Nov. 27, 2020

Class of 2020: Research on cannabis and driving leads to PhD

Human factors scholar Sarah Simmons now joining W21C Research and Innovation Centre

Solving puzzles is something Sarah Simmons looks forward to doing every day. Simmons, who graduated on Nov. 26 with a PhD in psychology from the Faculty of Arts, is a human factors researcher.

Human factors is an area of study that focuses on the interactions between humans and technological systems, with the general goal of making those systems safer and more user-friendly. Because it's an interdisciplinary field, human factors researchers come from a variety of backgrounds such as psychology, engineering, computer science or medicine. Simmons’ research has focused on driver and pedestrian safety.

Simmons worked under the supervision of Dr. Jeff Caird, PhD, as a member of the Cognitive Ergonomics Research Laboratory. There, they strived to contribute knowledge related to timely road safety issues. As Simmons was preparing to start her doctoral research, the federal government was in the process of legalizing cannabis for recreational use. Given the concerns about the effects of cannabis on road safety, she decided to focus her dissertation on evaluating the effects of cannabis and alcohol on driving performance and behaviour.

The results of her dissertation clearly indicate that cannabis is bad for driving.

“People under the influence of cannabis do suffer driving performance decrements," says Simmons. "Although drivers appear to attempt to compensate by reducing their driving speed, those attempts to compensate are inadequate."

She also compared the effects of cannabis on driving performance and behaviour to those of alcohol.

“It looks like the effect of cannabis is similar to lower levels of alcohol in terms of driving performance decrements,” says Simmons.

While preparing her dissertation project, Simmons had to develop broad background knowledge. For example, she had to learn more about the pharmacokinetics and pharmacodynamics of cannabis and alcohol and become familiar with impaired driving legislation and countermeasures. One of the first things she noticed was that cannabis and alcohol are totally different drugs, and legislative countermeasures to cannabis-involved driving would need to reflect that.

“We tend to think about preventing impaired driving based on how we think about alcohol," says Simmons. "We have imposed blood alcohol limits, and we can assess blood alcohol concentrations with a breathalyzer. However, we should not necessarily do the same for cannabis.”

Simmons thinks of her projects as puzzles and enjoys the experience. “The most rewarding thing about this area of study is the fact that I can talk to just about anyone and immediately they get interested in it," she says. "A lot of people think ‘I know exactly how cannabis must impact driving,’ so getting to challenge them a little bit and get them to really think through it with you [is fun]." 

Now, Simmons gets to shift her focus to a new human factors puzzle: making health care better. After completing her dissertation, she is now a human factors research associate at the W21C Research and Innovation Centre in the O’Brien Institute for Public Health at the Cumming School of Medicine. Sarah now applies her foundational human factors knowledge to improving patient safety and understanding how people interact with health-care environments, systems and processes.