ar wrote:
what is the current IAM advice for lane discipline?
and does this lead to the most efficient flow rates?
This is forgotten art - in fact it is not even taught in UK - and another reason perhaps for including drive on fast A road at least on L Test.
Part of COAST!
When you join motorway - stay in L1 to acclimatise to faster speed in any case.
Basically - you drive in LEFT HAND lane unless prevented to by lane closure or other cirumstances. After your overtake at 70 mph

, (and unless you wish to pass stream of slower moving L1 traffic (by slower I mean those HGVs on limiters and other slower moving traffic - and not L1 traffic travelling at 70 mph

and you blatting past at 75 mph and higher), you move back to L1 as soon as it is safe to do so (ie in that nice gap you spied which keeps your two second rule for yourself and others

). You avoid undertaking unless you are in one of those traffic queues caused by numpties braking hard when they spot the talivan and realise they were driving way too fast!
You should always look ahead - up to road horizons, scanning ahead, to rear and sides, being aware of blind spots.
Monitor opportunities to overtake - you check what is closing on vehicles in front and what is moving up behind. Match your speed of approach to blend into the traffic flow (70 mph limit

) make allowances for lane closurs, junctions etc. Watch body language of other drivers - speed, head movements vehicle movements - all provide clues as to intentions - they tend to do this before they signal!.
Avoid overtaking if you can see you will end up three abreast - all at same speed in all three lanes!
At junctions - goes without saying that people will be joining and there will always be a last minute numpty!
If possible - adjust speed to let person join, change to L2
if safe to do so and ultimately it is vehicle joining the motorway who should give way. But two wrongs never make a right - so care required by all.
Basically - it is about applying COAST, keeping your cool, being courteous and using common sense!
And it should be taught - properly!
