High On The Highway: Challenges With Marijuana DUIs

Come January 14, Illinois will have a new pro-pot-legalization governor and a Democrat-held legislature, leading many to believe the state will legalize recreational cannabis. That’s exciting for some, concerning for others.

At a recent “News & Brews” community event about what legalization may mean for Illinois, several attendees asked how police officers plan to deal with marijuana-impaired drivers without pot breathalyzers.

Studies have shown that having a significant amount of THC (cannabis’ primary intoxicant) in the blood does impair driving — though the amount of impairment is debated, and studies on that are ongoing.

In one U.S. Department of Transportation study last year, researchers found that drivers who were drunk were more likely to drive faster, weave out of lanes and take more risks. At the same time, it found drivers high on marijuana drove slower, generally only weaving within their own lanes and following other drivers at greater distances, “attempting to compensate for the subjective effects of using marijuana.”

Still, consuming cannabis while drinking alcohol can have compounding negative effects on driving, which makes setting limits on either more difficult.

There’s been efforts to create a “pot breathalyzer,” but it’s still difficult to tell exactly how much someone ingested. While blood tests can be used, THC stays in the blood longer than alcohol. If someone tests positive, they may have consumed days before driving, which makes it difficult to tell if it was cannabis or something else that influenced erratic driving.

In Colorado, where recreational marijuana has been legal for nearly five years, officers generally rely on roadside sobriety tests to make drug-related DUI arrests.

“The determination if somebody is driving under the influence, be it alcohol, marijuana or any other controlled substance, it happens on the side of the road,” said Trooper Josh Lewis, public information officer for the Colorado State Patrol. He added that the blood and chemical tests are “secondary, after-the-fact.”

Lewis said Colorado troopers are trained in both standard field sobriety tests and Advanced Roadside Impaired Driving Enforcement (or ARIDE), and that the state patrol has over 50 drug recognition experts.

Still, he added, “Just by plain experience and being around [impaired driving] more, seeing it more, that is a key component to being able to recognize if somebody is a danger to themselves or somebody else as they’re driving down the road.”

Colorado troopers have been dealing with stoned drivers since the creation of the Colorado State Patrol in 1935, according to Lewis. In the last four years, he said, marijuana was a factor in 15 percent of DUIs, which could mean someone could have consumed pot products alone, or mixed them with alcohol and other intoxicants.

In Denver, the city police department got so many questions about marijuana enforcement, they created a video and fact sheets explaining what they’re doing. The department noted that only 3.3 percent of DUI arrests in the city were marijuana-related.

Illinois State Police Master Sgt. Mike Link said all Illinois patrol officers were required to take ARIDE training in 2015, around when Illinois made cannabis legal to use for medical reasons. Link agrees that roadside sobriety testing is the primary way to tell if someone is too impaired to drive.

“Our main concern is removing impaired drivers from the roadway regardless of what’s causing the impairment,” he said.

Benjamin Hansen has done a lot of research on crime economics, impaired driving and marijuana legalization as an economics professor at the University of Oregon and as a research associate at the Bureau of Economic Research. He said it would be best to figure out exactly how much THC (or other key cannabis compounds) impairs drivers and be able to test that.

Hansen said that could mitigate concerns over police officers’ implicit biases when conducting roadside sobriety tests that don’t involve chemical testing.

“There appear to be substantial racial differences in how marijuana laws have been enforced in the past,” he said, noting that historically black people have been overrepresented in arrests for marijuana possession. A 2013 ACLU study found that blacks were more than seven times more likely to be arrested for pot possession in Illinois than whites —despite using the drug at similar rates.

Hansen said some groups have gotten grants to find new ways to measure impairment, like using a phone app that can track someone’s reaction time and hand-eye coordination, but it may be awhile before that technology can be widely used.

Still, he said those concerned about high drivers have some good news: People generally still get high at home or at a friend’s house because even where it’s legal, pot use is usually banned in public spaces.

Hansen said there’s also the misconception “that there’s a lot of evidence that marijuana is just as dangerous as drunk driving. I think there’s a lot of evidence that drunk driving is a lot more dangerous, and I think that those dangers are often concluded to be socially acceptable because so many of us drink.”

Stats and Data

At the Colorado State Patrol, Trooper Lewis said they collect data on how many cannabis-associated DUI arrests they make. But the agency only started differentiating marijuana-related DUIs from other DUIs after cannabis became legal in the state.

“So unfortunately we don’t have a baseline to be able to determine whether this has caused an increase, decrease, or otherwise stayed the same prior to the legalization,” he said.

He encouraged states considering marijuana legislation to start collecting that data now so police agencies can quantify the effect legalization has on impaired driving. So far, 10 states have legalized recreational marijuana, while 23 have legalized medical marijuana.

Illinois State Police officers were unable to comment on whether specific cannabis-related DUI information is collected in Illinois.

Hansen, the researcher, also wants more information. He said more accurate data could even lead to gradated punishments, like the increased penalties for those who drive extremely drunk (“aggravated” DUIs) or for speeding.

“I’m very familiar when I drive on the road that if I go 10 miles an hour over the speed limit, I’ll pay one fine. If I go 20 over, I know my fine will be higher,” he said, noting that increased risk correlates with increased penalties.

Hansen said he’d want to structure all DUI enforcements similarly with greater punishments for higher levels of intoxicants in the blood, and greater enforcements for mixtures of intoxicants, like alcohol and cannabis.

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