The ProLaser III can record a driver's speed from a mile away

The new hand-held ProLaser III device can record a vehicle's speed from a distance of up to 2,000 metres and is on trial on roads in Dorset.

The Dorset Safety Camera Partnership says it will save lives but organisations such as the RAC say there is too much emphasis on speed cameras.

They claim cameras are being used instead of police officers.

"There is a role for speed cameras but they should not replace actual police officers on the roads," said Edmund King, executive director of the RAC Foundation.

"Speed cameras can only clock if you are speeding - they can't detect drink-driving, tailgating or drug-driving.

"Cameras should be one element of traffic policing rather than the whole that they appear to be at the moment."

Andrew Howard, head of road safety at the AA Motoring Trust, said that while the majority of drivers accepted the need for speed cameras they thought they should be highly visible.

I would question the ability of a camera to take a driver's picture driving at 60 mph a mile away Andrew Howard, of the AA

"I would have concerns if a camera was used over that sort of range because it breaks the pledge on cameras being conspicuous.

"But to be honest I would question the ability of a camera to take a driver's picture driving at 60mph a mile away."

Johnny Stephens, project manager for the Dorset Safety Camera Partnership, said: "Our overriding priority is to reduce the number of casualties on Dorset's roads.

"We know that some members of the public race towards cameras and then brake hard as they pass and speed up again after the cameras.

"This new technology will assist the partnership in stopping this very dangerous practice."