but once you overload one you really end up with a mess.
That's what I see here over in Norwich where the ring road is full of the things. I try to avoid rush hour there, but the roundabouts are terrible with heavy traffic because anything not already on the ring road barely has a chance to get into the flow. So what's the traffic planners' solution? Put traffic lights on the roundabout!
What a mess.....
Fortunately, outside of the rush-hours, Norwich is pretty easy as British cities go, and a few miles out you're back on relatively quiet country roads.
If you
really want to get to grips with roundabouts though, try this one:
http://www.swindonweb.com/life/lifemagi0.htm 
