We drove up to find a bright yellow van parked alongside a busy road on the outskirts of Chester.

It was in this vehicle I would spend the morning learning about how speed camera vans save lives across the region every year.

I had been invited for a tour of the safety vehicle by volunteers from Cheshire Safer Roads Partnership, a multi-agency partnership which works to ensure lives are saved on roads across West Cheshire, Halton and Warrington.

From the road it looked as though no-one was in the vehicle as the front seats were empty, but inside two volunteers were busy monitoring the speed of each passing vehicle.

We entered the rear of the van to find ourselves inside a mini laboratory, surrounded by metallic walls and floor and advanced electronic equipment.

Against the back door, a futuristic-looking laser gun was trained on the moving traffic on Hough Green Road in Saltney.

Speed camera van operator Somer Blakemore invited me to take a seat while she explained how mobile laser guns work.

While the beams from the devices have less power than a television remote, they can track the speed of cars and lorries from 1,000 metres away at the click of a button.

The laser is aimed at the number plate and the return signal bounces back to the gun to determine the speed. Evidence of which number plate was targeted is recorded on video, or may be noted by the operator.

Sometimes the camera, which is automatically ‘zoomed’ at traffic, can give a clear view of the drivers themselves, making it easier to trace those breaking speed limits.

The laser system is more accurate than older radar guns and is able to determine speeds in as little as 0.3 of a second.

Various types of laser equipment are in use, but all currently use the same 904nM light beam.

I was invited to try out the machine. I aimed the laser at a couple of passing vehicles, clocking speeds between 22 and 25 miles an hour.

The speed limit in Hough Green Road was 30mph, so the vehicles were driving below the legal maximum. Perhaps they realised they were being monitored, I suggested.

Somer explained vehicles often slow down when drivers spot speed camera vans.

“We usually spend about two hours at each location,” she said. “It looks like we’re out and about, moving around, if we put ourselves in different locations.

“When drivers see us they automatically slow down. We are catching fewer people than we were two years ago simply because of our presence on the road, which shows a wonderful improvement across the borough.”

There are five safety vans in total across Cheshire West and Chester, which have been operating in the region for more than seven years.

Sgt Paul Martin, of the Cheshire Safer Roads Partnership, said the number of accidents is coming down each year.

“We are having a positive effect, but obviously the partnership is working very hard to reduce the numbers even further,” he added.

“We will go wherever the vans are most needed. Our message is for drivers to drive responsibly. We’re here to save lives.”

At 30mph, the survival rate for pedestrians hit by cars is 80 per cent. At 40mph, that figure drops to 20 per cent.

From 2007 to 2009, 51 people were killed and 595 were seriously injured across the former Cheshire County region due to roadside accidents.

The guns, which have only been approved since March, are featured in two new speed camera vans which are used by both the partnership and Cheshire Police.

It is reassuring to know people are working so hard to ensure our roads are getting safer.