It's called a "roundabout" they have then in Europe all over the place.
They even have them here in the States.
If you saw "National Lampoons European Vacation" you'd know all about them.
Traffic going into it yields to traffic already in the roundabout. Once you get in you gor one way around the circle and peel off to whatever road you want to get on. If done right it's very efficient to handle a large amount of traffic in a short amount of time.
I think it would be better if it actually had islands on it instead of just paint on the road. That might work in Europe, but if you had those in abundance in the states, OMG are you talking about an 200 car pileup waiting to happen or what!
Most roundabouts that I've seen have had an island in the middle of the thing. With a compound roundabout, though, you need to be able to see what's going on on the other roundabouts so that you can make a wise decision about what to do with your own vehicle.
Those wouldn't work too well in the states. Most drivers have problems navigating on CLOVERLEAFS. In Europe, though, drivers are put through much more rigorous testing and training, and accidents on the whole are less common. From what I understand, accidents on roundabouts generally spur from tourists trying to navigate them. :lol