trudee - your question seems to boil down to what is the correct procedure for merging at the end of these lanes.
In any of these situations I have come across the left lane continues and the right lane ends (by merging) rather than both lanes ending and a single lane starting. In my mind this puts the onus on the driver in the right lane (who is overtaking) to be sure that they can safely overtake within the confines of the lane they are in. The way I see it, if the driver in the right lane can't complete the overtake before their lane ends then they should reduce their speed and merge in behind the car.
There could be endless argument about whether individuals should 'police' the 'fast' lane, but in reality if we had regulations like they have in other countries where you have to pull over if there are more than X cars behind you then the problem would pretty much go away itself. That, plus a law enforcement organisation that was willing to/capable of writing tickets for *blatant* breaches of the law like speeding, broken lights, dangerous vehicles, dumbass overtakes, etc . . . would soon have behaviour on the roads in order. Unfortunately I can't see this happening in Ireland for a *long* time as things stand. Does anyone know whether we use car mounted mobile speed cameras here ? I got done once on New Zealand by a police car passing in the opposite direction with a camera pointed at oncoming traffic. That would cool a few jets here in Ireland. Actually it would probably be subject to a(nother) legal or constitutional challenge like we seem to excel at when it comes to road safety and life saving initiatives.
z