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Hi Vis yet again – the ‘interminable argument’ rumbles on…

Yes, Hi Vis got another forum working over in the last day or so. This time, it was a combination of:

1) advice from the IAM to young riders issued earlier this month (October), a time at which they are higher than average risk:

* Wear high-visibility gear. A solid colour, as opposed to broken up shapes makes you much more visible as a human


2) this ad from Hein Gericke:

HG hi vis

…that kicked off a discussion about the effectiveness of conspicuity aids in general, and hi-vis jackets in particular.

The problem with the jacket on the left above is that it doesn’t do a particularly good job of maintaining the rider’s silhouette, because it use blocks of colour that break up the solid shape. Ironically, the black jacket on the right does a better job of maintaining a human outline.

So what’s so important about solid colours and a human shape?

The rationale for the adoption of hi-vis and other conspicuity aids is that they turn potential collisions into actual near-misses; whilst they may be visible further off, that’s an essentially irrelevant side effect – it’s the very close up “sorry mate, I didn’t see you” incident that conspicuity aids are supposed to guard against.

That naturally puts a premium on very rapid recognition times when the rider is in close proximity to the driver who is about to make the mistake of not seeing the bike.

This is particularly important because other research suggests that drivers actually look for GAPS, not vehicles, and as a result they tend to look BEHIND vehicles that are close to them; knowing by experience the distance where a gap has to be to pull out safely, drivers (and riders!) look straight to this distance and fail to scan ‘near to far’.

How often have you heard someone say:

“I was so close he couldn’t possibly have failed to see me… but he did pull out!”

Because of the way the eye works, whatever is closer to you is out of focus and in peripheral vision, so effectively the eye simply fails to see it and the brain isn’t aware it’s there. So if you’ve looked straight past the object in the foreground, you’ll not see it.

So the rider has a couple of ways to attract attention. One way is to try to move across the background by changing position in lane. The other relies on the eye detecting light/dark contrast (not simply ‘bright’ per se). Both tend to make the eye move its angle and focus to bring the object into the foveal zone of highly focussed vision.

It’s then shape that allows the mid-brain to send a message to the part of the brain that takes action; that could either be the conscious, decision-making part of the brain (the neo-cortex), so you can make a conscious decision “Ah, there’s a bike there, I’ll wait” or it could be a ‘red alert’ the message sent directly to the ‘fight or flight’ centre (the reptilian brain), which stamps hard on the brake without you consciously having to make that decision.

But… and it’s a big but…

…the system needs a recognisable shape for it to trip either response. It’s not uncommon to hear:

“I was wearing hi-vis, I had my lights on, and he still pulled out”

There’s a reason. The mid-brain has been fed a visual input that’s not in its library of known shapes and so it’s either mis-identify the shape or it’s simply ignored it.

Research is pointing in the direction of coherent solid shapes and silhouettes (as in the IAM message) as the means of rapid pattern identification and thus rapid recognition and reaction to the hazard by the observing driver.

Recognition is important because sometimes you can see something and still not understand what you’re looking at. The chaotic collection of multiple lights on several vehicles attending the scene of an accident can actually serve to hide what it is that you’re actually seeing, particularly in terms of distance, as can some of the hi vis colour schemes that have been used on emergency vehicles in the past. Increasingly, schemes that preserve the outline of the vehicle are being used.

From the perspective of the rider at threat from a ‘SMIDSY’ collision, stripey hi vis risks breaking up that coherent shape / silhouette that allows for rapid recognition, and so the longer it takes the driver/rider to first of all see, then secondly identify what they’re looking at, the less chance that driver has of taking evasive action.

It’s hard to get this over to riders, who will constantly claim they can see other riders wearing hi-vis bike gear and using day riding lights, yet the accident statistics from the 1970s to the present suggest that the adoption of headlights and hi-vis through that period has NOT altered the distribution of accidents!

Malcolm Palmer:

“There was a trial years ago of various ‘conspicuity treatments’, involving participants being driven past side roads and asked to look for bikes.

“‘Unfortunately’ because they’d been asked to look for bikes, they did – and saw all the control, ‘inconspicuous’, bikes during the first drive-throughs – scuppering the entire trial.

“Another set of trials in the USA found that drivers spotted a police bike more often than a highly conspicious bike. Presumably the drivers thought there was an incentive to do so.”

So what’s happening? Yet more research suggests drivers with no experience of bikes don’t ‘recognise’ them. There’s some kind of emotional investment in what we ride that’s missing in the average non-biking driver.

But you can predispose people to look for bikes. In the trial, the drivers had been told to look for bikes – so they were aware of the pattern they needed to search for, and they found the ‘stealth’ bikes they weren’t supposed to be able to see.

As a rider, you see bikes because you are predisposed to look for them, and if you believe in the effectiveness of conspicuity aids, then so you’re predisposed to look for them too. That’s why riders consistantly report seeing headlights and hi-vis when the accidents say drivers don’t spot them.

The ‘incentive’ angle is an interesting one.

Apparently, various US police departments are moving back to “black and whites” because that’s what people consider the ‘right’ colour for a police car. Using hi vis colour schemes actually resulted in increased number of accidents where people didn’t see the supposedly highly visible police vehicles.

Back to that ’emotional’ investment I mentioned?

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