Rider Visibility

'Zaphod' made an interesting comment to a recent post, and rather than reply at length (as I think his comment deserves it) I thought I would start a new topic. The original post concerned the often negative consequences of 'safety' improvements, but the comments thread drifted somewhat into Risk Compensation Theory and road safety issues.

Zaphod said...

Does anyone have a viable solution to the "Sorry-mate-I-didn't-see-you" problem? Anger is justified, but doesn't actually help; and I see the point about lights and unintended consequences.

Riders always assuming that they haven't been seen, that's a bit unrealistic? I give bikers a nod when I'm waiting at a junction, so they know that I've seen em. That makes their life a little easier, but doesn't solve the big problem. And what about the one that I won't see, one day?

I read once that sailors are aware that anything on a collision course doesn't move relative to the background. That sounds a bit complicated, but it's important.

Car drivers- When coming out of a junction, don't just rotate your head. Move it about a foot, side to side. This gives your stereo vision an 18 inch baseline, instead of 6 inch. If you don't follow that explanation, just do it. It works. Make it a habit. Every little helps. Bikers don't want to die, and drivers don't want to kill.

I am assuming that Zaphod is writing from a car driver's perspective. My response would be:

A viable solution to the SMIDSY problem is indeed to ride on the assumption that you are invisible. If you assume that no-one has seen you, and that they may do anything within the laws of physics in front of you, then you are pretty safe from other motorists who actually haven't seen you. In effect, you have compensated for their lack of observation before the event.

To give an example which is a frequent occurrence near me at the moment: traffic lights controlling some road works on a major route, with long tailbacks of stationary cars and lorries occupying the nearside lane. A common error for riders is to see the offside lane clear and assume that they can ride up it as long as no-one is coming the other way because it's for opposing traffic, right?. What often happens is that a car driver gets frustrated and decides to do a U-turn and try another route. He doesn't check his offside mirror because no-one will be coming up behind him because it's for opposing traffic, right? (same error) and pulls out to make a sharp turn. The rider is caught unawares and T-bones the car in the side. He has effectively hit a solid stationary object, and the consequences for the rider can be severe. Oscar India described a similar incident here recently [1].

If the rider assumes a) that no other motorist is aware that he is there, and b) any other driver may do anything at any time, then the rider will perform this manoeuvre with great caution, by riding slowly past the stationary traffic, and as far away from the queue as possible - on the far side of the offside lane. If a driver does do something unexpected, firstly you are travelling slowly enough to be able to take avoiding action, and secondly the distance from the traffic queue means that you have the maximum room to work in.

That's the ideal, but none of us is perfect. If the situation happens on a regular basis (and I guess city riding and constant filtering are an extreme example), then the rider will travel a little quicker and perhaps a little closer - familiarity breeding contempt, and all that. That increases the risk, but it also increases the advantage of the bike to deal with congestion, so each rider will find his or her own level of risk/benefit ratio. But the principle remains - it's safest to assume that you are wearing a Harry Potter Cloak of Invisibility. To answer Zaphod's point - yes, it may be unrealistic to ride like that all the time, but riding according to the principle is by far the safest way to ride. And he is dead right in saying that anger (other than at yourself for your stupidity) serves no purpose in this kind of situation.

Nodding to acknowledge that you have seen a rider is appreciated - that's thoughful behaviour, and we would all wish that all car drivers were similarly aware of other road users. Personally, I will 'ride invisible' until I am sure that a car driver has seen me, either by such a nod, or by positive eye contact. After that, I will move a little more confidently, but still with caution. We have all known a situation where a car driver has looked us straight in the eye, and then pulled into our path anyway.

Zaphod's comment about car drivers moving their heads is a good one. Bike magazine did some research a few years ago in collaboration with SafeSpeed which demonstrated exactly this point. Recent car design, and especially the concern for protection in a roll-over accident, has led to the A-pillar of new cars (the one between the windscreen and the front windows) being much thicker than it used to be. This has two important consequences for car/bike interactions:

• The A-pillar is thick enough to represent a bike-length at a distance of about 20m - in other words, at normal traffic separation distances, the bike can be completely hidden behind the pillar, and
• The motion of a car pulling onto a roundabout and the simultaneous motion of a bike going round the roundabout can coincide so that the bike remains hidden for about 50m of travel - long enough for the driver to pull out and hit the bike which he has never seen, despite looking.

The advice that the magazine gave [2] was that drivers should do exactly what Zaphod suggests - look deliberately on both sides of the A-pillar, moving the head to do so. The main check should be round the front of the pillar, to avoid the risk of 'opposite tracking' a vehicle in the blind spot. Bikers can assist the process by being highly visible - high-viz clothing and headlights on dipped beam are the usual suggestions. I'm not a big fan of the high-viz approach, but I can see the logic here. Another thing riders can do (and I can recommend this, as it works) is to change course slightly. This works best if you are approaching a junction on a straight road, with a car waiting to pull out. The small profile of the bike and rider don't give enough information to the driver about approach speed and direction (compared to say a truck, which gets bigger very quickly as it approaches), but the eye is always attracted to something that moves from side to side. Just doing a gentle weave as you approach the junction makes you instantly visible to the driver. (He may just assume you are drunk or out of control, but the end result is the same: he knows you are there.)

Bikers don't want to die, and drivers don't want to kill.

This is spot on, and I am glad for a bit of debate that is co-operative rather than hostile. Car drivers can help by looking out for bikers, and bikers can help by realising that car drivers may not always have seen them for good reasons, and even if they have looked propely and not roar up into people's blind spots and act as if the whole world owes them safe passage.

(The reference to sailors and collision courses is correct, too. If you spot another vessel heading across your course, you take a compass bearing on it. If you take another compass reading in a few minutes and it is the same, then you and the other vessel are on a collision course. One or both of you should take avoiding action.)

[1] A good biking blog. He doesn't post often, but when he does it is always thoughtful and intelligent.

[2] Link to the SafeSpeed website here, which gives screenshots of all of the above, plus artciles by Spen King (designed of the Range Rover) and others, and a general review of the SMIDSY phenomenon. Worth a read.