Bending the subject a little, around 1980 Hemel Hemstead was the worst roundabout I ever encountered.
It had a large roundabout surrounded by 4 /5 ? mini roundabouts with traffic going in both directions. Someone tell me the practice has been abolished and the person who thought of it is not allowed to breath ! And there used to be a few cities with Roundabouts that had traffic lights, that only worked at rush hour. I think the A13 was better with bridges over for straight on traffic. 
