Implementing system on roundabouts

Implementing system on roundabouts

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Scott OSRS

Original Poster:

31 posts

31 months

Saturday 29th April 2023
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Hello,

I have been struggling with implementing system on roundabouts, so thought I’d ask for advice. I’ve tried to break it down into three examples which cover all the scenarios I’ve been having trouble with.

Example 1:



On approach to the above traffic light controlled roundabout, if the lights are on green I am aiming to be off the brakes about a lorry length away from the give way line to give me time to take the gear, such that I am on the gas as I cross the give way line. The problem I have is that, due to the road bending to the left just before the roundabout, the point at which I am taking the gear I am also having to steer to the left, and I believe gear/steer overlap is against system? Just wondering what the correct method is in this case - should I slow down earlier such that I can come off the brakes and get the gear before the road starts to curve to the left (but this might hold up the traffic behind me on the off-slip), or should I do a planned brake/gear overlap on approach so that I get the gear prior to steering?

Example 2:



If I have understood Reg Local correctly, he advocates only taking the gear when you can see the roundabout is clear to proceed. But some roundabouts, such as the above, jut out to the left just before entry, so sometimes I find the point at which I decide it is safe to go and I can take the gear, is just when I am having to steer to the left, resulting in a gear/steer overlap. In this case should I do a planned brake/gear overlap into eg 2nd on approach so that I have the gear prior to having to steer around the left curve?

Example 3:



Again, regarding Reg Local advocating only taking the gear when you can see it is clear to go: I have found on poorly sighted roundabouts, such as this one, as I only get the view late, by the time I have seen it is clear and gotten the gear/engaged the clutch, I have already coasted across the give way line. This doesn’t feel particularly safe (as eg if someone is speeding towards me from the right, I have no acceleration available to accelerate out of danger). In this case should you do a planned brake/gear overlap into 2nd gear on approach?



Thanks in advance for any help provided, it is much appreciated. smile

Edited by Scott OSRS on Sunday 30th April 10:58

Pica-Pica

13,825 posts

85 months

Saturday 29th April 2023
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It will all depend on the gearbox and engine flexibility, traffic (and pedestrians at the crossing ramp in ex.3). However, I think avoiding a steer/gear overlap is much more important than avoiding a brake/gear overlap.

vonhosen

40,243 posts

218 months

Saturday 29th April 2023
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Think of the roundabout as two separate hazards. (We'll assume for this example you are going ahead at the roundabout).

The give way line is the first hazard.

You should be braking to stop smoothly at the give way line utilising 3 stage braking.
Your plan is to stop at the give way line, but you'll go if it's safe to.
Use stage 1 & 2 brakes to the roundabout (carrying a bit of inertia to the end of stage 2 brakes) & then fractionally ease up on the brakes (stage 3) as you set your steering to the desired course (pull with left hand) for where you want to go into the roundabout.
As you are approaching the give way line you'll get the vision to the right to make your decision.
If there's no gap then you just comfortably stop & get first gear.

If there is a gap in traffic to the right though, then the give way line is no longer a hazard that you need to apply the system to.
You have the vision that tells you that is so, so you can now apply the system to the second hazard, which is the right hand turn to negotiate the roundabout.
So having set the steering for your course into the roundabout, you should be at a correct speed that you can fit an unhurried gear change between the point you release the brake & your arrival at the right steer movement that you need in order to go around the roundabout.
So having set the correct steering amount to enter with a left hand pull, you place your right hand at 12 O'clock on the wheel (ready to pull right) & take the gear as you go over the give way line (which is no longer a hazard), having the clutch up before you steer right on a light throttle.

If you get the speed correct on approach (where you are finishing 2nd stage brakes), it will look like, whether you stop or go, that you always intended to do that, because you'll be at the sweet spot (speed) to do either on approach. Not so fast that you can't stop smoothly & not so slow that you are a sitting duck if you enter into a gap in traffic into the roundabout.

You'll have no brake/gear overlap & no active steering whilst taking the gear either.

Does that make sense?

Scott OSRS

Original Poster:

31 posts

31 months

Sunday 30th April 2023
quotequote all
Thank you for the responses. Makes sense but just wanted to clarify a couple of things:

vonhosen said:
Your plan is to stop at the give way line, but you'll go if it's safe to.
Use stage 1 & 2 brakes to the roundabout (carrying a bit of inertia to the end of stage 2 brakes) & then fractionally ease up on the brakes (stage 3) as you set your steering to the desired course (pull with left hand) for where you want to go into the roundabout.


When you say to carry a bit of inertia after 2nd phase braking, do you mean you should be off the brakes and rolling up to the roundabout at ~10mph to give you time to get the view, and if there is a car coming you re-apply the brakes to stop (but since you are crawling anyway this won’t be a harsh stop). Or do you mean you should be planning to stop at the give way line, but off 2nd phase braking earlier and dragging 3rd phase out longer so that you get time to get the view as you approach (as opposed to firm 2nd phase braking up to near the line and a short 3rd phase, which means you approach at speed and don’t get much time to get the view)?

vonhosen said:
So having set the correct steering amount to enter with a left hand pull, you place your right hand at 12 O'clock on the wheel (ready to pull right) & take the gear as you go over the give way line (which is no longer a hazard), having the clutch up before you steer right on a light throttle.
In the third example, if going straight over the roundabout (2nd exit) you approach the give-way line straight on, but then (assuming straight-lining the roundabout isn’t possible) there is an abrupt need to steer to the left as you cross the line. In that case should you:

A) Overlap the gear change with the braking to avoid having to overlap it with the steering as you cross the line
B) As you cross the line, take the gear with the left hand whilst simultaneously steering left with the right hand
C) Wait until you have the correct amount of left hand steering before taking the gear (but this may mean coasting quite a bit across the roundabout before you are ready to get the gear, and potentially nearly coming to a stop since it is on an uphill slope)?

vonhosen

40,243 posts

218 months

Sunday 30th April 2023
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Scott OSRS said:
Thank you for the responses. Makes sense but just wanted to clarify a couple of things:

vonhosen said:
Your plan is to stop at the give way line, but you'll go if it's safe to.
Use stage 1 & 2 brakes to the roundabout (carrying a bit of inertia to the end of stage 2 brakes) & then fractionally ease up on the brakes (stage 3) as you set your steering to the desired course (pull with left hand) for where you want to go into the roundabout.


When you say to carry a bit of inertia after 2nd phase braking, do you mean you should be off the brakes and rolling up to the roundabout at ~10mph to give you time to get the view, and if there is a car coming you re-apply the brakes to stop (but since you are crawling anyway this won’t be a harsh stop). Or do you mean you should be planning to stop at the give way line, but off 2nd phase braking earlier and dragging 3rd phase out longer so that you get time to get the view as you approach (as opposed to firm 2nd phase braking up to near the line and a short 3rd phase, which means you approach at speed and don’t get much time to get the view)?
The latter.
You want the wheels to be straight when braking firmly (2nd stage) & as you need to steer left into the roundabout you don't want to be braking firmly whilst doing that. So you ease up on the brakes a fraction (NOT releasing & then reapplying) as you steer & look to your right. If there's a space to the right whilst you are doing that, then release the brake & take the gear with the steering set on your path in. If there's no gap stay with the brake stopping at the give way line.

Scott OSRS said:
vonhosen said:
So having set the correct steering amount to enter with a left hand pull, you place your right hand at 12 O'clock on the wheel (ready to pull right) & take the gear as you go over the give way line (which is no longer a hazard), having the clutch up before you steer right on a light throttle.
In the third example, if going straight over the roundabout (2nd exit) you approach the give-way line straight on, but then (assuming straight-lining the roundabout isn’t possible) there is an abrupt need to steer to the left as you cross the line. In that case should you:

A) Overlap the gear change with the braking to avoid having to overlap it with the steering as you cross the line
B) As you cross the line, take the gear with the left hand whilst simultaneously steering left with the right hand
C) Wait until you have the correct amount of left hand steering before taking the gear (but this may mean coasting quite a bit across the roundabout before you are ready to get the gear, and potentially nearly coming to a stop since it is on an uphill slope)?
You get the speed right so you can do as before. Your third picture doesn't look challenging for it.
Set the steering with the left hand, right hand to top of steering wheel, then take gear & clutch up before you steer right on roundabout.
The space required for the gear change dictates the speed you enter.

Scott OSRS

Original Poster:

31 posts

31 months

Monday 8th May 2023
quotequote all
vonhosen said:
The latter.
You want the wheels to be straight when braking firmly (2nd stage) & as you need to steer left into the roundabout you don't want to be braking firmly whilst doing that. So you ease up on the brakes a fraction (NOT releasing & then reapplying) as you steer & look to your right. If there's a space to the right whilst you are doing that, then release the brake & take the gear with the steering set on your path in. If there's no gap stay with the brake stopping at the give way line.


You get the speed right so you can do as before. Your third picture doesn't look challenging for it.
Set the steering with the left hand, right hand to top of steering wheel, then take gear & clutch up before you steer right on roundabout.
The space required for the gear change dictates the speed you enter.
Thanks. I’ve been practicing your technique this past week and it’s starting to feel more natural now.

One thing I’m not certain on is roundabouts where you get a view well in advance that it’s going to be clear to proceed (be that either due to a wide open view on approach, or due it being traffic light controlled and on green). For example if I was going straight across (2nd exit) on the roundabout below, where I can see it is going to be clear to proceed due to the green light, should I still be off the brakes at the give way line, set the steering with my left hand, hold it with right hand whilst getting the gear in time to be clutch up and driving through the right curvature, or do I need to be treating it more like a corner and be off the brakes, gear selected and clutch up before I cross the give way line?

The problem I find when I have been trying the latter is that most roundabouts seem to be double apex bends (gentle initial left curve into it which tightens as you go around), such that you don’t get the view of the limit point moving until you are near the give way line, by which point it is too late to perform a full separation prior to crossing the give way line.



Edited by Scott OSRS on Monday 8th May 11:31

Pica-Pica

13,825 posts

85 months

Monday 8th May 2023
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Scott OSRS said:
… “where I can see it is going to be clear to proceed due to the green light”

Edited by Scott OSRS on Monday 8th May 11:31
Never base it just on the green light, always check right. I’ve seen too many red-light runners.

Scott OSRS

Original Poster:

31 posts

31 months

Monday 8th May 2023
quotequote all
Pica-Pica said:
Never base it just on the green light, always check right. I’ve seen too many red-light runners.
Fair point, that.

vonhosen

40,243 posts

218 months

Monday 8th May 2023
quotequote all
Green light you are still braking & planing to stop at the stop line until 'the point of no return' which if you've got the approach speed right should never result in you contravening a red light. You should still be on the (3rd stage) brakes while you set the steering (left) onto the desired line into the roundabout, then release brakes & take the gear.

Where you have great early vision to the right, your entry speed is limited by the speed you can safely negotiate the right hand turn in the roundabout to go straight ahead & the space you need to take an unhurried gear at that speed (gear still taken between the steering set left & clutch up before you steer right).

Scott OSRS

Original Poster:

31 posts

31 months

Thursday 11th May 2023
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vonhosen said:
Green light you are still braking & planing to stop at the stop line until 'the point of no return' which if you've got the approach speed right should never result in you contravening a red light. You should still be on the (3rd stage) brakes while you set the steering (left) onto the desired line into the roundabout, then release brakes & take the gear.

Where you have great early vision to the right, your entry speed is limited by the speed you can safely negotiate the right hand turn in the roundabout to go straight ahead & the space you need to take an unhurried gear at that speed (gear still taken between the steering set left & clutch up before you steer right).
Thanks. I’ve been practicing your techniques and getting the hang of them now.

I do struggle with the technique on roundabouts where you both get a late view (and so will likely be coasting across the line) and need to steer abruptly left as soon as you cross the line (eg on the roundabout below, you get a late view, and whether going left or right you need to steer abruptly left on entry).

I’ve found on those types of roundabouts I don’t get a chance to take the gear whilst the steering is ‘set’ as you need to steer very abruptly. Additionally, because I am crossing the line slowly due to a late view, if I wait until steering is constant before taking a gear (eg on roundabout below, if going right this would likely entail coasting over line, steering left and then getting the gear before steering right), I am going comically slow to the point where I might stall in 2nd if I don’t slip the clutch and feel like a bit of ‘sitting duck’ in the roundabout.

So I’ve taken to just getting the gear (usually 2nd on these types of roundabouts) as I am on 3rd phase braking in these cases. Maybe with more practice I’ll get more fluid at it and will be able to do it even in those sorts of cases.



Edited by Scott OSRS on Thursday 11th May 23:07

mph999

2,715 posts

221 months

Tuesday 16th May 2023
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Scott OSRS said:
Thanks. I’ve been practicing your techniques and getting the hang of them now.

I do struggle with the technique on roundabouts where you both get a late view (and so will likely be coasting across the line) and need to steer abruptly left as soon as you cross the line (eg on the roundabout below, you get a late view, and whether going left or right you need to steer abruptly left on entry).

I’ve found on those types of roundabouts I don’t get a chance to take the gear whilst the steering is ‘set’ as you need to steer very abruptly. Additionally, because I am crossing the line slowly due to a late view, if I wait until steering is constant before taking a gear (eg on roundabout below, if going right this would likely entail coasting over line, steering left and then getting the gear before steering right), I am going comically slow to the point where I might stall in 2nd if I don’t slip the clutch and feel like a bit of ‘sitting duck’ in the roundabout.

So I’ve taken to just getting the gear (usually 2nd on these types of roundabouts) as I am on 3rd phase braking in these cases. Maybe with more practice I’ll get more fluid at it and will be able to do it even in those sorts of cases.



Edited by Scott OSRS on Thursday 11th May 23:07
For this, I’d get the speed and gear sorted by the giveway line (if you’re not stopping) then all you have to do is steer.

Scott OSRS

Original Poster:

31 posts

31 months

Sunday 28th May 2023
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mph999 said:
For this, I’d get the speed and gear sorted by the giveway line (if you’re not stopping) then all you have to do is steer.
Yes I agree. I’ve been practicing more and I’ve come to realise that with roundabouts like that one, even if you’re going right, the first proper point of steering (ie that which will require pull-push instead of fixed grip) is that abrupt left deviation just beyond the give way, and so I need my gear sorted before then. As opposed to the majority of roundabouts, where if you’re going right you would just need to get your gear before the right turn, as the left offset on entry would negate the need for any abrupt left steering after entry.

PhilAsia

3,822 posts

76 months

Wednesday 14th June 2023
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Scott OSRS said:
mph999 said:
For this, I’d get the speed and gear sorted by the giveway line (if you’re not stopping) then all you have to do is steer.
Yes I agree. I’ve been practicing more and I’ve come to realise that with roundabouts like that one, even if you’re going right, the first proper point of steering (ie that which will require pull-push instead of fixed grip) is that abrupt left deviation just beyond the give way, and so I need my gear sorted before then. As opposed to the majority of roundabouts, where if you’re going right you would just need to get your gear before the right turn, as the left offset on entry would negate the need for any abrupt left steering after entry.
I would also consider pre-position...if you haven't already...