Wide lines, tight lines, right lines - the law of Diminishing Returns
    
When I did the Bikesafe course back in October last year, one of the very few negative comments on the day was the way the police rider out with us held a wide line, out on the white line, round left hand bends even though there was traffic coming the other way.

The argument resurfaces from time to time on Visordown.com as other riders watch a copper doing exactly the same.

One resulting discussion produced some comments that surprised me, the one that caused the most consternation was the suggestion that by keeping wide if a half-second extra view could be obtained, then it was worth it.

The other was that I over-complicate things. Sometimes I wonder if I really AM awkward... and then I remember how many riders are killed in bends...

The crux of the matter was a statement by another instructor:

"There are times when position for view is the last thing (but not 'final') to be considered. Narrow lanes, tight blind corners? Forget 'progress', hug the left verge."

I agreed that seeing the spiky thing that impales you on the front of the tractor a fraction of a second earlier is no use to anyone.

Then up popped a third instructor with:

"seeing something half a second earlier CAN make a differance. What is important is that your speed is right such that you are able to deal with any situations as they occur.

"Very often people are simply carrying too much speed as opposed to being in the wrong position. The 2 combined are a lethal combination, 2mph can be tioo much, just lose it and manage the problem."

This caused me some consternation. I replied:

"There's an inverse relationship between the added time your position gives you and the distance you have to stop/swerve even if you reduce your speed. Diminishing returns..."

The more gentle the left hand bend, the more time you have to see the oncoming car and vice versa and the more confidence I'll have in a wide line being safe. But...

...the problem arises not only on single track lanes but also on a road with two narrow (but still defined by a central line) lanes with a very sharp left kink (not necessarily a right angle, it could be a 45deg elbow) with obscured view (often a building at a "pinch point" - there is a classic example on the A338 north of Wantage) where the oncoming driver will not be seen till the last moment and may be cutting the corner.

In some ways, an "elbow" bend is worse - it positively encourages corner cutting from the opposite direction. So you have to bear in mind the other driver's possible approach to the bend too.

For the moment, let's just take a middle of the lane path and just consider if we can stop - because as we know, we should be able to stop in the distance we can see to be clear. For most drivers and riders, the two second rule isn't actually enough, because they need recognise what they are seeing and then time to think of the correct response. So add another second. That's the kind of view in terms of time that the basic stopping rule would suggest we need to safely negotiate a bend at 30mph.

So, let's find out what distance is involved were we to measure it out. At 30mph, that's 132 feet or 40 metres of distance we need to deal with a STATIONARY object - nearly half the length of a football pitch.

Now consider a vehicle on a collision course - that car that cut the corner. Assuming the driver responds in the same way and stops, and isn't going any faster than us, you've now got 20m to stop from 30mph. It's gonna be tight even if we are already covering the brakes and poised to do an emergency stop! Is the other guy thinking this way?

Unlikely - I can easily work out that other drivers aren't likely to take as much care as me so the chances of meeting someone head on are quite high! There is nothing I can do to manage their speed or course. So it's not a risk I can manage.

Now let's consider the "Health and Safety" type assessment of that risk. If I go round that corner on a line which may conflict with an oncoming car cutting the corner, and the other driver is travelling too fast to stop in his own "clear" distance, and I'm hit, then the implications of a collision and its effect on me are fairly serious.

And there is a further consideration. If we put the brakes on hard in a left hand bend, the bike sits up and goes where? Straight onto the other lane, quite likely into the path of the driver who has swerved to avoid us!
 

So do we have an alternative strategy for getting out of trouble? We could swerve left, couldn't we? Hold onto that thought for a moment.

Let's go back to the view round the corner. What if we can squeeze an extra half second view by moving 2m to the right, by taking a course out by the white line? Well, that gives us an extra 22ft or 7m view. So we each have 3.5m extra to stop or swerve. Stopping is still a no-no in the bend, particularly as you are now even more exposed. Swerving is still probably your best option but now you have to swerve an extra 2m to the left to avoid the car - and only 3.5m in which to do it. And think on this too - is the driver coming the other way more or less likely to panic when he sees a bike in the middle of the road rather than in the centre of the other lane?

So, is half a second really enough time to be useful? The answer to that is a resounding NO!

So any other alternative strategies? If I take a tighter line out of the likely course of anyone cutting the corner, I need to consider that takes me closer to hazards on the left.

Now let's do another risk assessment. First thing I can say is that any hazard on my side of the road isn't likely to be moving at anything like the speed of something on the right - even an emerging car is almost always heading laterally across your path and not towards you - thus any collision is likely to have less serious implications for me. (Compare
the results of "car emerges from left" vs "car turns right across bike's path" type accidents).

What are the additional hazards of moving left? I've can think of a number, but for argument's sake let's consider pedestrians. I can assess the kind of road and the likelihood of coming across a pedestrian. In a touristy area it's quite high. It's a risk I can assess fairly easily. So, I simply adjust my speed so I can stop before I hit a pedestrian or emerging car.

Say I move two metres left and say I lose one second of my three second view, so I can only see 88ft / 27m ahead. If I'm on the ball I can still stop at 30mph!! But because I am a sensible rider, I take 10mph off the speed. I'm now well ahead of the game and can stop easily should I meet a pedestrian or emerging car.

Is that not an advantage? So is not the tighter line safer to the point where there is relatively little risk of any collision at all?

Have I not eliminated a big risk I can't control (ie - the oncoming car that can't avoid me) and substitued a smaller risk I can do more to control by my own actions (ie - avoiding running over a pedestrian)?

And one final point. For how LONG in real terms are we going slower? A couple of seconds in the tightest part of the bend? Is it going to materially affect our journey time?

I'm not saying that you should take a tight line on all bends, as the proponent of the half-second extra view seemed to think, but that we question where we can position to advantage and use the extra view and when it's time to change your line when faced with a hazard.

Sometimes we need to sacrifice position and view simply to be in a safer place per se. What we have to work out is where the crossover is from advantage to risk. I know we are talking about narrow roads, tight turns, very restricted views which are at one extreme of a continuum with wide sweepers at the other end, and most riders rarely venture onto those kind of roads, but I do quite a lot and I see some crazy lines.

The conclusion I draw from this says to me that post test training doesn't emphasise the risks enough - after all we can only know what is good and bad when we know the risks as well as the advantages, and I think we are too much concerned about "advantage" and "progress".

I know I haven't persuaded the other instructor, and he certainly hasn't changed my mind, but to my mind the important thing is that the debate opens up the issue to people who use wide lines but may not have thought about the special problems of tight bends, and to those who may not have used wide positioning in the past thus giving them a chance to see the advantages. And it was noticable that the non-expert opinion was with the tighter line.

Give them the information, let them make their own informed choice.