See also: Readers Weigh In on Stoned Driving
The intoxication research, a new addition to a larger annual traffic study conducted by AAA, highlights the need for centralized laws pertaining to drugged drivers, according Peter Kissenger, president and CEO of the AAA Foundation for Traffic Safety, and he called for just that in a press release:
While all states prohibit driving under the influence of drugs, there's significant variation in the minimum acceptable levels of marijuana or its traces in a driver's system. Sixteen states forbid any presence of prohibited drugs, while five others have specific limits for marijuana. With a lack of uniformity, it's no surprise we found that more than half of American drivers are unaware of the laws that exist in their state.
With recreational marijuana already legal in Colorado and Washington for a year, and Alaska, Oregon and Washington D.C. voting to follow suit, the AAA says that the number of stoned drivers will only increase as cannabis prohibition declines. Use of marijuana can impair driving performance for up to three hours, the study suggests -- but current blood tests are inadequate for accurately determining impairment.
According to AAA Denver spokeswoman Wave Dreher, it's still too hard to pinpoint a universal level of marijuana impairment for drivers. "How much is too much? How soon after using is too soon? We don't really know, and we don't really have the testing abilities or the data yet to answer those questions," she says. "So our education is: If you're going to use, just don't drive."
Under Colorado law, it is illegal to operate a vehicle if the driver has five nanograms of THC in his system. According to a 2008 study by The Journal of Toxicology, the amount of THC peaks at over 100 nanograms after inhaling marijuana, and declines rapidly afterward, reaching single-digits within an hour. However, for habitual users of marijuana, residual THC can last for days in the system of a person who is more than sober enough to drive, as William Breathes proved when he had his blood tested eighteen hours after consumption, and tested well beyond the limit.
Despite the objections of habitual marijuana users, Colorado state law says "a person is guilty of a DUI if he or she operates a motor vehicle while under the influence of alcohol and/or one or more drugs, OR he or she operates a motor vehicle as an habitual user of any controlled substance."Even if the driver is a medical patient, the marijuana is still considered a controlled substance and the driver who tests beyond the limit could be arrested for driving under the influence.
Marijuana isn't the only medicine making the roads unsafe, according to AAA. Its study claims that taking antidepressants increases the risk of a crash by almost 41 percent, although other studies say the risk is impacted heavily by the driver's age and dosage. And Americans are even less concerned about driving under the influence of prescription drugs, the study says, with barely 25 percent feeling the same way about them as alcohol.
Dreher believes the current warnings on prescription drugs share some responsibility as well, and views the "Do not operate heavy machinery" label as outdated-- drumming up images of threshers and tractors. "The warning label doesn't say, 'Don't drive,' so I'm not really thinking about cars," she says.
Buying over-the-counter drugs doesn't keep you in the clear, either. Mixing cold or flu medicine with the wrong substance can create a reaction similar to alcohol, which is why Dreher says AAA developed RoadwiseRX -- an application designed to show drivers the effects of the medications they take while keeping a log of their dosages.
"Many people who can't fall asleep might take a Lunesta or some other sleep aid at 2 a.m. and have to get up and drive six hours later," Dreher says. "The effects haven't worn off yet. People have been pulled over and charged with driving while intoxicated for that."
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