SOBS September 2 The science behind motion camouflage

[The Spin Doctor]

Over the years I've been talking about the 'Science Of Being Seen' #SOBS I've been discussing the issue of 'motion camouflage' and how it affects the ability of a driver to detect an approaching bike and rider.

The problem most commonly arises when a driver is either about to emerge into a main road from the rider's nearside, or where an oncoming driver is about to turn into the side turning by turning across the rider's path.

Although we tend to be very familiar with these 'right of way violations (ROWV) collisions, calling them the 'SMIDSY' crash (from "Sorry Mate, I Didn't See You"), these crashes aren't unique to the UK, Europe, North America and Australia / New Zealand.

Whilst they have been studied more widely in the western world, the fact is that they happen whenever powered two wheelers and cars, vans, trucks and buses share the road.

And that tells us one important thing:

"these crashes are NOT the result of lack of rules, or lack of enforcement of rules or 'poor driving', but are the consequence of the same human error which happens wherever humans interact."

And one of the issues implicated in these 'looked but failed to see' crashes (LBFTS) is a phenomenon known as motion camouflage.

In the world of biology - my original field of research - we've known about motion camouflage for decades. But only recently has it become a topic for concern for motorcyclists.

So what is it?

Let's look at where it all began - trying to understand how one animal detects another, and the strategies animals make to avoid detection.

Most animals and insects use vision to detect other animals and insects around them. Not surprisingly, many want to remain concealed, either because the prey is likely to be eaten for lunch, or because the hunter wants to be hidden from the prey they are lining up for dinner.

There are various methods of concealment but to be effective many camouflage techniques rely on prey or hunter to remain stationary.

Staying motionless is a technique employed by both prey but also some hunting animals - they stay still and rely on the prey coming to them.

But as soon as they move, prey and hunter become relatively easy to detect. As one paper puts it:

"An object that moves is spotted almost effortlessly; it ‘‘pops out’’."


So other hunters have learned to employ an active hunting strategy where they utilise a specific stealth strategy to remain hidden even when moving to capture the prey.

In the simplest instance where the prey doesn't move - and I'll come back to a more complex case in the next article - a simple straight line approach will prevent the stalking animal from moving relative to the background and make it more difficult to detect - it'll just get bigger.

This is known as 'motion camouflage' and is employed not just by insects and animals to achieve prey capture, but also to stalk a mate or to patrol and defend territory from competitors.

pouncing lion.jpg (32.89 KiB) Viewed 886 times

Only when the object is so close it fills the visual field does the buffalo detect the lion that's just pounced on it. This is the phenomenon known as 'looming'.

Humans share much of the visual perception system with animals - in fact, there are plenty of animals out there with more sophisticated visual hardware and more effective visual processing. And we too find it difficult to detect anything that is coming straight towards us...

...at least, until it's right on top of us.

So put yourself in the driver's seat in a vehicle stopped and waiting to turn across a lane of traffic with a motorcycle approaching on a straight road - we can be looking the right direction. But since the bike is heading almost straight for the car, the driver can fail to detect the bike...

...because it's motion camouflaged. With no lateral movement against the background the bike won't 'pop-out' and will remain undetected even when in clear sight.

Only when the bike is so close that it's just filled the car's side window do we spot it, even though we were looking in the right direction!

This is the basis of the motion camouflage issue I have been talking about online for the last decade and more, as part of the SOBS project which was used by Biker Down courses across the UK.

It's the simplest case for motion camouflage and the failure to detect a motorcycle approaching a junction on a priority road, and is an explanation for those "the driver was looking right at me and still pulled out" collisions and near-misses that so many riders report.

There is a more complex case, and I'll talk about that next, and there are also two consequences which I think are currently not considered in road safety. I'll be exploring the issues further in this mini-series of articles. Stay tuned!

REFERENCES:

'The pop out of scene-relative object movement against retinal motion due to self-movement'
Simon K. Rushton, Mark F. Bradshaw, Paul A. Warren
Cognition 105 (2007) 237–245 September 2006



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[Scootabout]

Hence the value of deliberately creating lateral movement by moving across one's lane when approaching the waiting vehicle. Also, I suppose, being offset, eg close to the white line when approaching a car waiting to emerge from the left, as this creates the appearance of movement through a parallax effect (I think that's the term?)

[Horse]

Hence the value of deliberately creating lateral movement by moving across one's lane when approaching the waiting vehicle. Also, I suppose, being offset, eg close to the white line when approaching a car waiting to emerge from the left, as this creates the appearance of movement through a parallax effect (I think that's the term?)

Many riders on a 'middle of the lane' line will move away from the potentially encroaching vehicle, so moving across the driver's field of view. Ironically, riders already near the centreline won't move so far as they approach.

With Z Line, the first move is towards the vehicle, then away - maximising the move through the FoV.

Sketch of Z overlaid on Oullet's zones:


Final blog post of a set of five:
http://the-ride-info.blogspot.com/2008/ ... s.html?m=0

[slowsider]

They might be safer on the correct side of the road

[Horse]

Alternative suggestion is the 'SMIDSY Weave', waggle the bars to break out of the background.

[Horse]

They might be safer on the correct side of the road

Correct.

Especially if the correct side doesn't have opposing traffic

[The Spin Doctor]

Alternative suggestion is the 'SMIDSY Weave', waggle the bars to break out of the background.

Much less effective with fairing mounted lights.

You could also flick high beam on and off.

PS sleeveless hi-vis behind tall screens are far less conspicuous than SLEEVED hi-vis!

[slowsider]

Flicking high beam on and off to STOP someone pulling out on you ?

[Dodgy69]

I've started doing the weave, not quite as positive as vid but just changing headlight direction a little. At the very least, the waiting car might think wtf is he doing.

[Horse]

I've started doing the weave, not quite as positive as vid but just changing headlight direction a little. At the very least, the waiting car might think wtf is he doing.

Ever had someone try to block you from filtering past into a space ahead of them?

Give the bars a wiggle, make it look as if you can't control the bike. Most times they'll fear for their paintwork and make space.

I call it 'constructive weave'

[The Spin Doctor]

Flicking high beam on and off to STOP someone pulling out on you ?

Bad choice of words... a couple of seconds of high beam, not a flash.

Horns have a very limited range - so the headlight IS an option at longer distances, and also in low light / night time riding.

Yes, there IS a risk that a flash will be seen as an invitation to pull out, but so long as you bear that in mind...

[Horse]

Alternative suggestion is the 'SMIDSY Weave', waggle the bars to break out of the background.

Much less effective with fairing mounted lights.

Do you mean 'headlamp', ie that the wiggle may achieve more from the side-to-side movement of the forks and so headlamp beam?

Potentially - and only a guess - it might slightly improve in effectiveness with 'triangle' lights (eg at engine height) as the bike's changing angle could be emphasised. Have a look at the GS's rocker covers in the video.

PS sleeveless hi-vis behind tall screens are far less conspicuous than SLEEVED hi-vis!

Worse still, waistcoats typically have a grey- coloured retroreflective strips over the shoulders, so even less fluoro to be seen.

And ditto big top boxes.


PS re video, two riders turning left at the end, a horribly late lifesaver by the second rider. As described by a police trainer: "the only benefit is you'll get a chance to read the number plate of the car that's going to hit you."

[The Spin Doctor]

Much less effective with fairing mounted lights.

Do you mean 'headlamp', ie that the wiggle may achieve more from the side-to-side movement of the forks and so headlamp beam?

Yes, because with a conventional headlight, it'll turn with the forks.

Potentially - and only a guess - it might slightly improve in effectiveness with 'triangle' lights (eg at engine height) as the bike's changing angle could be emphasised. Have a look at the GS's rocker covers in the video.

Of course, not much use if you don't have a BMW.

Worse still, waistcoats typically have a grey- coloured retroreflective strips over the shoulders, so even less fluoro to be seen.

And ditto big top boxes.

All in www.scienceofbeingseen.org.uk

PS re video, two riders turning left at the end, a horribly late lifesaver by the second rider. As described by a police trainer: "the only benefit is you'll get a chance to read the number plate of the car that's going to hit you."

I wouldn't be taking a turn from that wide. It's an invitation for someone to come flying up the inside... it won't be a car on the nearside, it'll be another bike.

[Horse]

Potentially - and only a guess - it might slightly improve in effectiveness with 'triangle' lights (eg at engine height) as the bike's changing angle could be emphasised. Have a look at the GS's rocker covers in the video.

Of course, not much use if you don't have a BMW.

They don't have a monopoly on additional lights

Although sometimes it seems almost mandatory

Worse still, waistcoats typically have a grey- coloured retroreflective strips over the shoulders, so even less fluoro to be seen.

And ditto big top boxes.

All in www.scienceofbeingseen.org.uk

I mentioned it for the benefit of those who haven't read SOBS

[slowsider]

Potentially - and only a guess - it might slightly improve in effectiveness with 'triangle' lights (eg at engine height) as the bike's changing angle could be emphasised. Have a look at the GS's rocker covers in the video.

Of course, not much use if you don't have a BMW.

They don't have a monopoly on additional lights

Although sometimes it seems almost mandatory

Worse still, waistcoats typically have a grey- coloured retroreflective strips over the shoulders, so even less fluoro to be seen.

And ditto big top boxes.

All in www.scienceofbeingseen.org.uk

I mentioned it for the benefit of those who haven't read SOBS

A dwindlingly small number, shirley.

[Horse]

All in www.scienceofbeingseen.org.uk

I mentioned it for the benefit of those who haven't read SOBS

A dwindlingly small number, shirley.

I've quoted this to get Spin some more readers

[Scootabout]

What about this for visibility, from the V85TT? Actually a serious question, as I now have one.

https://images.app.goo.gl/gyYC9nE1SfvVmt8d9

[The Spin Doctor]

Of course, not much use if you don't have a BMW.

But you won't get the width. So the effect is diminished. Also important to be aware that there's little evidence the triangle prevents SMIDSYs in urban areas.

[The Spin Doctor]

What about this for visibility, from the V85TT? Actually a serious question, as I now have one.

https://images.app.goo.gl/gyYC9nE1SfvVmt8d9

Evidence from studies suggests a single headlight is still most easily recognised as 'motorcycle'.

Wacky LEDs like this aren't easy to recognise as belonging to a bike.

If you do want a day riding light, I'd wire one headlight up although there's little evidence a dipped beam is particularly effective either.

[Horse]

Of course, not much use if you don't have a BMW.

But you won't get the width.

'Lateral' thinking?








The point is that they might emphasise the wiggle.

If mounted on the lower fork leg that might emphasise fork leg movement.

there's little evidence the triangle prevents SMIDSYs in urban areas.

Didn't say there was.