Making progress

This time I want to ramble about maintaining good progress, which is one of the items the examiner is watching.

• Here are some quotes from the IAM manual Pass Your Advanced Driving Test. Page30: "Bearing in mind road, traffic and weather conditions, do you keep up a reasonable pace and maintain good progress?"
• Page 79: "You will need to show that you can drive briskly and that you are not afraid to cruise at the legal limit when circumstances permit - progress with safety."

This sounds like a good thing to me. For each road situation there is an appropriate maximum speed, sometimes determined by the law and sometimes by road conditions, other traffic or the weather. Making good progress involves both keeping down to this speed and up to this speed. Keeping down to speed is surprisingly difficult: one of the, most important lessons learned on my observed drives has been to look at the instruments, in particular the speedometer, much more often. (And to notice the speed limit signs as they come up, of course!).

There have been occasional embarrassing incidents like accelerating onto a roundabout and glancing at the speedometer, only to find the spoke of the steering wheel obstructing the view of the speed. It is also easy to exceed the limit going down a hill in a 30 m.p.h. zone. I find it a bit stupid to be treading on the foot brake in this situation and much prefer to stay in third gear in towns.

What about the situation of a clear road, good weather and a speed limit? Simple, you say - bring the speedometer needle up to the limit and keep it there. Alas, it is not so simple: a fixed pressure on the accelerator will not result in a constant speed at the road wheels because of hills, gusts of wind, or corners (rounding a corner at a given speed requires more power than the same speed in a straight line). The sound of the engine is related to power rather than speed and is similarly deceiving. There is a limit to the amount of attention you can pay to the speedometer (there are many other things to be looking at, after all) so the compromise appears to be a target slightly below the legal speed limit. Five m.p.h. below is too much, but 2 m.p.h. below should be easy enough to keep to: occasional excesses should still be legal.

Another tip: when accelerating through the gears towards the current limit make the last gear change at least 5 m.p.h. below the limit.

How else can I set about improving progress? The next stage is to review all movements which slow down progress. There is not much one could do do speed up the movement of the steering wheel, though it can always be done more tidily (see previous musing). Changing gear, however, is a different matter. Performed badly, it not only is apt to ruin either the gearbox or the clutch, but also delays progress, as all the time the clutch is disengaged wind resistance is slowing the car down again. It is even worse when starting up a steep hill, when gravity takes over. Speed up the gearchange, I thought, tidy up the coordination with the clutch, and more progress is assured. Not on your Nelson: every time I tried my new improved gearchange technique on my observers they said in unison "You are snatching your gearchanges".

Now this, when you think about it, was a very strange statement. What I was doing was demonstrating that a modern gearbox can be used to change gear rapidly, which is inherently a Good Thing. Why else would a recent BMW advertisement boast that the new assisted manual box could change gear in 250 milliseconds? Those gearchanges were not rushed or snatched or hasty. They were practised, polished and smooth. However, bear in mind, fellow Associates, that your job is to pass the test, and that this involves listening to your observers in silence.

However, in the face of this nonsense, what is a fellow (or lass, for that matter) to do? In desperation what this fellow eventually did in order to slow the gearchange down again was to go back to double-declutching, a technique of relevance only to non-synchromesh gearboxes and therefore dating back to the Ark. It takes a lot longer, and certainly does not count as a snatched gearchange, so it keeps some people happy. To my fellow Associates who have not acquired this peculiar knack I would make this suggestion: watch Damon Hill on a Grand Prix circuit. Not to watch his slick gearchanging, but so that you complete your change only after he has left the pits and is already a quarter of the way round the circuit. The time in between you can spend chanting the mantra "Out of gear is out of control".

Copyright PHP Harris 1999

Chief Observer's reply

There are of course a few points that I should like to pick up on. The first, being the assertion, that it is somehow easier to maintain a speed of 2 mph below the limit than to drive at the limit. This leaves me somewhat bemused, It is far better to develop a feel for what 30 mph feels like, and with practice there should be no need to constantly be checking the speedo. Bear in mind also that in the real world no one is going to be prosecuted for minor excesses. A 10% speedo inaccuracy is and always has been allowed!

The next point is the assertion that it is a good idea to change up at least 5mph below the speed limit. This work for you but is too general for an assertive comment that may be misinterpreted. I can think of some cars, that when going up hill, would, if this were applied be back to the speed of the next lower gear by the time the clutch was back up. This is in fact what I would consider a gear change fault under some circumstances, where the engine had not been allowed to develop sufficient power in one gear before a subsequent one was selected.

Next I move on to gear changes, snatched or otherwise, not every slick gear-change could be classed as snatched. This is only so when the whole thing is messed up by faulty clutch control, combined with a rushed or poorly co-ordinated hand/foot action. Successful gear-changing takes much practice, and there are very few run of the mill drivers out there that can do a good one.
Your comment about double-de-clutching being from the ark and of no value is also way off mark. Firstly in the face of a poor gear changer it is a very successful method of helping to properly time the gear changes. On the Police advanced course it was standard practice for the entire course and I still use it today in some circumstances. Secondly as I think I mentioned in a previous musing reply synchro is a friction device, wear on which can be greatly reduced by adoption of the method. Ask any metro owner about second gear synchro! That said, it is not an essential part of advanced driving. But don't, as they say, knock it till you've tried it?

With regard to having to sit and listen to observers in silence. Don't suffer in silence this is a foolish thing to do. We are all here to learn and it may be that the observer has it wrong also.

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