DON'T BE A DOPE

If you're going to smoke a joint, don't drive home

IT'S official: smoking dope makes you a worse driver. But cannabis has less
effect on driving ability than alcohol, according to a study by the
Transport Research Laboratory (TRL) in Crowthorne, Berkshire.

The Department of Environment, Transport and the Regions asked the TRL
Safety Department to investigate the effect of cannabis intoxication on
driving ability. Cannabis is by far the most common illegal drug found in
the bloodstream of road accident victims, and THC-the active ingredient in
cannabis-can remain in the body for more than a month.

Barry Sexton and his colleagues at the TRL recruited 15 volunteers to
complete driving tests while under the influence of low or high doses of
cannabis, or no drug at all. The volunteers either smoked readyrolled
cannabis joints or rolled their own with resin supplied under government
licence. They were then put through their paces on a sophisticated driving
simulator.

The researchers measured their accuracy at steering the car, known as
"tracking ability", and other psychomotor responses, such as hazard
perception and braking responses. They took blood and saliva samples at
regular intervals and also tested the subjects' coordination, balance and
timing.

The first thing the researchers noticed was that the subjects drove more
slowly under the influence of dope, compensating for their intoxication by
driving more cautiously. Tracking ability was the only test criterion that
was adversely affected: the volunteers found it very difficult to follow a
figure-of-eight loop of road when given a high dose. Reaction times to
motorway hazards and performance on cognitive tests in the lab were not
significantly affected.

Trials previously completed under similar test conditions at the TRL have
shown that alcohol and tiredness have a more adverse effect on driving
ability, affecting higher cognitive processes. The results of the cannabis
and driving study agree with similar research carried out in Australia, the
US and Holland.

Pete Henshall of the Legalise Cannabis Alliance, which is a British
political party, comments that "any person who is not in full control of
their body should not drive, be it through tiredness, alcohol, cannabis or
drugs ... but everything must be seen in proportion. We need to legalise
and regulate cannabis in a similar way to alcohol to be able to see the
size of the problem."

Jane Eason of the Royal Society for the Prevention of Accidents favours the
roadside tests to spot cannabis intoxication now being tried by British
police. "We would welcome any measure that might make the roads of Britain
safer."