'Can you stand on one leg, please?'

A new roadside drugs test, which includes making motorists stand on one leg and touch their nose, is expected to lead to 20,000 arrests a year, the police said yesterday.

A new roadside drugs test, which includes making motorists stand on one leg and touch their nose, is expected to lead to 20,000 arrests a year, the police said yesterday.

The decision to introduce the test nationally was based on the results of pilot studies in some areas, which suggested drug-driving was more widespread than previously believed. An estimated 700 road fatalities a year are linked to drugs. The Association of Chief Police Officers announced yesterday that all forces would start training their officers in techniques for detecting drugs in drivers, such as the field impairment testing (FIT) procedure.

The FIT technique involves officers observing suspects performing a number of roadside tests, including standing on one leg, closing their eyes and touching their nose with their head tilted back; and walking a straight line performing balance turns.

Police will also be trained to detect what type of drug a suspect may have taken. Holding a card next to a suspect's face with varying sizes of pupils printed on it, the size of the motorist's pupils will be matched with those on the card - very small pupils indicate the use of heroin, for example, while dilated ones suggest the use of amphetamine or ecstasy.

Motorists suspected of being under the influence of drugs will be taken to a police station for a urine or a blood test. The low-tech tests are to be used while more sophisticated procedures involving automatic drug scans are being developed.

Arrests for driving under the influence of drugs are expected to increase ten-fold with the new test, the Association of Chief Police Officers said.

Richard Brunstrom, the association's spokesman on drugdriving and the Deputy Chief Constable of North Wales Police, said of those who died on the roads, six times as many had traces of drugs in their bodies than they did 10 years ago.

He said the FIT tests had been piloted in six force areaswith great success. Derbyshire's police conducted 92 of the roadside observations, resulting in 35 arrests and 31 positive drug samples, he said. The majority of those caught had taken cannabis or heroin.

Lord Whitty, the minister for roads, said: "We need to make sure drug-driving does not get out of hand. The techniques being applied to achieve this are simple and straightforward and can be applied anywhere to help enforce existing laws with greater rigour in the interests of road users."

Lynn Watson, the mother of a victim of drug-driving, welcomed the police initiative. Her son William Hancock was 21 when he died in a car driven by his best friend, which spun out of control on a bend, hit a lorry and overturned.

Mrs Watson, of Wells-next-the-Sea, in Norfolk, said: "The driver had taken speed and cannabis. William was in the back and the car was racing another one when it hit the lorry. William died on the way to the hospital." She said the new police measures were a "step in the right direction".