Motorway driving part 3

[Swanny87]

SK425 said:

Why will the gap you want to move into disappear if you wait longer? If it's because the next car back in the lane outside you will fill it, it sounds like you might be trying to pull in front of them close enough that you need their co-operation but before you've confirmed you have their co-operation.

I guess you're right about waiting for someone to confirm they're letting me out but I don't think people really get that. You can wait a long time with your indicator on and people do nothing, hence why I like to get in gaps ASAP.

[SK425]

Advance warning is great but I wouldn't merge before I was at least close enough to see that the obstruction or lane closure actually exists. Probably reflecting what the OP said about striking a compromise, when merging I would aim to do it by slowing to, but not below, the speed of the continuing lane. So if the whole thing is stationary or crawling, zip merging at the obstruction is fine. But if the continuing lane is flowing, merging that late might involve too much slowing - for me and for the person behind who I need to let me in - and I'd prefer to merge a little earlier and keep my speed up and that of those around me.

[SK425]

Swanny87 said:

I guess you're right about waiting for someone to confirm they're letting me out but I don't think people really get that. You can wait a long time with your indicator on and people do nothing, hence why I like to get in gaps ASAP.

Really? I think we're talking about some, but not huge, speed differential - say trying to move from a lane doing 60 into a lane doing 70. In my experience, when I put a signal on to request co-operation from someone outside and behind, the immediate reaction can look like "NO! ME FIRST!!" (and bear in mind that it's their priority to give, not mine to take) but the further back in the queue someone is, the more time they have for their conscious humanity to take over and dispel any combative instinct. I would usually aim to put the signal on as one vehicle is level alongside. It's maybe 50:50 whether the next driver back will choose to let me out or continue past. Rarely, the second driver back will choose to continue past too. I'm not sure I've ever had a third driver not choose to let me out either.

[R_U_LOCAL]

Swanny87 said:

Am I doing this right? I've started to pick up on what I think is a bad habit; when changing lanes after a car has just passed me I start to move across as soon as the car has passed me. I feel as if I leave it a bit longer the gap I want to move into will disappear. I do come off the throttle once in the new lane to create braking space behind the car that just passed me.

I guess the problem with this is if the driver brakes sharply as I'm coming in behind them I don't have any braking distance. I can however just pull back left and cancel the manoeuvre.

The reality of driving on motorways these days is that traffic is much busier than it used to be and generally travels much closer together than it used to. If your forward observations and assessment of other vehicles' speeds are good, then there is nothing inherantly wrong in moving in to a close position behind a vehicle which has just overtaken and still has "plus speed" on you. Your forward observations should identify if there is anything which may force the vehicle to slow and your speed assessment should tell you if the vehicle behind is matching its speed or catching up. The plus speed of the overtaking vehicle means that the gap will quickly open up to a safe following position and as long as your move is accompanied by some appropriate acceleration, you won't hinder the vehicle behind.

It may not be textbook roadcraft, but I don't have any issues with it.

XJ Flyer said:

The idea of zip merging at the point of the lane closure is flawed in that it means all the traffic has to slow to a crawl to allow the traffic in the closing lanes time to merge before running out of road.

I don't agree. Merging in turn does not cause the traffic to slow - it is the fact that vehicles travel too close together and too quickly which generally causes the slowing. To explain further, there is a phenomenon called "traffic waves", whereby if a number of vehicles are travelling quickly but too close together, when the front vehicle brakes, the next vehicle brakes fractionally harder and longer, the next one brakes a little harder and longer etc, etc, until the traffic much further back comes to a complete stop. This is what causes those otherwise unexplainable tailbacks in heavy traffic when there is no obvious physical cause and you eventually move off wondering what the hold up was.

At roadworks with reduced running lanes, traffic simply backs up due to vehicles travelling too close and then entering a semi-permanent traffic wave, but in this case with an obvious, physical cause. The actual merging of vehicles wouldn't cause traffic to slow if people kept more reasonable distances between their vehicles.

XJ Flyer said:

What's needed is for the lane closure advanced warning signs to be the first signs put out at the 2 and 1 mile points which allows the merging to be done at higher speeds because there is a lot more room ahead before the obstruction.The rules also need changing to give traffic in the closing lanes the priority when changing lanes to the remaining open ones instead of relying on muppets in whatever lane to follow the zip merge idea.While the idea of merging at the point of the obstruction also contradicts the idea of advanced lane closure signs and the red cross,all well before the obstruction/closure,in other cases.

This wouldn't really be making the best use of the available road space though. If merging is left until vehicles are right up to the roadworks, the potential tailback on a three-lane stretch of motorway could, in theory, be one third the length of the tailback caused if vehicles were forced to merge early. A longer tailback has more potential to cause knock-on traffic problems for other roads and more potential to cause accidents.

[XJ Flyer]

R_U_LOCAL said:

XJ Flyer said:

The idea of zip merging at the point of the lane closure is flawed in that it means all the traffic has to slow to a crawl to allow the traffic in the closing lanes time to merge before running out of road.

I don't agree. Merging in turn does not cause the traffic to slow - it is the fact that vehicles travel too close together and too quickly which generally causes the slowing. To explain further, there is a phenomenon called "traffic waves", whereby if a number of vehicles are travelling quickly but too close together, when the front vehicle brakes, the next vehicle brakes fractionally harder and longer, the next one brakes a little harder and longer etc, etc, until the traffic much further back comes to a complete stop. This is what causes those otherwise unexplainable tailbacks in heavy traffic when there is no obvious physical cause and you eventually move off wondering what the hold up was.

At roadworks with reduced running lanes, traffic simply backs up due to vehicles travelling too close and then entering a semi-permanent traffic wave, but in this case with an obvious, physical cause. The actual merging of vehicles wouldn't cause traffic to slow if people kept more reasonable distances between their vehicles.

XJ Flyer said:

What's needed is for the lane closure advanced warning signs to be the first signs put out at the 2 and 1 mile points which allows the merging to be done at higher speeds because there is a lot more room ahead before the obstruction.The rules also need changing to give traffic in the closing lanes the priority when changing lanes to the remaining open ones instead of relying on muppets in whatever lane to follow the zip merge idea.While the idea of merging at the point of the obstruction also contradicts the idea of advanced lane closure signs and the red cross,all well before the obstruction/closure,in other cases.

This wouldn't really be making the best use of the available road space though. If merging is left until vehicles are right up to the roadworks, the potential tailback on a three-lane stretch of motorway could, in theory, be one third the length of the tailback caused if vehicles were forced to merge early. A longer tailback has more potential to cause knock-on traffic problems for other roads and more potential to cause accidents.

Firstly how can traffic that needs to merge from a closed lane/s ahead maintain speed when it's already on top of the said closure.IE at that point it has to slow to a relative crawl or hit the cones.In which case the traffic in the open lanes also has to slow to a crawl to allow that traffic to merge.The fact is anything other than lane 1 is for overtaking only and there's no way that anyone can overtake if the overtaking lane/s are closed or no longer overtaking lane/s because of the closure of lane 1 .Which is why on the continent lane closures are usually subject to no overtaking warning signs long before the closure and that's the time to get all the merging done and finished with.

As for leaving it until the obstruction,as I said,that would also obviously contradict the idea of advanced lane closure warnings and the red cross sign all long before the actual obstruction.So why the selective difference in some cases but not others.

[R_U_LOCAL]

XJ Flyer said:

Firstly how can traffic that needs to merge from a closed lane/s ahead maintain speed when it's already on top of the said closure.IE at that point it has to slow to a relative crawl or hit the cones.In which case the traffic in the open lanes also has to slow to a crawl to allow that traffic to merge.The fact is anything other than lane 1 is for overtaking only and there's no way that anyone can overtake if the overtaking lane/s are closed or no longer overtaking lane/s because of the closure of lane 1 .Which is why on the continent lane closures are usually subject to no overtaking warning signs long before the closure and that's the time to get all the merging done and finished with.

There is no ideal answer, mainly because the majority of the motoring public tend to conform to what they think is correct, rather than what may be considered to be a "better" approach. As I pointed out in my original post, the best approach (perhaps I should have stated the best theoretical approach) is to merge at the closure rather than before, because of the advantages I listed, however I did also state that there are also real problems with merging at the closure, foremost of which is that most other drivers don't understand the principle, and feel that they are somehow being moved backwards in the queue if they allow someone to merge in front of them (which, again, is a bit daft as they're still generally moving forwards at this point, but the position of other vehicles presents the illusion of being forced backwards).

The reality is that if everyone left a much larger gap between vehicles on the approach to roadworks, and allowed merging in turn, all the vehicles would actually get through the roadworks more quickly and efficiently. Hence the increasing numbers of motorway roadworks governed by 40mph limits rather than the 50mph limits we're more familiar with.

Perhaps these misunderstandings are based on the current absence of any motorway training for most drivers, but that may be an argument for another thread.

Suffice to say, as in my original post, whatever the theoretical best practice is, the actions of the majority of other drivers means that in this case, I don't actually practice what I preach and I tend to compromise by merging earlier than perhaps is ideal.

XJ Flyer said:

As for leaving it until the obstruction,as I said,that would also obviously contradict the idea of advanced lane closure warnings and the red cross sign all long before the actual obstruction.So why the selective difference in some cases but not others.

As I also previously mentioned, the advanced warning signs are a legal requirement and should allow drivers to start their plan for the roadworks, as opposed to suddenly being faced with a lane closure whilst driving at speed.

Illuminated red cross signs aren't generally used for roadworks and are usually reserved for emergency incidents. Continuing in a lane governed by an illuminated red cross is an offence. Is that the selective difference you're referring to?

[XJ Flyer]

R_U_LOCAL said:

As I also previously mentioned, the advanced warning signs are a legal requirement and should allow drivers to start their plan for the roadworks, as opposed to suddenly being faced with a lane closure whilst driving at speed.

Illuminated red cross signs aren't generally used for roadworks and are usually reserved for emergency incidents. Continuing in a lane governed by an illuminated red cross is an offence. Is that the selective difference you're referring to?

That's exactly the contradiction I was referring to.IE why the selective difference between different forms of lane closure when a lane closure is a lane closure regardless of why it's been closed.The advanced lane closure warning and stop sign all long before the actual obsruction seems like the logical answer to me in all cases.

While having said that I also like the logic of the continental idea of mainly relying on no overtaking signs to do the same job as lane closure warning signs.IE no overtaking means what it says return to lane 1 in all cases.Then they either divert all the already merged traffic from lane 1 using the lane closure signs and cones if it's that lane that's subject to the closure.Or it all stays where it is in lane 1 if it's the overtaking lane/s that are closed.In all those examples all the merging is done and finished with long before the obstruction and generally keeps the traffic moving much better.

[SK425]

XJ Flyer said:

Firstly how can traffic that needs to merge from a closed lane/s ahead maintain speed when it's already on top of the said closure.IE at that point it has to slow to a relative crawl or hit the cones.In which case the traffic in the open lanes also has to slow to a crawl to allow that traffic to merge.

I get that bit.

XJ Flyer said:

The fact is anything other than lane 1 is for overtaking only and there's no way that anyone can overtake if the overtaking lane/s are closed or no longer overtaking lane/s because of the closure of lane 1 .

But what does that mean? Prior to the closure, all the lanes still exist and the overtaking lanes are just as much overtaking lanes as they would be if there were no closure ahead. After the closure there are fewer lanes, but unless the closure reduces the number of lanes all the way down to one, there is still a left-most driving lane and one or more overtaking lanes to its right.

What influence the closure has on the traffic and therefore what overtaking opportunities there are - both before and after the point of closure - is a different question.

[Martin_M]

greygoose said:

I remember an amusing bit on Police Interceptors when they pulled a German RS4 on the motorway and advised him to get up to speed on the hard shoulder before rejoining and the bloke blasted off to 70 in about 3 seconds to the astonishment of the coppers sat behind him.

I remember this - tried to find the video but it seems they have all been removed. He was caught doing 140mph and claimed that he thought he was still on the Autobahn lol

[XJ Flyer]

SK425 said:

XJ Flyer said:

The fact is anything other than lane 1 is for overtaking only and there's no way that anyone can overtake if the overtaking lane/s are closed or no longer overtaking lane/s because of the closure of lane 1 .

But what does that mean? Prior to the closure, all the lanes still exist and the overtaking lanes are just as much overtaking lanes as they would be if there were no closure ahead. After the closure there are fewer lanes, but unless the closure reduces the number of lanes all the way down to one, there is still a left-most driving lane and one or more overtaking lanes

Surely the same could be said in the case of lane closures subject to advanced lane closure signs followed by the red cross stop sign in the case of anyone who hasn't merged long before the actual obstruction.In which case it's no excuse to say that it' ok to pass the red cross stop sign because all the lanes were open up to that point.While anyone who reaches the sign having failed to merge at the advanced warning signs is rightly viewed as having not used sufficient planning in that case.Whereas in other cases it's being seen as a good thing to run right up to the obstruction and then try to merge from a crawl if not stop at that point.The contradiction simply makes no sense.

IE it would/should mean exactly the same as it would mean 'if' it was a lane closure subject to advanced lane closure warnings and the red cross stop sign.The difference in that case being ( rightly ) that all the required merging is 'supposed to be' done and finished with long before the red cross stop sign let alone the actual obstruction.While in that case how can the overtaking lanes still be viewed as overtaking lanes when any or all of them are under an advanced lane closure warning.Thereby requiring the need for traffic to merge into whichever lanes are remaining open according to the advanced lane closure signs.

As I've said the more logical layout should firstly be no overtaking signs.In which case all traffic should return to lane 1 followed by the relevant lane closure signs and cones diverting the traffic to which ever lanes are remaining in use or keeping the traffic where it is in lane 1 as appropriate.Which has more or less been the practice on the continent for years in the event of lane closures either in the case of emergencies or for roadworks.

[SK425]

XJ Flyer said:

Surely the same could be said in the case of lane closures subject to advanced lane closure signs followed by the red cross stop sign in the case of anyone who hasn't merged long before the actual obstruction.In which case it's no excuse to say that it' ok to pass the red cross stop sign because all the lanes were open up to that point.While anyone who reaches the sign having failed to merge at the advanced warning signs is rightly viewed as having not used sufficient planning in that case.Whereas in other cases it's being seen as a good thing to run right up to the obstruction and then try to merge from a crawl if not stop at that point.The contradiction simply makes no sense.

IE it would/should mean exactly the same as it would mean 'if' it was a lane closure subject to advanced lane closure warnings and the red cross stop sign.The difference in that case being ( rightly ) that all the required merging is 'supposed to be' done and finished with long before the red cross stop sign let alone the actual obstruction.While in that case how can the overtaking lanes still be viewed as overtaking lanes when any or all of them are under an advanced lane closure warning.Thereby requiring the need for traffic to merge into whichever lanes are remaining open according to the advanced lane closure signs.

As I've said the more logical layout should firstly be no overtaking signs.In which case all traffic should return to lane 1 followed by the relevant lane closure signs and cones diverting the traffic to which ever lanes are remaining in use or keeping the traffic where it is in lane 1 as appropriate.Which has more or less been the practice on the continent for years in the event of lane closures either in the case of emergencies or for roadworks.

I still don't see where you're coming from on overtaking lanes. Any lanes other than the left-most are overtaking lanes - that's the definition of an overtaking lane. The only difference after the lane closure is that there will be fewer of them (perhaps none). For example, if there are two lanes remaining after the closure and while driving in the left lane I catch a slower vehicle, I will use the right lane to overtake them just as I would on any other two lane piece of road.

And what's the hang up on red crosses? The latest point you can possibly merge is at the lane closure. Whether that closure is effected by an actual obstruction like some cones or a red cross on a sign is irrelevant - you must merge before the closure. Continuing in lane beyond the red cross would be exactly the same as continuing in lane and driving through the cones. Merging much earlier than you need to is as much nonsense as driving all the way up to the closure such that you have to slow right down or stop when the lane you want to merge into is flowing at some speed.

[XJ Flyer]

SK425 said:

XJ Flyer said:

Surely the same could be said in the case of lane closures subject to advanced lane closure signs followed by the red cross stop sign in the case of anyone who hasn't merged long before the actual obstruction.In which case it's no excuse to say that it' ok to pass the red cross stop sign because all the lanes were open up to that point.While anyone who reaches the sign having failed to merge at the advanced warning signs is rightly viewed as having not used sufficient planning in that case.Whereas in other cases it's being seen as a good thing to run right up to the obstruction and then try to merge from a crawl if not stop at that point.The contradiction simply makes no sense.

IE it would/should mean exactly the same as it would mean 'if' it was a lane closure subject to advanced lane closure warnings and the red cross stop sign.The difference in that case being ( rightly ) that all the required merging is 'supposed to be' done and finished with long before the red cross stop sign let alone the actual obstruction.While in that case how can the overtaking lanes still be viewed as overtaking lanes when any or all of them are under an advanced lane closure warning.Thereby requiring the need for traffic to merge into whichever lanes are remaining open according to the advanced lane closure signs.

As I've said the more logical layout should firstly be no overtaking signs.In which case all traffic should return to lane 1 followed by the relevant lane closure signs and cones diverting the traffic to which ever lanes are remaining in use or keeping the traffic where it is in lane 1 as appropriate.Which has more or less been the practice on the continent for years in the event of lane closures either in the case of emergencies or for roadworks.

I still don't see where you're coming from on overtaking lanes. Any lanes other than the left-most are overtaking lanes - that's the definition of an overtaking lane. The only difference after the lane closure is that there will be fewer of them (perhaps none). For example, if there are two lanes remaining after the closure and while driving in the left lane I catch a slower vehicle, I will use the right lane to overtake them just as I would on any other two lane piece of road.

And what's the hang up on red crosses? The latest point you can possibly merge is at the lane closure. Whether that closure is effected by an actual obstruction like some cones or a red cross on a sign is irrelevant - you must merge before the closure. Continuing in lane beyond the red cross would be exactly the same as continuing in lane and driving through the cones. Merging much earlier than you need to is as much nonsense as driving all the way up to the closure such that you have to slow right down or stop when the lane you want to merge into is flowing at some speed.

Firstly assuming that there's any overtaking lanes remaining open then that would/should obviously be shown on the advanced lane closure warning signs.In which case it's only lanes 2 and/or 3 and/or 4 for example which will need to merge with the remaining lanes 1 and/or 2 and/or 3 on the approach to the closure.Although as I've said the usual procedure on the continent is just to return all traffic to lane 1 by putting in no overtaking signs and then sort it all out from there which seems to work fine in practice.

As for driving up to the red cross stop sign without merging according to the advanced lane closure signs before reaching it that's exactly the same thing as driving all the way up to the cones before merging.In which case both would then obviously result in having to merge with moving traffic from a crawl or even a stop.Which is exactly my point.

While your final sentence shows the contradiction which I'm referring to,between the idea of the correct procedure in the case of the red cross type closure in which the merging should all be done long before reaching it.As opposed to the idea of driving all the way up to the closure by continuing to use the overtaking lane/s before merging.Which inevitably means having to merge at a crawl at best.On that basis,merging as soon and as far back from the obstruction as possible,is exactly what's needed,to keep traffic flowing at reasonable speeds on the approach to lane closures.

Edited by XJ Flyer on Friday 4th July 11:46

[SK425]

XJ Flyer said:

Firstly assuming that there's any overtaking lanes remaining open then that would/should obviously be shown on the advanced lane closure warning signs.In which case it's only lanes 2 and/or 3 and/or 4 for example which will need to merge with the remaining lanes 1 and/or 2 and/or 3 on the approach to the closure.Although as I've said the usual procedure on the continent is just to return all traffic to lane 1 by putting in no overtaking signs and then sort it all out from there which seems to work fine in practice.

Presumably that's only in the case where only one lane is going to remain open? There'd be no point in shoe-horning everyone into one lane in advance if, after the closure, more than one lane is still open.

XJ Flyer said:

As for driving up to the red cross stop sign without merging according to the advanced lane closure signs before reaching it that's exactly the same thing as driving all the way up to the cones before merging.In which case both would then obviously result in having to merge with moving traffic from a crawl or even a stop.Which is exactly my point.

Yes. I think we agree on that one. Although sometimes the lane you need to merge with will be crawling or stopped too. Sometimes it will be flowing somewhat faster.

XJ Flyer said:

While your final sentence shows the contradiction which I'm referring to,between the idea of the correct procedure in the case of the red cross type closure in which the merging should all be done long before reaching it.As opposed to the idea of driving all the way up to the closure by continuing to use the overtaking lane/s before merging.Which inevitably means having to merge at a crawl at best.On that basis,merging as soon and as far back from the obstruction as possible,is exactly what's needed,to keep traffic flowing at reasonable speeds on the approach to lane closures.

I'm trying to say that because the effect of a red cross is the same as the effect an actual obstruction, the procedure is the same. I'm not trying to suggest any contradiction - exactly the opposite. The procedure I would suggest is to make sure you merge far enough back that you can match speed with the lane you are merging into. That won't eliminate the need for people to slow to let you in - because, as R_U_LOCAL said, by and large they won't be leaving a big enough gap for you to get in without them at least having to lift a bit to open the gap up - but it should minimise the need for people to slow. How far back is far enough? That depends on the speed on the traffic you need to merge with. If that lane is flowing at some speed, you need to plan your merge so that you have time to match speed with a gap and have negotiated your way in by the time you reach the closure, otherwise you'll have to slow down slower than the other lane and bugger everybody up. On the other hand, if the lane you want to merge into is already stationary or crawling, you probably can drive right up to the closure without a problem.

I don't see any need for 'as far back from the obstruction as possible'. In particular, as I said earlier, never merge so far back that you can't see that the obstruction or closure really exists, just in case it doesn't .

[Ross_T_Boss]

Great informative posts, only came across these today and made for interesting reading on the train.

Quick thoughts on 'zip merging' - I'm sure it is a contentious topic at times as it drives me nuts - simply put it's the best, fair way to behave. Otherwise where do you merge? 1/2 mile before? I mile before? You'll end up with some people carrying on later in the outside lane, making good progress because alot of traffic in front is merging early, which further hinders the 'already merged' traffic and before you know it there's a progress differential and breeding discontent.

Also the merge should not be 'at higher speeds'. There is reason the speed limit decreases a good bit before the lane closure; it's to increase the motorway capacity. Now let's make an assumption that all traffic leaves a 2-sec gap (of course it doesn't which is where this breaks down in reality), but in theory, if everyone does this then the capacity is increased as traffic slows and a reduction from 70>50 shouldn't be too painful as capacity is not massively reduced. I modelled this mathematically once on a time to prove it; you slow then merge. Only thing I'd say is that you do need 1/3 of the cars in lane 2 to merge into lane 1 at the same point else you do get a tail-back in lanes 2/3 with 1 moving nicely.

Finally - there's been numerous times I've stuck to my lane and been the victim of blocking and various hand gestures, only to not end up merging - I'm using a turn-off or the lane closure simply hasn't been 'done' yet. Yes I agree obey the speed signed and expect the merge, but it doesn't always mean it is going to happen. It's quite amusing to see the chaos caused; if everyone followed Reg's guidance to merge in turn nearing the closure point you'd just get traffic slowing to 50 then increasing back to 70 with no tail-back.