I tried but

[plumber]

I have always found overlapping to be smooth safe and simple and seperation as being awkward. I was overjoyed at Chris Gilberts defense of BGOL in his second DVD which was rational, considered and one to which I fully agreed. After much protestation within my local IAM group I have been urged to actively practice separation (for my fifth year)because apparently I do not understand.

I almost came unstuck last Thursday night. I was driving along the A57 through Rainhill Village toward Liverpool intending to turn right into a street which forms a cross road with one on the left which had a car stopped, waiting and indicating for an opportunity to turn right across me. I had no traffic coming toward me nor anything in the street to my right. With this opportunity I planned to brake to around 2nd gear and get off the brake by the start of the mouth of the right turn. As I came to the gear change the car in View road shot out into my path. Having anticipated this I stopped and he drove past me with a hand of apology.

I was shaken and livid but my wife, also an IAM member, concluded that separation communicated indecisiveness and the driver had misunderstood my actions as slowing/stopping to let him out. The obvious look of shock and his apology led me to agree with that sentiment

to Purist Seperators I doubtless made a huge mistake but am at a loss as to what

[martine]

I sympathise. I passed my advanced test, Observer test and Senior Obs test all with overlapping - so I really wouldn't get too hung up about it. There are some purists, as you call them, that practice complete seperation but I am happy to do what most would call "partial overlap'. If you don't know, this is where you might be on the brakes during the gear change but by the time the clutch needs to come up, you're off the brakes - thus allowing rev-matching etc.

For me, I feel with partial overlap, the approach to junctions is smoother without upsetting those around (as you experienced). It might be sloppy in some people's eyes.

[irf520]

Yes, I have experienced this as well. If you slow down well before the junction to avoid overlap, other drivers think you are letting them go first.

'The System' doesn't prescribe separation 100% of the time. This situation is one of the times where an overlap would be acceptable - it's explicitly described in Roadcraft (page 69 of mine, which is the 2010 print). If there are other drivers around who could be misled by your slowing down early, then plan to overlap, otherwise separate.

[jcochrane]

I sympathise. I passed my advanced test, Observer test and Senior Obs test all with overlapping - so I really wouldn't get too hung up about it. There are some purists, as you call them, that practice complete seperation but I am happy to do what most would call "partial overlap'. If you don't know, this is where you might be on the brakes during the gear change but by the time the clutch needs to come up, you're off the brakes - thus allowing rev-matching etc.

For me, I feel with partial overlap, the approach to junctions is smoother without upsetting those around (as you experienced). It might be sloppy in some people's eyes.

I would agree with you Martin, partial overlap, as you describe, is usually far smoother and blends in better and seamlessly. Apart from the benefit in training to get people to slow down more and earlier I can see little advantage to it. The usual argument I hear for full separation is for rev matching but as you rightly point out it is quite possible during partial overlap. It is easier and quicker to teach full separation than partial and I sometimes wonder if this has an influence on promoting it?

[Gareth]

I planned to brake to around 2nd gear and get off the brake by the start of the mouth of the right turn. As I came to the gear change the car in View road shot out into my path.

One aim of separating the braking from the gear change is to simplify what you're doing as you approach the turning, at the time when most of your attention ought to be aimed at other road users. Until you master it, though, this aim won't be met.

To completely separate and still get the gear change in before starting to turn, you need to have completed the braking earlier than if you are doing a partial separation. This doesn't mean you must take a long time over the braking; if you feel it would be to your advantage you can make the braking quite firm. If you do this you'll be less likely to give the impression of being indecisive.

It's very important to be in a flexible gear before you start braking, especially so in a car with a diesel engine. You should be doing this anyway, as a matter of course. If you are not, perhaps for reasons of economy, you really ought to consider returning to a flexible gear before you run though the sequence for approaching a hazard.

For me, in our cars, flexible means using either 2nd or 3rd gear in a 30 mph limit. One reason this is trickier in cars with diesel engines is that the engine management works to keep the engine turning if it drops much below the idle speed, and the gearing is such that this is likely to happen if the engine is already turning slowly before you start to brake on approach.

A related issue may be the speed at which you change gear. If you properly rev-match, the gear change can be very quick indeed and still completely smooth. I only mention this because some people take an excessively long time to change gears in an attempt to make their gear changes smoother. This isn't a good idea, and definitely not when other road users may see it as indecisive.

In order to make an informed decision about whether complete separation holds any benefits for you, the technique will need to be mastered in situations where there won't be any conflict with other road users. Once you have mastered it, you may decide that you will do a partial overlap to avoid slowing away from hazards when it might mislead other road users, and completely separate at other times.

The advantage of partial overlap is that you can complete the braking later and carry out the gear change closer to the hazard. If this is your aim, the obvious next step is to practice heel & toe ...

[ROG]

It takes time to perfect for every situation so do not do it all the time

Do it when its planned for and will not cause you or others problems

Some like me can do it all the time and have to plan NOT to do it !!

[waremark]

It's very important to be in a flexible gear before you start braking, especially so in a car with a diesel engine. You should be doing this anyway, as a matter of course. If you are not, perhaps for reasons of economy, you really ought to consider returning to a flexible gear before you run though the sequence for approaching a hazard.

Not IPSGA then? Something tells me we have been here before! I agree with the partial overlap bit but not with the importance of being in a flexible gear.

My approach to the scenario described would probably be to approach in 4th (or the highest gear in which the car runs smoothly when no adjustment of speed is required), to start to brake, to declutch before the engine starts to labour (so partial overlap), to move the gear lever to 2nd and to let the clutch out only when ready to pick up the drive. Gareth, I need to go for a drive in your car to find out whether this really feels awkward with your drivetrain.

[superplum]

BGOL, who needs BGOL! The salient point from the OP was "I planned to brake to around 2nd gear and get off the brake by the start of the mouth of the right turn". In essence, that was too late and he should have already been in the correct gear by that time - earlier actions would have allowed additional time for the other driver to have accomplished his manoeuvre without causing any grief.


Ex Senior Obs
now Training Officer and Tutor

[jcochrane]

The advantage of partial overlap is that you can complete the braking later and carry out the gear change closer to the hazard. If this is your aim, the obvious next step is to practice heel & toe ...

I know that's the usual reason for heel & toe but I must admit I like to do it so that I get the gear in earlier than otherwise. I cover both pedals and squeeze on extra throttle to rev match, as in a sustained change. Once the clutch has re engaged, with my right foot on both pedals, I then slowly roll of the throttle and roll on a little more or less brake as required. I find doing this allows me to focus on modulating the brake to more precisely adjust to the speed I want. Does any one else do this?

The above I use mainly for brisk rural driving and full separation for urban driving but will remain flexible so heel & toe might be used in an urban environment if going downhill and making a turn for example.

[Standard Dave]

Like some of the other techniques in roadcraft and other high speed or advanced driving they are carried out to the letter by some without really knowing why they do it.

I've found that below the 90 to 95% total commitment required for response driving that BGOL and some other techniques make little or no difference to safety or smoothness.

When your braking from 40 mph in a 40 to around 20mph to go round a corner it is not as important to leave separation for a safety marging than if your braking from 80 mph in a 40 down to 20-25mph to round a corner.

I'm not however very keen on drivers who dispute the safety or usefulness of a technique just because they can't do it or find it inconvenient. Every driver especially those who claim some level of skill above that of the majority should be able to perform multiple techniques and pick the most appropriate for any given situation.

[Stephen]

The scenario described is one I see time and time again on test,and in my opinion it all boils down to your understanding of seperation and the situation that you are approaching. If you slow down too soon on the approach to a hazard with other vehicles waiting,then there is always the danger that you will give the impression that you are perhaps allowing them to take precidence,by the sheer fact that you are slowing down too soon.

The Information phase should tell you that if you are going to plan a good seperation then you have to practise for dangers at hazards as well as for clear hazards,if that makes sense. When you approach a junction like this then you should leave your braking until closer to hazard,then brake more firmly that way you wont give the wrong signal / information and you can still plan to carry out the manoeuvre without BGOL.

Remember phase 1 is the most important and runs through the other 4,so,at phase 3 you should know what you intend to do is acheivable without BGOL,if it is not then you are approaching too fast and not planned in time,and as we all know HTBABD and Roadcraft allow for BGOL that you plan and this will be determined by what you see at phase 1.

Remember if you treat all other drivers on the road as idiots then you shouldnt come unstuck by getting caught up in incidents of poor driving standards,you wont fail your test if you BGOL,however if it is continual then it could be judged that you can not plan or manage hazards with a number of the other competencies required.

I have been using the system for best part of 23 yrs and analyse my driving everytime I drive and everytime I make a mistake it is mainly down to bad planning and too much speed not (excessive),experience at dealing with all types of single and multiple hazards is key to developing good seperation.

[Gareth]

I agree with the partial overlap bit but not with the importance of being in a flexible gear.

I remember being told we should be in a flexible gear at all times. I figured that if we then choose to change to a less flexible gear because we know there are no hazards around and don't require any acceleration, we should be equally prepared to return to a flexible gear when that situation changes. I reckon people tend to do the former but forget to do the latter.

A possible example that springs to mind - I remember the one time I drove on a motorway with John Lyon, as I was passing countdown markers for the exit he told me to change from 5th (the cruising gear) to 3rd (the flexible gear) prior to taking the off-slip.

Back to the OP's question ...

There have been numerous threads about BGOL (and its avoidance). In Brake Gear Overlap (BGOL) - 1 vonhosen wrote a detailed description on page 1 that's worth a read. On page 3 the issues with separation in cars with modern turbo-diesel engines is discussed.

There is more discussion in Brake Gear Overlap (BGOL) - 2 which also benefits from vonhosen's detailed replies as well as some by others.

Some other threads for your delight and entertainment :-
BGOL - A Different View
Brake/gear overlap - is my technique OK?
BGOL (just a quickie)

[waremark]

Gareth, I did say that we had been here before! For what it is worth, today I made a right turn into a country road from an NSL major road in a turbo diesel car. I approached in 5th (top) gear, braked, declutched at about 1,000 rpm, selected 2nd in a leisurely fashion, and raised the clutch to pick up the drive just after I finished braking and as I turned into the side road. All of the following were present - partial overlap, rolling with the clutch down under braking, not holding up traffic behind me unnecessarily, rev matching the down change, planned approach, economy both of the car and of driver input, and safety and smoothness. I don't see what use of an intermediate gear would have added in my scenario.

[ROG]

BGOL, who needs BGOL! The salient point from the OP was "I planned to brake to around 2nd gear and get off the brake by the start of the mouth of the right turn". In essence, that was too late and he should have already been in the correct gear by that time - earlier actions would have allowed additional time for the other driver to have accomplished his manoeuvre without causing any grief.


Ex Senior Obs
now Training Officer and Tutor

Those who can do it properly never have that issue - I know because I do not

That means it is down to how its applied and the ability of the driver

[fungus]

I find that in many situations full separation is not the best option because of following traffic. Braking later and more firmly takes the following driver by surprise as they are expecting you to enter the hazard at a higher speed, where as overlapping braking and gear changing, braking can be more evenly spread and still give time to select the appropriate gear and lift the clutch up fully before entering the hazard. I appreciate the reasons given for full separation in response situations where red mist could easily take over, thus forcing the driver to allow sufficient time and space to prepare for the hazard, but in normal every day driving an advanced driver should be disciplined enough to approach a hazard at the correct speed with the correct gear engaged, by whatever method is used.

Like fixed grip steering, heel and toe, double de clutching etc. as long as the driver has not compromised safety and control, is there really an issue, after all they are all tools in the toolbox for the driver to use if they have the skill.I think there is a danger of being too prescriptive when discussing driving techniques, as nothing in driving is black and white, it comes in many shades of grey. What is important, is that whatever system is used, it is safe, smooth, and unobtrusive.