DORSET’S unmarked police cars can catch speeding motorists using just a shadow on the road – and they’ll even get you if you’re driving too fast behind them.

The force’s roads policing vehicles are fitted with VASCAR, a type of device for calculating the speed of a moving vehicle.

The device records the moment a vehicle passes fixed objects – such as a bridge, a road sign or even a shadow cast on the carriageway.

The vehicle’s average speed can then be calculated over a minimum distance of 0.125 miles.

On Friday, officers from Dorset Police’s roads team carried out a patrol in one of the vehicles along the Dorset Way in Poole.

The stretch is subject to a 50 mile per hour limit, despite it being a dual carriageway.

Officers say one of the reasons for the speed limit is because the road is busy with a high volume of traffic throughout the day.

There is also a short sliproad leading traffic onto the westbound carriageway.

PC Simon Hatch began operating the system for a red Vauxhall Astra travelling behind the unmarked car. VASCAR gave a reading of slightly above the 50mph limit.

“It’s a useful tool for us, especially in an unmarked car,” he said.

“We can use posts, bridges, even a shadow on the road to stop a driver who’s going too fast.”

PC Duncan Roberts, who also joined the operation, said: “There are a lot of serious crashes on the Dorset Way, which is one of the reasons the speed limit is what it is here.

“This is a tried and tested way of catching people who drive too fast on our roads.”

Speeding is one of Dorset Police’s ‘fatal five’ – actions a driver can take which makes a serious or fatal collision more likely.

The list also includes using a mobile phone, drink or drug driving, failing to wear a seatbelt and careless or inconsiderate driving.

Traffic officers say 98 per cent of collisions are caused by human error, with just two per cent caused by unavoidable issues such as mechanical failure.

The Daily Echo will feature a different piece on road safety in Dorset every day this week.

As reported, a service of remembrance for those killed or injured on our roads will take place at Wimborne’s Minster church for the first time this Saturday at 11am.

All are welcome to attend the service, which will be led by the Bishop of Sherborne, the Rt Rev Karen Gorham, as well as the chaplains who serve Dorset Police.

The leader of Dorset Council, the High Sheriff of Dorset and the Chief Constable of Dorset Police will also attend the service.

In the first six months of this year, 16 people died in crashes – the same number who lost their lives during the whole of 2018.

For more information and advice on road safety, visit