[andymc]

If it's clearly signposted that the right lane approaching the roundabout is for turning right only, then yes one should stay in the left lane on the approach to the roundabout in order to go straight across. If however the signage indicates that the right hand lane approaching the roundabout is intended to be used for going straight across as well as for turning right, it's a waste of infrastructure not to use it as intended. There is no rudeness or unfairness in doing so.

The same principal applies at temporary lane closures on the motorway/dual carriageway. For simplicity's sake, assume the outer lane on a two-lane carriageway is due to close, and the usual "countdown" signage is there to warn drivers of this, e.g. 1 mile, 800m, 600m, 400m, 200m, 100m. There's no point in having a long queue in the left-hand lane half a mile (or however long) before the merge point, leaving an empty-but-usable outside lane. The most efficient way of maximising the capacity of the road is for both lanes to be used right up to the merge point, and people should have the wit and wherewithal to merge in turn, aka the zipper movement (oo-er missus!).

Problems arise when some people who have moved into the inside lane as soon as they saw the first sign believe, wrongly, that anyone continuing to use the outer lane up to the merge point is somehow being rude or selfish, and deliberately obstruct them from entering the inner lane. This stems from the psychology of queuing, of course, and it's true that no polite person standing in a queue would barge ahead of someone else. However the two scenarios are simply not the same.

I am far from a boy racer or aggressive driver - my overall attitude is to make it easy for people to merge ahead of me and indeed to make it easier for other people to share the road with me generally (including pedestrians, bikers, cyclists, buses, HGVs, horse riders ...). My philosophy is that a little courtesy and consideration goes a long way. However I will never feel guilty about making full use of the infrastructure, which has been put in place at our collective expense, for its intended purpose!