The police suspect that thousands of young people drive drugged, but there's nothing they can do about it, reports Ellie Hughes
"Having a few spliffs in the car is a way of kicking off a holiday," says Patsy, a marketing executive. "I get stoned every night and I don't think twice about driving. I have the usual thing of discovering I'm driving much more slowly than I think I am and sometimes I get home and wonder `How on earth did I get here?' But I've never even come close to having an accident."

This view is shared by a huge number of recreational drug users. In March, however, the police expressed concern at what they say is the growing problem of drug-driving. Using figures from a 1996 Forensic Science Service study, Metropolitan Police Assistant Commissioner Paul Manning told a drug driving conference that if people who were given breath tests for alcohol were also tested for drugs, around 18 per cent (more than 109,000 cases a year) would prove positive. Bear in mind that the police can't breath test at random - the driver has to be doing something wrong - and, they say, you start to get an idea that there is a problem, both in terms of the number involved and the effect drugs have on driving ability.

The first difficulty the police face is that, although recreational drug use has been part of mainstream popular culture for the best part of a decade, there is no official government research into drugs and driving. To this end, last October the Department of Transport set up a three-year study involving the routine screening of adult road fatalities for all illicit drugs. If this shows a link, the police will then face a harder problem - the practical difficulties of stopping drug-driving.

Patsy recalls: "I was recently stopped by the police and cautioned for having too many people in my car. In fact, I was also completely stoned. I even got out of the car to talk to them, which made me really paranoid, but they didn't have a clue. They obviously didn't know what a stoned person looks like." Most drug drivers are familiar with the idea that they are unlikely to be caught. British police are not trained to notice signs of drug use. And, although they are aware that most people leaving raves are the worse for wear with no way of getting home other than driving, as a spokeswoman for the Association of Chief Police Officers told me: "There's no equivalent to a breathalyser for drugs, so apart from getting them for other motoring offences, there's nothing we can do."

But perhaps the biggest problem the police face is changing attitudes. It is just a matter of time before one of the many sweat or saliva-based drug screening devices currently being tested proves acceptable, and work is already being done to introduce basic police training. But most drug- drivers have been pursuing their habit unharmed for a long time, are used to the effects of different drugs and are confident they know how to handle it. Angela, a 29-year-old charity worker, is typical. "I am morally responsible for my actions, including driving, and I'm not aware of any reason why having cannabis in my system impedes my ability."

In particular, the police face an uphill task in realising their aim, as stated by Manning, of making drug-driving as socially unacceptable as drink-driving. Simon, a junior doctor, recently found himself driving from a rave near Oxford to work in London during the small hours of a Sunday morning, while coming down from a night on E. "I would never drive totally off my face," he says, "or drunk, as alcohol kills your judgement and reactions and makes you aggressive. But, in this case, I felt pleasantly calm. I was probably more awake than the other drivers on the road at that hour and I didn't feel any anger when they made stupid mistakes. So, I'd say, on any long journey, take an E."

If you're on one...

Cannabis slows your reaction time, impairs concentration and distorts the perception of time

Cocaine/speed affects your accuracy, judgement and perception. Drivers feel as though they are driving better but are actually driving more recklessly

Ecstasy severely affects your accuracy, judgement, perception and concentration

LSD hallucinations alter your reaction times and driving will become erratic