Medical Marijuana

Even with recreational marijuana becoming legal on Jan. 1, 2018, in California, law enforcement agencies are still struggling with how to find a way to determine when drivers are impaired by cannabis and should be arrested. So far, no reliable marijuana breathalyzer-type test, like those used to measure blood alcohol level, has been developed.

Marijuana Affects Users Differently

Blood tests can measure how much marijuana is in a person's bloodstream. However, traces of the drug don't dissipate as quickly as alcohol does. Further, a driver could have cannabis in his or her bloodstream, even from recent use, and not be impaired.

As one of the directors of the University of San Diego's (UCSD) Center for Medicinal Cannabis Research notes, marijuana impacts people in very different ways. Further, he says, "There are indications that the more experienced you are, the more tolerance you develop." With many regular pot users, "their body is adjusted to it, they know what to expect."

Finding New Ways to Measure Impairment

California law enforcement officers are concerned that people are going to try marijuana for the first time now that it's legal without any idea of how it will affect them. They fear the tragic results that could ensue. Their fears aren't unwarranted. Over a third of drug-related driver fatalities in 2015 involved marijuana.

Researchers at UCSD are working on ways to help police determine whether a person has ingested too much marijuana to legally be behind the wheel. Currently, officers are trained to recognize signs of impairment. However, as one California Highway officer acknowledges, this is "very much is a judgment call."

In an effort to help officers get more empirical evidence of whether a driver is actually high, the UCSD researchers are putting test subjects in a simulated driving environment. All of them smoke a "joint" first, but, in some cases, that joint contains real marijuana and in others it doesn't.

The simulator requires "drivers" to determine things like what to do at an off ramp. Interestingly, police told researchers "that's one of the areas that are most difficult for impaired drivers to handle," according to the center's co-director.

Tests subjects are also asked to perform tests that measure their memory and ability to multi-task. Researchers are looking at potentially developing a tablet test that officers can use on the scene at traffic stops.

Regardless of the laws regarding marijuana use in your state, it's never legal to drive impaired. As noted, however, determining impairment when it comes to marijuana can be a highly subjective call by an officer and difficult to prove in court. That's why those facing marijuana-delated DUI charges should seek the guidance of a criminal defense attorney.