On 31/10/2011 08:48, Mortimer wrote:
"Nightjar" wrote in message
...
On 30/10/2011 16:21, Nick Finnigan wrote:
On 30/10/2011 08:03, Basil Jet wrote:
At the crossroads of Exhibition Road and Cromwell Road SW7, traffic
approaching from three directions is now banned from turning left or
right.
This is signified by the green light being a forward arrow. At other
junctions where both turns are banned you would see a vertical white
arrow
on a blue background beneath the three traffic lights, but they have
not
done that here.

I would expect to see 'no left turn' and 'no right turn' signs in red
circles alongside or under the green arrow.

According to the Traffic Signs Manual, at lights controlled crossings,
a single arrow indicating the only permitted direction of travel is
the correct choice of sign. At uncontrolled junctions, either that or
two signs, showing no left turn and no right turn are acceptable.

But why do they make a distinction based on something which is supremely
irrelevant to most drivers? Why not make the signage consistent in both
situations: make them both say "no left or right turn" since it is
better to tell people that they cannot do something that were intending
to and which is therefore uppermost in their mind at that instant,
rather than say "you can (only) go straight ahead" to people who weren't
planning to go straight ahead.

It has been found that too many signs or signal creates confusion, so
the aim is to ensure that no more than two, or occasionally three, are
mounted on the same post or on different posts at the same place. The
lights count as one sign for this purpose, so there should, if possible,
be no more than one more sign at a lights controlled junction while at
an uncontrolled junction there can be two.

Colin Bignell