Garda to test car number reading system

A working group has been set up by the Garda to examine the use of technology to read vehicle number plates to help crime detection and traffic policing. The automatic number plate recognition (ANPR) technology uses fixed cameras and mobile units in police cars to scan number plates and check them against lists of stolen vehicles, or vehicles suspected of being used in crime. It can also detect uninsured or untaxed cars.

In the Dáil last month the Minister for Justice, Michael McDowell, said he would liaise with the Minister for Transport, Martin Cullen, and the Minister for the Environment, Dick Roche, to try to ensure technology of this kind is available to the Garda.

The British government is investing €22 (£15) million in the technology after running a series of trials. The Police Service of Northern Ireland (PSNI), which has had a mobile unit on trial, will announce shortly it's also introducing ANPR.

A key use for such a system in the Republic would be to combat joyriders who stole more than 12,390 cars in 2003, the last full year for which data is available. Only 63 per cent of these vehicles were recovered.

The ANPR system can also be used for traffic management, and South Dublin County Council is installing cameras along the N7, N4 and N81 to collect statistical traffic information as part of a three-year congestion study. The system uses two fixed cameras to tell how long it takes a car to travel between the two points. It can also give an accurate guide to the number of vehicles using the route.

Tesco's Clearwater store in Finglas, Dublin, is the first commercial user of the technology in the State. Liam Morrissey, head of risk management and security at Tesco Ireland, says the technology was introduced last summer "to deter people from driving off without paying for petrol".

As a result the company says the number of "drive-offs" has fallen by almost 50 per cent. Many cases of "drive-offs" at Clearwater are referred to the gardaí, and Tesco is now considering extending the system to other outlets. Morrissey stresses that the company is compliant with data protection laws because all data gathered is encrypted.

Mike Dickinson, sales manager of the British PIPS company which developed the ANPR system, says: "We encrypt the number plates into an algorithm, so we match the algorithms and don't ever know that number. This is to ensure a level of data privacy so people don't go around smashing the cameras. A police force such as the Garda would want access to the number and they would be given the encryption key to compare the data with their databases."

ANPR uses self-triggering, infra-red cameras which work equally well, day or night. They can read a number plate on a car doing 190km/h (120mph) and can check up to 3,000 vehicles an hour.

"The cameras can be used in the back of a patrol car driving at slow speeds," says Dickinson. "As other cars overtake it, a computer scans every number plate and checks the registration against the list of stolen, wanted, or suspect vehicles. If a number matches a listed number, a siren goes off and the driver will be pulled over. The police don't have to do anything - just drive along and wait for the system to go off."

According to the Association of Chief Police Officers of England, Wales and Northern Ireland (Acpo), areas where the ANPR system was used under trial saw arrest levels and prosecution rates increase significantly.

Dickinson stresses that the cameras are not "gatso speed cameras" and that the system is not used for speeding, although it could be. He says that the system is able to screen 95 per cent of all vehicles.

"You can never, ever be 100 per cent accurate. If the camera can't see the number plate it can't read it. If traffic is bad and cars are tailgating, there is not a sufficient gap for the camera to see the plate. Really poor weather and broken or dirty number plates are reasons why the camera can't read."