Thor Benson / Cannabis News Box Contributor

Though social use cannabis sales have already started in California, lawmakers are still trying to figure out the best way to definitively determine if someone who has been pulled over by a police officer is too high to drive. States have grappling with this for years, and California has been relatively cautious as it works to find the best solution.

Certain states, like Washington and Colorado, have decided that someone is too high to drive if they take a blood test and have 5 nanograms or more of THC per milliliter of blood. This is problematic, scientifically, because THC sticks around in the blood for a long time. It doesn’t disappear relatively quickly like alcohol. A regular user of cannabis might have 5 nanograms of THC per milliliter of blood 10 hours after smoking, which would essentially mean they can never drive. Thus, California has so far decided not to set this kind of limit.

Certain companies are working on cannabis breathalyzers, but none of them have been found to be effective at determining intoxication yet. Some argue the science behind them is also extremely flawed. It will likely be a while before any progress can be made doing it this way.

As it stands, California law enforcement are relying on the same kind of sobriety test an officer might use for someone who seems drunk. The one where you walk in a straight line and such. However, even this method of detection appears to be flawed.

“When I was working as a sheriff’s deputy in Los Angeles, I was told what the protocols were were carved into stone. If a person exhibited these particular signs, there was no doubt this guy was under the influence of [a specific drug],” Former Deputy Sheriff Nick Morrow, who is a member of Law Enforcement Action Partnership (LEAP), told Cannabis News Box.

However, Morrow has learned over the years that these protocols are not always accurate. He said detecting if someone is high on cannabis is actually quite difficult. “The signs and symptoms of marijuana use, unless it’s at a really high level, are very subtle a lot of the times,” Morrow added.

Morrow said telling if someone is high based on their driving can also be very challenging. It’s often easy to tell if someone is driving drunk, because they’re swerving or generally driving recklessly, but high drivers make much smaller mistakes.

“Normally what happens with marijuana is somebody gets pulled over for a minor traffic violation that a sober person would commit or some kind of equipment violation,” Morrow said. An equipment violation might be a broken tail light or something similar.

The most concerning aspect of all of this is that Morrow claims officers often determine if someone is high based on smell. If they smell marijuana when someone rolls down the window, they usually give them a DUI, he said. Morrow said this is wrong, because that smell can linger on someone for a long time.

Unfortunately, it seems unlikely California law enforcement agencies will update their practices when it comes to how they check if someone is high. Morrow claimed most don’t want to put in the time and money it would take to revamp the system.

“A lot of law enforcement agencies have just buried their heads in the sand,” he said. “They’ve gone with those protocols that have been taught in the past, and nobody’s very interested in rewriting the manual on that kind of stuff, because now you have to retrain everybody.”