Slip-roads

[TheInsanity1234]

I was just thinking about motorway driving and all the issues with it, then joining a motorway came up in my head, and was followed by a question:

What do you do if you're joining a motorway on a slip-road, and there's a space and you do all the things and it's going well, but suddenly someone moves from L2 into L1, taking the space that you were planning on moving into, and there are no other spaces immediately available at that moment, as you're approaching the end of the slip-road.

Do you stop at the end of the slip-road, or do you slow down and treat the hard shoulder as an extension of the slip-road if it's clear?

[zadocbrown]

No, and no is the short answer.

The only time it's reasonable to stop on a motorway slip road is if traffic is stationary (or almost so) in queues; or possibly on one of those horrid city centre motorways (which probably won't have a proper hard shoulder anyway).

Going onto the hard shoulder would be less bad, but still a serious error.

This problem should really never arise. Aim to join the motorway sooner rather than leaving it to the last minute and you will have time to change your plans without getting into difficulty. In fast moving traffic there will always be a gap, it just needs a bit of spacial awareness and confidence to manoeuvre into it.

[jont]

This problem should really never arise. Aim to join the motorway sooner rather than leaving it to the last minute and you will have time to change your plans without getting into difficulty. In fast moving traffic there will always be a gap, it just needs a bit of spacial awareness and confidence to manoeuvre into it.

A decent amount of power helps too

[TheInsanity1234]

It's never happened to my parents, and nobody I know has actually gotten into that kind of situation, but there's always that 0.00000000001% chance it's going to happen on a god-awful Friday to end a week from hell

But yeah, I was just curious as to what people would do.
I would always plump to go on the hard-shoulder rather than stop, simply because accelerating into a gap from 30 is far better than trying to accelerate into a gap from standstill.

[Rick101]

I think it's just down to observation and planning. I know you can't always get a good view, especially across lanes 2 and 3 but I would imagine a vehicle coming into lane 1 would be slowing, as you're under acceleration you should be able to get in front easy enough. I think it would be better to accelerate rather than decelerate on that section of road.

[WhoseGeneration]

OP, once you're driving yourself and taking on board what you read here you'll come to understand how to deal with such situations.

"Acceleration Sense" is often mentioned and this is one of those situations, along with being in the right gear for any situation.
Usually Lane 1 will be at the speed of the slowest in that lane, usually LGVs, so 56mph.
So, in virtually any car, in the right gear, you should be able to slot into a space using observation to decide whether that space is in front or behind the one who took your original space.

You have to also take account of what those behind you might be looking to do also.
You might have to join without that precious 2 seconds gap to the one in front, alas, that's the reality of Motorway driving.

[TheInsanity1234]

I perfectly understand the definition of acceleration sense, and one of the things that annoy me are people who use their brakes unnecessarily, especially on the motorway.

I'm certain I'd have to join without a 2 second following distance, but hopefully as I join, I would have a good view of the traffic ahead so I can reasonably predict what would happen, and as soon as I've joined the flow, I would immediately reestablish the 2 second following distance, or perhaps a 3 second following distance to allow those last minute joiners some room to merge in safely.

[zadocbrown]

This problem should really never arise. Aim to join the motorway sooner rather than leaving it to the last minute and you will have time to change your plans without getting into difficulty. In fast moving traffic there will always be a gap, it just needs a bit of spacial awareness and confidence to manoeuvre into it.

A decent amount of power helps too

Or just being in the right gear. It's not a horsepower hungry manoeuvre - we are gaining or losing 10 mph at the most, usually less. The lowest powered modern car will be quite adequate if driven well, and mega torque won't a silk purse make if the timing is wrong.

[waremark]

One of the most important aspects is to plan so that you are never alongside another vehicle on the slip road when your lane merges with another. Often the right lane of the slip road merges quite abruptly, whereas the left lane merges over a much longer distance. You must not come to the end of the right lane alongside a vehicle in the left lane unless you can see for certain sure that there is room for you to join the main motorway - and even then it is not the best situation to be in.

[Gareth]

accelerating into a gap from 30 is far better than trying to accelerate into a gap from standstill.

Neither are good; you need to be traveling at close to the speed of your chosen gap before slotting into it.

If speed adjustment is needed, easier to slow.

[TheInsanity1234]

accelerating into a gap from 30 is far better than trying to accelerate into a gap from standstill.

Neither are good; you need to be traveling at close to the speed of your chosen gap before slotting into it.

If speed adjustment is needed, easier to slow.

No, what I mean is that it's better if you're already moving at a decent speed before having to accelerate to take a gap.
If you're doing 30, and you see a clear gap approaching, you can accelerate to match the speed of the gap, which is probably about 60 in L1, whereas if you're at a standstill, and you see a gap, you'd probably have problems accelerating to match the speed of the gap in the little time you have before it's alongside you, unless you're in a really powerful car.

[jcochrane]

One of the most important aspects is to plan so that you are never alongside another vehicle on the slip road when your lane merges with another. Often the right lane of the slip road merges quite abruptly, whereas the left lane merges over a much longer distance. You must not come to the end of the right lane alongside a vehicle in the left lane unless you can see for certain sure that there is room for you to join the main motorway - and even then it is not the best situation to be in.

I certainly agree with you Mark. I was with a RoADA tutor the other day and argued this very point with him. But then I also strongly disagreed with him in a narrow lane (just possible to squeeze two cars past each other, with high hedges allowing no forward vision, that approaching left hand blind bends in the centre of the road was not the best place to be. He insisted he was right and this is what an examiner would expect and that he knew best because he had got a Gold. I think I might have mentioned something about "excrement from a bull" (I always try to be polite ), slowed down and tucked in at which moment a car came rather quickly round the bend in the opposite direction and partially across the centre of the road. Proved a point I thought. I resisted the urge to rub it in but I think he might have already got the message. He was rather quiet for the rest of the drive. What was also upsetting was that as well as being awarded a Gold he was an ADI.

[Gareth]

If you're doing 30, and you see a clear gap approaching, you can accelerate to match the speed of the gap, which is probably about 60 in L1

30 is much too slow if the gaps are moving at 60.

[GJD]

Do you stop at the end of the slip-road, or do you slow down and treat the hard shoulder as an extension of the slip-road if it's clear?

Well both are (undesirable) options. I don't think there's any benefit to trying to decide a rule in advance that you would always do one or always do the other.

With fast-moving traffic and a proper motorway slip road I don't think I've ever stopped on the slip road. I can remember one occasion (someone had done what you describe - moved from lane 2 to lane 1 and nabbed my spot) where I extended onto the hard shoulder a short distance. I was accelerating, not slowing down though. Are you talking about continuing onto the hard shoulder while you still haven't figured out yet where you are going to merge into the lane 1 traffic? That's very different to planning a normal merge, losing your slot and then deciding that the best option now is ahead even though you won't quite get there before the slip road runs out so you'll need to extend a short distance onto the hard shoulder.

[Astraist]

One way that helps to avoid this situation is to combine the forward observation and early planning with the use of the entire slip road, which many drivers fail to do.

You identify the gap and initiate a move, but you prolong the move by merging at a shallow angle and progressively accelerating to a speed slightly above traffic speed in L1.

By making the move longer, aborting the attempt to merge into a certain gap (if it has been suddenly occupied) would be made possible, and you could quite possibly drop back into another gap.