Young cyclist killed

"[email hidden]" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

ok, I'll bite now. The object you describe as invisible does not exist
(and not just because it would be hard to see). I am not arguing that
a stealth cyclist will not be harder to see and be likely to be noticed
later by a competent driver, but a pefrfectly non-reflective cyclist?
That's like assuming your cyclist is a point mass before trying to
calculate his potential top speed

Not really. While a pure, black object probably does not exist, more than
adequately camouflaged ones do. Because of the difference in sensitivity of
rods and cones, night vision is almost monochromatic, which means that the
few folds of a dark jacket that might be visible from close in are very
likely to be interpreted as something else (e.g. the branches of a bush).
Whatever, the broken outline and patchy rendering of a "stealth" road user
is not readily recogniseable as a cyclist or pedestrian.

At least we agree that stealth road users are harder to see, and hopefully
that we should do what we can to ensure that our own visibility is
adequate.

in message <[email hidden]>,

(') said:

Will Cove said:

Danny Colyer <[email hidden]> wrote in news:45734352$0$8747
[email hidden]:

Quoted message said:

Read it, don't accept it. If your lights are unable to illuminate a
dark, unlit object in your path in the distance that you require to
stop, then either your lights or inadequate or your speed is too high.

Ye canny change the laws of physics.

Pure black reflects no light - so it doesn't matter how bright your
lights are or how fast you're going you will not see a pure black object
by direct illumination. The only way that you can see a pure black
object is by its silhoutte - and against a pure black surface there will
not be one.

ok, I'll bite now. The object you describe as invisible does not exist
(and not just because it would be hard to see). I am not arguing that
a stealth cyclist will not be harder to see and be likely to be noticed
later by a competent driver, but a pefrfectly non-reflective cyclist?

Even a (theoretical) perfectly non-reflective cyclist would be visible at
night because there are (on Earth) no perfectly non-reflective
backgrounds.

Quoted message said:

Quoted message said:

Whether or not you accept it what I wrote, if any cyclist or pedestrian
goes out on an unlit road at night in dark clothing and without adequate
marker lights or reflectors they are an accident waiting to happen.

They stand a greater chance of being run down by a less-than-adequately
observant motorist and contributory negligence could potentially be
argued

They're certainly being irresponsible, and they're certainly exhibiting
contributory negligence, but it does not let the driver off the hook. We
have to apply higher standards of competence to people driving a ton of
metal around.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; We don't just borrow words; on occasion, English has pursued other
;; languages down alleyways to beat them unconscious and riffle their
;; pockets for new vocabulary -- James D. Nicoll

in message <[email hidden]>, Mark
Thompson ('pleasegivegenerously@warmmail*_turn_up_the_heat_to_reply*.com'😉

Quoted message said:

Quoted message said:

However, your personal attack is pointless because I'm not saying that I
would or would not have a better chance of seeing a stealth cyclist than
any other road user

You're saying that even with headlights you find it impossible to see
them
(under certain conditions) until you're just a few feet away. I
understand what you're saying, but it is so removed from my experience of
not running stealth peds over that there is either something wrong with
your eyes, or something wrong with your example.

There's something wrong with his speed; he considers it acceptable to drive
at speeds at which he cannot with confidence be certain that the road
ahead is clear for at least his stopping distance under the conditions.

He's not alone. Most drivers - especially younger drivers - do. It's
something we have to change.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Morning had broken, and we had run out of gas for the welding torch.

Will Cove said:

David Hansen <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

In a war of escalating brightness on the roads we can easily say who
the losers will be. Those with a limited area to cover in bright
material and those with limited capacity to carry and power ever
brighter lights.

And your answer is? Do we further limit the amount of lights that
motorists can use?

Yes, that seems like a sensible and workable solution. Limit the optical
output (luminosity?) of car headlights, particularly in urban areas.

Quoted message said:

Do we require all roads to be fully lit (and the power
requirements of that)?

No.

Quoted message said:

Personally, I think that segregation would be safest because motorised
and human-powered traffic can't collide if they don't share the same
space.

Motorists might object if they were denied access to the roads in order to
ensure cyclists safety...

Quoted message said:

For example, we could legislate for a proper network of cyclepaths
so that every A road must have adequate (i.e. at least 2m wide, sealed
surface, and separated from the main carriageway by verge or barrier)
cyclepaths or an alternative, dedicated route. In most towns it wouldn't
be too difficult to choose "back road routes" that run parallel to the
main drags, make those routes "no motor vehicles except for access", and
give those routes priority at intersections.

Again, this won't happen anytime soon. Motorists will object to having to
give way to cyclists at all junctions, even if they already have to at some
junctions.

Quoted message said:

Out of towns there might be
issues because of the limited width available but in most cases the
missing component would be the political will and (unfortunately) it
would cost the government twice over (infrastructure costs and lost
motoring taxes) to put such a plan into action.

So it's a bit of a non-starter then.

--
Chris

"The C Programming Language -- A language which combines the flexibility of
assembly language with the power of assembly language."

On Mon, 4 Dec 2006 09:37:22 -0000 someone who may be "p.k."
<[email hidden]> wrote this:-

Quoted message said:

It is self evident

Only if people are machines. The mistake engineers make is thinking
that people are machines and that is where the road "safety" lobby
has gone wrong for decades.

I recommend some of the standard reference books on risk
compensation and danger reduction.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Mon, 4 Dec 2006 09:58:29 GMT someone who may be Helen Deborah
Vecht <[email hidden]> wrote this:-

Quoted message said:

Quoted message said:

Quoted message said:

Do you use lights on your bike when riding after lighting-up time? Do you
wear high-vis clothing? Do you ride legally?

Quoted message said:

Only lights are a legal requirement.

<pedant>

and a red rear reflector AFAIK

<pedant>

And some other reflectors on some bikes, but reflectors were not
mentioned in the original posting so I left them out.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 04 Dec 2006 10:21:57 GMT someone who may be Will Cove
<[email hidden]> wrote this:-

Quoted message said:

Quoted message said:

The point is that optical physics is not the only thing involved in
"seeing".

Not the only thing involved in perception perhaps but certainly the most
important.

Evidence for this assertion?

The Department of/for Roads has been asked for evidence many times
and has yet to come up with anything convincing AFAIAA.

Quoted message said:

Quoted message said:

In a war of escalating brightness on the roads we can easily say who
the losers will be. Those with a limited area to cover in bright
material and those with limited capacity to carry and power ever
brighter lights.

And your answer is?

De-escalate the arms race. Otherwise arms races tend to lead to wars
when relatively minor things happen, like the murder of the heir to
the Hapsburg empire.

Quoted message said:

Do we further limit the amount of lights that motorists can use?

Are there currently any limits on the number of lights motorists may
use?

There are limits on the input power of some lights, but that means
that with better engineering the light output of a light increases
for the same input power.

I would start the de-escalation by limiting the number and light
output of lamps attached to motor vehicles.

Quoted message said:

Do we require all roads to be fully lit

Certainly not.

Quoted message said:

Personally, I think that segregation would be safest because motorised
and human-powered traffic can't collide if they don't share the same
space.

Totally segregated junctions? Very expensive. Note that junctions
are where most crashes happen.

Would buildings have separate doors, one leading to the bike
bhantustan.

Quoted message said:

For example, we could legislate for a proper network of cyclepaths
so that every A road must have adequate (i.e. at least 2m wide, sealed
surface, and separated from the main carriageway by verge or barrier)
cyclepaths

What sort of motor vehicle would this verge or barrier prevent from
reaching the bhantustan?

Quoted message said:

or an alternative, dedicated route.

How far apart to prevent some motorist emulating Mr Hart?

Quoted message said:

In most towns it wouldn't
be too difficult to choose "back road routes" that run parallel to the
main drags, make those routes "no motor vehicles except for access",

Then you are not advocating segregation.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 04 Dec 2006 10:33:08 GMT someone who may be Will Cove
<[email hidden]> wrote this:-

Quoted message said:

Quoted message said:

I understand what you're saying, but it is so removed from my
experience of not running stealth peds over that there is either
something wrong with your eyes, or something wrong with your example.

How do you know that you haven't missed hitting a stealth ped?

Presumably he has not heard the thud they make as they damage the
paint and body work of the car as one drives off.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Quoted message said:

How do you know that you haven't missed hitting a stealth ped?

Presumably he has not heard the thud they make as they damage the
paint and body work of the car as one drives off.

When you miss, there is no "thud".

Helen Deborah Vecht said:

"p.k." <[email hidden]>typed

Quoted message said:

I've told here before the time I saw very late a black, cyclist on a
black bike, dressed all in black who I only saw when his black,
dressed crossbar passenger smiled and my lights reflected off his
smile.

Likewise, I've told people here before of almost getting doored at
1pm, whilst wearing dayglo orange from neck to ankle...

You were doored by an idiot.

A stealth cyclist could be hit by a properly observant driver - eg, an other
hazard occurs and driver swerves across onto the "empty" side of the road in
a way they would not have done had the cyclist been more visible.

Stealth cycling puts the cyclist at more risk. Full stop. No ifs. No buts.
No caveats.

pk

David Hansen said:

On Mon, 4 Dec 2006 09:37:22 -0000 someone who may be "p.k."
<[email hidden]> wrote this:-

Quoted message said:

It is self evident

Only if people are machines.

ah so there is no point in stage hands dressing in black to move scenery on
a darkened stage!

Once again I marvel at the mental gyrations that so many here go through to
avoid criticising any action by any cyclist.

pk

David Hansen <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Quoted message said:

Quoted message said:

The point is that optical physics is not the only thing involved in
"seeing".

Not the only thing involved in perception perhaps but certainly the
most important.

Evidence for this assertion?

I responded to something that metioned "seeing" - so we're talking about
visual perception here. Sight relies upon rays of light (or photons -
take your pick) reaching retinal receptors. If there is no light, there
can be no sight, and hence no visual perception. Every aspect of visual
perception relies upon optical physics, which must therefore be the most
important.

Quoted message said:

Quoted message said:

Do we further limit the amount of lights that motorists can use?

Are there currently any limits on the number of lights motorists may
use?

Yes, the lighting regs limit you to two dipped beam headlights at a time
and they must use euromarked bulbs, which effectively limit them to 2 x
55W. Also, no lights may be used so as to dazzle or discomfort other road
users (and yes, that does mean car drivers should dip their headlights
for cyclists). However, motorists can use an unlimited number of marker
and rear position lights.

Quoted message said:

Quoted message said:

Personally, I think that segregation would be safest because motorised
and human-powered traffic can't collide if they don't share the same
space.

Totally segregated junctions? Very expensive. Note that junctions
are where most crashes happen.

Very expensive, yes. I said safest, not cheapest, and I consider that
road users have already paid many times over for such a system.

Quoted message said:

Quoted message said:

For example, we could legislate for a proper network of cyclepaths
so that every A road must have adequate (i.e. at least 2m wide, sealed
surface, and separated from the main carriageway by verge or barrier)
cyclepaths

What sort of motor vehicle would this verge or barrier prevent from
reaching the bhantustan?

Something like Armco could help prevent out of control vehicles from
reaching the cyclepath. However, that isn't the key. The purpose of this
is to give cyclists their own space that motorised traffic is not
permitted to use except (for example) if they live on a street designated
as a cycle route. That would greatly reduce the interaction between
cyclists and cars. Even though these streets are places where doors are
likely to be flung open, there would be enough room for cyclists to not
ride in the door zone and so less overall chance of a "dooring".

Quoted message said:

Quoted message said:

or an alternative, dedicated route.

How far apart to prevent some motorist emulating Mr Hart?

?? Who Mr Hart?

I'm thinking of routes like the Camel Trail in Cornwall, Tarka Trail in
Devon, and the Bristol-to-Bath cyclepath. Is there currently a problem
with motorised traffic on such routes? If not, what reason is there to
expect problems in the future? FWIW, I've ridden on both the Camel and
Tarka trails recently and not seen any vehicles where they shouldn't be.

In practice, this means a cycle network to link most conurbations. The
provision for alternative routes would deal with instances where a
parallel cyclepath either isn't possible, desirable, or the best
solution.

Quoted message said:

Quoted message said:

In most towns it wouldn't be too difficult to choose "back road
routes" that run parallel to the main drags, make those routes "no
motor vehicles except for access",

Then you are not advocating segregation.

Not complete segregation. However, I am advocating segregation as far as
practically possible and giving non-motorised traffic priority where
segregation is not possible.

Will Cove said:

I responded to something that metioned "seeing" - so we're talking about
visual perception here. Sight relies upon rays of light (or photons -
take your pick) reaching retinal receptors. If there is no light, there
can be no sight, and hence no visual perception.

When was the last time you were on a road with "no light"? By which I
mean actually *no* light.

Quoted message said:

Every aspect of visual perception relies upon optical physics

No, that's only to do with the information that arrives to form an
image. If that image is formed correctly and how it is subsequently
interpreted is a while other story.

Quoted message said:

Very expensive, yes. I said safest, not cheapest, and I consider that
road users have already paid many times over for such a system.

Only safest if you can magically do all of them at once: otherwise those
shared junctions left for later will be used by folk with less
experience of how to use a shared space, resulting in less rather than
more safety.

Quoted message said:

Not complete segregation. However, I am advocating segregation as far as
practically possible and giving non-motorised traffic priority where
segregation is not possible.

A bit like NL. Not actually quite the cycling paradise it's often seen
as, and that's (a) starting some time ago and (b) implemented by people
with a Clue about cycling. The real difference in NL for me on the
occasions I've ridden there is that if I'm riding on the road I get
noticed and deferred to.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Quoted message said:

ah so there is no point in stage hands dressing in black to move
scenery on a darkened stage!

Shine a car headlight at 'em. That'll show the buggers up.

Quoted message said:

Once again I marvel at the mental gyrations that so many here go
through to avoid criticising any action by any cyclist.

Cyclist riding at night without lights = illegal and silly. None here
condone it. Pavement cyclists and red light jumpers are also bullied until
they change their ways or bugger off. Don't you ever read the cycling
threads?

On Mon, 4 Dec 2006 12:08:53 -0000 someone who may be "p.k."
<[email hidden]> wrote this:-

Quoted message said:

Stealth cycling puts the cyclist at more risk. Full stop. No ifs. No buts.
No caveats.

What a surprise, proof by assertion.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Peter Clinch <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Quoted message said:

I responded to something that metioned "seeing" - so we're talking
about visual perception here. Sight relies upon rays of light (or
photons - take your pick) reaching retinal receptors. If there is no
light, there can be no sight, and hence no visual perception.

When was the last time you were on a road with "no light"? By which I
mean actually *no* light.

I referred to the amount of light arriving from the stealth object and its
immediate surroundings. If this is entirely below the "black threshold", it
will not be visible because there would be insufficient light.

Quoted message said:

Quoted message said:

Every aspect of visual perception relies upon optical physics

No, that's only to do with the information that arrives to form an
image. If that image is formed correctly and how it is subsequently
interpreted is a while other story.

Without an image you have nothing to interpret. The formation of the image
(i.e. the optical physis) is the foundation upon which all aspects of
visual perception depend. Thus every aspect of visual perception relies
upon optical physics.

On Mon, 4 Dec 2006 12:14:33 -0000 someone who may be "p.k."
<[email hidden]> wrote this:-

Quoted message said:

ah so there is no point in stage hands dressing in black to move scenery on
a darkened stage!

Turn the stage lights on and the stage is no longer darkened and see
if the scenery shifters are still invisible.

Quoted message said:

Once again I marvel at the mental gyrations that so many here go through to
avoid criticising any action by any cyclist.

Nice try. However, your assertion relies on reading my mind. You are
not very good at reading my mind.

The option for you to study the standard reference works on the
subject and thus be capable of discussing it in an informed manner
remains.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Quoted message said:

ah so there is no point in stage hands dressing in black to move
scenery on a darkened stage!

Turn the stage lights on and the stage is no longer darkened and see
if the scenery shifters are still invisible.

That's a bit like trying to turn the sun on at night. With reduced
illumination concentrated on the place of interest (like a spotlight on the
main players, or dipped beam on the kerb line) peripheral, stealth objects
all but disappear (like the "extras" in this linked clip, or stealth
cyclists).

(The clip's funny enough to watch in its own right!)

David Hansen said:

On Mon, 4 Dec 2006 12:14:33 -0000 someone who may be "p.k."
<[email hidden]> wrote this:-

Quoted message said:

Once again I marvel at the mental gyrations that so many here go
through to avoid criticising any action by any cyclist.

Nice try. However, your assertion relies on reading my mind. You are
not very good at reading my mind.

I don't need to read your mind. Your posts make abundantly clear your
approach to these things.

Two cyclists

1 without lights and without relective clothing on a dark street at night

2 with lights and reflectives on adark street at night.

Whick one is likey to be more safe?

pk

On 04 Dec 2006 12:34:43 GMT someone who may be Will Cove
<[email hidden]> wrote this:-

Quoted message said:

Quoted message said:

Quoted message said:

Not the only thing involved in perception perhaps but certainly the
most important.

Evidence for this assertion?

I responded to something that metioned "seeing" - so we're talking about
visual perception here. Sight relies upon rays of light (or photons -
take your pick) reaching retinal receptors.

Incorrect. Something is only seen when the image reaches the brain,
is recognised and any necessary action taken.

Quoted message said:

Quoted message said:

Are there currently any limits on the number of lights motorists may
use?

Yes, the lighting regs limit you to two dipped beam headlights at a time

Ah, so I can call up the police and report all those drivers with
more than those lights switched on. I wonder what the police will
do.

Quoted message said:

and they must use euromarked bulbs, which effectively limit them to 2 x
55W.

I note that you snipped my discussion of the difference between lamp
input power and light output.

Quoted message said:

However, motorists can use an unlimited number of marker
and rear position lights.

What is the difference between a marker light and any other sort of
light?

Quoted message said:

Quoted message said:

What sort of motor vehicle would this verge or barrier prevent from
reaching the bhantustan?

Something like Armco could help prevent out of control vehicles from
reaching the cyclepath.

Only small motor vehicles.

Quoted message said:

However, that isn't the key.

Then why did you type, "Personally, I think that segregation would
be safest because motorised and human-powered traffic can't collide
if they don't share the same space", earlier? We have now determined
that motorised and human-powered traffic can collide, even where
they are segregated.

Quoted message said:

The purpose of this
is to give cyclists their own space that motorised traffic is not
permitted to use except (for example) if they live on a street designated
as a cycle route.

Then they are sharing the same space, which you earlier claimed they
would not.

Quoted message said:

Quoted message said:

How far apart to prevent some motorist emulating Mr Hart?

?? Who Mr Hart?

http://www.google.co.uk/search?hl=en&q=hart+motorist&meta=cr%3DcountryUK%7CcountryGB
has just come up with several links about Mr Hart. It was the first
search term I used.

Quoted message said:

Not complete segregation. However, I am advocating segregation as far as
practically possible and giving non-motorised traffic priority where
segregation is not possible.

History tells us about claims of separate but equal facilities. One
of the groups is rather more equal than the others.

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54