These are "turbo roundabouts"The typical roundabout we went around, for instance where a B-road style through-road bypasses aFa town and a local road goes off, has two fairly wide lanes around a large central circle. The two lanes are separated by concrete kerbs, so that if you want to turn right you have to get into the (kerb-separated) right-turning lane a hundred yards before the roundabout. We did come across roundabouts with three concentric kerb-separated lanes, one to go right, one to go straight on or right and one to go straight on or left. I still can't work out how that makes sense. Each kerb-separated lane on the roundabout demands a kerb-separated lane in the rundup, and there's no attempt to gently guide you into the new lane, it just appears.
Invented by a researcher at the university here in Delft.