Banana vs. triangle overtake:

Banana overtake (top). The driver accelerates up behind the target vehicle, moving out as they do. The decision point is just behind the target, at the point where vision develops fully. However by now the driver is travelling at a faster speed than the target, so aborting requires a lot of speed to be lost. In contrast in the triangle overtake (bottom), the driver moves out for a view ahead, while still matching the speed of the target. If the overtake is on, he can accelerate past the target. If it isn't, dropping back in behind the target is a matter of simply moving back sideways.

The short triangle vs. the long (momentum) triangle:

In the long triangle (top), the driver approaches the target with speed in hand, perhaps along a long straight stretch of road. Approaching the target, he moves well out to the offside for a view ahead. The decision point is some way back from the target vehicle, to give time to reduce speed and drop back behind it if necessary. If the overtake is on, no alteration in speed is necessary. Once past the target, a smooth move back to the nearside is initiated. In the short triangle (bottom), the driver first follows the target vehicle in a "contact" position (closer than normal following distance, but not so close as to block vision unnecessarily). He then moves out to the offside for a view ahead, but without increasing speed. The decision to overtake or not is taken at this point. Accelerating past the target vehicle, a smooth move back to the nearside is initiated.

Edited 19 May, 200917 yr by ncarring

Thanks, Nick - those diagrams are much clearer than my explanations One other thing your diagrams jogged me into remembering is that one of the other advantages of the short triangle is that you get the overtakee's reaction before committing...

Chris

Edited 20 May, 200917 yr by ScoobyChris
Additional thoughts........

Could be just another dangerously ill informed driver though...

You could well be - This generally only applies to queues of traffic, not free flowing traffic.

i am pretty shocked by the number of times people have said they would partake in what would arguably be described as dangerous driving. I trust certain suggestions are tongue in cheek, but having just driven a thousand miles in 5 days try to remember you are in charge of nearly 2 ton of metal, childish speeding up or preventing someone else to make progress could get someone including yourself killed, never mind simply arrested if an unmarked car catches you at it.

Be safe out there

This raises an interesting point. As you approach a corner, you have a view into it which may range from none-at-all (ie severe bend) to 100% (nice open sweeping bend). So, as long as your speed is such that you can stop in the space you can see (ie up to the limit-of-vision point) you should be safe if anything untoward is waiting for you as the view unfolds? Do you have an escape route that you can use, or is there no way out?

But then do you risk having the twazzocks who can't see what you're doing up your behind causing more of a risk - would be worse being rear ended and front ended at the same time (for want of a better way of describing it ). I guess "knowing the road" is something that helps greatly with this though.

But then do you risk having the twazzocks who can't see what you're doing up your behind causing more of a risk - would be worse being rear ended and front ended at the same time (for want of a better way of describing it ). I guess "knowing the road" is something that helps greatly with this though.

It's certainly a delicate balance although I'd ask is it better to have a head on at a higher speed (cos the person behind is pushing you to go faster) or a lower speed and be rear-ended too. I have no idea - neither sounds especially nice

"Knowing the road" is another interesting topic. How many times have you heard someone tell you that they can't drive quickly because they "don't know the road"? In theory, you should be able to drive at the same levels of safety and progress on any road known or unknown because the information you have available should be limited to what you can see. However, in practise, that's not very realistic because in some cases you will have local knowledge of an area and you can use this to your advantage, especially if things like warning signs have been damaged or are missing. The problem comes when local knowledge starts to override what you can see and you lose the focus on your safety margins, eg I know I can go round this bend at 60mph rather than the distance I can stop in means I can only go round here at 40mph. If there's a dead sheep in the road that wasn't there last time, guess which driver is going to need a change of underpants

Anyways, I'm rambling again :rofl:

Chris

What really grips my **** though are daydreaming idiots and inconsiderate drivers.

If I am trying to turn right out of a side street and they are trying to turn right into it, where is the harm of letting me out? I'm not going to be in their way. It winds me up even more if they see me there when they arrive at the junction and still block me off. I was there first dammit.

And? According to the rules I was taught traffic on the main road always has right of way regardless of whether you arrived at the junction with the major road second, or 3 hours earlier!

"Knowing the road" is another interesting topic. How many times have you heard someone tell you that they can't drive quickly because they "don't know the road"? In theory, you should be able to drive at the same levels of safety and progress on any road known or unknown because the information you have available should be limited to what you can see. However, in practise, that's not very realistic because in some cases you will have local knowledge of an area and you can use this to your advantage, especially if things like warning signs have been damaged or are missing. The problem comes when local knowledge starts to override what you can see and you lose the focus on your safety margins, eg I know I can go round this bend at 60mph rather than the distance I can stop in means I can only go round here at 40mph. If there's a dead sheep in the road that wasn't there last time, guess which driver is going to need a change of underpants

Anyways, I'm rambling again :rofl:

Chris

See, I think that works the other way. There are places where, if I didn't know the road, I'd be lifting for a false apex, or an apex just over a crest, that makes the corner look tighter, and/or the vanishing point nearer, than it actually is.

See, I think that works the other way. There are places where, if I didn't know the road, I'd be lifting for a false apex, or an apex just over a crest, that makes the corner look tighter, and/or the vanishing point nearer, than it actually is.

Would a situation like this mean you're making assumptions about the state of the road beyond what you can see, and actually carrying more speed as a result?

Chris

Would a situation like this mean you're making assumptions about the state of the road beyond what you can see, and actually carrying more speed as a result?

Chris

Not really, unless a pothole has opened in the last 16 hours or so!I'll not get into discussions about "slippery surfaces" since they're not always identifiable.

Or a dead deer in the road, perhaps? Or a fridge ...

Or a haybale fallen off the back of a small pickup truck, as happened to me out on a very progressive drive a few months ago. Luckily the lady who was driving is very good, and was able to stop in time.

Not really, unless a pothole has opened in the last 16 hours or so

Which sounds a teensy bit like an assumption to me that could potentially get you into trouble

Chris

The more i think about this the more I would actually want to do some advanced training really.

I have really mellowed the past few years with my driving and take great pleasure in reading the road ahead when nobody else does and knowing what is coming and not having to slam my brakes on at the last minute.

The drive to work this morning I decided to take the ring road and althogh it is a few miles longer and has lots of roundabouts and even traffic lights as I get nearer work I still managed to not have to stop at all the whole way there while sat watching other cars infront and behind just focusing on the bumper of the car in front of them then having to brake and wait at lights and roundabouts.

Would be really keen to attend some day/event you might be organising.

Phil

Nick, I've been there, done that, and missed out on the venison by not hitting the deer, several times. The point is that it's a false apex or crest that looks like it vanishes way faster than it does.

Chris, I've never seen a pothole open that fast without giving an advance warning by throwing gravel from the point where the hole develops. Yes, it's an assumption, but I'll bet that you sometimes assume that a surface you can see is dry and looks non-greasy actually is dry and non-greasy! Tree sap sometimes looks like that, and some authorities unhelpfully signpost places where it's a problem as "skid risk", with an amplifying endorsment of "icy road", which is no help when you know the temperature to be +10C because you will assume there to be no ice!

Ken, if you can't see the road, you can't see what's lying in it, regardless of whether you regard the crest or apex as "false" or not. That's the point Chris and I are making. Travelling too fast to be able to stop in the distance you can see to be clear is a risk, that you are happy to take, but which is, strictly, too much of a risk for an advanced driver with safety in mind.

Let's try this again - It looks like the sightline is shorter than it actually is. Explain to me how you get from that to "you must be driving faster than you can actually see clear" please?

Define "sightline"

To me it says - "as far as I can currently see". The fact that it may change soon (I'm assuming that's your definition of a "false" crest or apex), doesn't alter the fact that currently, that's as far as I can see, therefore I have to be able to stop by that point.

If I've misunderstood your definition, feel free to expand.

Chris, I've never seen a pothole open that fast without giving an advance warning by throwing gravel from the point where the hole develops.

It's funny you should say that Mystery hole reappears - News - Manchester Evening News

Nick sums up nicely my other point

Chris.

Edited 20 May, 200917 yr by ScoobyChris

Not quite; I'm saying that an optical illusion leads someone unfamiliar with the road to believe that they can see a certain distance at a certain point on the road, but someone familiar with the road realises that they can see a greater distance, say because the fall line of a downslope is only a vanishingly small amount different to a line drawn from the eyes to the point where the crest is.

This is difficult to describe, pretty much impossible to find a good illustration of, and I'm having difficulty believing that neither you nor Chris have ever encountered an example!

The more i think about this the more I would actually want to do some advanced training really.

Would be really keen to attend some day/event you might be organising.

I'm happy to organise a day in the next couple of months (based around Andover) if there's enough interest and I could try and round up some advanced driving coaches to help. Failing that there are a few other days in the calendar which other people are organising and in fact there's one in Yorkshire that is pencilled in at the end of May (30th/31st I think) so if you'd like me to put you in touch with the organiser, let me know.

Next one down this way is based around Newbury and is on the 6th June and likewise if people are interested in attending, drop me a PM and I'll put you in touch with the chap organising it

There's also the HPC Young Driver's Day on 1st August - Young Drivers Day

Chris

Not quite; I'm saying that an optical illusion leads someone unfamiliar with the road to believe that they can see a certain distance at a certain point on the road, but someone familiar with the road realises that they can see a greater distance, say because the fall line of a downslope is only a vanishingly small amount different to a line drawn from the eyes to the point where the crest is.

But the tarmac you can't see is still "dead" ground that is not visible? It's a vanishingly small amount, but what if it's full of glass from a shunt that occurred since you last drove it? Or a whole heap of nails/screws that were shed by a careless van driver? Are you giving yourself ample opportunity to deal with anything that you can't see or are you assuming it'll be clear, as it was previously, and relying on muscle memory to drive rather than the facts as presented?

Chris

But the tarmac you can't see is still "dead" ground that is not visible? It's a vanishingly small amount, but what if it's full of glass from a shunt that occurred since you last drove it? Or a whole heap of nails/screws that were shed by a careless van driver? Are you giving yourself ample opportunity to deal with anything that you can't see or are you assuming it'll be clear, as it was previously, and relying on muscle memory to drive rather than the facts as presented?

Chris

If you're going to take this tack, can I presume that you never drive through standing water without first stopping and checking in it for tacks, broken glass etc?

If you're going to take this tack, can I presume that you never drive through standing water without first stopping and checking in it for tacks, broken glass etc?

After running over some debris in standing water a year or so ago during the "floods", the answer these days would be a resounding yes, if the option is available to me. Fortunately in my incident I'd scrubbed off plenty of speed before entering the water (and the dead ground), rather than driving at a speed dictated by the distance I could see beyond the dead ground, and no lasting damage was done

Chris

With the traingle vs banana overtaking manouvers I do agree that the triangle is better and safer, but if you have a less powerful car *koff* mine *koff koff* you must "do" the banana in order to get up the speed differential to overtake on NSL roads, I find. Knowing the road helps a lot because when you know there is an overtaking spot coming up, you can drop back a bit in order to get a little bit of a run-up, as it where

With the traingle vs banana overtaking manouvers I do agree that the triangle is better and safer, but if you have a less powerful car *koff* mine *koff koff* you must "do" the banana in order to get up the speed differential to overtake on NSL roads, I find. Knowing the road helps a lot because when you know there is an overtaking spot coming up, you can drop back a bit in order to get a little bit of a run-up, as it where

Assuming a straightish road, how about performing the triangle over a longer distance? Ie, move offside early to maximise your view ahead and do the catch phase on the offside? If things change, you can always tuck back in and then move back out again when it's safe to.

When you're offside you have 3 choices wrt the overtake. a) Yes it's on, No it's not on and c) Maybe it's on. Assuming all is good, you'll stay at "maybe" until you reach the point of no return and then you need to commit to either yes or no. Of course your decision point is still earlier than is ideal, but potentially is later than a "banana" overtake where you're pretty much committed before you have any view.

This sort of overtake is particularly good for overtaking large or slow vehicles where you don't want a massive speed differential but you want to know all your options and give them a chance to see you approach and your intent.

Chris

And? According to the rules I was taught traffic on the main road always has right of way regardless of whether you arrived at the junction with the major road second, or 3 hours earlier!

True, true. The thing is there is a group of rules that some people remember and most don't. There are fewer still people actually drive to them.

How many times have you and another driver both gone "round the flagpole" when you were both turning right?

Or seen someone at a roundabout wait until their intended exit was clear before they got onto the roundabout. Or discovering their exit was blocked just continuing round the circle until it clears.

I haven't, I see a lot of people drive onto it and stop. Blocking the whole roundabout, not just the exit they wanted to use.

The thing is most people on the road are fisters, I was nearly taken out this evening by a teenage girl who indicated to come of a roundabout at the exit to the right of mine.

She steered towards her exit so I pulled out, then she changed her mind, still indicating left and accelerated right at me. Then did an emergency stop on the roundabout, blocking the whole thing.

I faeconated myself.

So given that most of the drivers of the road ignore the rules you have to replace them with something that works, what about politeness? I mean, yes I may not be on the main road but all they would have to do is pull up 5 yards earlier and I could cross the carriageway and turn right.

The amount of times I have been turning right and have stopped to wait for someone who was turning left or going straight on and they have just looked at me all confused.

Just a little consideration and thought on the roads would be nice, we in Britain and specifically in Kent live in an area with some of the highest population and traffic densities in the world.

With all the cars on the road the only way to get anywhere is to be polite and hope you get it back.

Incidentally "right of way" isn't the correct term, one car would have priority over another...