SPEED cameras have become a common sight along Britain's roads in the past 10 years, and their numbers are set to increase.

In Swindon a mix of both mobile and stationary cameras are used to catch speeding drivers. Now the police are clamping down further with more mobile cameras being set up randomly on the streets of the town.

In a crackdown on Wednesday and yesterday on Thamesdown Drive in North Swindon, 140 drivers were caught speeding in a total of four hours.

And in a previous operation last week, 108 drivers were caught in five hours, or an average of one every three minutes.

In that operation, mobile cameras were used in accident hot spots such as Ermin Street in Stratton, Queens Drive in Walcot, and Tewkesbury Way in West Swindon. Police caught 34 speeding drivers in Queens Drive, 15 in Ermin Street and none in Tewkesbury Way.

A further 46 drivers were caught were caught on the A419 in Blunsdon and 13 on the A346 at Chiseldon.

The choice of sites is one of the reasons why the police insist that cameras aren't just to catch out speeding drivers. Most cameras are now referred to as Road Safety Cameras. In the operation using mobile cameras, sites were targeted because of long histories of collisions resulting in serious injuries and fatalities.

Sgt Nick Blencowe of Wiltshire Police's Safety Camera Unit, said: "We have 16 fixed camera sites across Wiltshire and Swindon but one of those is a red traffic light camera located at Blunsdon. The cameras have been very successful over the past seven years. They have slowed down drivers and they have reduced casualties."

The use of both fixed and mobile cameras, must according to Government rules be advertised with clear signing.

Wiltshire Police have in addition decided to paint all their fixed cameras bright yellow as an additional deterrent, although this is not a legal requirement.

Mobile speed cameras are becoming an increasingly familiar site around Swindon.

These are essentially video cameras fitted inside marked vans parked by the roadside.

The cameras are connected to a laser, which can measure the speed of a car nearly one kilometre from the mobile camera vehicle.

Sgt Blencowe explained: "With the fixed cameras, people have an idea of how far the cameras can see. But with the mobile system, the cameras can see long distances and detect driver speeds before they slow down for the camera. The mobile cameras, by their nature, can be moved around every day."

Although mobile cameras are becoming more familiar the fixed camera is more common.

Using radar, this type of camera emits high-frequency radio waves. These can bounced onto a vehicle and reflected back to a receiver, and the camera calculates whether the driver is speeding and whether a picture should be taken.

Film is collected by officers for examination. However in recent months, the cameras have become the victim of a so-called camera rage.

Sgt Blencowe explained: "The cameras have been running for seven years but in the past 12 months, three in the county have been damaged including one set on fire and another uprooted, probably with a digger.

"I don't like to use the term camera rage. It is criminal damage and totally unacceptable."

Statistics have revealed that for every 1mph that drivers cut from their speed, there is a five per cent reduction in collisions.