Dutch researchers studying the association between drug use and traffic accidents have found "no increased risk" of accident-related trauma in drivers who have been using marijuana. The finding comes amidst increasing controversy over "drugged driving" and the federal push to see zero-tolerance DUID (Driving Under the Influence of Drugs) laws passed nationwide (http://stopthedrugwar.org/chronicle/329/driving.shtml). Under federal model legislation, those laws would define drivers found with even traces of illicit drugs in their system as impaired -- without requiring any showing of actual impairment.
The study, which was conducted by scientists at the Institute for Road Safety Research in the Netherlands, reviewed the cases of 110 drivers hospitalized in traffic accidents, as well as an additional 816 control subjects selected at random as they drove down Dutch roads. All 926 subjects underwent blood or urine drug testing. The main objective of the study, wrote the authors, "was to estimate the association between psychoactive drug use and motor vehicle accidents requiring hospitalization." Researchers used the "odds ratio," or the likelihood that the use of single or multiple drugs would increase the odds of getting into a traffic accident requiring hospitalization.
Unsurprisingly, the study found that driving under the influence of alcohol dramatically increased the odds of getting in wreck. Even people who consumed less than the legal limit (those between 0.5% and 0.8% blood alcohol levels) had a five-fold increase in the risk of serious accident, while drivers above the US legal limit were 15 times more likely to get in bad wrecks. Likewise, drivers using benzodiazepines, such as Valium and Rohypnol, were five times more likely to smash up. And drivers using multi-drug or drug and alcohol combinations were also much more likely to have an accident requiring hospitalization.
For drivers using amphetamines, cocaine, or opiates, the researchers found some increased risk, but qualified it as "not statistically significant." And the pot-heads?
They didn't actually live up to the portrayal of them by the drug warriors as a highway menace. "There was no increased risk for road trauma found for drivers exposed to cannabis," is how the authors put it in their abstract.
The complete article, "Psychoactive
substance use and the risk of motor vehicle accidents," published in the
professional journal Accident Analysis and Prevention, is not available
online unless you want to pay $30 to the publishers (http://www.sciencedirect.com),
but an abstract is available at PubMed at: