CDOT launched its first Drive High, Get a DUI campaign in 2014, coinciding with the opening of the state’s first recreational marijuana dispensaries. But cannabis-impaired driving has continued to be a problem. In 2018, more than 13% of drivers involved in fatal crashes tested positive for cannabis.

The solution was a frank conversation with the state’s marijuana users to address the problem. The Cannabis Conversation was launched in 2017, a two-year study meant to engage residents in building solutions to reduce impaired driving. The department connected with more than 18,000 Coloradans through a series of in-depth surveys, public meetings and focus groups. Officials believe the results will help to make a difference in changing behaviors.

“It was the biggest public engagement campaign in the country on the topic of marijuana and driving,” said Sam Cole, CDOT communications manager. “We are actually sharing the information with other states, because they’re very interested in what we’ve learned.

“As more and more states legalize they want to know some of the best practices when it comes to targeting cannabis consumers in their state about the dangers of driving high. I think the results will be enormously helpful in the years ahead.”

Perhaps the biggest takeaway is that people who consume cannabis more often consider driving under its influence as less dangerous. Respondents who don’t drive after using cannabis, and those that don’t consume it at all, felt uncomfortable with the idea of high drivers on the road. But more heavy users don’t necessarily feel the same, according to the report.

Cannabis users said they consume less when they know they’ll be driving, but many daily users said they at least occasionally drove under the influence. Most respondents said their top considerations before driving were travel conditions, feeling alert enough and how recently they consumed cannabis.

Many daily marijuana users said they considered driving under the influence of cannabis to be safe.

“Sadly we heard from a lot of cannabis consumers that don’t believe that it’s dangerous, and a small minority even believe it makes them a better driver,” Cole said. “We also know that the cannabis consumers that are going to be most difficult to target are the ones who use daily versus less frequent users. What we learned is the more you use marijuana, the more likely you are to think its less dangerous when it comes to driving.”

Many cannabis users also said they were skeptical of policies and enforcement when it came to driving under the influence, and wanted more comprehensive data on the dangers of drugged driving, better research around ways to measure impairment, and guidelines for dosage limits and waiting periods.

Research into alcohol impairment has returned solid guidelines using principals like the Widmark formula, which estimates blood alcohol concentration based on variables like weight, gender and the amount of alcohol consumed in a given period.

“What has been done with alcohol, and has yet to be done with marijuana, is Widmark’s equation,” said Corporal Carrie Jackson, a drug recognition expert with the Colorado State Patrol in Eagle and Summit counties. “Widmark determined Theta, the rate of change: If you consume x amount of alcohol and you wait this many hours its going to be processed through your body at this rate.

“Because marijuana is not legal federally, we do not have the grants in place to do a study like Widmark and find out what that rate of change is within the human body.”

In lieu of more accurate measurements, cannabis users said they relied more on gut instinct. Most said they’d felt uncomfortably high at times and knew they were not safe to drive after using cannabis.

CDOT is hoping to put the new information to work immediately. Study participants said they wanted authentic and conversational messaging that avoids scare tactics and stereotypes.

Cole said the department has already designed a new ad campaign called Uncomfortable High, a concept officials hope invokes a feeling of discomfort around cannabis-impaired driving.

“We heard from close to 20,000 people about their attitudes, beliefs and behaviors when it comes to driving under the influence of marijuana,” Cole said. “We definitely learned a lot about what to do, and what not to do when it comes to reaching cannabis consumers across the state.”

While officials continue efforts to more effectively engage with cannabis users, impaired driving remains a problem in areas like Summit County.

“I’d say at least half of my impaired driving arrests are drug-impaired driving arrests,” Jackson said.

Jackson continued to say that with the continued prevalence of legal marijuana, the state patrol is making efforts to expand training for advanced roadside maneuvers. Police are also using newer methods to familiarize themselves with impaired drivers. A few years ago, Chris Halsor, founder of Understanding Legal Marijuana LLC, debuted the “green lab,” which helps train law enforcement to detect cannabis-impaired drivers. The lab features volunteers who consume marijuana and then submit to roadside maneuvers and questions to help officers better understand impairment.

But more studies will be needed to fully understand the impacts of cannabis-impaired driving, and marijuana usage at large.

“I’m curious to see, looking at national trends, at what point it will be legalized nationally,” Jackson said. “And I’m curious to see if we will finally have that laboratory study for the rate of change. It’s just not there yet. …

“Going back to what studies have been conducted (cannabis) can be impairing for up to 24 hours. I say wait that full 24 hours. When in doubt use public transportation, an Uber or a Lyft. If you’re unsure if you’re safe to drive, don’t. It’s an unnecessary risk.”