Magic Roundabout (Swindon)
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 you're on it. It can handle a much higher traffic flow than other kinds of roundabouts. The only potential downside is that you need to know where you want to go before you enter the roundabout. There's no possibility to keep going around until you figure out where you want to go.[0] https://nl.wikipedia.org/wiki/Turborotonde 
(In Dutch, but with images. "Rotonde" is Dutch for roundabout.)