If Lino Spiteri (Talking Point, July 21) was "done" for allegedly travelling at 62 km/h in an area limited to 60 km/h, then he should contest this.

There is probably no vehicle speedometer that is capable of reading to this degree of accuracy (3.2 per cent).

Anyone who has the slightest idea as to how speed measurement is taken by a vehicle and how such a measurement is then converted by the speedometer into the human-readable position of a needle on a dial will understand why such a degree of accuracy is just not realistically possible for each and every vehicle that leaves the production line. Even the innocent act of replacing one's tyres will affect this reading.

So much so that in other countries where speed cameras are in use, due to this fact it is customary to allow a 10 per cent margin of error in the driver's favour.

Further reinforcement of the inaccuracy of speedometers, when a vehicle's performance is being tested, the car's instruments are never used. Previously, a "fifth wheel" contraption linked to accurately calibrated instruments was commonly employed; latterly, GPS satellite measurement is used.

Therefore, allowing for the maximum 10 per cent in the driver's favour, Mr Spiteri could very well have had a reading of just over 56 km/h on his speedo while he was "nicked" for doing 62 km/h.

Then again, this incident is proof, if ever any were needed, that speed cameras as set up are money-making machines first, safety devices second. Quite unsurprising when considering that the organisations responsible for the running of these devices partake in profits from their use.