BLO Baby BLO ... As a result, it gets difficult to even understand how risky blazed driving is. Traffic studies that rely on blood THC measures could also be inaccurate if blood is drawn too late and THC has already left the system. And some state traffic databases, including Colorado's, according to state traffic officials, link accidents to 11-nor-9-carboxy-THC, a byproduct of marijuana metabolism that marks only recent exposure and not intoxication. That might result in an overestimation of marijuana-related accidents.
In the meantime, Haney says, the challenge shouldn't deter people from trying to find a marijuana DUI solution. People are working on breath tests, saliva, other blood markers and behavioral tests, just nothing that so far has stuck, she says. "We need something, because it's an important public health issue. But how we're going to get there? I just don't know."