Colorado police are rapidly preparing to find ways to target drivers who may be operating their vehicles under the influence of marijuana. According to state trooper Josh Lewis, such investigations typically begin with a roadside sobriety test.
"Can somebody essentially do two things at once," said Lewis. "Can they count out loud and walk a line? We know in driving you're going to be required to do more than one thing at any given time."
If the officer suspects that someone is driving while high, they have two recourses.
"For marijuana there is no breath test. It's a blood test or a refusal ... You're going to lose your license longer by refusing."
The blood test is designed specifically to determine how high someone is at the moment, following concerns that a urine test would flag how much marijuana someone had smoked in the preceding days or weeks. Redditor and former DUI/DWI prosecutor VerticalNystagmus explains the process by which an officer could force a suspect to submit to a blood test; non-accident DUIs would require a warrant to administer the more intrusive blood test.
However, it's unclear whether the blood test accurately measures intoxication. Westword pot reporter William Breathes waited 15 hours on top of and a night of sleep after smoking weed and still tested nearly three times higher than the proposed legal limit, despite not being impaired.