Are speed cameras reliable?

On February 2 at 1.38 a.m. a relative was driving back home on an empty stretch of road at Burmarrad.

The speedometer, which he happened to be watching, was reading between 70 and 65 kilometres per hour. On the 13th he received a notice of contravention from the St Paul's Bay local council indicating that he was driving at 75 kph (46.87 miles per hour), exceeding the 70kph(43.75 mph) by just five kilometres, or three miles an hour.

In my opinion 46.87 mph on an empty road at 1.38 a.m. can hardly be termed irresponsible or dangerous driving. It is also to be noted that the ordinary speed limit out of town is 80 kph.

However my preoccupation is the evident lack of comprehension of the margin of error inherent in both car speedometers and the electronic speed measuring equipment used to monitor the speed of passing cars.

I note that a VRT test does not include calibration of speedometers, and my enquiries so far indicate that there is nowhere one can go to obtain a calibration certificate either, leaving a hapless motorist in the greatest difficulty to defend himself.

As a chief inspector with over 30 years experience of a precision engineering company engaged in the production of aerospace components, part of my responsibilities was to ensure that all my measuring equipment carried a valid calibration certificate directly traceable to the NPL (National Physics Laboratory) at Twickenham.

Can someone assure me that the same rigorous standards of calibration are maintained with regard to the speed cameras that are proliferating everywhere and which are clearly being misused, either as a means of tax gathering or simply through ignorance and understanding of their actual reliability?

We clocked a stationary wall at 58 mph - now that's motoring.

During a routine test carried out by the RAC a stationary car was clocked as doing 4mph by a latest generation speed camera.

The unevenness of the road a car happens to be travelling on at the time also has a bearing on the recorded speed.

Given that the degree of accuracy that can be reasonably ascertained by both car speedometers and speed cameras often falls outside the + or - 5 kph under ideal conditions, common sense suggests that a certain amount of leeway would be in order. After all a Lm30 fine and the time and inconvenience involved in defending oneself are not justified in such cases.

This is merely iniquitous harassment giving rise to grave suspicion as to the real intention behind the use of these cameras.