"Andrew P Smith" wrote in message
...
In article m, Martin
Underwood writes

"Robert Woolley" wrote in message
.. .
On Sun, 19 Oct 2003 17:18:43 +0100, Andrew P Smith
wrote:

In article , Robert
Woolley
writes

Speed does kill. You don;t have to be a genius to understand that
the
faster the speed of a vehicle, the longer it takes to stop. And the
faster it hits something else the greater the damage.

No. Bad driving kills. The driver selects what speed they drive at. If
that speed is inappropriate then it's bad driving. Nothing else.

I'm a former member of the Institute of Advanced Motorists. Are you?

Nope.

But I hold a PSV licence, gained after comprehensive training. I also
hold a RoSPA road safety engineering certficate, a BSc in Transport
Management and Planning, Chartered Membership of the Chartered
Institute of Logistics and Transport, plus Corporate Membership of the
Institution of Highways and Transportation.

OK. Maybe you can answer this question: what are the circumstances under
which a single 4-way roundabout should be replaced by two linked 3-way
mini
roundabouts? There's a sod of a junction near me which always gets
snarled
up with traffic (junction of Drayton Road, Spring Lane and the two halves
of
Ock Street in Abingdon) and it seems to me that it would have a much
greater
throughput of traffic if it was converted back to a single larger
roundabout
because it would save drivers having to check twice for vehicles from
their
right - once on the first roundabout and then again on the second.


Martin

I know the junction you mean.

We have an even worse one here in High Wycombe and as for the Magic
Roundabout in Swindon.......

Yes, the Magic Roundabout in Swindon is a pain in the bum: it's as if the
road designers decided to make it as tortuous as possible - being cynical, I
wonder if they decided to make it hazardous so as to keep the traffic speed
down: which is silly because the deliberate hazards distract the drivers'
attention from the hazards that they should be looking for - other road
users!

And then there's the roundabout in Hemel Hempstead. This started out as one
big 6-way roundabout. It worked fairly well. Then the traffic planners took
it into their silly meddlesome heads to place a mini roundabout where each
road joins the big roundabout (which they reduced in diameter). To negotiate
the roundabout, you now have to go round several mini roundabouts. Moreover,
if you are turning right, you go clockwise round each mini roundabout but
*anti-clockwise* round the central roundabout, which feels very wrong:

http://www.martinunderwood.f9.co.uk/hemel.gif

There are now three places (marked with an X) where a driver must check for
traffic on his right, whereas on a normal roundabout there is only one -
normally once you are on a roundabout you do not have to give way to anyone.


Strangely the roundabouts in High Wycombe (I presume you mean the ones near
the Fire Station and at the bottom of Marlow Hill) don't seem too bad -
maybe because they are spaced far enough apart that they don't seem like one
big junction - you have you sufficient time and distance to "recover" from
one before encountering the next.


Another question for our road layout expert: who decides which mini
roundabouts are raised up and which are simply white discs painted on the
road? You'd think it would be determined by the amount of circulating space:
if there's plenty, have a raised-up one and make traffic go round it; if
there's no enough maneouvring space, have a painted disc and let traffic go
over the top of it - it's there purely to establish fair play. But no, the
"experts" in Didcot have one on the Broadway (the high street) which it is
impossible to drive round even in a small car - there's just not enough
space between the roundabaout and the kerb. And this one is raised - it's
like going over a one-sided speed hump. If anyone were to misjudge its
severity and negotiate it too fast, they'd lose control and go straight into
the shoppers on the pavement. If only that was a painted roundabout, it
would be so much easier.