Safe Speed Forums

Hi Folks,

At work I've entered a competition about driving - as a consequence on Friday I spent an hour with an ADI to assess my driving. I also managed to pick up a few useful nuggets of information..

Firstly the bad :-

Steering: When I'm at junctions (and pretty much only then) I tend to use the hand-over-hand technique (I had warned him in advance that I did this). However in a modern car this is bad because of the airbag in the middle - if it deploys while there is an arm across the steering wheel a broken nose may be the result. This is made worse (for me) because a large percentage of accidents happen at junctions (and this is where I mainly do hand-over-hand). Feeding the wheel means there are no obstructions when the airbag deploys.

Road Position: Apparently I tend to hug the inside lines of bends (didn't realise I did this) whereas it's better to be on the left-hand side of the road on a right-hand bend and vice-versa (allows you to see further around the bend, and other cars to also see you earlier).

Other than that he seemed reasonably impressed - and suggested getting Roadcraft and brushing up if I want to take things further.

Some other useful nuggets of info:-

When in urban areas you should try to keep the engine between 2000-3000rpm as this allows good response for acceleration, and also good engine braking when you lift off. This can make a difference if you have to perform an emergency stop, for example. However in my car this means that at 30mph 4th gear is too high, whereas 3rd gear is about right (different to when I was taught). He also said I may be suprised about the difference in fuel consumption - as the accelerator is barely open it may even be more economical.

According to the Highway code, at 70mph it takes 315 feet (~96 metres) to stop. The white posts alongside the hard shoulder are every 100 metres along the road, therefore you have a handy rough guide to the stopping distance.

If you are driving at the same speed as another car (e.g. on a 40mph dual carriageway towards a roundabout) try not to sit exactly alongside, drop back to be level with their bumper (safer, and appears less aggressive).

Overall I found it a good experience, since passing my driving test (13-and-a-bit years ago) this is the first time anyone with a critical eye has commented about my driving, I definitely recommend it.

Cheers - Matt.

That doesn't seem right. The accelerator is more likely to be 'barely open' in 4th than in 3rd, surely?

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-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

I've just quoted (pretty much verbatim) as he said it, though I must admit I thought it sounded a bit odd myself. However it is true that the accelerator is still "barely open" in 3rd at 30mph (in my car).

Perhaps this is another common assumption - similar to "slower = safer", maybe "lower revs = more economical" may actually be untrue?
I'm going to monitor things and see if I notice anything (good or bad)..

Matt.

It's certainly important not to sit alongside - to do so reduces everyone's margin for error.

But this specific position (as described) isn't right either. We need to adopt a position where we will be visible in the other vehicle's mirrors too. In most cases, the "level with the rear bumper" position will be in the other vehicle's blind spot. I'd recommend about 1 car's length further back.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Point taken Paul - I now wonder if he was commenting about a better position for the actual situation we were in (rather than a rule of thumb). If I'd dropped back a further car length I'd probably have then been level with the next car back..

I also wonder if the 2nd mirror on the inside of the Windscreen for the hour affected what the Jag driver thought - he came alongside a car doing the speed limit , with 2 mirrors and 2 burly blokes in the front, maybe that's why he suddenly lost the will to overtake..

Matt.

Ah yes, that's true - if your revs are too low, then it's less efficient. I remember reading in both mine and my dad's car handbook (both Vauxhalls) that the engine operated most efficiently between 2 and 3krpm. I tend to use 3rd for 30s in the Corsa as it can't really cope with it in 4th, starts stuttering at the mere sight of a hill - plus it gives some good acceleration coming out of towns, can get up to 50 (in 3rd) not too shabbily - avoids annoying people behind!

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-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

It's certainly the case in my car. At 30 in 4th the engine is barely above idling speed, and it makes practically no difference if I press the pedal halfway to the floor. Even 3rd gear is a bit too high for 30, so I tend to drive in 2nd gear - at 2000rpm I'm barely touching the pedal, and I've got a lot of instant response if I need it.

Oops, another point I didn't notice.



Ah-ha! I'd never really understood the reason for push-pull being so strongly suggested. This certainly makes sense. However, does that mean that other steering techniques are acceptable in a car that has no airbag!? Guess it's a good idea to get into the habit anyway, as everyone will surely drive an airbagged car at some point. Can't remember if my instructor's was - I guess it must have been though, it was fairly new.

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-mike[F]
Caught in the rush of the crowd, lost in a wall of sound..

Tend to use the classic pull-push myself as it makes for better overall smoothness and control. Would use rotational in very slow and very high speed manoeuvres.

Gears? Advisable to know the manufacturer's peak engine performance recommendations for your car, listen to the engine - that gives clues as to whether or not you are in correct gear for the road speed- and know the approximate max road speed for each gear. You can wreck the engine by over accelerating in low gear, burn fuel, and even cause misfire or engine cut-out.

My rule of thumb -select lower gear at low speeds, going up a hill, going down a hill (assists braking and jolly useful in scamera land! ), on approach to any hazard, on sliipery roads (helps avoid a skid!)

Third gear, though, is great for town work and negotiating those little hazards otherwise know as people, pelicans, zebra crossing, j-walkers, children, speed cameras..... You can decelerate for numpty in good time .Also means you can accelerate more smoothly and efficiently when road conditions allow you to. Most modern cars appear to be quite happy to trundle around town in third - because at 26-27mph (which is the speed you are probably doing - even though your speedo reads 30 (Yup - have b2s and a Road Angel in my own private cars ) - engine would not be over-revving. Depnds on make and model. You should know and understand your vehicle. If on straight hazard free 30mph - then fourth gear copes very well for 30mph cruise! Top gear produces the speed - but not the power!

As for the advice about dropping back to someone's rear bumper instead of driving alongside. I would make sure I would not be in blind spot just the same. Similarly if I were the next car back and in danger of being "neck and neck" - again I would drop back and give space. But then - not an ideal world - and all the more reason for those assessments with a smuch more stringently trained ADI!

Really? And how does the engine know which gear you are in?

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

Since they were suggesting pull-push long before air bags, there has to be another reason.

I think the true benefit of pull-push is that it's slow. Because it's slow, it forced us all to look a few tenths of a second further ahead when we were learning to drive. The way things turn out, that's a massive benefit and is a significant small component of our having the safest roads in the world. Yes. Really.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

When it screams for mercy!

The one I blew up that way obviously did! It was a track day - and Cousin WildCat and the rest of the girlies have never let me live it down! It was - um - their car I blew up (an old Triumph Toledo - in which Wildcat and her sister had replaced the old standard engine with a really sports car engine -I was testing WildCat's servicing. Still say she got it wrong - but then again wimmin

Only cars I've wrecked on the job - were done intentionally!

But anyways - this is what they tell us on retraining days anyway!

Well, of course you could always try downshifting to second at 95mph, but I wouldn't describe that as over accelerating... over revving perhaps!



Ahhh Rovers.



Certainly exceeding the rev limit is dangerous to the engine, and in a track situation downshifting at too high a road speed is a common problem, AND the rev limiter won't save you.

Then it's true that the drive train will be subject to around double the max torque in first compared to any other gear. (And that's before crank/flywheel inertia gets added to the equation by clutch dumping antics.)

But the engine still doesn't know what gear you're in when you accelerate.

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Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

A few months ago, the IAM put out a press release advocating using 3rd gear in 30 limits, which made a valid point, but to my mind took too much of a one size fits all approach. As you say, it depends both on the gearing of the car and the road conditions. As with many things, common sense and mechanical sympathy are better guides than hard-and-fast rules.

http://www.iam.org.uk/Pressroom/News_Re ... nr0326.pdf

I have driven some cars, diesels in particular, that would not be happy at all in 4th at 30, but in my experience most smaller petrol engined cars will cruise comfortably in 4th at 30 at around 1800 rpm, and in 3rd feel as though they're asking for an upchange.

If you're in a hazard-rich environment such as a shopping area or minor residential road with parked cars, where in practice much of the time you're likely to be doing below 30, and may need to lose speed rapidly, it makes sense to stay in 3rd for the greater flexibility. However, if you're on a suburban main road where smooth cruising is possible, then 4th may well be a better option. Also, realistically, in the latter situation, most drivers are likely to be doing somewhat more than 30 in free-flowing conditions - cruising speeds of an indicated 35-38 are more typical.

Regards,

Peter

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Problem with airbags.
Listening to early morning radio 2, the story went, stood in traffic, was watching a truck driver next to me, playing the steering wheel bongo's, can't have been what I was listening to, he must have hit a hard note and his airbag went off, the look on his face was magical

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Semper in excreta, nur quantitat variat.

The push-pull was around a long time before airbags. AFAICT on the race track, push-pull steering is verboten ("I don't want to see any of that BSM-shuffle!" - Race-driving instructor in an edition of 5th Gear)

I've long suspected that push-pull is drummed into you to give police pursuit drivers a better chance in a chase! However, there are times when you need more lock than you can get without letting go with at least one hand.

Also on the subject of steering, if you're travelling on a rough road it is a good idea to get your thumbs out of the wheel because a "kick" in the steering could break your thumbs if you don't.

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Will

True! On race track - they use Fixed Input Steering. You get early "feel" as to onset of skid etc. Relaxed grip and gently close ring around steering wheel with thumb and forefinger (or around the 9& 3 o'clock spokes) This is OK for race and circuit tracks - but don't use in rallies - as Will says - you could break your thumbs from kick-back on the wheel on the rough surfaces. If bend gets tight - revert to pull-push. (WildCat's family introduced me to all this - racing family!)