Ian G:
I never move over, even if there’s room. Far too many reasons not to go compared to far too few reasons to help out someone in a car who can have any gap they want, forward or aft.
I agree, and I never flash them out either. I think by flashing you are committing yourself and if all goes wrong - you’re to blame 
dri-diddly-iver:
Crack on driver don’t give way, if you give way once they will expect it every time. Avoid an accident if at all possible (don’t put anyone else at risk) but licence holders sometimes have to learn the hard way.
My sentiments entirely…TOSSERS
i had an idiot in a van bounce off the side of my skelly trailer on the A30 heading towards Exeter at the airport junction because i didn’t (couldn’t) move over
he was rather ■■■■■■ off when i informed him, and also my office informed him that he had just admitted liability for the accident
it cost him his pride and a new wing mirror 
I only wish people joined highways like this here, either slowed or speed up to merge but most of the idiots get to the bottom of the ramp and instead of using the accereration lane to get to a required speed the stop dead and look back which causes a back up behind them, then they start from 0mph and just drive onto the road.
Sadly this isn’t a new problem. It has been on-going since motorways were first constructed. Motorists need to be re-educated in this issue as many don’t realise or refuse to accept that vehicles already travelling on the motorway have right-of-way. I mean it, they blatently refuse to accept it. Many don’t even understand what the broken lines mean at the end of the slip-road. They still argue that everyone should move over to let them in! So it appears from the previous comments, re-education it is, or suffer the consequences for their ignorance. I know what I’d choose.
Same old, same old.
Dotted white line means give way, simples.
Just because there isn’t a triangular sign.
Anyway how can a joiner in ,say, a Megane know that lane two is clear for you to use? Instant realtime Google Earth?
Answer, he/she can’t.
Motorway driving is not taught, and is not part of (as far as I know) the driving test. Not the theory but actually behind the wheel. And this is in my opinion part of the problem.
I blame car ads, too - they always show some dik zipping down a slip road and straight into lane 1. Buy this car and your merging troubles are over. Fantasy nonsense. But some will buy into it. Until the sidebars remove the Simonize.
Socketset:
Motorway driving is not taught, and is not part of (as far as I know) the driving test. Not the theory but actually behind the wheel. And this is in my opinion part of the problem.
If there is a dual carriageway nearby the driving test centre, then you are usually expected to do a stint on it and this can involve (not always) joining from a slip road. So it is in the ‘syllabus’. Unfortunatly though people are only taught how to pass their test, so if you aren’t likely to go on a dual carriageway or merge from a slip road during your test you won’t get taught it.
New drivers can do that ‘Pass Plus’ thing after they pass their test but I think less and less people are doing it because the insurance discounts they claim it can give are pretty much negliable.
selby newcomer:
Aot of people don’t look to see if they can safely get on to the motorway until they are just about to cross the lines, then panic sets in when they realise there’s no space for them, then they try and force themselves into a space that isn’t there.I’ve taken the “I’m not moving over or slowing down” attitude lately, as it’s getting beyond a joke, as has already been said, some people need to learn the rules and regs the hard way
+1 
Car drivers expect us to move over because they do it for us, difference is we’re alot bigger so theres less chance of there being a gap big enough move into, also half the time theres some dawdling car driver passing me who decides to sit alongside as i pass the sliproad, i swear theyre doing it on purpose 
Im not one for moving over unless i really have to, i.e. if theres a slow lorry or and line of slow moving cars joining, sounds selfish but i dont expect people to move over for me and i respect that, but then when im joining from a slip road im making enough observation to allow me to adjust my timing and speed accordingly.