For a country with so many round abouts, we are blissifully ignorant how they should be used. I did my test while living in London, and the use of roundabouts was always a source of friction with my instructor. My particular bug bear is indicating - my instructor reckons you would fail the test for hesitation there if the other driver isn't indicating and you were trying to guess what way he was going (no indiction means going straight through only). I found this funny, cos in Ireland you'd quickly end up in an accident, and sure enough only 12 months after moving back I was T-boned by an idiot in an ESB artic turning left in the right hand lane at the M50 / M1 junction (he was wondering what I was doing there, I thought the fact I was in the left lane and indicating left was pretty obvious) . In the UK, you use them as follows:
left hand land - for straight ahead and left only. Indicting left means going lweft, no indicators means going straight through. On larger roundabouts, tou may have to indicate as you are approaching the exit your going off at.
Right hand lane - right hand turn only. Indicating right.
I would expect the same to apply here, gioven the drive on the same side of the road as us. As far as I know that applies to single & dual lane carraigeways only. I'm not sure of the rules when it comes to road markings when these are marked differently, although where ther are marked people still ignore them and do whatever they like.
I think the government need to run a campaign as to how these should be used, it's chaos out there.