Looked but FAILED TO SEE!

Last time out I began explaining how in around one-third of all collisions, the bike was in a place the driver could have seen it but for some reason FAILED TO SEE the machine – a ‘detection error’ where the driver looked in the right place, but failed to identify the presence of a motorcycle in the moments before making his manoeuvre.

We need to look beyond ‘not looking properly’ as an explanation. Human visual perception isn’t ‘camera-perfect’ and it’s not true to say that “if it’s visible, and if you look hard enough, you’ll see it.”

Any illusionist or soldier knows that.

Motion camouflage

In the last article, I mentioned that we have some ability to detect light / dark contrast as well as sudden bright stimuli and movement in peripheral vision. Anything that gets our attention is called an ‘attractant’ because it automatically results in our eyes moving to focus on whatever caught our attention – and at that point (and not before) it pops into our consciousness. That’s when we ‘see’ the object.

The problem is that it’s LATERAL movement that we are sensitive to – that is, ACROSS the background.

Movement directly TOWARDS the viewer is much more difficult to pick up. It’s well-known – I was aware of the issue from my science degrees – that hunting animals stalking prey will approach along a line that keeps them motionless relative to the background from the perspective of the prey animal. If the prey animal moves, the hunter subtly adjusts their own path so that they stay on the same relative bearing. This is how big cats and dragonflies operate, and they are exploiting the phenomenon known as ‘motion camouflage’. The only clue to movement is that the apparent size of the hunting animal increases as it gets closer, but it can get remarkably close before it gets so ‘big’ that it suddenly dominates the background. At that point, the hunting animal is finally detected – this phenomenon is known as ‘looming’.

Think about the typical motion of a motorcycle, riding along a straight road and approaching a stationary driver waiting to turn at a junction – the most common collision of all. It cannot be seen moving across the background.

With no lateral movement, we are also motion camouflaged.

And now there’s a significant risk that a driver will fail to detect our approach until we’re right on top of him / her when we ‘loom’ into view by filling the background.

You can check this out for yourself on YouTube. Watch this:

https://www.youtube.com/watch?v=4iOoiEbtf2w

(PS – keep the volume down if necessary – there are some expletives!)

Even though we can hear the Spitfire’s engine, we cannot see it against the background for two reasons:

:: our eyes are focused on the presenter, so the plane is initially in peripheral vision

:: even when the camera shifts, giving us a hint where to look, there is no lateral movement to help us detect the plane – it’s motion-camouflaged.

It is not until the plane is almost on top of us that we see it –  a Spitfire is a LOT bigger than a motorcycle.

Saccadic masking

Here’s another issue. When we’re scanning left and right, we need to shift our eyes. But there’s a problem. This movement of the background is known to cause disorientation and dizziness.

So as we scan across a scene, we don’t move our gaze smoothly across the background although that’s what most of us think happens, and what most books on riding and driving imply we should be doing.

Our eyes don’t behave like a movie camera panning across the scene but work in a completely different way, much more like a still camera taking a series of snapshots of different parts of the view. Our eyes move in a series of jerks, pausing on one particular area – a ‘fixation’ – before moving very rapidly to the next. Then they move on again… and again… and so on.

The movements between the fixations are called saccades but unbeknownst to us, the brain ceases to process retinal images during these saccades. This is known as ‘saccadic masking’ or ‘saccadic suppression’.

Once again, this phenomenon has been known about for a very long time. It’s even exploited by dancers during fast turns – the dancer turns the body but ‘spots’ on a fixed location, then turns the head faster to catch up. Saccadic masking kicks in as the background blurs through the vision, helping maintain balance and prevent dizziness.

And now you can see why when we look left and right saccadic masking shuts down the visual processing system as our eyes move. Rather than ‘scanning’ right through the visual scene as we think we do (and as we’re told we should), it’s only where the eyes stop on an object of interest, in a stationary fixation (remember that from last time?) that we get a visual ‘snapshot’ that the brain can actually process. So rather than a ‘movie’, we get that series of snapshots interspersed by blank gaps.

But – just like the dancers – we are unaware of the shut-down and believe we have searched the entire scene because the brain synthesizes the missing visual data to give the impression of a continuous scan. Only if we are ALREADY tracking a moving object are we able to follow it without saccades.

Saccadic masking isn’t ‘carelessness’ or ‘failing to look properly’, it’s a fundamental limitation of – and a visual illusion created by – the human visual system.

There’s a second, but interlinked problem. As humans we learn. It’s a fundamental part of being human. And our learning often involves discovering shorter, quicker and most importantly, less energy-intense ways of doing something. At junctions, we’re always told to “look for vehicles” before turning. But it turns out to be an ineffective strategy, because if we look for vehicles, all we see are vehicles…

…and what we actually need if we’re to make the turning manoeuvre is empty space between those vehicles. So we discover very quickly – perhaps within half an hour of beginning to drive – that what we need to spot GAPS.

Now, remember the issues I mentioned last time – the narrow foveal vision cone, and the depth of field. There’s not just the possibility that a driver will look BEYOND the motorcycle, but a real risk that in turning the head to look both ways, the bike will be ‘blanked out’ by a saccade.

It’s worth pointing out that exactly the same issue can happen to bikers. There’s some evidence from countries with a lot of powered two-wheelers that suggests riders pull out in front of other bikes equally as often as drivers! So an attentive driver – or motorcyclist – can look both ways and yet fail to see an approaching vehicle.

How can we overcome this problem? Slowing down the head-turn doesn’t eliminate fixations and saccades but it does narrow the blank gaps and offer a better chance of a fixation landing the eyes on the bike.

Kevin Williams / Survival Skills Rider Training www.survivalskills.co.uk

(c) K Williams 2020

The Science Of Being Seen – the book of the presentation £9.99 plus P&P and available now from: www.lulu.com

The ‘Science Of Being Seen’ is a presentation created in 2011 for Kent Fire and Rescue’s ‘Biker Down’ course by Kevin Williams. Biker Down is now offered by over half the nation’s FRSs as well as the UK military, and many deliver a version of SOBS. Kevin personally presents SOBS once a month for KFRS in Rochester. He toured New Zealand in February 2018 delivering SOBS on the nationwide Shiny Side Up Tour 2018 on behalf of the New Zealand Department of Transport.

Find out more here: https://scienceofbeingseen/wordpress.com

Looked but FAILED TO SEE!

The most common collision between a motorcycle and another vehicle happens at a junction, when the other vehicle (usually a car) turns across the motorcyclist’s path. It accounts for the majority of crashes in an urban area but is also a relatively common crash on a rural road too.

I’ve already mentioned that a significant proportion of these crashes happen when the driver COULD NOT see the bike in the run-up to the crash – the motorcycle might have been hidden by other vehicles, pedestrians or roadside furniture, or concealed by the driver’s own vehicle.

But in around one-third of all collisions, the bike was in a place the driver could have seen it, but for some reason FAILED TO SEE the machine. This is a ‘detection errors’ – ie, the driver looked in the right place, but for some reason failed to identify the presence of a motorcycle in the moments before making his manoeuvre.

Road safety has always treated this as ‘not looking properly’. This ‘fault’ of the driver is nearly always presented as a simple ‘common-sense’ truth, as in “if it’s visible, and if you look hard enough, you’ll see it.”

Sadly that’s simply not true, as any stage illusionist or camouflaged soldier knows.

Illusionists and camouflage both exploit human visual perception limitations, so if we’re to understand why drivers might fail to spot a motorcycle that should be in clear sight, we need to understand a little about how the human eye works with the brain to present a representation of the outside world into our conscious mind.

The starting point is to understand that the human eyes and brain are not the equivalent of a camera and film (or digital sensor). If you plonk a bike in front of a camera, the bike is what the camera sees. But if you put a human in front of the same scene there are a number of reasons that something in plain view can go missing.

So if we’re to understand just how invisible we can be whilst on two wheels, we need to look for a genuine understanding of visual perception, not just resort to the tired old blame-game approach by saying “the driver didn’t look properly”. I’ll start by looking at two human visual perception issues, before finishing off this investigation in the next article.

Narrow foveal zone and peripheral blindness

Hold your arm straight out, clench your fist and give a ‘thumbs-up’. Look at your thumb nail. Now shift the focus of your attention to the top knuckle instead. Your eyes just moved. Although your thumb nail is only a couple of centimetres below your thumbnail, your eyes had to shift FOCUS because the cone of clear, focused colour vision – the foveal zone – is just a couple of degrees of visual angle deep.

Turn your thumb on its side and repeat. Your eyes moved again.

We have to move our eyes because only a tiny patch of the retina – known as the fovea – that actually transmits a sharp camera-like image to the brain and, to see a particular object in detail, we need to line up the fovea to the ‘fixation point’. The zone where we have this ‘foveal’ clear vision is also just a couple of degrees of visual angle wide.

Although the retinas of both eyes combine to give us visual coverage which extends slightly more than 180 degrees left-to-right, outside of the fovea, that light falls on a part of the retina with a very different construction. This ‘peripheral vision’ becomes increasingly blurry and lacking detail, and colour vision fades increasingly to black-and-white the further we move away from the fovea.

Why this limitation? There’s a simple answer – transmitting ALL the visual data that falls on the retina to the brain at the same high fidelity as the fovea would require an optic nerve bigger than the eye – there simply isn’t the capacity to carry, let alone process, the data.

Interestingly, designers of high definition Virtual Reality goggles have hit much the same problem. To get a high pixel density – and thus high realism imagery – across the entire goggle would require more computing power than any domestic computer or phone can deliver. So they are trying to exploit this phenomenon by increasing pixel density ONLY where the user is looking. The screen therefore provides increased resolution where necessary and where the eye can USE it, rather than attempting to display it across the entire screen and frying the processor.

But here’s the remarkable thing. We don’t notice that because the brain creates an illusion. It’s so good that few of us ever notice, but it’s there. The phenomenon has been known to visual science for centuries – it’s attributed to Leonardo da Vinci.

Given the tiny coverage of the fovea, the vast majority of the incoming visual data falls into peripheral vision. Just 20 degrees off the line-of-sight, our clarity of vision (or ‘visual acuity’) is about one tenth of that of the fovea.

Nevertheless, we do have some ability to detect light / dark contrast in peripheral vision, but we’re much more likely to detect sudden bright stimuli and movement.

But once we do, we automatically turn our head to bring the attractant into our line-of-sight so we can examine it with the fovea’s high-resolution vision – this is called a fixation.

Depth of field

Just like a camera, the human eye has a depth-of-field. If we focus on something close to us, everything in the background is out of focus. And vice-versa – if we’re focused on a background object, those closer up tend to blur. Combine depth-of-field with the narrow cone of foveal vision and not only does this have consequences in terms of detecting / not detecting other vehicles in peripheral vision, it also leads me to question the concept of ‘eye contact’ that’s so frequently proposed in the motorcycle safety literature. It seems a doubtful concept at best. Anecdotally, I have heard (and I’m sure you have too) motorcyclists say many times:

“I had eye contact with the driver and he/she still pulled out.”

I’d suggest this is the explanation; that although the driver appears to be looking at us, his actual visual fixation is behind us, and our machine is actually in his peripheral vision. I think that the best we can say is that if the driver is looking our way, we MIGHT have been seen, but it would be wise to assume the driver hasn’t spotted us.

So here’s this month’s takeaway. Never forget that the eye is not a camera, and no two people see the same scene in the same way. And if there’s one vehicle that’s likely to go missing when drivers search the road environment, it’s a motorcycle.

Don’t assume you’ve been seen… EVER.

…to be continued

Kevin Williams / Survival Skills Rider Training www.survivalskills.co.uk

(c) K Williams 2020

The Science Of Being Seen – the book of the presentation £9.99 plus P&P and available now from: www.lulu.com

The ‘Science Of Being Seen’ is a presentation created in 2011 for Kent Fire and Rescue’s ‘Biker Down’ course by Kevin Williams. Biker Down is now offered by over half the nation’s FRSs as well as the UK military, and many deliver a version of SOBS. Kevin personally presents SOBS once a month for KFRS in Rochester. He toured New Zealand in February 2018 delivering SOBS on the nationwide Shiny Side Up Tour 2018 on behalf of the New Zealand Department of Transport.

Find out more here: https://scienceofbeingseen/wordpress.com

‘RIDE BRIGHT’ or ‘THINK BIKE’ success?

I’ve made a start on what the Science Of Being Seen – both the research and the presentation – is all about, and I mentioned a bit about the background context and just why I felt it necessary to put this work together.

The answer is that although the ‘RIDE BRIGHT’ motorcycle conspicuity campaigns aimed at bikers and their logical counterpart, the ‘THINK BIKE’ campaigns that exhort drivers to look harder for the difficult-to-see two wheeler, have been running from the mid-70s to the current day, and although they have run all over the world, and either adopted voluntarily or enforced through legislation, there’s no significant evidence that either strategy has had any significant impact on collisions between bikes and cars.

Drivers still suffer the ‘Looked But Failed To See’ (LBFTS) error and commit the ‘Right Of Way Violation (ROWV). As you can see, they’ve been happening for so long and studied so intensively, the research has created a pair of acronyms.

And riders still sail into these crashes all too regularly. Riders have also known about this collision for so long they’ve given it their own their own nickname – the ‘Sorry Mate I Didn’t See You’ SMIDSY.

So let’s go back to the beginning of the story.

As long ago as 1975, the Greater London Road Safety Unit identified powered two-wheelers (PTWs) as being over-represented in accidents. Detailed analysis followed and the results indicated that a major contributory factor was that other drivers failed to see the motorcycles in the general street scene.

The Greater London ‘Ride Bright’ campaign followed. It’s likely it was the first road safety campaign specifically designed to encourage riders of powered two-wheelers to improve their conspicuity by wearing bright clothing, preferably of fluorescent material, and by switching on their headlights in daytime. The campaign was extensive, involving radio advertising, a poster campaign, leaflets distributed through a number of routes (including dealers, garages, colleges, businesses and by London’s Metropolitan Police Service) and give-away items such as combs, pens and key-rings.

At around the same time, a US researcher named Harry Hurt (of whom you may have heard) working with Dupont wrote in 1977 that:

“the most likely comment of an automobile driver involved in a traffic collision with a motorcycle is that he, or she, did not SEE the motorcycle…”.

Hurt became synonymous with research into motorcycle crashes a few years later when he put his name to a mammoth study that became known as the ‘Hurt Report’ (1981). It has become a seminal work and you can find it easily online. Based on his research in California, what Harry Hurt found (amongst other things) was that:

“Approximately 3/4 of motorcycle accidents involved collision with another vehicle at an intersection. The driver of the other vehicle violated the motorcycle right-of-way and caused the accident in 2/3 of those accidents and did not see the motorcycle or did not see the motorcycle until too late to avoid the collision. Most involved passenger cars…”

A few years later, on our own side of the Big Pond, Keith Booth looked at 10,000 motorcycle crashes in London. Although I cannot find the original research, he released a report called “Characteristics of Urban Motorcycle Accidents” through the Institute of Motorcycling. Booth’s observation was that in London:

“62% of motorcycle accidents were primarily caused by the other road user. In 2/3 of motorcycle accidents where the driver was at fault, the accident was due to the driver failing to anticipate the action of the motorcyclist.”

In other words, much the same crashes were happening in big cities on both sides of the Atlantic and in much the same proportions.

The obvious question was: “Why?” Hurt drew much the same conclusion as the earlier GLC study in London:

“The origin of this problem seems to be related to the element of conspicuity (or conspicuousness) of the motorcycle; in other words, how easy it is to see the motorcycle. When the motorcycle and the automobile are on collision paths, or when the vehicles are in opposing traffic, the conspicuity due to motion is very low, if it exists at all.”

I’ll be coming back to this concept of ‘motion conspicuity’.

Hurt continued, “Consequently, recognition of the motorcycle by the automobile driver will depend entirely upon the conspicuity due to contrast.

“If the approaching motorcycle and rider blend well with the background scene, and if the automobile driver has not developed improved visual search habits which include low-threat targets (such as motorcycles and bicycles, as contrasted with the high-threat targets presented by trucks and buses) the motorcycle will not be recognized as a vehicle and a traffic hazard exists.”

Note that phrase about depending ‘entirely on the conspicuity’ – it’s going to be important too.

These accidents are often categorised as ‘Looked But Failed To See’ errors (LBFTS), because the driver claims that they looked in the appropriate direction for conflicting traffic, but did not see the approaching motorcycle.

If drivers were colliding with motorcycles that they hadn’t seen because the motorcycle had poor conspicuity,  what was the answer? Not surprisingly, the road safety bodies came up with two ‘common sense’ answers:

• motorcyclists should make themselves more conspicuous by wearing light-coloured, reflective and fluorescent hi-vis clothing and white helmets, and to ride with dipped headlights on, and if they did, this would help drivers see them
• drivers should look harder for motorcycles – drivers were told to ‘Think Bike’ and to look twice or take longer to look for them, and if they did this they would see bikes.

And that’s pretty much where we are now.

So… did any of this work?

Clarke et al (2007) investigated a sample of crashes involving motorcycles in the UK:

“A sample of 1790 accident cases was considered, including 1003 in detail, from UK midland police forces, involving motorcyclists of all ages, and covering the years 1997-2002 inclusive. Significant differences were discovered in the sample with respect to types of accidents involving motorcyclists (and their blameworthiness). There seems to be a particular problem surrounding other road users’ perception of motorcycles, particularly at junctions. Such accidents often seem to involve older drivers with relatively high levels of driving experience who nonetheless seem to have problems detecting approaching motorcycles.”

Even more recently, Helman et al (2012) wrote in a paper for the Transport Research Laboratory (TRL) that:

“It is widely accepted that one key factor in motorcyclist crashes around the world is the difficulty other road users have in detecting an approaching motorcyclist or correctly appraising their speed and position. This is of particular concern at road intersections, when drivers need to detect gaps in oncoming traffic to make turns either across or into traffic flows. If a motorcyclist is not detected by a car driver in this situation (so-called ‘looked but failed to see’) then this can lead to a manoeuvre that violates the motorcyclist’s path, and a potential crash.”

If we look outside the UK but still within Europe, the pan-European study ‘Motorcycle Accidents In-Depth Study’ (or MAIDS for short), first released in 2004 then updated in 2009, found that just over half of all crashes involving a powered two-wheeler (ie a motorcycle or moped) took place at an intersection. 60% of these collisions were with a car, 72% of the accidents took place in urban areas, and in 50% the car driver was to blame. And the important conclusion was that in over 70% of the collisions resulting from an error on the part of the other driver, the collision involved a failure to see the a motorcycle.

And the latest study from Transport for London on motorcycle crashes in the capital repeated the findings that the car – motorcycle collision at a junction remains the biggest single issue facing riders.

So, the conclusion is inescapable. The interventions first recommended in the 1970s and early 80s don’t seem to have had any effect on the prevalence of the LBFTS error. And so the SMIDSY remains the most common crash involving a bike and another vehicle.

If our generation of riders is to do any better, we need to look for a better explanation. And we need to do it ourselves, not rely on what we’re told. And that’s why I’ve spent so much effort working on SOBS over the last nine years.

Kevin Williams / Survival Skills Rider Training www.survivalskills.co.uk

(c) K Williams 2020

The Science Of Being Seen – the book of the presentation £9.99 plus P&P and available now from: www.lulu.com

The ‘Science Of Being Seen’ is a presentation created in 2011 for Kent Fire and Rescue’s ‘Biker Down’ course by Kevin Williams. Biker Down is now offered by over half the nation’s FRSs as well as the UK military, and many deliver a version of SOBS. Kevin personally presents SOBS once a month for KFRS in Rochester. He toured New Zealand in February 2018 delivering SOBS on the nationwide Shiny Side Up Tour 2018 on behalf of the New Zealand Department of Transport.

Find out more here: https://scienceofbeingseen/wordpress.com

SMIDSY – there’s more than one driver error

Thanks to decades of ‘Think Bike’ style campaigns which in essence tell drivers to “look harder” or “look longer” for motorcycles it’s not surprising that most riders believe that the SMIDSY results from poor driving skills and specifically from “not looking properly”. This advice and these beliefs have arisen from ‘post-hoc’ analyses of crashes. That is, they tell us WHAT happened and we find that out by starting at the end point of the collision, and working backwards till we find the error. It’s pretty straightforward in the case of the SMIDSY; the driver didn’t see the bike.

But post-hoc analyses don’t tell us two things:

• how OFTEN the crash occurs – in fact, with 30+ million active drivers and between 1 and 2 million active motorcyclists in the UK, serious collisions are remarkably rare – just over 2000 in total in 2017. The vast majority of drivers see the vast majority of bikes – we just notice the ones who don’t see us.
• WHY the driver failed to see the bike – for that we need to start at the other end of the crash and ask why an everyday interaction went wrong.

Last time I talked about the ‘looked but COULD NOT SEE’ issue, where the motorcycle is simply not where it could be seen. But what about those events where reconstruction suggests that bike was actually in a place it could be seen?

In fact, there’s a chain of perceptual events to be completed between the driver looking and the bike being seen. The ‘Looked But Failed To See’ problem can result from a breakdown at any of the stages:

• firstly, the driver has to look – if he / she doesn’t look, the driver will not see the motorcycle
• secondly, the bike has to be where it can be seen when the driver looks – if not, the bike is not visible and the driver cannot see the motorcycle
• thirdly, the driver has to look and perceive the motorcycle – if the motorcycle is not perceived, the driver will not see the motorcycle
• fourthly – and this one is hot off the press, straight out of a paper published late in 2019 – the driver has to look, perceive the motorcycle and then retain that knowledge right through the manoeuvre – if the driver forgets that he or she saw the motorcycle, the manoeuvre will be performed as though the driver did not see the motorcycle
• fifth and last, if the driver perceives the motorcycle, the driver has to assess speed and distance correctly – if the driver misjudges either, the result is likely to be a faulty decision to turn and an unsafe manoeuvre

The proportions of the different errors may surprise you.

‘Did not look’ falls into the smallest segment of the chart, and includes collisions where drivers are using mobile phones. An IAM report entitled ‘Licensed to skill: contributory factors in road accidents: Great Britain 2005 – 2009’ looked at over 700,000 items of official crash data from the UK and found that ‘driver using mobile phone’ was the cause of 0.8% of fatal crashes, and just 0.2% of all injury crashes. I should point out that these are crashes involving ALL vehicle types, and that given the huge increase in smartphone use the figures may be outdated, but the inference is that the crash rate between motorcycles and drivers using a phone is almost certainly much lower than most riders believe.

In fact, the three main factors are:

• the driver looked but the bike COULD NOT be seen – between one-fifth and one-quarter of all collisions
• the bike was visible, and the driver ‘Looked But FAILED to see’ – around one-third of all collisions *
• the bike was seen and the driver ‘looked, saw but MISJUDGED speed and distance’ – around one-third of all collisions

(This total is likely to include the newly proposed ‘looked, saw but FORGOT error’).

From our perspective as riders, it’s important to understand that each error is different, with different causes and different possible solutions. Treating them all as a ‘driver didn’t look properly’ issue has held back our understanding of collisions between cars and motorcycles for over forty years. It’s time to move our understanding and our strategies for dealing with these crashes forward.

Kevin Williams / Survival Skills Rider Training www.survivalskills.co.uk

(c) K Williams 2020

The Science Of Being Seen – the book of the presentation £9.99 plus P&P and available now from: www.lulu.com

The ‘Science Of Being Seen’ is a presentation created in 2011 for Kent Fire and Rescue’s ‘Biker Down’ course by Kevin Williams. Biker Down is now offered by over half the nation’s FRSs as well as the UK military, and many deliver a version of SOBS. Kevin personally presents SOBS once a month for KFRS in Rochester. He toured New Zealand in February 2018 delivering SOBS on the nationwide Shiny Side Up Tour 2018 on behalf of the New Zealand Department of Transport.

Find out more here: https://scienceofbeingseen/wordpress.com