What should A have done?

[LouBlue1507]

What should car A have done?

1. Brake, slow down and pull in behind car C

1. Continue to gather speed and continue in the same lane

Any other option?

Cars should adjust their speed to merge with traffic on the main carriageway however this does not mean they have right of way. Whilst it is good manners to move out if possible it is not mandatory. Sorry op you were in the wrong . You should have adjusted your speed whilst on the slip and been aware of what traffic was on the main carriageway.

But the lane she went into was free.

Lorry clearly wasn't keeping an eye on traffic coming from the slip road and was an idiot to try to move over just at the point where people were joining the left hand lane from the slip road.

You should have slowed and gone behind car c otherwise you are undertaking the lorry which is a massive no no (traffic offence?) pretty sure undertaking is classed as dangerous driving.

Logically, you just pull onto motorway at a reasonable speed i.e. same or slower than the lorry. You shouldn't have undertaken him (although I probably would too). The lorry should also check the inside lane was clear before pulling into it. So you were both wrong.

If there's no one ahead I'd accelerate to get away from the lorry, I wouldn't want to be level with him in case what happened to you happened.

Imo he was in the wrong

Surely it's not undertaking as she's joining the motorway/faster road and fitting around that traffic?

It would be less safe to brake harshly, I was always taught you can speed up and get in front if safe to do so on the slip road.

Undertaking for me is either intentionally pulling into the left hand lane to go around a slower vehicle or going faster than a vehicle on the left rather than pulling out into the overtaking lane to go around them/behind them.

Carry on driving.

You shouldn't pass him on the left unless he is in some sort of moving queue, really, but slamming your brakes on is probably worse. While I agree that you shouldn't join faster than traffic, that tends to apply to the lane you're joining, not other ones.

It's a really silly place for the lorry driver to move left, when anyone in the left hand lane or slip road are busy dealing with each other. He should have just kept out until well clear of the slip, giving you time to sort yourselves out. Don't worry about it.

I would probably have sped up to get in front.

Although not quite as you have drawn, what you did is (nearly) a pet hate of mine. If you had have been behind the lorry as you entered the motorway, I hate it iyswim?
I.e. IM in the left hand lane on the motorway, move over to middle to let cars from slip road on. Then the fuckers just keep undertaking you and not letting you get back in to the left lane.

If you joined alongside the lorry then yeh, speeding up would be the best option imo. It's a weird one though, surely the lorry had pulled into that lane to let people join from the slip road, but then acts like no one is there.

Ah, I have assumed the lorry kindly moved over for you to joIn, and wanted to get back in.

Speed up and beep your horn to let the lorry know you're there.

But if you passed him that's undertaking isn't it? Did you see the lorry coming or is it a bit of a blind spot?
Not knowing the roads theoretically I would have joined at a slower speed, allowed the lorry and car to pass and then pulled into a faster lane if needed.

This was no ones fault - but you both got a fright. His reaction to that is to get aggressive and blame you (or more accurately, anyone but himself), your reaction is to blame yourself.

Possibly you were sitting in his blind spot and he didn't see you.

Or possibly your acceleration wasn't even/wasn't quick enough and he didn't realise that you were planning to full ahead of him.

I would have been expecting the lorry to pull back in (as he pulled out to let you join) and therefore made sure I accelerated ahead of him pretty quickly, but how easily you could do that depends on your car.

None of us can say whether you were in the wrong from the diagram as there are several variables. If you kept accelerating after he signalled his intention to pull back in then I can see why he would be annoyed.

YWNBU OP. I would have done option 2 also. It's a lot safer, although essentially 'undertaking'. The lorry should have been more aware of their surroundings considering, I assume, they purposely moved into the next lane to make way for cars approaching from the slip road. Hope you're ok, such a scary situation.

Sounds to me like lorry driver was a twat. He should have known you were there having seen you approaching on the slip road, or otherwise he should have known that there was a blind spot and taken account of that.

Sorry OP but I think you were in the wrong there by undertaking. Should have dropped behind car C to overtake the lorry.

I think you were in the wrong too. I assume the lorry was in the fast lane as he moved over to let you pull out. In which case you should have went slower and pulled out after Car C. Actually it doesnt really matter why the lorry was in the fast lane, it doesnt give you the right to undertake. Thats just piss poor driving.

My diagram is wrong! My slip road lane is a new lane if that makes sense, there's no road before it. Maybe that makes a difference?

If you had already joined the motorway then technically you undertook him by speeding up. If you were on the slip road I would say it's ok to speed up in a bid to move in front of him.

No, you still shouldn't have undertaken the lorry regardless of where the road/lane starts. Traffic on the motorway has priority over the traffic joining it.