WITHOUT even knowing it, thousands of North-East motorists are helping to test a revolutionary piece of high-tech equipment designed to cut pollution on Britain's roads.

Drivers in Bishop Auckland, County Durham, and on Teesside, this week, have been unwittingly caught on camera by a £250,000 computer device which has tested the amount of carbon monoxide being sent into the atmosphere by their vehicle's exhaust.

County Durham and Teesside have been chosen by the Vehicle Inspectorate for the first British trials of the American-built Remote Sensing Device - already widely used across the Atlantic and in Europe.

Roadside sensors employ ultra-violet and infra-red rays to pick up exhaust emissions in a fraction of a second.

As each vehicle passes, it is snapped by a digital camera which flashes its image and carbon monoxide "score" to a computer screen monitored by vehicle examiners parked a few yards away.

If the examiners spot any emissions over the legal limit, they radio to police, the driver is stopped and a second team of examiners put the vehicle through a conventional MoT-style check.

Out of 2,000 vehicles checked in Tindale Crescent, near Bishop Auckland, on Thursday, 30 were directed to the testing site. Vehicle examiner Karl Hunt said: "It means we can target the vehicles which seem to have exhaust problems without disrupting the flow of traffic.

"Most of the drivers weren't aware they had been checked."

Vehicles which fail the second test can be served with a prohibition notice which means they can be taken off the road until they pass a further MoT.