Time magazine reported last month that at weekend traffic stops, seven percent of California drivers tested positive for marijuana.
These people were not necessarily impaired. They were participating in a voluntary survey, for which they were paid, and faced no legal consequences if they showed impairment. They may not have even smoked recently: as your high school guidance department warned you, the active chemicals in marijuana remain present in the body for more than a week after use.
Still, the report is … sobering, especially since there is reason to expect that the most impaired drivers may have refused to participate. Most disturbing of all:
Because of the scientific controversy over the link between marijuana fluid levels and impairing effects, few states have set standards for stoned driving detection. Colorado has debated them but legislators cannot come to an agreement.
They may have to soon, since the survey shows that drivers are toking up and getting behind the wheel. Studies clarifying how marijuana can affect decisions on the road will be more critical as more states grapple with legalization of the drug.