Gears at Junctions

Author
Discussion

foxtrotmike

Original Poster:

26 posts

118 months

Thursday 3rd July 2014
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I have just completed a set of refresher runs with my IAM group and one of the main issues that came up, and never could really get my head around is use of gears at Give way Junctions.

The Observer was happy in general with my drive overall from day one and we were just applying polish, gear selection was good but could be better if you see what i mean.

When approaching a junction thats blind or perhaps on an upward hill he asked me to select 1st, in the past I have aimed for 2nd and has generally ok, but did agree with him that use of first would of given better control, the other aim was to ensure that my clutch is up and in the right gear before crossing the give way line (assuming i haven't stopped).

Now to get into 1st Gear in this scenario i have to slow loads more before the junction, this seems to hinder progress but pays off with better control.

The problem seems to be that my box wont let me into 1st unless im doing 12mph or less (10 mph comfortably) and therefore It just seems impossible to achieve all this together, whilst achieving brake gear separation, make sensible progress and avoid double gear selection and double braking at junctions.

But i must say that at some very busy junctions it has paid dividends as I have been able to get out quickly.

Any assistance gratefully received.


SK425

1,034 posts

148 months

Thursday 3rd July 2014
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I found that double declutching allowed me to change into lower gears at higher speeds than I'd previously been able to smoothly. If you feel that you would like to be able to use 1st gear for these situations, maybe DDC could help the gear change happen at the time and speed you want for the whole thing to flow better.

Also, if you're worried about double gear selection and double braking because you want to think in terms of one braking phase and one gear selection per hazard, could you consider any of these junctions as two hazards? The first hazard being some aspect of the approach (e.g. the uphill-ness) requiring a change down to 2nd, and the second hazard being emerging from the junction itself, requiring 1st gear.

james_gt3rs

4,816 posts

190 months

Thursday 3rd July 2014
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I had this same problem! I learnt to double declutch, and it's quite easy for this situation as you are at low speed and no need to brake.

foxtrotmike

Original Poster:

26 posts

118 months

Thursday 3rd July 2014
quotequote all
So does that mean i can shift into 1st at a higher speed, ie say 20mph?

omegac

358 posts

218 months

Thursday 3rd July 2014
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foxtrotmike said:
Now to get into 1st Gear in this scenario i have to slow loads more before the junction, this seems to hinder progress but pays off with better control.
As it should if you work to the four S's, safe/system/smooth/speed...
foxtrotmike said:
The problem seems to be that my box wont let me into 1st unless im doing 12mph or less (10 mph comfortably) and therefore It just seems impossible to achieve all this together, whilst achieving brake gear separation, make sensible progress and avoid double gear selection and double braking at junctions.
At a junction with limited visibility i.e. where you need 10mph or below you're not looking for brake/gear separation. Don't be too rigid with the system.

Edited by omegac on Thursday 3rd July 15:10

SK425

1,034 posts

148 months

Thursday 3rd July 2014
quotequote all
foxtrotmike said:
So does that mean i can shift into 1st at a higher speed, ie say 20mph?
Should do. You obviously can't change down at a speed that's too high for the rev red line in the new gear, but I bet your car can do more than 20mph in 1st.

p1esk

4,914 posts

195 months

Thursday 3rd July 2014
quotequote all
SK425 said:
I found that double declutching allowed me to change into lower gears at higher speeds than I'd previously been able to smoothly. If you feel that you would like to be able to use 1st gear for these situations, maybe DDC could help the gear change happen at the time and speed you want for the whole thing to flow better.

Also, if you're worried about double gear selection and double braking because you want to think in terms of one braking phase and one gear selection per hazard, could you consider any of these junctions as two hazards? The first hazard being some aspect of the approach (e.g. the uphill-ness) requiring a change down to 2nd, and the second hazard being emerging from the junction itself, requiring 1st gear.
IMHO the feeling (that some people appear to have) that we're only 'allowed' one brake application and one gearchange on the approach to a hazard, seems to cause a quite unnecessary amount of agonising, and I wouldn't bother about it.

If we're reasonably versatile and reliable in our use of brakes and gears, why worry about it?

Honestly, the amount of fuss that's made about doing things in a particular way in order to be recognised as being 'advanced', seems to me somewhat excessive in relation the actual benefits.

omegac

358 posts

218 months

Thursday 3rd July 2014
quotequote all
p1esk said:
IMHO the feeling (that some people appear to have) that we're only 'allowed' one brake application and one gearchange on the approach to a hazard, seems to cause a quite unnecessary amount of agonising, and I wouldn't bother about it.

If we're reasonably versatile and reliable in our use of brakes and gears, why worry about it?

Honestly, the amount of fuss that's made about doing things in a particular way in order to be recognised as being 'advanced', seems to me somewhat excessive in relation the actual benefits.
You're right, it shows how outdated some elements are, i.e. try and come to a stop in a diesel from a high gear without dipping the clutch earlier than used to be acceptable when all we had were petrol cars on courses.

foxtrotmike

Original Poster:

26 posts

118 months

Thursday 3rd July 2014
quotequote all
omegac said:
You're right, it shows how outdated some elements are, i.e. try and come to a stop in a diesel from a high gear without dipping the clutch earlier than used to be acceptable when all we had were petrol cars on courses.
And it also seems, and proves your point that to Double De-Clutch is very outdated

Sometimes I think that the 2nd gear in my car is quite versatile and ideal for most applications I currently wonder what the real pay back is.

SK425

1,034 posts

148 months

Thursday 3rd July 2014
quotequote all
p1esk said:
SK425 said:
I found that double declutching allowed me to change into lower gears at higher speeds than I'd previously been able to smoothly. If you feel that you would like to be able to use 1st gear for these situations, maybe DDC could help the gear change happen at the time and speed you want for the whole thing to flow better.

Also, if you're worried about double gear selection and double braking because you want to think in terms of one braking phase and one gear selection per hazard, could you consider any of these junctions as two hazards? The first hazard being some aspect of the approach (e.g. the uphill-ness) requiring a change down to 2nd, and the second hazard being emerging from the junction itself, requiring 1st gear.
IMHO the feeling (that some people appear to have) that we're only 'allowed' one brake application and one gearchange on the approach to a hazard, seems to cause a quite unnecessary amount of agonising, and I wouldn't bother about it.

If we're reasonably versatile and reliable in our use of brakes and gears, why worry about it?

Honestly, the amount of fuss that's made about doing things in a particular way in order to be recognised as being 'advanced', seems to me somewhat excessive in relation the actual benefits.
I quite agree. I got the impression that the OP wanted to think in terms of a single braking phase and single gear change. I think he's just as entitled to use that model if that's what works for him as anyone else is entitled to not use that model if it doesn't work for them. I don't think he should feel constrained to use it when it doesn't work for him though.

SK425

1,034 posts

148 months

Thursday 3rd July 2014
quotequote all
foxtrotmike said:
And it also seems, and proves your point that to Double De-Clutch is very outdated

Sometimes I think that the 2nd gear in my car is quite versatile and ideal for most applications I currently wonder what the real pay back is.
You mentioned a couple of things (control and being able to get moving more quickly) that you perceived as benefits from using 1st gear. Was there a cost somewhere that outweighed the benefits?

foxtrotmike

Original Poster:

26 posts

118 months

Thursday 3rd July 2014
quotequote all
SK425 said:
You mentioned a couple of things (control and being able to get moving more quickly) that you perceived as benefits from using 1st gear. Was there a cost somewhere that outweighed the benefits?
To be honest I haven't realised any benefit or cost of changing the method yet but im keen to try it even though its not been sold to me yet.

The cost though as i see it at the moment is the fact of potentially 2 brake and 2 gear shift applications before the junction and the earlier brake and slower approach which is perceived to be hindering progress.

That said the desire to have the clutch up and settled before passing the give way line actually seems more beneficial to me at this moment in time.

R_U_LOCAL

2,676 posts

207 months

Thursday 3rd July 2014
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The technically correct answer to this question starts by recognising that every junction is different - they have different views on approach, different views at the give way line, different angles of approach, different gradients up or down etc. in other words, your plan on approach needs to be flexible in relation to a multitude of different factors. On that basis alone, approaching junctions with a plan to always change down to 1st limits your options and rigidly sets the gear phase in your mind, meaning that your plan is based more on what you think your observer or examiner is looking for, rather than what may actually be appropriate to the junction and traffic conditions.

The next thing to bear in mind is that the information phase runs throughout the system. Remember this?...



One of the reasons that information is displayed as a continuously enveloping phase is that the information available to the driver changes all the time. Approaching some junctions from a distance, you may have a good extended view across fields into the road that you plan to join, but get closer to the junction and you may lose that view due to trees and hedges at the junction itself. Conversely, a building line may seriously hinder your view on the approach to a junction, but your view may open up nicely as you get closer to the give way line.

So a rigid plan to change down to 1st every time sets in stone the speed phase, where, in reality you should keep a flexible mindset, and be ready to move from speed phase to gear phase whenever you are certain that it is safe to emerge from the junction. Sometimes this decision can only be made after stopping, looking carefully, creeping forward in first gear and even winding down the windows to listen for traffic. On other occasions, it may be perfectly safe and appropriate to emerge at 20 or 30mph in 2nd or 3rd (although I do appreciate that the OP specifically made reference to blind and uphill junctions).

So, you're on test and the examiner is a real stickler for roadcraft system. What to do? Well, they will be looking for good application of system, but they will also be looking for good planning, which requires the flexible approach described above. Ideally, once you reach the speed phase, you'll remain in the gear you've been driving along in, lift off the accelerator, start braking, press the clutch if the engine drops to idle speed, and stay on the brakes until you have the view and it is clear to go. As the OP mentioned, you should aim to have the gear engaged and the clutch released before you cross the give way line, otherwise the stickler examiner will consider your application of system to be late. The choice of gear is entirely dependent on what speed you are travelling at at the time you decide it is safe to go. The key is to choose the most flexible gear for the speed - i.e. the one which will allow you to accelerate away without either bogging the engine down, or revving it too highly.

In the case of a particularly awkward junction - say, one with a steep uphill approach and a very limited view - you should still aim to use the same technique, but treat the hill as a seperate hazard first, which may well require a change down to a lower gear on approach. That lower gear will give you the flexibility to time your approach and mostly use the hill and acceleration sense to reduce your speed on the approach to the junction. With a little practice, you should be able to time your approach so that you should only need a small amount of brakes right at the junction if you need to stop.

This won't always be the case though, and if you are slightly out with your timing, you may find that momentum alone will not get you right to the junction. In ths situation, there is no other option other than to change down to a lower gear to get you to the junction. Even in the eyes of our stickler examiner, this isn't really a problem - its perfectly acceptable to drop back from whatever phase you're on to the earlier phases if information changes (which, in essence it has - the hill was perhaps steeper or longer than you first thought). A quick consideration for position, speed is already correct, select a geat to get you to the junction, then look for the view. No biggy in the eyes of even the most critical examiner.

Just rememberr that correct gear selection is mostly dependant on the speed of the car, which will be different at every junction, so you must remain flexible in your planning.

foxtrotmike

Original Poster:

26 posts

118 months

Thursday 3rd July 2014
quotequote all
The more i think about this the more i think my gear choice is generally ok, i just maybe late in applying the system meaning the clutch is not up before passing give way, and i think im going to focus on this part of if before thinking again about gear choice, i may kill birds with one stone anyway.

Its useful to know that perhaps if i need to apply a first gear that the junction would require a double phase, and of course in queuing traffic at a junction that would be classed as two hazards and hence two applications of the system.

R_U_LOCAL

2,676 posts

207 months

Thursday 3rd July 2014
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I'm putting together a post on emergency response driving at the moment. Although that may seem hugely irrelevant to the point being discussed in this thread, its not. For many police students, this was the point at which roadcraft system would suddenly make complete sense. Staying on the brakes, waiting until an overtaking opportunity arises, or until traffic clears a junction and then taking the appropriate gear to make progress seemed to come more naturally even to those drivers who had, until that point, struggled with system.

Have a read when I post it - probably in the next week or so - and it may add some context.

MagicalTrevor

6,476 posts

228 months

Thursday 3rd July 2014
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I don't really understand why you'd double de-clutch? Why not just rev match? What are you gaining from DDC when you have a synchronised gearbox?

davepoth

29,395 posts

198 months

Thursday 3rd July 2014
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MagicalTrevor said:
I don't really understand why you'd double de-clutch? Why not just rev match? What are you gaining from DDC when you have a synchronised gearbox?
Changing into first is the hardest job the synchros have to do - the biggest torque ratio, and usually the largest mismatch between engine and shaft speed. DDC in that situation really does make the shift down a lot smoother; in fact since learning to DDC properly I shift down into first quite a lot in traffic where I would have trickled along in 2nd previously. It's another tool that's nice to have.

SK425

1,034 posts

148 months

Thursday 3rd July 2014
quotequote all
MagicalTrevor said:
I don't really understand why you'd double de-clutch? Why not just rev match? What are you gaining from DDC when you have a synchronised gearbox?
What davepoth said. It's a separate issue from what you're trying to do with rev matching.

That said, DDC can also help with rev matching, as you get some confirmation (or not) of whether you've raised the revs to the right level as you move the gear lever into the new position hoping to feel little or no resistance. I find there are times when I can change gear quicker double declutching than single.

omegac

358 posts

218 months

Friday 4th July 2014
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DDC isn't needed anymore, if you need to match engine speed to road speed, depress clutch and rev whilst it's depressed. Does any school still teach DDC?

SK425

1,034 posts

148 months

Friday 4th July 2014
quotequote all
omegac said:
DDC isn't needed anymore, if you need to match engine speed to road speed, depress clutch and rev whilst it's depressed. Does any school still teach DDC?
DDC does a different thing to matching engine speed and road speed (although as I said, when I've revved with the clutch depressed, I find it can sometimes help tell me whether I've revved the right amount or not before re-engaging the clutch and finding out the hard way).

Needed? Perhaps not in the sense that driving schools, I am sure, rarely if ever teach it. But then the OP is probably not the first person to come out of a driving school thinking that he needs to be going much slower than he really does to be able to change into 1st easily. In fact I know he's at least the second person as I had the same problem smile. I don't care how many driving schools teach it though. The fact is that DDC allows me to do things better than I could without it sometimes. That's enough for me.