Thursday's Dominion Rd crash killing a biker

**Pixie** · 14th December 2010, 08:33

Originally Posted by MarkH

http://www.nzherald.co.nz/nz/news/ar...ectid=10693281

It seems that the driver of the car is very distraught over killing the biker and believes that he was careful and DID check that the way was clear. I have some sympathy for that driver, this incident will have a rather devastating effect on his life.

To me this seems like a case of a driver looking, but not seeing. The bike must have been their to be seen, they don't really appear out of nowhere.

Motion Camouflage:

"An article in the March issue of the UK magazine Bike added a bit to the understanding of why cars pull out in front of motorcycles. Research on how certain insects attact prey was applied to the SMIDSY crash (sorry mate, I didn't see you).

When attacking, a dragonfly stays directly in the line of sight between its potential dinner and a fixed point in the distance. If dinner moves, the dragonfly alters its path just enough to stay on that line of sight. It doesn't swoop out to "lead" its victim. This tactic has the effect of keeping the dragonfly at the same point in the prey's visual field. Because the prey sees no change in the big picture, it is unaware of the impending attack. This is called motion camouflage.

Motion is difficult to perceive when it is directly along the line of sight. Because the object is stationary relative to the background, an observer doesn't see a change in the overall image and thus isn't cued to the presence of a moving object. Though the object increases in apparent size as it nears, the change goes unnoticed at first--moving from 1000ft distant to 900ft may not affect the image enough trigger a response. A motorcycle is particularly susceptible to motion camouflage because its cross-section area as seen by an observer is much less than that of a larger vehicle.

But as the object gets closer, apparent size increases more rapidly. At constant speed, an approaching object takes the same time to move from 200ft to 100ft as it did from 1000ft to 900ft, but the apparent size increase is greater. Eventually the object seems to grow suddenly in size, and the motion camouflage is broken. This is called the looming effect. According to the Bike article, when an observer is startled by the looming effect, he may freeze in his tracks. If the observer is an oncoming left-turner, he may stop in the middle of the intersection, making a bad situation even worse.

Duncan MacKillop, the riding instructor who related motion camouflage to motorcycling, suggests that diverging from the direct line of sight will break the motion camouflage and get the observer's attention. For example, a driver stopped at a cross-street on your right will be looking left at a slight angle to the path of the road. If you stay to the left of your lane, you will diverge from his line of sight, making yourself more noticeable. But if you're veering right (say, moving from the left to the right lane) you'll be moving along the crossing driver's line of sight, helping to hide your motion against the background.

MacKillop recommends: "I observed a smooth, gentle, single, zig-zag motion, at any point along the line, created a rapid edge movement against the background and destroyed the motion camouflage. Drivers' eyes snapped towards me and they froze the movement I swept left to right and back again."

**steve_t** · 14th December 2010, 08:46

Sweet, so it's all good to gently weave side to side in my lane around town. I tend to do it if I'm getting bored but now there's a good, safety reason for it

**Pixie** · 14th December 2010, 08:54

Originally Posted by danchop

ive not read the posts,but ive seen the pic on the website and this accident is the direct result of a biker,too cocky for his worth as a biker and more so for his pillion..
the impact of shattering his front rim suggests speed in well excess of 50k per hour
sadly he deserved what he got but peace be on the pillion

Wheel rims can fail during surprisingly slow impacts

**Pixie** · 14th December 2010, 09:07

Originally Posted by phill-k

I don't know renegade master but he and Katman have summed up the wider issue here about the "sorry mate I didn't see you" statement.

To quote "might is right" and it not much use being dead right.

As the vulnerable party motorcyclists must adapt a riding technique of assuming they are invisible and stop relying on other road users doing as they should.

We as riders must take responsibility for our own survival out there adapting methods to insure that our path is clear and never assume we have the right of way.

Personally I have three white forward facing lights, and when I hit full beam during daylight hours my light modulates, however if I'm approaching a conflict situation especially if I have no following traffic, I am looking for eye contact, watching the front wheels, and if unsure I'm starting to slow, brake, whatever, I'm looking at approaching traffic from the turning vehicles point of view - is there a small gap coming up that he might take advantage of, I also acknowledge a driver if I've taken these actions and they have become very aware of me, after all I ride for the pleasure and taking this responsibility for my own safety is a small price to pay. Likewise I pay a lot of attention to what is happening behind me, chastise myself if another road user can come up behind me without me seeing him approaching, many small things but I also accept that this may not save my skin on day, but hope that I am extending the odds out to a much greater extent.

Good defensive techniques, with the exception of checking for eye contact - it means nothing.The brain processes the visual data and you have no idea what the viewer is actually registering.

As for "eyewitness reports" these are meaningless too.
How do you know that their brains are not doing the Motorcyclist = speeding assumption.
There have been experiments that have had eyewitnesses say a criminal perpetrator was black when he was really white because that is what the viewer expected.

The brain's visual cortex fills in a lot of what we think we see with what could be referred to as "archive data".
See: The Invisible Gorilla Experiment

**MarkH** · 14th December 2010, 20:14

Originally Posted by Pixie

The brain's visual cortex fills in a lot of what we think we see with what could be referred to as "archive data".
See: The Invisible Gorilla Experiment

There is also a gap in the vision in each eye (blind spot) correlating to where the nerves go through. We don't notice it because the brain continually photoshops the image coming in and just fills in the details inside the blind spot to match everything around it. Also everything we look at is hitting our photo-receptors in our eyes upside down, our brains invert the image for us. If we wore glasses that flipped the image then we would see everything upside down, for a while (months I think), then the image would automagically invert and look normal unless we took off those glasses which would make everything look upside down again.

What we see is NOT what the eyes pick up, our sight is what our brains make of what info comes from the eyes + processing. We are not aware on the raw data, just the mentally processed data.

Bikes can be hard to see for car drivers that don't look for them, if they looked for bikes then they would be capable of seeing them.

**terbang** · 14th December 2010, 20:24

Originally Posted by Pixie

Motion Camouflage:

"An article in the March issue of the UK magazine Bike added a bit to the understanding of why cars pull out in front of motorcycles. Research on how certain insects attact prey was applied to the SMIDSY crash (sorry mate, I didn't see you).

When attacking, a dragonfly stays directly in the line of sight between its potential dinner and a fixed point in the distance. If dinner moves, the dragonfly alters its path just enough to stay on that line of sight. It doesn't swoop out to "lead" its victim. This tactic has the effect of keeping the dragonfly at the same point in the prey's visual field. Because the prey sees no change in the big picture, it is unaware of the impending attack. This is called motion camouflage.

A very real issue. Aviators have been plagued by this for years. The other aircraft that is motionless on your windshield is the hardest to see and yet is also the the one thats going to hit you.

**Ocean1** · 14th December 2010, 20:50

Originally Posted by Pixie

Good defensive techniques, with the exception of checking for eye contact - it means nothing.

Correct.

One of two cars I've gone over was a woman who I'd locked eyeballs with from 40ft away.

She never saw me until after I hit her pasenger door.

**swbarnett** · 15th December 2010, 19:06

Originally Posted by MarkH

There is also a gap in the vision in each eye (blind spot) correlating to where the nerves go through. We don't notice it because the brain continually photoshops the image coming in and just fills in the details inside the blind spot to match everything around it.

The brain does not fill in this blind spot by extrapolation. It is filled in by the fact that, even when you steer at something, the eye moves around involuntarily. We see a full picture because we're actually seeing a movie in which each frame has a hole but no two adjoining frames have the hole in the same place.

**buellbabe** · 15th December 2010, 20:04

Originally Posted by Ocean1

Correct.

One of two cars I've gone over was a woman who I'd locked eyeballs with from 40ft away.

She never saw me until after I hit her pasenger door.

Yep I can relate to that, I have had direct eye contact with car drivers and yet they still continue to move into the space i am already occupying.

Couple of days ago my mate and I were in the car (ironically we were talking about the Dom Rd tragedy), we were driving into the afternoon sun and could still CLEARLY see the headlight and shape of a bike travelling in the opposite direction.
We both said "HTF can a person NOT see that?" Even if a drivers brain doesn't register what the thing is, the fact that there is definately something there should be enough to stop them from pulling out in front of it.

**Ocean1** · 15th December 2010, 20:48

Originally Posted by buellbabe

I have had direct eye contact with car drivers and yet they still continue to move into the space i am already occupying.

There's actually 2 sorts of SMIDSY. The woman in the wee story above genuinely didn't see me. The arsehole in the DOC van a year ago saw me and smiled apologetically as he pulled over into my lane, exactly beside me, pushing me into the 2ft gap beside the median barrier.

Didn't manage to catch him then. But I definitely saw him, and I've got a fucking long memory.

**jrandom** · 15th December 2010, 20:48

Originally Posted by danchop

yep he deserved it alright,i ride that road a fair bit as a courier and its always chocker at that part,i didnt see it but one of of our car guys did
he was a fuckin idiot and deseverd to go down

ZOMG, 23 Danny. You need to get down here for a trackday so I can introduce you to Katman.

For what it's worth, folks, there's nothing inherently dangerous about Dom Rd unless you're a dozy twat. As Exhibit A I give you the above poster, who rides up and down it dozens of times a week with the clock ticking and an emotionally unstable Indonesian man yelling in his ear on an RT, and doesn't fall off.

Does anyone really want to argue that the dead rider in this instance wasn't a dozy twat?

WOTing it up the median barrier on Dom Rd on a tubby old superbike is essentially Russian roulette.

**MarkH** · 15th December 2010, 22:32

Originally Posted by swbarnett

The brain does not fill in this blind spot by extrapolation. It is filled in by the fact that, even when you steer at something, the eye moves around involuntarily. We see a full picture because we're actually seeing a movie in which each frame has a hole but no two adjoining frames have the hole in the same place.

Yeah, you are right that it doesn't use extrapolation, it actually uses interpolation.
Some links for your interest:
http://faculty.washington.edu/chudler/chvision.html
http://serendip.brynmawr.edu/bb/blindspot1.html
http://serendip.brynmawr.edu/bb/blindspot2.html
http://serendip.brynmawr.edu/bb/blindspot3.html
http://serendip.brynmawr.edu/bb/blindspot4.html
http://serendip.brynmawr.edu/bb/blindspot5.html
These links support what I have posted - the brain is doing a lot of processing and what is seen by the eye isn't all that makes up what we see.

Can you provide any links that give any credence to the microsaccades & ocular microtremors having anything to do with gathering data to fill the blind spot? The results of my google searches suggest that the involuntary micro movements of the eye have other purposes and have nothing to do with the blind spot. Most of the time the other eye covers that area anyway.