The largest-ever study into drugs and driving was published in Australia last October. The study was performed by the University of Adelaide and Transport SA, and found that drivers with cannabis in their blood were slightly less likely to cause accidents than those without.
The study analyzed 2,500 accidents, matching blood alcohol and drug levels of injured drivers with details from police reports. Researchers found that drug-free drivers caused the accidents in 53.5% of cases, while drivers with cannabis in their blood had a lower culpability rate of 50.6%. Injured drivers with a blood-alcohol concentration of more than 0.05% were culpable in almost 90% of accidents.
This study confirms the results of a comprehensive 1992 study by the US National Highway Transportation Safety Administration (NHTSA), which concluded that marijuana is rarely involved in driving accidents except when combined with alcohol, and that “there was no indication that marijuana by itself was a cause of fatal accidents.”
A 1983 study by the NHTSA which used stoned drivers on simulators concluded that the only statistically significant effect associated with marijuana use was slower driving! Another NHTSA study performed in 1993 dosed drivers with THC and tested them on real roads. It concluded that “THC’s adverse effects on driving performance appear relatively small.”
Despite these studies, efforts are being made by police around the world to determine just who is driving high and who isn’t. In 1996 German police announced they were working on a blood test which would determine more than just whether THC was present in the blood. Their “Cannabis Intoxication Factor” blood test is designed to reveal how high you are, with a CIF of 10 being considered equivalent to a 0.11 blood-alcohol level. How they arrived at that comparison in light of the above research is unknown.
Meanwhile, police in the US and Canada are being trained to identify drug using drivers by a variety of supposed traits and effects. Police trained in such techniques may be used to screen drivers at road blocks, with those drivers deemed suspicious being forced to take blood or urine tests.
? If you know anyone who has been arrested in a drugged-driving check, contact Dan Loehndorf at Cannabis Culture: (604) 669 9069; email email@example.com