still some of these individuals around).

What multiple studies involving bikes? I'm aware of the Odense study with flea-watt induction lights. Are there other bicycle studies involving DRLs?

People can use DRLs -- that's fine, but it's probably no more than a lucky rabbit's foot in most situations. It's like the Odense study where the cyclists with lights had lower one-bike accidents. I ride with lights at night and still have people pull out, pull in, push me over and do all the same stuff they usually do.

-- Jay Beattie.

On 4/6/2019 7:22 AM, Roger Merriman wrote:
Frank Krygowski wrote:
On 4/5/2019 7:11 PM, wrote:
On Fri, 5 Apr 2019 15:31:36 -0400, Frank Krygowski
wrote:

On 4/5/2019 2:50 PM, Joerg wrote:


Especially at night I had neighbors who passed me later say "Man, from
the distance I thought it was a cop so I tried to be on my best
behavior". Objective accomplished.

Similarly, I've had multiple people comment on how good my lights were.
On my nighttime route home from work, there were two different instances
where a motorist and a motorcyclist spontaneously complimented my lights
as we sat at a red light, saying they could see my lights "from way back
there." I've had pedestrians shout "nice lights" when I rode by. I had a
co-worker on a committee remark about seeing my "space-shipey" lights
when I rode by her house. I had a colleague from work stop me after he
drove by to ask "What's that super bright light down by your rear axle?"
(It was a reflector.)

I've had many motorists wait inordinately long for me to pass before
either making left turns across my path, or pulling out from stop signs
to my right. In all those cases, at least three cars would have had time
to make the same maneuver before I got to the intersection.

All the above is with lights that were powered by a 3 Watt dynamo,
and/or very ordinary reflectors. In almost all cases, the lights weren't
even LED. They were halogen bulbs.

A post rather reminiscent of Jorge and his story of how his bright
lights prevented motorists pulling out of parking into his path.

Which was my point. Joerg thinks this works only with eye scorchers.
Instead, it works with any good quality light. There's no need for overkill.


I was getting the occasional car pulling out when I just had a fairly
normal cheap light (day time) which clearly folks just hadn’t
noticed/looked, for other reasons I bought a nice front light, so I don’t
have to run two since it has a remote so can easily go from full to dip or
close enough.

But I have noticed that running it on low/dip during the day seems to have
stopped folks absent minded pulling out.

I do cross some fairly major roads so something to cut though is handy and
is zero cost essentially I also have some rear lights though blinding folks
is less of a issue with rear lights.

I'm curious about folks claiming a significant number of pull-outs. This
just never happens to me. Or rather, I recall only two instances in 40+
years of adult riding. Oh, plus one left cross in about 1977. I don't
ride with daytime lights, except at dusk. (I generally don't turn on my
headlight until actual sunset.) I don't usually ride with particularly
bright colors. When riding on vacation, my outer jacket is black. When
riding to work, I wore perfectly normal office casual clothes and a
normal windbreaker.

There are very few utility cyclists around here, so is it because I'm
unusual and therefore noticeable? (But that goes against the
conventional "safety in numbers" arguments.)

Is it because there are few bike lanes here, and I'm prone to taking the
lane most of the time? Do others ride where they are less visible?


--
- Frank Krygowski

On 4/6/2019 10:20 AM, sms wrote:


Since multiple studies have shown a big benefit for DRLs, for cyclists
and motorcyclists more than for cars, it would be pretty foolish not to
use them...

That's an excellent example of the hand wringer's Safety Inflation
Creed. "Someone claimed a big benefit, so it's foolish not to use it!"

No specifics are given on the "multiple studies" (at least one of which
is known to be crap). And in the general Safety Inflation case, no
studies are really needed. As long as someone's tried it and _believed_
it helped, it's foolish not to use it. No skepticism allowed!

As I recall, "sms" AKA Stephen M. Scharf has used the same "logic" to
say it's foolish to ride without a nautical strobe light on one's rear
rack; and a horizontal flippy flag sticking out into traffic; and an
electric horn powered by a big battery; and of course, multiple
headlights with various flashing / blinking patterns.

Why does he omit the six foot tall bike flags from the 1970s? After all,
they _might_ help!

--
- Frank Krygowski

On Sat, 6 Apr 2019 07:27:25 -0700, sms
wrote:

On 4/6/2019 4:22 AM, Roger Merriman wrote:

I was getting the occasional car pulling out when I just had a fairly
normal cheap light (day time) which clearly folks just hadn’t
noticed/looked, for other reasons I bought a nice front light, so I don’t
have to run two since it has a remote so can easily go from full to dip or
close enough.

But I have noticed that running it on low/dip during the day seems to have
stopped folks absent minded pulling out.

I do cross some fairly major roads so something to cut though is handy and
is zero cost essentially I also have some rear lights though blinding folks
is less of a issue with rear lights.

Exactly. The biggest change in driver behavior I've seen when using
adequate lights, both day and night, is a reduction in vehicles exiting
parking lots in front of me, or making right on red turns in front of
me. And as most of us that drive have also experienced, the "I just
didn't see you" excuse that vehicle drivers use, actually does have some
validity--you are MUCH more visible when you use an adequate light, both
day and night.

Since multiple studies have come to this conclusion regarding DRLs it
should not surprise anyone (well unless they abhor statistically
significant studies and research, and judging from the number of
climate-change deniers there are still some of these individuals around).

Yes the often mentioned Odense study (of some 1,845 users and some
2,000 non users over a 12 month period) showed permanent running
lights reduced accidents by 19%.

The study was initiated and funded by the company that made the
permanent running lights.

Which would seem to underwrite your argument until one discovers that
the "running lights" used in the study were tiny little lights powered
by two magnets attached to the wheel spokes which generated a short
flash as they passed the light which was attached to the forks. The
lights were manufactured by Reelight.

By the way, the study showed that the incident of solo accidents were
also reduced in the group equipped with lights.

Note: Both the entire study and Reelight's company advert are
available on the Web.
--
cheers,

John B.