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COPS USE SPEED GUN WHICH ADDS 30MPH
'One in three' results wrong
By Stephanie Busari
13 September 2005

BRITAIN'S most widely used speed gun can give readings that are 30mph ABOVE a car's real speed, it was claimed last night.

Motoring campaigners says measurements taken at a race track mean millions of "speeding" motorists, may have been wrongly convicted.

Paul Smith, founder of lobby group Safe Speed, said: "It is shocking. These devices are not suitable for gathering legal evidence of vehicle speeds."

The £2,750 Tele-Traffic LTI 20.20 - modified from a US model - recorded inaccurate speeds on seven out of 22 occasions when aimed at a vehicle travelling at 30mph.

Laser technology expert Dr Michael Clark found the hand-held device measured a stationary car as doing 6mph.

This was due to the gun not being held absolutely steady when a series of laser beams are fired at the vehicle.

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The mistake was repeated in tests on a lorry travelling at 30mph when speeds of up to 56mph were recorded. And it was calculated a car could be clocked up to 30mph above its speed.

"If someone's doing just below 70 mph on a motorway that puts him up in the 90s and they're going to be done by the police for sure," said Dr Clark.

The scandal was revealed by BBC consumer rights programme Inside Out after trials near Ringwood, Hants.

One motorist interviewed on the show had his conviction overturned after being pulled over for doing in excess of 90mph despite setting his cruise control at under 70mph. But the speed gun was defended by the authorities yesterday.

The Association of Chief Police Officers said it had been rigorously tested and approved by the Home Office.

A spokesman added: "The Home Office Scientific Development Branch is of the opinion that the UK version will perform within permitted tolerances if used in accordance with guidelines."

Its UK supplier also insists the modified British version is accurate.

The lightweight LTI 20.20, with a range of 500 yards, is used on both sides of the Atlantic and was developed from equipment used to measure the docking speed of America's space shuttle.

The error scare emerged seven months after use of the ProLaser III "supergun" that can trap drivers over a mile away was called into question.

It followed the acquittal of a driver said to have been doing 25mph above his car's top speed.

Police now have more than 3,000 mobile speed cameras in roadside traps and hidden in cars, vans and motorbikes.

Five million drivers are thought to have been convicted on the evidence of laser guns in the past five years and fined a total of £300million.

Mr Smith concluded: "These devices make mistakes and the BBC film proves it.

"Millions of drivers will be entitled to refunds, licence points removed and, in some cases, a large amount of compensation. This is a disaster of epic proportions."