Drivers high on marijuana represent an unrecognized crisis, experts tell the Los Angeles Times. A 2009 report from the National Highway Traffic Safety Administration (NHTSA), based on blood, breath and saliva tests collected on weekends from drivers in 300 locations nationally, found that 16.3 percent of drivers at night were impaired from legal or illegal drugs, including 9 percent of drivers who had detectable traces of marijuana in their system.
The article notes that in California, almost 1,000 deaths and injuries annually are due to drugged drivers. Law enforcement officials point to the increased use of medical marijuana as part of the problem. Gil Kerlikowske, Director of the White House Office of National Drug Control Policy, told the newspaper, “Marijuana is a significant and important contributing factor in a growing number of fatal accidents. There is no question, not only from the data but from what I have heard in my career as a law enforcement officer.”
There is no national standard on how much marijuana drivers should be allowed to have in their blood, the article notes. Thirteen states have zero-tolerance laws, while 35 states do not have a formal standard. These states instead rely on police to determine if a driver is impaired.
Jeffrey P. Michael, the NHTSA’s Director of the Office of Impaired Driving, acknowledged that it is not known what level of marijuana causes impairment in drivers.
To help answer this question, one study in Virginia Beach, VA, is using teams of federal researchers to ask drivers at accident scenes to voluntarily provide blood samples. They then return at another time to the same location at the same time and day of the week, and ask two random drivers who are not involved in accidents for blood samples.
The goal of the project is to determine whether drivers with specific levels of drugs in their blood are more likely to be involved in a crash than drivers without the drugs.