Roger Pearson looks at the implications of the most recent drug-driving ruling and the problems of ensuring that justice is carried out
The risks faced by drink-drivers are well understood, but a recent High Court decision has revealed that drivers who smoke cannabis are running far greater and less known risks than those who drink.
After a couple of glasses of wine or a pint and a half of beer, a driver may be confident that he is driving legally. But if a driver smokes a "joint" there are no legal specifications as to the level of the drug that has to be in his blood to render it illegal for him to drive.
A trace of cannabis in the bloodstream or even a drug which has been prescribed can be sufficient to put the driver in breach of section 4 of the Road Traffic Act 1988.
As a result, a driver could, as happened in the recent case, end up being prosecuted for driving under the influence of drugs.
Robin Leetham of Kent was fined £250 by magistrates at Sittingbourne and banned from driving for three years after minor traces of cannabis were found in his blood.
The High Court decision came during a week that police were piloting new methods of road-side drug tests for drivers.
The real danger in the case of cannabis more so than with some other drugs is that traces of it can remain in the bloodstream for up to a month after it has been smoked.
Leetham had been stopped by police who considered he had been driving erratically.
He admitted he was a regular cannabis smoker and that he had smoked the drug some four hours before being stopped.
However, he claimed the reason that he was red-eyed and had slurred speech when he was stopped had nothing to do with the drug.
Instead he attributed these two factors to long working hours and the fact that he suffers from dyslexia.
Despite his claims, the magistrates convicted him and the decision was upheld in the High Court by Lord Justice Rose and Mr Justice Sullivan.
Leetham's solicitor, Sitt ingbourne-based Andrew Mc-Cooey, says their decision gives cause for concern and spotlights a worrying distinction in the way drink and drug-driving laws are applied.
McCooey makes it clear that while he does not endorse the taking of illegal drugs, he considers it a matter of concern that someone who has smoked a small amount of cannabis could lose their driving licence and face other penalties, just because a tiny amount of the drug was detected in their blood after being stopped.
"Even if you have a tiny amount of a controlled drug in your system, and in the case of cannabis it could be there a month after it had been smoked, you run the risk of losing your licence even though you believe you are perfectly safe to drive," says McCooey.
"If you are stopped by police who form the view that your driving is impaired, it is no defence to say that the level of drug found in your blood stream was very small. There are no set legal levels, no calibrations to be followed, as there are with alcohol. There is now a real distinction between unfitness through drugs rather than drink," he says.
"You could get a situation where someone has been abroad on holiday, has legally smoked cannabis in the country they have visited and is then stopped and tested back in the UK weeks later and the drug shows up. Until the cannabis is out of the blood, a person risks his licence if he drives," says McCooey.