March 20, 2012 – A bill to establish a “zero-tolerance” DUI standard for marijuana has been introduced to the legislature by Assemblywoman Norma Torres (D-Pomona). The bill, AB 2552, would make the presence in blood or urine of any non-zero amount of cannabinoids (the distinctive ingredients of marijuana) presumptive evidence of driving under the influence. Included would be not only synthetic cannabinoids but also non-psychoactive metabolites, which can reside in the system for weeks after last use.
California NORML strongly opposes the bill. “AB 2552 would effectively criminalize every pot user in California who drives,” says Cal NORML Director Dale Gieringer, “The scientific evidence is unequivocal that the presence of cannabinoids in the system does not constitute impairment.”
Non-psychoactive cannabinoid metabolites, which have no effect on driving ability, are typically detectable in the urine for days or weeks after last usage. The primary psychoactive ingredient of marijuana, THC, which does have impairing effects, is detectable in the blood for many hours or days after use – over a week in heavy users -long after any impairment has faded.
“AB 2552 is akin to searching through drivers’ weekly trash and charging them with DUI if any empty beer or wine bottles are found,” says Gieringer. Norma Torres, the author of AB 2552. has been a recipient of funds from Anheuser Busch, the Wine Institute, Millercoors, and the California Association of Highway Patrolmen.
Under present California law, a driver is considered to be “under the influence” of a drug (legal or otherwise) if the balance of evidence in the case, including drug test results, shows that his or her driving performance was adversely affected by the drug. The only drug for which California has presumptive DUI limits is alcohol, which has a limit of 0.08% in blood. Alcohol is the only drug for which such an impairment threshold has been scientifically established. Although many other psychoactive drugs, such as prescription pain-killers and tranquilizers, are known to be impairing, anti-drug zealots have so far not sought to establish a numerical DUI threshold for them.
Nonetheless, the U.S. Drug Czar’s office has been pushing to establish fixed DUI thresholds for marijuana, arguing that recent surveys show an increase in the number of drivers with marijuana in their system. However, accident fatalities have actually declined over the same period, and there is no evidence that marijuana is adversely affecting highway safety. California ranks among the safest states in terms of highway safety. A study by D. Mark Anderson and Daniel Rees of the Institute for the Study of Labor found that the passage of state medical marijuana laws was associated with a 9% reduction in traffic fatalities, apparently due to reduced alcohol consumption.