Martin Underwood wrote:
"Richard J." wrote in message
...
Andrew P Smith wrote:
In article , Helen
Deborah Vecht writes

I think there's a similar one in Hemel Hempstead....

No, that's just 5 mini roundabouts in close succession similar to
those outside Hatton Cross tube station.

IIRC there are 6 mini roundabouts, placed around a central island.
This is an exactly similar configuration to the Swindon one,
except that Hemel has 6 roads entering instead of 5, and the
central island is bigger.

I thought the roundabouts at Swindon were placed randomly rather
than regularly around a central roundabout. Certianly they appear
fairly random when you drive around them.

If you look at the photo on the page that I referred to originally in
this thread*, you'll see that there is a mini-roundabout at the point
where each of the 5 roads enters the Magic Roundabout, forming a
more-or-less regular pentagon.

* http://www.swindonweb.com/life/lifemagi0.htm

--
Richard J.
(to e-mail me, swap uk and yon in address)

"Richard J." wrote in message
...
Martin Underwood wrote:
"Richard J." wrote in message
...
Andrew P Smith wrote:
In article , Helen
Deborah Vecht writes

I think there's a similar one in Hemel Hempstead....

No, that's just 5 mini roundabouts in close succession similar to
those outside Hatton Cross tube station.

IIRC there are 6 mini roundabouts, placed around a central island.
This is an exactly similar configuration to the Swindon one,
except that Hemel has 6 roads entering instead of 5, and the
central island is bigger.

I thought the roundabouts at Swindon were placed randomly rather
than regularly around a central roundabout. Certianly they appear
fairly random when you drive around them.

If you look at the photo on the page that I referred to originally in
this thread*, you'll see that there is a mini-roundabout at the point
where each of the 5 roads enters the Magic Roundabout, forming a
more-or-less regular pentagon.

* http://www.swindonweb.com/life/lifemagi0.htm

You're absolutely right! I've looked at the aerial photo and I can't work
out why this one appears so confusing and random when you're driving round
it whereas the one in Hemel seems more organised. How many exits does the
Hemel one have: is it six?

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.

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

On Sun, 6 Jun 2004 08:22:23 +0100, "Bob Wood"
wrote:

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.

I wonder how the usual option - traffic lights on the roundabout -
would perform in comparison?

I can think of a couple of roundabouts in Milton Keynes (other than
the one that already has lights) which could do with some slowing of
the traffic, as it sometimes approaches and negotiates the roundabout
at dangerous speeds (50mph is not impossible - the roundabout is so
wide that if there's very little traffic it's possible to take an
almost straight path across it so there is little need to slow down).

If anyone's interested, the main one concerned is the V11-H8
roundabout by the Kingston Centre. I've almost come to grief a few
times there - it's quite possible for traffic to approach up the H8
near the speed limit (70mph) and not be visible to someone waiting on
the V11 north side (due to the layout) until it is almost on the
roundabout. At that sort of speed, this is far too late and often
results in emergency braking being necessary (my car hasn't got enough
go to safely accelerate out of the way).

Neil

--
Neil Williams in Milton Keynes, UK
To e-mail use neil at the above domain