The history is kinda interesting<p>>Mini-roundabouts were developed by the Road Research Laboratory in the early 1970s as an experiment into whether the success of the priority-to-the-right rule at larger roundabout junctions could be applied to locations where there wasn't enough space to install a full-size roundabout. By summer 1971, 33 were in use across Britain.<p>>[Frank] Blackmore pursued this discovery, noting that the design was also superior to signalised junctions, following a Peterborough experiment where an extra 1,000 vehicles could be handled every hour by a new small roundabout at a previously signalised T-junction. He started to wonder if several small roundabouts could be linked to improve more complex junctions.<p>>...Blackmore didn't give up, [...] and in 1972 gave Britain a new design of Ring Junction. It was supposed to be in Birmingham, but the Council there was unable to fund the scheme, and so the RRL was invited to try its new design at a congested roundabout near Swindon town centre. For the first time, traffic could flow both ways right around the central island, meaning that if one side was congested, the other side could take up the slack. After a few days of Police control, in which time RRL researchers logged events from a crane-mounted camera, the experiment was branded a success.<p>>[It] is one of the few places where the jams have never really returned despite forty years of traffic growth.<p>>...They also have an excellent safety record, probably because all traffic is moving too slowly to do any real damage in the event of a collision.<p>from <a href="http://www.cbrd.co.uk/articles/the-magic-roundabout/" rel="nofollow">http://www.cbrd.co.uk/articles/the-magic-roundabout/</a><p>see also an obituary tribute <a href="http://www.mini-roundabout.com/tribute.htm" rel="nofollow">http://www.mini-roundabout.com/tribute.htm</a><p>Quite a colourful history for a roundabout guy - Born and brought up an expat in Algeria, studied engineering in Switzerland, RAF pilot in WW2 getting an Air Force Cross, became an Air Attaché in Beirut where duties included bugging the Russians next door with holes drilled through the wall. Then roundabouts.