visibility

We've discussed daytime lights from time to time, with a couple guys
saying they are absolutely necessary, and some others saying their
benefits are being grossly exaggerated (like lots of "bike safety" stuff).

Well, I happen to have the June 2016 issue of _Bicycle Times_ sitting
next to me on my desk, face down. The full page back cover ad is by
Bontrager. In the course of doing other things, I glanced at it from
time to time, vaguely registering that it shows a rear view of a cyclist
about to be passed by a car.

The cyclist is dressed all in black, riding the drops. The vegetation
forming the background is dark brown. I absentmindedly glanced at the
photo several times, noting the cyclist without reading the ad. Then I
suddenly wondered "What's this ad about?"

Ah! "Flare R Designed for daylight visibility" That explains the
large picture of a bike taillight in the lower right corner.

To me the most interesting aspect was this: I must have looked at that
cyclist's photo ten times without noticing that there's a tiny red light
- probably Photoshop enhanced - just below his butt. I saw the cyclist.
I didn't see the light.

(The cyclist is riding the white line, but it's not possible to see if
the lane is wide enough to safely share.)

--
- Frank Krygowski

I have seen bicyclists using rear tail lights in the daytime. But never noticed the light until I was right on top of them. So can't imagine it adds much if any extra visibility. Rarely see front head lights during the day.. And then only notice them when I am directly in front of the rider. In daylight the white headlights cannot be seen.

Concerning the black dressed rider riding in brown terrain, I HATE black jerseys. They should be outlawed. They have to be the most unsafe thing you can do when riding a bike. I cannot understand the concept of trying to make yourself invisible when riding in traffic. I favor orange and yellow jersey colors. I don't care if the black jerseys are cool looking. Dead and cool is not better than alive and uncool. I want to be seen when riding a bike.

On Thu, 23 Jun 2016 12:22:06 -0400, Frank Krygowski
wrote:

We've discussed daytime lights from time to time, with a couple guys
saying they are absolutely necessary, and some others saying their
benefits are being grossly exaggerated (like lots of "bike safety" stuff).

Well, I happen to have the June 2016 issue of _Bicycle Times_ sitting
next to me on my desk, face down. The full page back cover ad is by
Bontrager. In the course of doing other things, I glanced at it from
time to time, vaguely registering that it shows a rear view of a cyclist
about to be passed by a car.

The cyclist is dressed all in black, riding the drops. The vegetation
forming the background is dark brown. I absentmindedly glanced at the
photo several times, noting the cyclist without reading the ad. Then I
suddenly wondered "What's this ad about?"

Ah! "Flare R Designed for daylight visibility" That explains the
large picture of a bike taillight in the lower right corner.

To me the most interesting aspect was this: I must have looked at that
cyclist's photo ten times without noticing that there's a tiny red light
- probably Photoshop enhanced - just below his butt. I saw the cyclist.
I didn't see the light.

(The cyclist is riding the white line, but it's not possible to see if
the lane is wide enough to safely share.)

But as long as he/she/it is wearing a helmet they are SAFE.

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.
--
cheers,

John B.

On 6/23/2016 5:40 PM, John B. wrote:

snip

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.

Well I would not judge the visibility of lights in the daytime based on
what Trek sells under their Bontrager brand name since their lights
aren't great.

I am seeing more DRLs than ever on bicycles around here. Since the rain
has ended more people are riding to work again. I doubt you can even buy
a battery powered light in any store that doesn't have a flashing DRL
unless you can find a store selling German li.

I've only ever seen one study on the on the benefits of DRLs and it
showed a significant benefit. Since there is no real down side, it makes
sense to use them. http://www.ncbi.nlm.nih.gov/pubmed/22884376.

On Thu, 23 Jun 2016 18:12:59 -0700, sms
wrote:

On 6/23/2016 5:40 PM, John B. wrote:

snip

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.

Well I would not judge the visibility of lights in the daytime based on
what Trek sells under their Bontrager brand name since their lights
aren't great.

I am seeing more DRLs than ever on bicycles around here. Since the rain
has ended more people are riding to work again. I doubt you can even buy
a battery powered light in any store that doesn't have a flashing DRL
unless you can find a store selling German li.

I've only ever seen one study on the on the benefits of DRLs and it
showed a significant benefit. Since there is no real down side, it makes
sense to use them. http://www.ncbi.nlm.nih.gov/pubmed/22884376.




Strange isn't it that the NHTSA report of September 2008 titled "The
Effectiveness of Daytime Running Lights For Passenger Vehicles"

Under the sub-title
"Single-Passenger-Vehicle-to-Pedestrian/Pedalcyclist Crashes"
(Single-PV-to-PED/CYC)

States that:

None of the results were statistically significant at the 0.05 level.

Although not statistically significant, DRLs in cars were more likely
to reduce daytime Single-PC-to-PED/CYC fatal and injury crashes.

In contrast,
DRLs in LTVs seemed to have an unintended consequence against
single-LTV crashes involving pedestrians and pedalcyclists. The large
negative effects, although not statistically significant, cannot be
totally ignored.

For PCs and LTVs combined, DRLs seemed to have no effect on
Single-PV-to-PED/CYC fatal crashes.

However, DRLs seemed to have a negative impact on single-
vehicle injury and all crashes involving pedestrians and
pedalcyclists.
--
cheers,

John B.

On Fri, 24 Jun 2016 08:47:30 +0700, John B.
wrote:

On Thu, 23 Jun 2016 18:12:59 -0700, sms
wrote:

On 6/23/2016 5:40 PM, John B. wrote:

snip

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.

Well I would not judge the visibility of lights in the daytime based on
what Trek sells under their Bontrager brand name since their lights
aren't great.

I am seeing more DRLs than ever on bicycles around here. Since the rain
has ended more people are riding to work again. I doubt you can even buy
a battery powered light in any store that doesn't have a flashing DRL
unless you can find a store selling German li.

I've only ever seen one study on the on the benefits of DRLs and it
showed a significant benefit. Since there is no real down side, it makes
sense to use them. http://www.ncbi.nlm.nih.gov/pubmed/22884376.




Strange isn't it that the NHTSA report of September 2008 titled "The
Effectiveness of Daytime Running Lights For Passenger Vehicles"

Under the sub-title
"Single-Passenger-Vehicle-to-Pedestrian/Pedalcyclist Crashes"
(Single-PV-to-PED/CYC)

States that:

None of the results were statistically significant at the 0.05 level.

Although not statistically significant, DRLs in cars were more likely
to reduce daytime Single-PC-to-PED/CYC fatal and injury crashes.

In contrast,
DRLs in LTVs seemed to have an unintended consequence against
single-LTV crashes involving pedestrians and pedalcyclists. The large
negative effects, although not statistically significant, cannot be
totally ignored.

For PCs and LTVs combined, DRLs seemed to have no effect on
Single-PV-to-PED/CYC fatal crashes.

However, DRLs seemed to have a negative impact on single-
vehicle injury and all crashes involving pedestrians and
pedalcyclists.

Additional Studies:

The Minnesota Department of Transportation report
Published November 2010

Effects of 24-Hour Headlight Use on Traffic Safety

Effect on Crashes Involving Pedestrians and Bicyclists

DRLs have the potential to effect pedestrian and bicyclist safety in
at least two ways. It is possible that pedestrians
and bicyclists would become relatively less visible when motor
vehicles have their headlights on.

However, the enhanced conspicuity of motor vehicles may make them
easier for pedestrians and bicyclists to observe (Elvik et al.,
2003). Studies on this topic found the following:

The Elvik et al. (2003) meta-analysis found that DRLs reduced crashes
involving pedestrians, though some of the individual studies reviewed
showed an increase in crashes.

The 2008 NHTSA study found no statistically significant results for
crashes involving pedestrians or bicyclists.

The 2004 NHTSA study found that DRLs reduced daytime fatal crashes
involving non-motorists, pedestrians and cyclists by 12 percent.

An experimental 2004 European study (Brouwer et al.) found no evidence
of a reduced conspicuity of road users in the vicinity of a
DRL-equipped vehicle.
--
cheers,

John B.

On 6/23/2016 9:12 PM, sms wrote:
On 6/23/2016 5:40 PM, John B. wrote:

snip

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.

Well I would not judge the visibility of lights in the daytime based on
what Trek sells under their Bontrager brand name since their lights
aren't great.

:-) Note! You should instead buy the lights that give guerilla
marketer Scharf a commission!

I am seeing more DRLs than ever on bicycles around here.

Because riding a bike is so dangerous!! (Paranoia runs deep.)

I've only ever seen one study on the on the benefits of DRLs and it
showed a significant benefit. Since there is no real down side, it makes
sense to use them.

If there were no real downside, everybody would be using them. There
are advantages and disadvantages to everything.

http://www.ncbi.nlm.nih.gov/pubmed/22884376.

You've pointed to that propaganda piece before. The manufacturer gave
free lights to anyone who asked for them, on the condition that they
would later say whether they felt safer or not. Most people said "Yeah,
I feel safer." That's what passes for science in the "bike safety
product" realm.


--
- Frank Krygowski

with Frank Krygowski wrote:

*SKIP*
Ah! "Flare R Designed for daylight visibility" That explains the
large picture of a bike taillight in the lower right corner.

To me the most interesting aspect was this: I must have looked at that
cyclist's photo ten times without noticing that there's a tiny red
light - probably Photoshop enhanced - just below his butt. I saw the
cyclist. I didn't see the light.

Because strobe. The strobe is definetely visible when sun-light is
anyway obstructed. I can't say otherwise -- I can't observe myself and
here I'm doing it (strobe) alone. However, non-strobe is undetectable
in direct sun-light (from observation).

Also, thanks for notifing. I'm doing Flare1. That Flare R might be
even better, got to check it out.

*CUT*

--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom

On 2016-06-23 19:56, John B. wrote:
On Fri, 24 Jun 2016 08:47:30 +0700, John B.
wrote:

On Thu, 23 Jun 2016 18:12:59 -0700, sms
wrote:

On 6/23/2016 5:40 PM, John B. wrote:

snip

And there is rear light it probably makes them even safer. "Safer than
safe" as it were.

Well I would not judge the visibility of lights in the daytime based on
what Trek sells under their Bontrager brand name since their lights
aren't great.

I am seeing more DRLs than ever on bicycles around here. Since the rain
has ended more people are riding to work again. I doubt you can even buy
a battery powered light in any store that doesn't have a flashing DRL
unless you can find a store selling German li.

I've only ever seen one study on the on the benefits of DRLs and it
showed a significant benefit. Since there is no real down side, it makes
sense to use them. http://www.ncbi.nlm.nih.gov/pubmed/22884376.




Strange isn't it that the NHTSA report of September 2008 titled "The
Effectiveness of Daytime Running Lights For Passenger Vehicles"

Under the sub-title
"Single-Passenger-Vehicle-to-Pedestrian/Pedalcyclist Crashes"
(Single-PV-to-PED/CYC)

States that:

None of the results were statistically significant at the 0.05 level.

Although not statistically significant, DRLs in cars were more likely
to reduce daytime Single-PC-to-PED/CYC fatal and injury crashes.

In contrast,
DRLs in LTVs seemed to have an unintended consequence against
single-LTV crashes involving pedestrians and pedalcyclists. The large
negative effects, although not statistically significant, cannot be
totally ignored.

For PCs and LTVs combined, DRLs seemed to have no effect on
Single-PV-to-PED/CYC fatal crashes.

However, DRLs seemed to have a negative impact on single-
vehicle injury and all crashes involving pedestrians and
pedalcyclists.

Additional Studies:

The Minnesota Department of Transportation report
Published November 2010

Effects of 24-Hour Headlight Use on Traffic Safety

Effect on Crashes Involving Pedestrians and Bicyclists

DRLs have the potential to effect pedestrian and bicyclist safety in
at least two ways. It is possible that pedestrians
and bicyclists would become relatively less visible when motor
vehicles have their headlights on.


Hence one shall also have lights on as a cyclist. I always do when on
roads. It has substantially reduced the number of intrusions into my
path where I had to brake hard. People pulling out of gas stations, side
roads, parking lots, doing left turns or right turns in front of me, and
so on. IOW it works. When others diss daytime lights I simply do not care.

Neighbors have told me that my bikes really stand out when they see me
on the road. The front light on the MTB doesn't even have a flash mode,
doesn't need it because it is similar to a motorcycle light in
conspicuousness.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/

On 2016-06-24 01:15, Eric Pozharski wrote:
with Frank Krygowski wrote:

*SKIP*
Ah! "Flare R Designed for daylight visibility" That explains the
large picture of a bike taillight in the lower right corner.

To me the most interesting aspect was this: I must have looked at that
cyclist's photo ten times without noticing that there's a tiny red
light - probably Photoshop enhanced - just below his butt. I saw the
cyclist. I didn't see the light.

Because strobe. The strobe is definetely visible when sun-light is
anyway obstructed. I can't say otherwise -- I can't observe myself and
here I'm doing it (strobe) alone. However, non-strobe is undetectable
in direct sun-light (from observation).

Also, thanks for notifing. I'm doing Flare1. That Flare R might be
even better, got to check it out.


Something with LEDs in the 1/2W power range in there is better than an
assortment of little ones. It has a higher chance of catching the eye of
even a distracted driver.

What is often the pits with cycling lights is the flimsy mount. So I
usually saw that off and throw it away, drill and then bolt them to an
aluminum carrier with M5 screws. Like this:

http://www.analogconsultants.com/ng/bike/Rearlight1.JPG

That one is only the backup light which is always running alongside the
big light on the seat tube. Just in case the battery drains away while
riding.

--
Regards, Joerg

http://www.analogconsultants.com/