I hope this is a wind up!

Can't see how they could make it stick, speedometers cannot be accurate due to the variation in tyre diameter due to wear and manufacturing tolerences etc.

I understand the monitoring equipment has to be calibrated, David, and I read of a case being thrown out of court when the police couldn’t produce evidence of calibration.

Well I must say I'm shocked!

Merve - how come an obviously very discerning lady such as your wife actually reads the Daily Mail, let alone takes what it says seriously?  

Somebody has to read it as it UK's most popular daily I think

I quite agree that a 1mph allowance did you read the bit that you can do 79 mph on the motorway without getting fined this is not on, either we have speed limits which are there to protect everyone or we don't. How many times have I read on the club site caravan and motor  home owner complain about supposedly speading HGV 's

I live on a main road which has a 30mph limit which most do not do, so I am in favour of any measure to reduce speed. And you satnav will give you a better idea of your speed

Paul

Have I asked you to condone lawbreaking??? I can also see both sides and in an ideal world it would work. Unfortunately it’s not an ideal world. Odometers would have to be spot on to make this work. When I was a police officer we had to go to a chosen ‘mile’ and check the odometer each time we put a name in the book for speeding. Now, it’s just a photo so I say again, because of the innacuracies of speedos, we will have to travel at 2or 3 miles below the speed limit to be sure of staying within the law.

In principle you are correct, the problem is that until speedometers are GPS powered they cannot possibly be accurate for reasons I gave in my previous post and as such you cannot be prosecuted for something you have no way of knowing.

Hey, no need to get spiky, Merve. I didn’t say you asked me to condone law breaking. It was merely a statement.

Saying I could see both sides of the argument meant I accepted all the points you make, even if technology has negated some of it, but I still say the law is the law and we should not expect it to be OK to break it. 

Why do you call the Chief Constable a "cash cow"? I think that's rather a hasty assumption.

As tyres wear and the diameter reduces then a speedo will over-read so less chance of breaking the limit.

Just don't go above the indicated speedo reading and due to the manufacturers overead calibration everyone will be happy. Its people that want to push their luck by one or two extra MPH that are worrying about the loss of margin.

Speedo's cannot be GPS powered until our reliance on the USA military satellite is kicked into touch, its accuracy varies daily. Also atmospheric conditions, buildings, trees etc.

I fully agree with this post. Well said Merve.  It's good to read the opinion of those who really know what they are talking about. 

K