ADUK Archive

What is the current view on making progress whilst driving and undue hesitance.

It seems to me that perhaps that minor hesitation and making progress are not as high priorty as they were when I passed my car test, perhaps more so when road safety takes over where there is probably more of an emphasis now on that than when I passed.

I however also imagine that these issues are looked at more in Advanced driving than DSA tests.

Von sums it up nicely with the 4 S's...

Four S's in order of importance.

Safety
System
Smoothness
Speed (aka Progress)

On an advanced test, you'll be expected to make progress up to the speed limit, where it is safe to do so.

Chris

ScoobyChris wrote:On an advanced test, you'll be expected to make progress up to the speed limit, where it is safe to do so.

As you would on a DSA test.

fungus wrote:

ScoobyChris wrote:On an advanced test, you'll be expected to make progress up to the speed limit, where it is safe to do so.

As you would on a DSA test.

mmmm well yes but bearing in mind many DSA L-tests stick to 20/30/40 limits I really don't think it's as critical. We have an IAM examiner that will mark an associate down if they do 55 in a 60 for lack of progress. I think it also important to use 'brisk acceleration' when appropriate rather than drifting up to the limit eventually.

martine wrote: I think it also important to use 'brisk acceleration' when appropriate rather than drifting up to the limit eventually.

Providing that the Brisk Acceleration is smooth.

How does Brisk Acceleration fare for Economy?

But what about hesitation and progress at junctions, I like to take a few extra minutes to look and look again before pulling out checking for solos whether and vehicles overtaking.

Im also not very good at judging speed of other vehicles which doesnt help and need a few extra minutes to think.

foxtrot_mike wrote:How does Brisk Acceleration fare for Economy?

Haven't we done this before? It's braking that wastes fuel, not acceleration.

foxtrot_mike wrote:But what about hesitation and progress at junctions, I like to take a few extra minutes to look and look again before pulling out checking for solos whether and vehicles overtaking.

Im also not very good at judging speed of other vehicles which doesnt help and need a few extra minutes to think.

Do you really mean minutes? The examiners are looking to see you "make progress when safe to do so" and if you're hesitating at junctions where an examiner would have expected a quicker decision, you may be marked down. I notice you're an IAM associate - has your observer commented on this?

Chris

ScoobyChris wrote:

foxtrot_mike wrote:But what about hesitation and progress at junctions, I like to take a few extra minutes to look and look again before pulling out checking for solos whether and vehicles overtaking.

Im also not very good at judging speed of other vehicles which doesnt help and need a few extra minutes to think.

Do you really mean minutes? The examiners are looking to see you "make progress when safe to do so" and if you're hesitating at junctions where an examiner would have expected a quicker decision, you may be marked down. I notice you're an IAM associate - has your observer commented on this?

Chris

I never got marked down on my D1 test for it, I haven't started my observed runs yet but Im trying to to a bit of self study and evaluation before I do.

jont wrote:

foxtrot_mike wrote:How does Brisk Acceleration fare for Economy?

Haven't we done this before? It's braking that wastes fuel, not acceleration.

Brisk acceleration OR economic acceleration - the two are different

It depends what is apropriate for a driver to do or demonstrate (if on a demo/test) in a particular situation

I can turn left from a 30 road onto a 40 road at say 20 and use 2nd gear to get to 40 when I will then select 5th gear for brisk progressive acceleration followed by cruising
OR
I can turn left from a 30 road onto a 40 road at say 20 and use 3rd to 30, 4th to 40 and then cruise in 5th for economy - all done with very light acceleration

4th will be selected instead of 5th if accelerator sense is required at 40 in both cases

ROG wrote:Brisk acceleration OR economic acceleration - the two are different

I think the point Jon was making is that the fuel required to get to a speed is similar regardless of how you get there and that you won't use any more fuel getting there briskly (thirsty but for short period) than doing it slowly (less thirsty but over a significantly longer period). One of the manufacturers (Vauxhall?) published a study a few years ago but I'm struggling to find a link to it.

Economy basically boils down to braking because every time you press the brake pedal you have "wasted" the fuel you used to get up to speed.

Chris

foxtrot_mike wrote:I never got marked down on my D1 test for it, I haven't started my observed runs yet but Im trying to to a bit of self study and evaluation before I do.

It may be that you are worrying unduly about hesitation then, but something I'm sure your observer will help you with. Likewise with judging speed of approaching vehicles.

Chris

ScoobyChris wrote:Economy basically boils down to braking because every time you press the brake pedal you have "wasted" the fuel you used to get up to speed.

And wind resistance because, in broad terms, the faster your cruising speed the more fuel you use.

foxtrot_mike wrote:How does Brisk Acceleration fare for Economy?

I don't care about economy as such...it's not an important part of what I call 'advanced driving' but does improve as a side effect of good planning, using acceleration sense, not going down through the gears etc.

Even on the IAM test sheet eco-driving is not something you can fail on...the check box is there to give something else for the examiner to comment on (and satisfy the DSA).

ScoobyChris wrote:

ROG wrote:Brisk acceleration OR economic acceleration - the two are different

Economy basically boils down to braking because every time you press the brake pedal you have "wasted" the fuel you used to get up to speed.

It's not only that. Also the way you accelerate matters. According to eco-driving principles, the most economical way to accelerate is to use low revs (up to 2000/2500 rpm in diesel and petrol respectively) but full throttle. If you use high revs or open the throttle only partially then the fuel is not used as efficiently as it could. Of course the optimal revs differ in various engines, but if one uses these rules, they will work reasonably well in any car.

Of course maintaining a constant speed thanks to anticipation and and avoiding unnecessary braking are the most important things, as you said. Another important thing for economy is using engine braking when it is safe and practical (non-Roadcraft way, I know!).