(Sorry Mate, I Didn't See You)
Why are so many road accidents caused by road users failing to see one another?
Always available at
One cause that may be very significant is that windscreen pillars obscure drivers' vision.
Accidents involving motorbikes at junctions are commonplace. In a typical case, a car will pull across the path of a motorbike and the driver will say to the motorcyclist: "Sorry mate, I didn't see you". This type of accident is so commonplace that "Sorry mate, I didn't see you" has been shortened to the acronym: SMIDSY
Speed and Bike Magazine September 2004
Safe Speed has been working with BIKE magazine
to highlight these issues. A three page article was published in BIKE on
the 4th August 2004 and a joint press release was issued.
|We're approaching a roundabout.||
Many motorcycle accidents involve cars and other vehicles simply "pulling out in front". It is so common that the driver's typical words to the motorcyclist; "sorry mate, I didn't see you" have been shortened to the acronym "S.M.I.D.S.Y."
|There's a motorcyclist!||
||He didn't even look...
Well actually he probably did. Most smidsy accidents involve drivers who "looked but did not see".
|Where'd he go?||
||I had my headlight on! How
could he miss that?
Although it isn't well known, even quite large vehicles can momentarily disappear behind the driver's windscreen pillar. If their momentary disappearance coincides with the driver's "glance check" a smidsy is on the cards.
|It's clear. Let's go.||
||But your camera has only
got one lens. I've got two eyes.
It's true that sometimes, even often, your other eye can see around the pillar. But not every time, and then each of your eyes has a blind spot where the optic nerve joins the retina. So if the left eye view is blocked by the pillar and the biker is in the right eye's blind spot we might just have a smidsy.
||The frames on the left...
...are shot with a cheap ordinary video camera, captured with a cheap ordinary TV card. Converted to 15 fps and dumped out as single frames. We've then used every other frame for the sequence on the left. The frames are at a rate of 7.5 frames per second or an interval of 0.13 seconds per frame.
|Hang on, there's a motorbike!
Suppose we'd just started moving. See how the pillar could track the motorcycle and keep him hidden for longer?
||What should a driver do?
Always, always, always look for long enough that anything moving behind the pillar has a chance to emerge. Glance checks are never enough. An extended period of observation is good, two looks are better. Always think about bikes. Always think about anything that could be behind the pillar. Move you head to see around the pillar, but be aware that doing so could also mean that you make an equal and opposite head movement allowing the pillar to obscure the biker for longer.
|Good job we saw him! (phew)||
||How long was he invisible?
As near as we can reckon the motorbike was hidden behind the windscreen pillar for about 0.35 seconds.
|Is it clear?
Careful now, there might be a bike!
They used to say: "Think once. Think twice. Think bike". Good advice, but we were never sure if they really knew why they were giving it.
||What are we going to do
TELL DRIVERS. Shout it from the roof tops. Link to the web site. Get it on TV. In the papers. In the driving manuals. In The Highway Code. email your car driver friends.
|download: (308k bytes)||
||click the link to download the above sequence of frames as an avi file: 15 frames per second.|
|download: (247k bytes)||
||click the link to download the above sequence of frames as 40 small jpg images in a single zip file. (15 frames per second)|
|Background to the video.
I drove to the nearest roundabout. It happens to have a small little used service road. I parked in the service road positioned exactly as if I was going to pull out onto the roundabout, but 6 feet back from the give way line. I determined my normal head position in the driving seat, got into the back of the car and hand-held the video camera so the the lens was between where my eyes normally are. I adjusted the zoom to a reasonably wide angle and filmed for ten minutes. I was lucky that the two bikers happened along.
I was back home in less than 30 minutes.
|Other causes of SMIDSY accidents
The distraction effect
Something distant and highly visible may distract the eye from observing something closer but less highly visible. You've probably had this when planning to overtake in poorer light, you've seen and planned for the distant car showing dipped headlights, only to later notice a nearer dark green car without lights. If you haven't yet, you probably will. (owners of dark coloured cars take note...)
Some claim that you only see the types of object that you are looking for. e.g. while checking to see if there's a car coming you may not see a bike. This is clearly possible, but we don't presently believe it's a big smidsy causation factor.
Retinal blind spot
Every human eye has a 6 degree blind spot where the optic nerve meets the retina. Normally the other eye can see the portion of the view where the first eye is blind.
Complexity of visual processing
Our brains are incredibly sophisticated
at "cleaning up" the information from our eyes.
Send us email
|SMIDSY Links and information:
Stories of SMIDSYs here at www.smidsy.org.uk
New government report into "Looked but failed to see accidents".
Retinal blind spot everyone has two.
new long forgotten British research from 1963
newSpen King in AutoCar, 2nd March 2004
new Survival Skills - SMIDSY
|Article by Spen King
(This article was found in the pages of the Motorcycle Action Group. It is no longer available, but we rescued it from an Internet cache.)
The following is an extract of an article which appeared in: The Electronic Telegraph Tuesday 20 June 1995
When you simply can't see the obvious
Respected car engineer Spen King believes an important design flaw in many modern vehicles is causing accidents. He tells John Langley about it
You could argue that the most important faculty for drivers is to be able to see where they are going and, just as important, what is coming towards them. The motor industry has spent billions on making cars safer and cleaner. But, according to one of Britain's top car engineers and designers, Spen King, designers and legislators are overlooking a potentially lethal blindspot in modern cars loaded with seat belts, airbags, side-impact beams and all the other fashionable safety paraphernalia.
He is convinced that windscreen pillars have been allowed to become so thick and obstructive to vision that they are leading to many accidents. He says there is no real engineering reason for them to be so wide, and few drivers are even aware of the hazard until they have a near miss (or worse) with a vehicle, cyclist or pedestrian they inexplicably failed to see.
King, who was engineering chief at Rover, then BL, and responsible for the Range Rover and Rover 2000 among other outstanding designs, believes there has been so much emphasis on secondary safety - protecting the car occupants from the worst effects of an impact - that some of the fundamentals of primary safety (avoiding the crash in the first place) have been overshadowed.
He traces the problem back to an EEC regulation from 1977 allowing obstruction of up to six degrees, using both eyes, from the driving seat, applying to both driver and passenger screen pillars. "It means it is legal to have pillars so thick that at 50m, an object 5.2m wide (17ft 2in) can be completely hidden from the driver," he says.
"The EEC safety rules, when satisfied, seem somehow to relieve car companies of ethical or potential legal pressure that they might otherwise feel, so it is not surprising that screen pillar design has gravitated towards maximum legal thickness, although some car companies are exceptions."
King quotes a wad of accident investigation data indicating that forward vision restriction may be a factor in more than half of all collisions. One source reported that the offside screen pillar could obscure a pedestrian 10m or more away; another found that "most traffic events occur at 30 degrees to the straight ahead".
"This is a position where the offside windscreen pillar is normally located," says King. The danger was brought home to him when he stopped to let some pedestrians over a crossing. "I thought they were all clear; then, as I moved off, I found some more ha d followed behind them. They were hidden behind the screen pillar, and I had to jam the brakes on again." Other potential danger spots were junctions, roundabouts and right-hand bends. "Of course, if the driver moves his head he can see round the pillar. However, my observations and experience make me think drivers very often don't do this."
King believes the Transport Research Laboratory should look into the visibility problem "While car companies spend many millions on things like cleaning up emissions, here is something relatively inexpensive that might save thousands of lives, but nobody seems to be doing anything about it," he says. "Given a new design from scratch, the visual obstruction of screen pillars could be massively reduced.
However, he says, since getting European agreement to revised regulations could take years and would apply only to future new cars, it is essential to take action now. Car makers should be reminded of the importance of having unobstructive pillars on new models, and of reducing obstruction as far as possible on current vehicles.
King believes the Transport Research Laboratory should look into the visibility problem instead of concentrating so heavily on secondary safety. Just as important, drivers should be made aware of the hazard and get into the hab it of moving their heads to see round the screen pillars. "Even the Highway Code makes no mention of the screen pillar blindspot - it should," says King. "And so should the otherwise excellent Roadcraft police driver's handbook."
|Spen King in Autocar, 2nd
Solutions - what must we do?
It is outrageous, but sadly all too typical, that the risks associated with screen pillar obscuration of vision are not even considered in modern road safety research. Being able to see other road users is absolutely fundamental to the way road safety works in practice, but the UK authorities are not even asking the question.
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Last update: 18th August 2004