The beginning of 2014 marked the end of a 70-year ban on the sale of marijuana for recreational use, at least in Colorado. Colorado became the first state in the nation, and the first government in the world, to control and regulate a legal recreational marijuana industry.
With recreational marijuana shops set to open in Washington later this year and other states, including California, likely to soon follow, the question remains: Like the 0.08 BAC limit for driving drunk, is there a limit for driving high?
While all states have laws that make it illegal to drive while under the influence of drugs including marijuana, Colorado set a limit for driving with marijuana’s psychoactive component of marijuana, tetrahydrocannabinol (THC), in the system. Under Colorado’s new law, a person can be convicted of a DUI of marijuana if they have five nanograms of THC or more per milliliter of blood in their system. Drive over the limit and there is a “permissive inference” that you are too impaired to drive.
One problem: There is very little relationship between having five nanograms of THC or more per milliliter of blood in the system and being unable to operate a vehicle safely. In fact, the National Highway Traffic Administration has said, “It is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects. It is inadvisable to try and predict effects based on blood THC concentrations alone.”
THC can stay in the user’s system more than a month after smoking marijuana, which means that they can be arrested well after the user has sobered up and well after they stop posing a risk to the roads. In other, more eloquent words, users may “inadvertently become a criminal mechanism for law enforcement and prosecutors to punish those who have engaged in legally protected behavior and who have not posed any actionable traffic safety threat,” Paul Armentano of the National Organization for the Reform of Marijuana Laws said in a peer-reviewed report examining the limitations of per se cannabis driving laws.
Furthermore, according to a recent study by D. Mark Anderson of Montana State Universidy and Daniel Rees of the University of Colorado, there is no evidence that per se laws reduce traffic fatalities.
This isn’t the first time I’ve complained about the THC limit, nor will it be the last. Colorado’s law misses the mark and criminalizes sober driving weeks after driving.