How Does Amendment 64 Affect Laws Regarding Driving Under the Influence of Marijuana?

The text of Amendment 64 specifically states that it is not “intended to allow driving under the influence of marijuana” or to supersede the existing laws related to driving under the influence of marijuana.

Colorado lawmakers are taking additional steps to further address the issues surrounding driving under the influence of marijuana. The legislature is already trying to determine a blood standard for THC, much like a blood alcohol level, although all previous attempts have failed.

The current proposal, House Bill 1114, which passed in the House of Representatives on April 5, 2013, includes a 5 nanogram THC limit. This standard includes a “permissive inference” and would allow a driver accused of driving under the influence the opportunity to rebut the presumption of intoxication and prove they were not impaired, even though they tested at or higher than 5 nanograms.

Drivers can argue that they were unimpaired due to high tolerance, size or weight, or other factors.

All previous attempts have included a per se rule of intoxication, meaning that if a driver tested at or above the limit they would automatically be guilty of driving under the influence of marijuana. This “permissive inference” is supposed to address concerns for medical marijuana patients who would consistently test at or above 5 nanograms, but be unimpaired nonetheless.

However, unlike Alcohol which rapidly dissolves in your system, marijuana remains in a person’s system much longer. Research shows that many marijuana users can be consistently over 5 nanograms of THC, yet not necessarily under the influence.

This means that many medical patients are potentially at risk of being charged with DUI any time they drive and then forced to argue in court that their driving ability was not impaired.

Much like being charged with a DUI for alcohol, police must have probable cause to stop drivers and test them for intoxication. However, testing for marijuana requires a blood test. Just as with a breathalyzer, if a driver refuses the blood test they may lose their license.

House Bill 1114 still must be approved by the State Senate.

It is more important than ever for marijuana users, such as medical patients, to know their rights under the new law and have an attorney who understands how to protect them.