A better solution for high traffic flow is the turbo roundabout[0] which is getting increasingly popular in Netherland. Before you enter the roundabout, you select the lane for the direction you want to go. You only cross traffic when entering the roundabout for the first time. After that, you simply follow your lane and it delivery you where you want to go. It looks complicated from above, but it's very simple once…
In a "traditional" roundabout, all motorists could perform an extra round and thus clear the roundabout fast and easy. This doesn't work that great in these kind of roundabouts, I guess.