Flashing LEDs to be made legal

[Richard Bates]

On Sat, 05 Feb 2005 21:10:14 +0000, Danny Colyer
<[email protected]> wrote:

>"At night. It is safer not to ride on the road at night or in poor
>visibility, but if you do, make sure your horse has reflective bands
>above the fetlock joints. Carry a light which shows white to the front
>and red to the rear."

My new invention: The "Horse Dynamo"

 

[JLB]

Richard Bates wrote:
> On Sat, 05 Feb 2005 21:10:14 +0000, Danny Colyer
> <[email protected]> wrote:
>
>
>>"At night. It is safer not to ride on the road at night or in poor
>>visibility, but if you do, make sure your horse has reflective bands
>>above the fetlock joints. Carry a light which shows white to the front
>>and red to the rear."
>
>
> My new invention: The "Horse Dynamo"
>
Excellent. Runs on gas, I suppose?

--
Joe * If I cannot be free I'll be cheap

 

[Nigel Cliffe]

Danny Colyer wrote:
> Simon Brooke wrote:
>> And as a driver I find flashing lights on bicycles greatly
>> preferable to steady ones. They're not only highly visible at a
>> distance, they're highly diagnostic at a distance.
>
> I've responded to you making that comment before. I find it very much
> easier to track the movement of a steady light. If I know that
> there's a cyclist ahead of me then I like to know where he is, so
> that I can make sure I don't hit him. That's easier if he doesn't
> keep disappearing and then reappearing somewhere else. As Peter B
> wrote, it's a subjective matter.

Its not a subjective matter.... its a function of how the human visual
system works. And the arguments presented in the thread as to which people
prefer seem to back that.


Steady light - good for getting an accurate position, good for tracking
positing when in the centre of the visual field. Can get attention in the
peripheral vision, but only by the movement of the bike across the retina
(so depends on direction of cycle relative to the observer). So, once you've
seen something, a constant light is the best to work out where the item is
and how to avoid it.

Flashing light - good for attracting attention, particularly in the
peripheral vision. Poor at fixing position. Thus, good for drawing attention
to oneself from a distance and poor at giving accurate position information.


Constant lamps side by side can give the impression of a motorcar at a
different distance. This is why new motorcycles are no longer permitted to
show two lights at the front which are side by side (the makers of
motorcycles with twin side-by-side lamps supply them with a switch which
illuminates one or the other, but many riders swap the wiring to illuminate
both. I'm not sure whether such a swap is legal).


My personal view on what's good on a bicycle; If only one lamp, then use a
constant lamp. If more than one lamp, then one flashing, one constant. If
possible positioned above each other rather than beside.


- Nigel (university studies included the mechanisms of human perception)


--
NC - Webmaster for http://www.2mm.org.uk/
Replies to newsgroup postings to the newsgroup please.

 

[Tony Raven]

JLB wrote:
> Richard Bates wrote:
>
>> On Sat, 05 Feb 2005 21:10:14 +0000, Danny Colyer
>> <[email protected]> wrote:
>>
>>
>>> "At night. It is safer not to ride on the road at night or in poor
>>> visibility, but if you do, make sure your horse has reflective bands
>>> above the fetlock joints. Carry a light which shows white to the
>>> front and red to the rear."
>>
>>
>>
>> My new invention: The "Horse Dynamo"
>>
> Excellent. Runs on gas, I suppose?
>

Nope, the answer is in Velovision
http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=2

Tony

 

[James Annan]

Nigel Cliffe wrote:


>
> Its not a subjective matter.... its a function of how the human visual
> system works.

Nevertheless, it does not seem to have been shown clearly (or indeed at
all) as to which type of light is better in practice on the back of a
bicycle.

> And the arguments presented in the thread as to which people
> prefer seem to back that.

Seems to me that people are doing the usual thing of choosing whatever
evidence happens to suit their prejudices.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

 

[Peter B]

"James Annan" <[email protected]> wrote in message
news:[email protected]...
> Is SMIDSY to do with not noticing someone, or not being able to
> accurately position someone, or something else entirely?

In case your question isn't rhetorical:

I'd hazard a guess that the main reason is not actually looking hard enough.
Motorists become programmed to looking for car-sized, and above, objects and
don't spend enough time actually looking for cyclists.

Then there is distraction.
And then there are those whom I suspect are visually impaired.

Pete

 

[Tony Raven]

James Annan wrote:
>
> Is SMIDSY to do with not noticing someone, or not being able to
> accurately position someone, or something else entirely?
>

I suspect its hardwired into our construction. The eye and brain are
designed to protect us from threats. So the eye has a very small
central area (the fovea) that sees in colour and can process complex
information like face recognition and a very large area of peripheral
vision that is sensitive to a wide field and to motion but with little
processing capability. Try looking at the edge of the TV screen during
the news and while still looking at the edge try to recognise the
newreader with your just off centre vision to see just how small the
processing area is.

Next the brain has two visual circuits, the concious vision and the
blindsight vision which is not linked to conciousness. Its a bit like
computers. A lot of processing goes on in blindsight in the background
with no concious awareness with the information being elevated to
conciousness if it needs greater attention. Again think of a busy room
with lots of movement going on around you and someone from the side
lunges at you. Before you've even thought about it your head, body and
eyes have shot round to point your fovea at the threat to identify it
and classify the level of threat and your muscles and body have prepared
for evasive action. Otherwise known as they made you jump.

So overall we have a system that is designed to detect moving threats in
a wide visual field, classify them and elevated the potential real
threats to conciousness so we can take self preserving actions. To a
car driver, a cyclist does not represent a threat and therefore remains
in the unconcious brain until the SMIDSY happens.

Its worse if there is a lot going on that the driver is concentrating
on. Spotters are taught not to intently look for things but to let
their gaze wander. The more you concentrate on one thing, the higher
the priority a background task has to become before its noticed. So in
a busy street or with complex traffic manoevers we are even less likely
to be seen.

The gorilla video is a good example but I bet if they repeated it with
the gorilla running towards the subject looking fierce or the gorilla
was replace with a lion every one of those subjects would have noticed
it. As it was the subjects were asked to concentrate on the ball and
the gorilla presented no immediate threat.

The flashing lights are probably better at getting noticed but worse for
being tracked and trajectories/threats worked out. Also there is a no
attention paid to the flash frequency for maximum attention getting. The
moving and flashing ones are better still but the one I suspect would be
best is a blue/green randomly flashing and moving light that is
unpredicatable enough to be unusual and needing attention. One problem
is all our assessment of lights and their effectiveness is made using
central and concious visual processing whereas in use it the unconcious
peripheral visual impact that is important.

Just my $0.02

Tony

 

[James Annan]

Tony Raven wrote:

> James Annan wrote:
>
>>
>> Is SMIDSY to do with not noticing someone, or not being able to
>> accurately position someone, or something else entirely?
>>
>
> I suspect its hardwired into our construction.

ROFL.

Yeah, right. That explains why the risks differ so greatly across
countries - it's that massive genetic difference between the Dutch,
Danes, Americans and British.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

 

[Peter B]

"James Annan" <[email protected]> wrote in message
news:[email protected]...

> Exactly. Which means that all this waffle about perception seems to be
> missing the point rather spectacularly. AFAIK there is precious little
> evidence that lights of any sort make much difference to cyclist safety.

My brother and I have both been struck on quiet roads with good sight lines
in perfect daylight visibility, as well as the usual near misses, so there
are no guarantees.
However, I'd still not like to venture out in the dark without good lights
and a few reflective adornments, not because they give guarantees but
because I believe they alter the odds in my favour.
In fact it may be safer riding like this at night on less well lit, or
unlit, roads due to the contrast to the environment.
As a driver commuting in well lit built-up areas I rate high vis jackets as
they make the cyclist appear big.

Pete

 

[Peter B]

"Peter B" <[email protected]> wrote in message
news:[email protected]...
>
> "James Annan" <[email protected]> wrote in message
> news:[email protected]...
>
> > Exactly. Which means that all this waffle about perception seems to be
> > missing the point rather spectacularly. AFAIK there is precious little
> > evidence that lights of any sort make much difference to cyclist safety.
>
<snipped stuff>

And I should have added that when I'm using higher powered front lamps
motorists waiting to emerge from side roads seem more cautious and those
approaching on unlit roads normally dip their lights.
(I appreciate this is off-topic to rear lights).

Pete

 

[James Annan]

Peter B wrote:

> "James Annan" <[email protected]> wrote in message
> news:[email protected]...
>
>>Is SMIDSY to do with not noticing someone, or not being able to
>>accurately position someone, or something else entirely?
>
>
> In case your question isn't rhetorical:
>
> I'd hazard a guess that the main reason is not actually looking hard enough.
> Motorists become programmed to looking for car-sized, and above, objects and
> don't spend enough time actually looking for cyclists.

Exactly. Which means that all this waffle about perception seems to be
missing the point rather spectacularly. AFAIK there is precious little
evidence that lights of any sort make much difference to cyclist safety.

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

 

[Velvet]

Danny Colyer wrote:
> Helen C Simmons quoted:
>
>> "David Jamieson, the road safety minister announced in the committee
>> stage of the Road Safety Bill that there will be a change in the law
>> regarding the use of LED flashing lights on bicycles. Currently these
>> lights - while bright and mega conspicuous - are only legal when used
>> in conjunction with a static light.
>> The tidying up of the law concerning LEDs is long overdue but will
>> mean that displaying a flashing LED light by itself will be made legal.
>
>
> I thought the proposed change was to allow the use of flashing lights
> used alongside steady lights, which /isn't/ currently legal whatever the
> minister might think.
>
> I'd object quite strongly to any proposal to legalise the use of
> flashing lights on their own.
>

I'd have to agree with that too, steady PLUS flashing is good, flashing
on own is very BAD, when you might only get a couple of glimpses due to
traffic, in those glimpses it is all too possible that the light is in
the 'off' cycle of the flash pattern.

--


Velvet

 

[JLB]

James Annan wrote:
[snip]
Which means that all this waffle about perception seems to be
> missing the point rather spectacularly. AFAIK there is precious little
> evidence that lights of any sort make much difference to cyclist safety.

Perhaps what's needed is something that ensures that as many drivers as
possible *want* to see any cyclists that are out there. Drivers look out
for things like HGVs out of self-interest. They don't have any such
motivation in respect of cyclists.

The answer is to fix one or two pounds of high explosive to every bike
used on roads, with a fuse that detonates the explosive only if the bike
goes horizontal. This will quickly result in drivers showing paying much
more attention to bikes.

Might cramp some cyclist's riding style, though.

--
Joe * If I cannot be free I'll be cheap

 

[Pete Biggs]

David Martin wrote:

>> Why? They seem to me to be much more visible than steady lights,
>> either
>> LED or filament lamp types.
>
> You'd actually be wrong. They are much harder to place spatially. Yes
you
> know there is something there, but cannot tell exactly where it is.

At first, perhaps, so you're forced to take more care until you can tell
where it is. Good.

It's no use being able to locate a light if you don't notice it (or the
bike & rider) at all. Trouble with steady lamps is that they have to be
quite a lot more powerful to get the attention in the first place. So if
I'm going to use small and lightweight lights, I will use flashing ones.

> I don't use lights in flashing mode (except the tireflys) for
> precisely this reason. I'd much rather a driver could tell how far
> away I wasn't instead of leaving there foot on the accellerator till
> they realise how close I really

In my experience they ease their foot off the accelerator if they're not
initially sure where I am or what I'm doing. I've actually noticed
drivers waiting longer or giving more room when I've been using flashing
lights versus steady lights of similar brightness.

~PB

 

[Pete Biggs]

Nigel Cliffe wrote:
> Steady light - good for getting an accurate position, good for
> tracking positing when in the centre of the visual field. Can get
> attention in the peripheral vision, but only by the movement of the
> bike across the retina (so depends on direction of cycle relative to
> the observer). So, once you've seen something, a constant light is
> the best to work out where the item is and how to avoid it.

The driver can locate and track the cyclist by means other than the
cyclist's lights. Street lights illuminate the rider well enough on urban
streets and the driver's headlights on unlit roads.

~PB

 

[Helen C Simmons]

"JLB" <[email protected]> wrote in message
news:[email protected]...

>
> The answer is to fix one or two pounds of high explosive to every bike
> used on roads, with a fuse that detonates the explosive only if the bike
> goes horizontal. This will quickly result in drivers showing paying much
> more attention to bikes.
>

Remind me never to lay such a bike down on a nice grassy verge whilst I stop
for lunch in the middle of an all-day bike ride ;-)

Cheers, helen s

 

[Pete Biggs]

Velvet wrote:

>> I'd object quite strongly to any proposal to legalise the use of
>> flashing lights on their own.
>
> I'd have to agree with that too, steady PLUS flashing is good,
> flashing on own is very BAD, when you might only get a couple of
> glimpses due to traffic, in those glimpses it is all too possible
> that the light is in the 'off' cycle of the flash pattern.

That particular problem solved by using a *fast*-flashing light, one that
flashes a few times per second.

~PB

 

[Tony Raven]

JLB wrote:
>
> The answer is to fix one or two pounds of high explosive to every bike
> used on roads, with a fuse that detonates the explosive only if the bike
> goes horizontal. This will quickly result in drivers showing paying much
> more attention to bikes.
>
> Might cramp some cyclist's riding style, though.
>

Cue lots of cyclist gingerly pushing their bicycles along the pavement.

http://darwinawards.com/darwin/darwin2002-27.html

Tony ;-)

 

[Alan J. Wylie]

On Sun, 06 Feb 2005 16:33:44 +0900, James Annan <[email protected]> said:

> Is SMIDSY to do with not noticing someone, or not being able to
> accurately position someone, or something else entirely?

There has been some interesting research done on this, by Dr. Daniel
Simons of the University of Illinois, Dr. Christopher Chabris of
Harvard University and Dr. Daniel Levin of Vanderbilt University.

Google cache of Daily Telegraph article:
<http://64.233.183.104/search?q=cache:BVGr-2MSRmgJ:www.telegraph.co.uk/connected/main.jhtml>

Volunteers were asked to watch a video of a basketball game, and count
the passes made. Whilst concentrating on this, they were oblivious to
a woman dressed in a gorilla suit wandering across the court.

University of Illinois Visual Cognition Lab:
http://viscog.beckman.uiuc.edu/djs_lab/IB.html

Original Paper
http://www.wjh.harvard.edu/~cfc/Simons1999.pdf
(Google cache in HTML)
<http://64.233.183.104/search?q=cache:uZANQ1MOAr0J:www.wjh.harvard.edu/~cfc/Simons1999.pdf>

They won an igNobel prize for this research
<http://www.improb.com/ig/ig-pastwinners.html>

--
Alan J. Wylie http://www.wylie.me.uk/
"Perfection [in design] is achieved not when there is nothing left to add,
but rather when there is nothing left to take away."
-- Antoine de Saint-Exupery

 

[Tony Raven]

Alan J. Wylie wrote:
> On Sun, 06 Feb 2005 16:33:44 +0900, James Annan
> <[email protected]> said:
>
>
>> Is SMIDSY to do with not noticing someone, or not being able to
>> accurately position someone, or something else entirely?
>
>
> There has been some interesting research done on this, by Dr. Daniel
> Simons of the University of Illinois, Dr. Christopher Chabris of
> Harvard University and Dr. Daniel Levin of Vanderbilt University.
>
> Google cache of Daily Telegraph article:
> <http://64.233.183.104/search?q=cache:BVGr-2MSRmgJ:www.telegraph.co.uk/connected/main.jhtml>
>
>
> Volunteers were asked to watch a video of a basketball game, and
> count the passes made. Whilst concentrating on this, they were
> oblivious to a woman dressed in a gorilla suit wandering across the
> court.
>

Careful or you'll have James ROFLHAO. Forget all that academic tosh
about visual perception, that's all waffle to cover up for the fact none
of the dozy b****rs were looking hard enough ;-^)

Tony