Invisible Cyclists in Solstice Dark

"Survival of ... the Brightest" (with apologies to Darwin).

Chris Street
www.BeSeenOnABike.com

Chris Malcolm wrote:
Of course lights and light-coloured clothing makes you more easily
seen than if camouflaged in dark clothing, but the problem with night
time streets is the illumination war between motorised vehicles is
already quite far advanced. Some of the lights modern cars use in
well-lit urban streets not only blind me but actually hurt my eyes.
There is so much competition from glaring light sources all over the
place that even white clothing can be obscured, and cyclists simply
can't carry enough power to compete with motorised vehicle light
power.

That's the *huge* advantage of reflective material -- it directionally
bounces back a good fraction of the light aimed at it, in effect
borrowing some the light power of the motorised vehicle, and greatly
reducing the effect of the inverse square law on distance. Almost
everyone greatly underestimates the visibility adantages of reflective
materials, possibly because their optical behaviour is so
counter-intuitive that we find it hard to believe what they actually
do.

max wrote:
In article ,
Simon Brooke wrote:

in message , Just zis Guy, you know?
') wrote:

Chris Malcolm wrote:

Of course lights and light-coloured clothing makes you more easily
seen than if camouflaged in dark clothing,

I wasn't aware that was in dispute.

It's in dispute. I dispute it. In the dark, the colour of your clothing
makes no difference; when illuminated by headlights, retro-reflectives
so outperform any colour that - provided you have retro-reflectives -
the colour is irrelevant.

Here's a link http://www.occunomix.com/3mscotchlite.html that puts the
pertinent data in a short, convenient table. Tasty and easy to digest.

The difference is profound.

basically: for motorist travelling at 60 mph. (time to react/ distance detected)

dark shirt = 0.6 sec / 55 ft
white shirt = 2.0~2.5 sec / 180~220 ft.
reflective stuff = 17~22 sec / 1500~2000 ft.

I'd say that these figures accord closely with actual experience on the
road and should be no suprise. I expect they will be disputed however!
Are there any figures anywhere for visibilty of flashing or
non-flashing lights? Common sense tells one that non-flashing lights
are more visible as flashing lights are switched off intermittently.

cheers

Jacob

crabsallover wrote:
snip
www.BeSeenOnABike.com was born!

Interesting to see two members of this parish apparently endorsing Mr
Street's website he

http://www.beseenonabike.com/bsoab/#news

quote Nov 11th 2005: "When I'm cycling after dark, and in full
low-flying UFO mode due to acres of lights (static & flashing) & acres
of reflectives, the comments I've had from motorists have all been
along the lines of "I wish other cyclists would
be as easily visible as you" helen s (uk.rec.cycling)... "That's a well
lit cyclist" ... a friend described my bike as "Danny's spaceship" :-)
Danny Colyer /quote

best wishes
james

I reviewed the sheldonbrown findings:
http://www.beseenonabike.com/bsoab/b...y_problems.htm

also see:
http://bikexprt.com/bicycle/reflectors/reflwrk.htm
for another discussion on reflectors use by cyclists.

Jeff Williams wrote:
http://sheldonbrown.com/reflectors.html for a discussion of why
reflectives are not so effective for cycling.

Chris Street
www.BeSeenOnABike.com

From the Dept of Transport stats "Death rates among cyclists were 10
times greater than those among car users in 2002.

http://www.statistics.gov.uk/StatBas...ank=1&Rank=272


Pedestrians have 44 killed per billion Km; cyclists only 29 (2002 figures, but the trend is
consistent). Surprising though it may seem, cycling really is safer than
walking.

Chris Street
www.BeSeenOnABike.com

wrote in message
oups.com...

crabsallover wrote:
snip
www.BeSeenOnABike.com was born!

Interesting to see two members of this parish apparently endorsing Mr
Street's website he

http://www.beseenonabike.com/bsoab/#news

quote Nov 11th 2005: "When I'm cycling after dark, and in full
low-flying UFO mode due to acres of lights (static & flashing) & acres
of reflectives, the comments I've had from motorists have all been
along the lines of "I wish other cyclists would
be as easily visible as you" helen s (uk.rec.cycling)... "That's a well
lit cyclist" ... a friend described my bike as "Danny's spaceship" :-)
Danny Colyer /quote

best wishes
james


I don't remember being asked if I wanted to be quoted on a web site...

Cheers, helen s

crabsallover wrote:
From the Dept of Transport stats "Death rates among cyclists were 10
times greater than those among car users in 2002.

http://www.statistics.gov.uk/StatBas...ank=1&Rank=272


Pedestrians have 44 killed per billion Km; cyclists only 29 (2002
figures, but the trend is consistent). Surprising though it may
seem, cycling really is safer than
walking.


A distortion of statistical meaning that is trotted out here quite
regularly, sometimes innocently sometimes with deliberate intent to deceive
and confuse. to which camp do you belong?

pk

Retro-Reflective clothing can be the difference between being hit by a
car and avoiding an accident!

Look at the Typical Stopping Distances taken from the Highway Code. If
a car is travelling at 20mph the typical stopping distance is 12metres.
So the person should not be hit by the motorist who can see someone in
dark clothing up to 30m away.

But if the motorist is travelling at 40mph, the darkly clothed person
may easily be hit by the motorist. The typical stopping distance at
40mph is 36m - but dark clothing is only visible by the motorist up to
30m! At 70mph a motorist may not have time to avoid hitting someone
wearing white clothing.

Wearing dark clothes whilst on a bicycle is really an accident waiting
to happen. The cyclist may be seen too late by a motorist to avoid an
accident.

A cyclist wearing retro-reflective clothing should be seen by the
motorist at 213m (700ft). So no matter what speed the motorist is
travelling at, the cyclist wearing retro-reflective clothing should be
safer.

http://www.beseenonabike.com/bsoab/b...flectivity.htm

Chris Street
www.BeSeenOnABike.com


Chris Malcolm wrote:

Of course lights and light-coloured clothing makes you more easily
seen than if camouflaged in dark clothing,

I wasn't aware that was in dispute.

It's in dispute. I dispute it. In the dark, the colour of your clothing
makes no difference; when illuminated by headlights, retro-reflectives
so outperform any colour that - provided you have retro-reflectives -
the colour is irrelevant.

Here's a link http://www.occunomix.com/3mscotchlite.html that puts the
pertinent data in a short, convenient table. Tasty and easy to digest.

The difference is profound.

basically: for motorist travelling at 60 mph. (time to react/ distance detected)

dark shirt = 0.6 sec / 55 ft
white shirt = 2.0~2.5 sec / 180~220 ft.
reflective stuff = 17~22 sec / 1500~2000 ft.

Brian Huntley wrote:
Zoot Katz wrote:
I think cello-taping large denomination bills to frame tubes, fenders
and helmet would have the best chance for increasing ones visibility.
Most everyone is looking for money.


Ooo - you've given me a great idea for the next frame I wrap (previous
ones have been wood grain and rubber.)

Now, where can I get lots of old Yugoslav, Turkish, or Italian bills?

I can get you Chinese money.

(My LBS occasionally displays a frame covered in stamps. Very pretty.)

crabsallover wrote:

Wearing dark clothes whilst on a bicycle is really an accident
waiting to happen. The cyclist may be seen too late by a motorist to
avoid an accident.


So Chris, exactly how many of the ~130 cyclists a year killed on the
roads were killed at night?

--
Tony

"The best way I know of to win an argument is to start by being in the
right."
- Lord Hailsham