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PostPosted: Wed Apr 17, 2013 01:48 
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What an RAF pilot can teach us about being safe on the road
By Andreas on 01/11/2012 in Safe cycling in London

RAF fighter pilot“Sorry mate, I didn’t see you”. Is a catchphrase used by drivers up and down the country. Is this a driver being careless and dangerous or did the driver genuinely not see you?
According to a report by John Sullivan of the RAF, the answer may have important repercussions for the way we train drivers and how as cyclists we stay safe on the roads.

John Sullivan is a Royal Air Force pilot with over 4,000 flight hours in his career, and a keen cyclist. He is a crash investigator and has contributed to multiple reports. Fighter pilots have to cope with speeds of over 1000 mph. Any crashes are closely analysed to extract lessons that can be of use.

Note: You can now download the original article by John Sullivan which includes further insights: Dropbox link.
Our eyes were not designed for driving
We are the result of hundreds of thousands of years of evolution. Our eyes, and the way that our brain processes the images that they receive, are very well suited to creeping up on unsuspecting antelopes and spotting threats such as sabre-toothed tigers.
These threats are largely gone and they’ve been replaced by vehicles travelling towards us at high speeds. This, we’ve not yet adapted to deal with.

Why?
Light enters our eyes and falls upon the retina. It is then converted into electrical impulses, that the brain perceives as images. Only a small part of your retina, the centre bit called the fovea, can generate a high-resolution image. This is why we need to look directly at something, to see detail.

The rest of the retina lacks detail but it contributes by adding the peripheral vision. However, a mere 20 degrees away from your sightline, your visual acuity is about 1/10th of what it is at the centre.

Try this scary test to see quite how much detail you lose in your peripheral vision
Stand 10 metres away from a car.
Move your eyes and look just one car’s width to the right or left of that car.
Without moving where you eyes are now looking, try and read the number plate of the car.
Try the test again from 5m.

The test shows you quite how little detail you are able to truly capture from the side of your eyes.

That’s not to say that we cannot see something in our peripheral vision – of course we can. As you approach a roundabout, you would be hard pressed not to see a huge lorry bearing down upon you, even out of the corner of your eye – obviously, the bigger the object, the more likely we are to see it. But would you see a motorbike, or a cyclist?

To have a good chance of seeing an object on a collision course, we need to move our eyes, and probably head, to bring the object into the centre of our vision – so that we can use our high-resolution vision of our fovea to resolve the detail.
Here’s when things get really interesting

Your brain fills in the blanks
When you move your head and eyes to scan a scene, your eyes are incapable of moving smoothly across it and seeing everything. Instead, you see in the image in a series of very quick jumps (called saccades) with very short pauses (called fixations) and it is only during the pauses that an image is processed.
Your brain fills in the gaps with a combination of peripheral vision and an assumption that what is in the gaps must be the same as what you see during the pauses.
This might sound crazy, but your brain actually blocks the image that is being received while your eyes are moving. This is why you do not see the sort of blurred image, that you see when you look sideways out of a train window.
The only exception to this, is if you are tracking a moving object.

Another test to try
If you are not convinced, try this test.
Look in a mirror.
Look repeatedly from your right eye to your left eye.
Can you see your eyes moving? You can’t.
Repeat the test with a friend and watch them. You will see their eyes moving quite markedly.

You can’t see your own eyes move because your brain shuts down the image for the instant that your eyes are moving. This is called Saccadic masking.
In the past, this served us well. It meant we could creep up on antelopes without our brain being overloaded by unnecessary detail and a lot of useless, blurred images.
However, what happens when this system is put to use in a modern day situation, such as a traffic junction?

Why we miss motorbikes and bicycles
At a traffic junction all but the worst of drivers will look in both directions to check for oncoming traffic. However, it is entirely possible for our eyes to “jump over” an oncoming bicycle or motorbike.

The smaller the vehicle, the greater the chance it will fall within a saccade.

motorbike in a saccade
This isn’t really a case of a careless driver, it’s more of a human incapacity to see anything during a saccade. Hence the reason for so many “Sorry mate, I didn’t see you” excuses.

The faster you move your head, the larger the jumps and the shorter the pauses. Therefore, you’ve got more of a chance of missing a vehicle.
We are effectively seeing through solid objects, with our brain filling in the image.

Additionally, we tend to avoid the edges of the windscreen. The door pillars on a car therefore create an even wider blindspot. This is called windscreen zoning.

The danger of playing music
Our ears help us build up a picture of our surroundings. However, inside our cars or with music playing, our brain is denied another useful cue. Additionally, bicycles are almost completely silent, so won’t be heard by car drivers.
How accidents happen

Let’s say you are driving along. You approach a junction and you notice a lack of traffic. You look left and right and proceed forward. Suddenly you hear the blast of a horn, as a motorbike flashes in front of you, narrowly avoiding an accident.

What just happened?
On your approach, you couldn’t see there was another vehicle on a perfect collision course. With a lack of relative movement for your peripheral vision to detect and the vehicle being potentially hidden by being near the door pillar, you miss it entirely.

Lulled into a false sense of security you looked quickly right and left, to avoid holding up the traffic behind you, and your eyes jumped cleanly over the approaching vehicle, especially as it was still close to the door pillar in the windscreen. The rest of the road was empty, and this was the scene that your brain used to fill in the gaps! Scary, huh?

You were not being inattentive – but you were being ineffective.
Additionally, if you didn’t expect there to be a cyclist your brain is more likely to automatically jump to the conclusion that the road is empty.
Now that you’ve been warned. What can you do?
motorbike can't be seen

Forewarned is forearmed, so here’s what we can do.

Drivers:
Slow down on the approach of a roundabout or junction. Even if the road seems empty. Changing speed will allow you to see vehicles that would otherwise be invisible to you.
A glance is never enough. You need to be as methodical and deliberate as a fighter pilot would be. Focus on at least 3 different spots along the road to the right and left. Search close, middle-distance and far. With practise, this can be accomplished quickly, and each pause is only for a fraction of a second. Fighter pilots call this a “lookout scan” and it is vital to their survival.
Always look right and left at least twice. This doubles your chance of seeing a vehicle.
Make a point of looking next to the windscreen pillars. Better still, lean forward slightly as you look right and left so that you are looking around the door pillars. Be aware that the pillar nearest to you blocks more of your vision. Fighter pilots say ‘Move your head – or you’re dead’.
Clear your flight path! When changing lanes, check your mirrors and as a last check, look directly at the spot which are going to manoeuvre.
Drive with your lights on. Bright vehicles or clothing is always easier to spot than dark colours that don’t contrast with a scene.
It is especially difficult to spot bicycles, motorbikes and pedestrians during low sun conditions as contrast is reduced.
Keep your windscreen clean – seeing other vehicles is enough of a challenge without a dirty windscreen. You never see a fighter jet with a dirty canopy.
Finally, don’t be a clown – if you are looking at your mobile telephone then you are incapable of seeing much else. Not only are you probably looking down into your lap, but your eyes are focused at less then one metre and every object at distance will be out of focus. Even when you look up and out, it takes a fraction of a second for your eyes to adjust – this is time you may not have.

Cyclists and motorcyclists:
Recognise the risk of being in a saccade. High contrast clothing and lights help. In particular, flashing LED’s (front and rear) are especially effective for cyclists as they create contrast and the on-off flashing attracts the peripheral vision in the same manner that movement does. There’s nothing wrong with leaving these on during the day. (Especially if they are rechargeable)
The relatively slower speed of bicycles means that they will be closer to a point of collision if a vehicle begins to pull into their path. Turn this to advantage – when passing junctions, look at the head of the driver that is approaching or has stopped. The head of the driver will naturally stop and centre upon you if you have been seen. If the driver’s head sweeps through you without pausing, then the chances are that you are in a saccade – you must assume that you have not been seen and expect the driver to pull out!
Recognise that with a low sun, a dirty windscreen or one with rain beating against it drivers are likely to have less of a chance of seeing you.
Cycle instructors have been saying it for years: Ride in a position further out from the kerb as a driver is more likely to be looking in this location. See: How to make your next bike ride safer than the last.

What should we do with our human weakness?
John Sullivan’s findings and suggestions are excellent. However, they rely on drivers changing well embedded habits. Personally I believe that, unlike RAF pilots, a driver is very unlikely to change their behaviour. Therefore, I’d suggest that this is another reason we should be looking at building safety in to our roads, with Dutch style cycling infrastructure.

Two important takeaways for cyclists: Increasing your contrast helps you be seen. Think flashing bike lights. Also, remember the importance of good road positioning.
Can't say that I have learned anything but interesting and I'm sure helpful to many ! :)
The phrase from Sherlock Holmes novels saying "We look but we do not see" also suggests that is was common knowledge back then too. I know that I try to ensure I really see what I look at but we can all make mistakes... Interestingly I had an RAF Tutor teach me to drive (well I was already driving but properly!). :)

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PostPosted: Wed Apr 17, 2013 10:43 
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I found that interesting - I didn't know the detail of of saccades

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PostPosted: Wed Apr 17, 2013 10:52 
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Yep it is interesting and I wonder how many driving instructors and other Road Safety parties are even aware of it?
It takes concentration to ensure that we really look, register and process what we really see. :)

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PostPosted: Wed Apr 17, 2013 10:55 
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I think it's interesting too. I didn't know about the "windscreen zoning" thing. When cars do their type approval tests, there are obscuration angle limits that the A pillars can create, but they are assessed using a dummy with light sources for it's eyes and because of that, the obscuration angle recorded is the bit that blocks out one or both light sources. This means the "official" obscuration angle is likely to be smaller than the "real" one if the driver is "windscreen zoning".

Are Saccades and fixations responsible for the "stopped watch" effect we sometimes get when we glance at a watch and think it has stopped because the second hand isn't moving? I do generally try to look twice to the right (once to the left) before pulling out of a T junction. I guess (though I didn't know about "saccades") this would help avoid them. If anything IS there. the chances of it being invisible on both looks must be pretty small?


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PostPosted: Wed Apr 17, 2013 11:36 
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This point is interesting:

Quote:
Changing speed will allow you to see vehicles that would otherwise be invisible to you.

So does driving along at a constant speed of 30mph mean you will "see" less? Will drivers adapting their speed to the conditions (i.e. changing speed) notice more?

Another point is that I have always been concerned with is the impact of peripheral vision on safety. Children appear to have little peripheral vision. I have tested this by coming up next to various children and waving my hands about until they see me. (No I didn't get arrested!). They don't appear to see you until you are almost in front of them. Is this a reason for the high proportion of child casualties?

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PostPosted: Thu Apr 18, 2013 01:58 
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It's more about making your brain think and not assume what you think you might see.
By altering the speed it makes the brain think rather than the 'speed alteration' providing anything IMHO.
Its an action to force a rethink. By slowing you are likely too to alter the bodies position and thus 'move' around the pillar a little too, although I'd far rather people were far, far more aware of the pillar problem and be taught that they must move their heads around it.
Thus teaching and learning the right movement that becomes a habit that keeps us all safer. :LOL:

I don't know about stats for kids and on the edge of peripheral vision. I have never seen anything on that, I wonder if the Medical Assoc does ?
The assumption that they haven't seen you is clearly wise but it would be good to teach the kids if they don't know. I wonder if it is learnt or if eyes develop ?

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PostPosted: Thu Apr 18, 2013 09:57 
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Children aren't as good at adults at judging vehicle speeds either. They need a much bigger amount of difference to notice if one car is travelling faster than another. 20mph I think it was, whereas an adult usually needs 7 mph difference or so. Explains why children do just step off the kerb... I wonder if in 20mph zones this actually makes child casualties more likely as a vehicle going more slowly is going to look like it is stopped to a child but if it were travelling at 30mph they would realise it was moving?

The book 'the invisible gorilla' is well worth a read. It has a lot on visual perception and the illusions the brain creates.


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PostPosted: Thu Apr 18, 2013 11:50 
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That's interesting .... :scratchchin:

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PostPosted: Sat May 11, 2013 19:36 
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teabelly wrote:
Children aren't as good at adults at judging vehicle speeds either. They need a much bigger amount of difference to notice if one car is travelling faster than another. 20mph I think it was, whereas an adult usually needs 7 mph difference or so. Explains why children do just step off the kerb... I wonder if in 20mph zones this actually makes child casualties more likely as a vehicle going more slowly is going to look like it is stopped to a child but if it were travelling at 30mph they would realise it was moving?

The book 'the invisible gorilla' is well worth a read. It has a lot on visual perception and the illusions the brain creates.


Most ridiculous straw man against 20mph limits I've seen so far.

Children can see a vehicle is moving, but they can't judge the speed, so can't tell the difference between 20 and 40.

Tell you what, how about not blaming children for stepping out in front of vehicles, but the vehicle driver for hitting them, that's what I'd be doing if I were in charge.


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PostPosted: Sat May 11, 2013 20:27 
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We know Weepy...

...but fortunately, you're not...


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PostPosted: Sat May 11, 2013 23:23 
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weepej wrote:

Tell you what, how about not blaming children for stepping out in front of vehicles, but the vehicle driver for hitting them, that's what I'd be doing if I were in charge.



Would it be better if we taught kids about road safety . Lok left & right , then once again ,there could be some recklest cyclist on the footpath . And that's the truth these days. More chance of a kid gettin hurt on the road ( as drivers keep their eyes open for kids) because of some idiot on a bike.

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PostPosted: Sun May 12, 2013 08:10 
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botach wrote:
Would it be better if we taught kids about road safety . Lok left & right


Yes, you can tell them to look left and right but as you've seen, humans and particulary children appear to have difficulty seeing things moving faster than 20mph and/or working out what speed they are coming at, so I'd say blame the thing that's moving faster than 20mph in an urban environment, not the pedestrians.

http://www.cyclorama.net/blog/cycling-news/20s-plenty/


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PostPosted: Sun May 12, 2013 11:58 
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Fair enough - but let's wait for the outcome of that project. The article is full of words like "may" and "appears to" and "suggests". Needless to say, supporters of 20 limits have seized on these and it's already "fact" as far as they're concerned.

Personally, watching my kids (and their mates) in the school playground, they seem infinitely better than me at tracking a football doing (what I imagine is) rather more than 20 MPH!


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PostPosted: Sun May 12, 2013 14:27 
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Yes, I agree with Mole, Weepy, you need better bedtime reading if you are going to accept every "maybe, think, suggest, hope, feel, wonder, perhaps", as being hard fact.

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PostPosted: Sun May 12, 2013 21:29 
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Mole wrote:
Fair enough - but let's wait for the outcome of that project. The article is full of words like "may" and "appears to" and "suggests". Needless to say, supporters of 20 limits have seized on these and it's already "fact" as far as they're concerned.

Personally, watching my kids (and their mates) in the school playground, they seem infinitely better than me at tracking a football doing (what I imagine is) rather more than 20 MPH!


And cricket balls. But why there's all this ho ha about blame. If kids at a set age are not fit to be out alone, then it's up to the parents to do the job. Leave a young child alone at home and there's hell to pay. Let the same parents let a toddler out and it's saferty suddenly becomes everyone's responsibility .
OK, 20 LIMITS WILL HELP . But ,I'll quote a case locally where a toddler was found on a main estate through road . How did it get out. Perhaps that should be the focus of the investigation, rather than the venom thrown at road users . It transpired that it got out of the lounge ,into the hallway , out of the front door and out of the garden which was gated . We have had this problem with GS, so we puit the chain on .

I see the same mentality with this lot of blame merchants daily. Asda has a stack of Mother & Toddler spaces next to two disabled spaces , close to the cash machine. Regularly I see mothers use the disabled spaces, with no apparent disabled badge in view. But if a disabled person takes a mother space because the disabled spaces are full of dyslexic mums - venom flies .

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PostPosted: Tue May 14, 2013 10:58 
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weepej wrote:
teabelly wrote:
Children aren't as good at adults at judging vehicle speeds either....

The book 'the invisible gorilla' is well worth a read. It has a lot on visual perception and the illusions the brain creates.
Most ridiculous straw man against 20mph limits I've seen so far.

Children can see a vehicle is moving, but they can't judge the speed, so can't tell the difference between 20 and 40.

Tell you what, how about not blaming children for stepping out in front of vehicles, but the vehicle driver for hitting them, that's what I'd be doing if I were in charge.
It's an interesting possibility. It's not saying every single child is incapable but that their findings suggest .... and so if many might then this is of interest, and to add to our understanding and perception of road safety.
Many children who concentrate on crossing a road will leave massive space before crossing if by themselves.
If playing in the street then their attention is elsewhere and probably not considering traffic at all. This topic though is not specifically about 20mph so take that elsewhere please.

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PostPosted: Wed May 15, 2013 22:54 
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SS2- I reside in an urban area ,where it's common for kids of a very young age to be let out to play on the road etc. Years ago , social services would be invilved in asking if the mothers placed the kids in danger, but not now in "Modern Britain" where it's tghe driver's responsibility to have x ray vision to see a kid runing out from behind a car , rather than the mother's responsibility to teach road safety and contain the kids . However, I note that kids learn to look out for danger on the road. Kids see a moving car in our road and get on the pavement, whilst the mums sit back and chill out on lashings of soap and possibly jeramy Kyle.

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