On 26/05/2011 05:51, Doug wrote:
On May 25, 9:29 am, "Nightjar\"cpb\"@""insertmysurnamehere wrote:
On 25/05/2011 07:17, Doug wrote:
...

Well we know from past surveys that a majority of motorists knowingly
exceed speed limits,...

When the Road Research Laboratory did an extensive study of speed
limits, their conclusion was that the purpose of speed limits should not
be seen as being to keep traffic at or below the set limit.

Source? Link? I would like to verify your claim.

A bound volume of Road Research Laboratory reports that was in Hove
Public Library reference section, when I last looked. I think it changed
its name to the Transport and Road Research Laboratory in the early
1980s, so I rather doubt RRL reports are available online.

Rather, they
should be seen as a way to avoid large differentials in traffic speed
and as a way to reduce significantly the number of vehicles that grossly
exceed the set limit. Their suggestions of what constituted 'grossly
exceeding' the limit quite closely match the ACPO recommendations on the
point at which prosecution would be appropriate.

So what are you suggesting here, that its OK to exceed speed limits as
long as its not by very much?

Unlike you, I do not encourage people to break the law. I am simply
reporting the conclusions of the Road Research Laboratory. However, the
Association of Chief Police Officers does seem to think that, as a
general rule and providing there is no other offence, it is acceptable
for vehicles to travel at a little above the limit without penalty.

I know there is some latitude because of
speedometer inaccuracies

Not in speed limits. Any speedometer errors must result in the vehicle
travelling slower than indicated, not faster.

but it doesn't make it OK in principle. What
about places where locals want speed limits to be lowered anyway,
particularly past schools?

The same principles apply, whatever the limit, although the RRL did make
the point that, to be effective, speed limits need to match the drivers'
perception of a safe speed for the road, so lower limits will normally
require traffic calming measures as well.

Colin Bignell