In s.com,
Martin Underwood typed:

I think I still prefer a nice simple arrangement with one big
roundabout, they you only have to gave way ONCE, as you're entering
the roundabout, rather than having to be prepared to stop at every
roundabout on your route.

I lived in Hemel before the mini-roundabouts were put there. The problem
was that the big roundabout was so big that traffic already on it was able
to travel at such a speed that it was impossible for other traffic to join;
hence huge queues built up.

After the changes were made, speed through the junction lessened
considerably but so did the length of the queues. Overall the time spent
getting through the whole queue/junction was much shorter. I suppose it can
be likened to the variable speed limits on the M25 - reduce the
traffic speed and more traffic gets through the area in a given time.


Bob