New study in Spokane looks at driving under the influence of cannabis

We’ve long known the dangerous effects of driving under the influence of alcohol, but there’s been fewer studies about the possible impacts of cannabis.

But with a study by the Virginia Tech Transportation Institute (VTTI) currently underway in Spokane, this is changing.

There are also opportunities for people to participate in this study, help shape policy around driving and cannabis use, and be compensated for it.

The Pioneer Research Study is a subset of VTTI’s larger “ADAS” study that looks at how people drive vehicles equipped with advanced driver assistance systems, such as lane-keeping assistance and adaptive cruise control. Volunteers for the ADAS study who use cannabis can also participate in the Pioneer Study that helps researchers determine the impacts of marijuana on driving decisions and actions.

“The Pioneer Study lets us see what the driver sees, road conditions, and the dashboard,” said Kaitlyn Fitzgerald, project manager and research associate with VTTI. “When a big event happens, we can see the cause, the reaction, and how we can improve both, whether through policy, manufacturers, or other methods.”

Both studies are new to the Spokane area, although ADAS has been underway for over a year in Virginia and Washington, D.C.

The Pioneer Study concept originated in Colorado between 2013 and 2015. With 25 participants at first, researchers decided to expand the study to increase sample size and dataset. Spokane was chosen both because marijuana is legal here and the city has infrastructure hard to find in other parts of the country.

“It’s so historical in Spokane and so many of the roads are one-way multi-lane,” said Fitzgerald. “That’s not something we get to test as much in Virginia. LiDAR (light detection and ranging sonar that uses laser waves to map the distance to surrounding objects) and more research is needed to understand if sensors struggle with multi-lane one way streets. Plus, we get a lot of snow in Spokane that wears off street markings, which LiDAR sensors need.”

Participants in the Pioneer Study are asked to do everything they normally would when driving, including use cannabis if that is part of their routine.

“We started a new style of driving research, called naturalistic driving. We don’t want them to change consumption habits or driving habits,” Fitzgerald said.

Those habits will all be recorded by cameras in the car as part of the study. One looks at the driver’s face for identification purposes and to study time looking between the dashboard and the road, one is focused on the dashboard, and one looks out the windshield.

For those worried about privacy or information on their driving or consumption being publicized, Fitzgerald says there are built-in confidentiality assurances.

“That is people’s biggest red flag, right?” she said. “The National Institute of Health has issued us a Certificate of Confidentiality. Your personal participation cannot be used in court against you, even federally. Say you are driving under the influence, you get pulled over by an officer and he sees you have cameras in your car. We provide you with a letter about the study to help protect you.”

The Certificate of Confidentiality means that the data collected can’t be used against you in legal proceedings. Researchers also aren’t looking to get anyone in trouble for bad driving habits, unless they recognize behavior that puts the participant or others at risk repeatedly.

“People ask if they accidentally do something like run stoplights, will they be in trouble? We likely won’t see that until the end of the study. We just chalk most of that up to human behavior.”

All video collected will be reviewed by technicians when participation is complete. Before that, study participants are asked to self-report every time they drive. That includes documenting any time they take prescription drugs or use marijuana, when they experience a peak feeling of intoxication, and their current level of intoxication when they get in the car.

A smartphone app also prompts participants to do breathalyzer tests. A once-a-month self-administered drug test is required.

To ensure confidentiality, this information is stored separate from personal identifiers.

“In my eyes you are participant No. 001. I only know your driving data and your substance use data by number, not name,” said Fitzgerald.

The Pioneer Study will be underway for three years. Fitzgerald expects it to take about a year to analyze data and publish results.