Drug driving facts

18% of road traffic fatalities had taken drugs 800,000 people annually travel with driver under influence of cannabis 280,000 travel with driver under influence of speed 140,000 travel with driver under influence of ecstasy, cocaine or heroin

The new measures have been brought in after recent research showed one in six road accident victims had traces of drugs in their blood.

Motorists will be made to walk in a straight line and perform turns and estimate when 30 seconds is up with their heads tilted back.

The tests are being brought in nationwide following pilot schemes in chosen force areas across England, Wales and Scotland.

The government is considering the introduction of a drug test, similar to a breathalyser, for motorists.

Richard Brunstrom, a spokesman for the Association of Chief Police Officers, said there had been an clear increase in the numbers of people unfit to drive because of drugs.

He said: "The techniques help officers recognise if a driver has been taking drugs and whether there is any resulting impairment in a person's ability to drive."

Roads minister Lord Whitty welcomed the new measures which come into force on Thursday.

He said: "The techniques are simple and straightforward and can be applied anywhere to help enforce existing laws with greater rigour in the interests of all road users."

The Royal Automobile Club has called for a campaign to warn motorists of the dangers of driving while using illegal drugs and prescription drugs.

The RAC also wants to see the introduction of a three-tier warning system for over-the-counter drugs so drivers know at a glance which drugs pose a driving hazard.