High Vis question

Horse

21/02/2007 at 11:39

trogggy wrote

(although a vehicle without lights at dusk does seem to stand out like a sore thumb because it's unusual).

Just as I'm not making a claim re hi-viz because the proof isn't out there and the evidence is ambiguous.

Two key points there.

First, if everyone was using hiviz and headlamps then the 'shock' value goes completely. It'll be worse when all cars have daytime lights.

If you want to be seen, be different - I've posted many times the comment by a mate after he followed me (in a BMW C1) on his Varadero (him, 21 stone on a big bike) "No-one saw me - they were all looking at you!"

Second, we are continually being told that lights & hi-viz is the way to go, from CBT onwards. Someone asked how such things were relevant to bikers? With the DSA's new register of post-test (ie 'advanced') trainers it will be mandatory to use hiviz & ligts during training. I was told by the DSA that it was 'best practice'.

You have asked for research; PM me an email addy and I'll send you a copy of some research in to police car conspicuity. Did you know that after they changed to the 'battenburg' scheme, more people drove in to them when they were parked?

Training info is (C) Malcolm Palmer. He asserts his right to be identified as author under the Copyright Design Patents Act 1988 & may be quoted only as part of a post in the Visordown bb by another board member. Author should be contacted for written permission before any other use, storage, transmission or recording, by any means.

Read my mutterings:

http://the-ride-info.blogspot.com/

big bald one

21/02/2007 at 11:41

Horse wrote

OK, have a black aircraft on the ground Also, note the hi-viz 'yellow' bit of airfield furniture in the black, sorry, background.

A black aircraft stands out well against a very light background.

Ain't that a surprise?

Anne

21/02/2007 at 11:59

Horse wrote

I didn't say - because I don't know - how accurate speed judgements are with and without headlamps.

no you didn't say but you did quote Shaw

Horse wrote

[I]Shaw [UK] 1979
Compared the accuracy with which subjects estimated the speed of a motorcycle with headlamp on, and off.

Subjects over-estimated the speed for lower speed of approach
Subjects under-estimated the speed for higher speed of approach

The reversal from over- to under- took place between 50-55mph with the headlamp off, and between 35-40mph with the headlamp on.

over-estimated and under-estimated ie judged the speed inaccurately

trogggy

21/02/2007 at 12:00

Horse wrote

Two key points there.

First, if everyone was using hiviz and headlamps then the 'shock' value goes completely. It'll be worse when all cars have daytime lights.

If you want to be seen, be different - I've posted many times the comment by a mate after he followed me (in a BMW C1) on his Varadero (him, 21 stone on a big bike) "No-one saw me - they were all looking at you!"

I think I agreed with that in my last post. Common sense tells us that lights at dusk = seen, but if you don't put them on everyone notices you .............because you're different?

Quote

Second, we are continually being told that lights & hi-viz is the way to go, from CBT onwards. Someone asked how such things were relevant to bikers? With the DSA's new register of post-test (ie 'advanced') trainers it will be mandatory to use hiviz & ligts during training. I was told by the DSA that it was 'best practice'.

There doesn't seem any justification for that to me on the evidence I've read. But neither does that mean the opposite is true (ie we would be safer, for example, in black). The proper advice at the moment would seem to me to be read the evidence that is out there, think about it, make your own mind up but whatever you wear don't expect that everyone will loopk at you or everyone will see you.
OTOH, to go back to your first point, if everyone was wearing hi-viz on bikes then wearing black would possibly be more conspicuous as it would be unexpected (no evidence, just speculation

Quote

You have asked for research; PM me an email addy and I'll send you a copy of some research in to police car conspicuity. Did you know that after they changed to the 'battenburg' scheme, more people drove in to them when they were parked?

I've read it on SS a few times.

It's an interesting observation, is there a conclusion as to why? Maybe because it's a broken-up design as opposed to a block of colour?
Anyway I'd appreciate it, I'll send a pm.

Horse

21/02/2007 at 12:02

Anne wrote

no you didn't say but you did quote Shaw

over-estimated and under-estimated ie judged the speed inaccurately

But I don't know much the estimates were wrong.

Read my mutterings:

http://the-ride-info.blogspot.com/

Horse

21/02/2007 at 12:11

trogggy wrote

Maybe because it's a broken-up design as opposed to a block of colour?

Good point - and think about the 'shell suit' designs applied to bikes and leathers over the years, classic 'disruptive' patterning . . .

If you've seen the battenburg crashes mentioned before, have you seen the 'battenburg tank' pics?

Have you read this thread?
www.visordown.com/forums/showthread.php?t=307420

About:
IPWEA NSW Division Annual Conference 2004

NOW YOU SEE ME, NOW YOU DON'T
Dr Martin Langham
Principal Consultant (Human Factors), TRL [ www.trl.co.uk ], United Kingdom
Nigel McDonald [ nmcdonald@trllimited.com.au ]
Principal Consultant (Road Safety), TRL [ www.trl.co.uk ], NSW Australia

Includes:

Cognitive Conspicuity
However conspicuity is not just about how bright things are in their environment. People drive into large vehicles claiming they don't see them (eg Cercarelli, 1992). They even drive into highly conspicuous police cars claiming they didn't see them (Langham et al 2002). Not only does an object such as a maintenance or works vehicle need to be 'seen', it needs to be 'recognised' for what it is - an increased risk and potential hazard.

This is a concept known as cognitive conspicuity and relates to expectation in perception and can explain why, for example, a driver can look straight at a cyclist or motorcyclist and then drive straight into them. In such a scenario, experts believe that the driver is looking for cars or larger vehicles. Applying this concept, the aim is to signal the possible presence of a vehicle, (what it is likely to look like, where it is likely to be, or both) so that people are more likely to detect it and react in time. Therefore, the challenge is to create a vehicle livery and markings that are of a bright colour (i.e. are physically conspicuous) and match the expectations of the approaching driver.

Vehicle and Personal Protective Equipment Conspicuity Research
Significant research has been undertaken investigating conspicuity focussed on small vulnerable road users - pedestrians, cyclists and motorcyclists. Despite differences in road user characteristics and methodological problems, in broad terms if something is bright and makes good contrast with its background AND the viewer recognise what they are presented with, they will react accordingly.

Research that has promoted just one of these factors alone has achieved, at best, mixed results.

For example, increased lighting alone on motorcycles does not always guarantee detection, nor does increased warning lights on small maintenance/works vehicles or extra reflective tape on pedestrians.

And:

Testing
Given what we have said here the most important thing to do is to test the intended livery. But how? Typically liveries are tested by placing a vehicle on an empty airfield and people are asked €œCan you see the conspicuous vehicle?€ This task poorly reflects the task of a real driver. We don't drive with someone asking us if we can see conspicuous things?

At TRL we have been attempting to use models from psychology and human factors to bring a lot more ecological validity to the domain. That is to say we test and measure the livery in such a way that reflects the real life scenario the vehicle will need to perform under.

For example we ask people to drive in TRL's driving simulator and don't warn them about the type of hazard they will encounter. We allow them to drive for 20 minutes (just when research says they become less vigilant) and suddenly present them with a vehicle in the lane they are driving. We measure the participant's ability to detect the vehicle just as they would in the real world. Therefore we test what drivers actually do. We test based on models of both physical and cognitive conspicuity.

Overall we measure what is important not just an attitude towards a vehicle

To do less, results in some of the examples we show. For example a grey car that needs to make a good contrast against a grey road. Or a livery that has not a passing resemblance to a camouflage pattern popular in WW1 Unfortunately in both cases these are emergency response vehicles.

For example, a 'dirty' working environment would need particular considerations for markings and ongoing maintenance of markings. Generally, any road environment will be 'dirty' to some extent.

We also need to thing about training. Recent work shows that training people wearing high visibility garments that they are still difficult to see by drivers - €œIt's a uniform silly not a force field€ may gain more accident reduction than attempting new uniform designs.

Read my mutterings:

http://the-ride-info.blogspot.com/

Anne

21/02/2007 at 12:13

Horse wrote

But I don't know much the estimates were wrong.

yes true but

FourTwenty wrote

A vehicle with lights on make it harder to judge the speed of approach.

what Shaw was indicating (as far as I understand what was written) that the lights on or off didn't make a difference.... oh ffs whatever

trogggy

21/02/2007 at 12:16

Horse wrote

Good point - and think about the 'shell suit' designs applied to bikes and leathers over the years, classic 'disruptive' patterning . .
If you've seen the battenburg crashes mentioned before, have you seen the 'battenburg tank' pics?

I think I rode into it.