Laser meters are inaccurate: BBC

TV show tonight condemns 'dodgyscopes'

Dodgyscope

BBC TV programme "Inside Out" has been testing a laser speed meter, and will broadcast this evening a film showing two laser speed meters pointing at the same vehicle showing markedly different speeds. The regional programme will air in London and BBC South West region this evening at 7:30pm.

Under UK law, offences must be proven 'beyond a reasonable doubt'. The BBC film illustrates a potentially commonplace error. Millions of drivers have been convicted with unsound evidence, and many prosecutions are ongoing.

The error in question is known as 'slip error'. It happens when the aiming point of the beam moves across the target vehicle. This works because laser speed meters do not directly measure speed. Instead they take a series of distance measurements. If the aiming point moves along the target vehicle the change in distance of the aiming point adds to or subtracts from the true speed.

Sources tell us that the Home Office did not test for this error before issuing type approval.

Safe Speed road safety campaign founder Paul Smith said: "No wonder we get a steady stream of indignant motorists complaining to us that they know for sure that they were not driving at the speed of which they are accused. And no wonder that people have christened the most common laser speed meter the 'dodgyscope'.

"I am certain that these devices are not suitable for gathering legal evidence of vehicle speeds. They make mistakes and the BBC film proves it. The Home Office must immediately suspend type approval on these devices pending a full investigation. Millions of drivers will be entitled to refunds, licence points removed and in some cases a large amount of compensation."

At a very rough estimate, over five million drivers have been convicted on the basis of laser speed meter evidence in the last five years. The fines refund alone will run to £300 million."