Colorado: Workgroup Rejects Call For THC Per Se Legislation

Denver, CO: Members of an eight-member workgroup deadlocked on the question of whether to recommend statewide legislation that would define a driver as criminally impaired if they operated a vehicle with levels of THC in their blood above 5ng/ml. Members of the state’s Drug Policy Task Force and the Colorado Commission on Criminal and Juvenile Justice will likely revisit the issue this fall.

Earlier this year, lawmakers rejected legislation that sought to expand the state’s drugged driving laws by enacting per se standards for THC, the primary psychoactive substance in marijuana.

Workgroup members who opposed the establishment of a per se statute, including co-chair Sean McAllister of the NORML Legal Committee, argued that additional legislation was unnecessary, unsupported by science, and unlikely to significantly improve public safety.

According to the U.S. National Highway Safety Traffic Administration, driving fatality rates in Colorado fell over 20 percent despite the enactment of medical marijuana legalization in 2001. Further, according to statistics presented to the workgroup by a representative of the Colorado Judicial Department, some 90 percent of those charged with DUI drugs or alcohol in the previous four years have been convicted. Members also cited data indicating that some chronic cannabis consumers may continue to test positive for the presence of low levels of THC in their blood long after the impairing effects of the substance have subsided.

A 1993 study commissioned by the US Department of Transportation previously rejected the notion of equating blood THC levels with driver impairment, concluding, “One of the program’s objectives was to determine whether it is possible to predict driving impairment by plasma concentrations of THC and/or its metabolite, THC-COOH, in single samples. The answer is very clear: it is not. Plasma of drivers showing substantial impairment in these studies contained both high and low THC concentrations; and drivers with high plasma concentrations showed substantial, but also no impairment, and even some improvement.”

To date, 15 states have enacted so-called zero tolerance per se DUI drug laws which make it a criminal offense to operate a vehicle with any level of drug or in some cases, inert drug metabolites, present in one’s system. Three additional states — Nevada, Ohio, and Pennsylvania — have enacted per se DUI drug laws prohibiting motorists from operating a vehicle if they have detectable levels of illicit drugs or drug metabolites over an arbitrary state-mandated threshold. In all other states, prosecutors must demonstrate actual drug impairment to gain a DUI criminal conviction.

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. NORML’s state-by-state summary of DUI laws is available online at: http://norml.org/index.cfm?Group_ID=6669. NORML’s updated white paper assessing cannabis intoxication and psychomotor performance, ‘Cannabis and Driving: A Scientific and Rational Review,’ is available at: http://www.norml.org/index.cfm?Group_ID=7459.