Among 5,630 Canadian emerging adults, both habitual (OR=1.77) and casual (OR=1.79) cannabis users had significantly higher odds of past-year traffic violations, with age and other drug use moderating the relationship.
Young drivers, driving safety educators, traffic safety researchers
Both habitual and casual cannabis use linked to ~1.8x higher odds of traffic violations
What the researchers found
Both habitual (OR=1.77) and casual (OR=1.79) cannabis users had higher odds of traffic violations than non-users. Early emerging adults (15-19) who were casual users and middle emerging adults (20-24) who were habitual or casual users showed higher odds. The association was stronger in the absence of other drug use.
Why it matters
The finding that casual cannabis use carries similar traffic violation risk as habitual use challenges the assumption that only heavy users are at risk, suggesting even occasional use may affect driving-related outcomes.
The numbers in context
5,630 respondents; habitual cannabis OR=1.77; casual cannabis OR=1.79; male prevalence 19.2% vs female 9.9%; violations higher in middle (16.2%) and late (19.4%) vs early (8.8%) EAs
How the study worked
Cross-sectional analysis of 5,630 respondents from the 2012 Canadian Community Health Survey-Mental Health, categorized as early (15-19), middle (20-24), and late (25-29) emerging adults.
What this study cannot tell us
Cross-sectional self-reported data. Traffic violations include many types beyond impaired driving. Cannot establish that cannabis caused the violations. 2012 data predates legalization.
How to read the evidence
Large national health survey with multivariate analysis but cross-sectional design
When this study was published
Published in 2021 using 2012 pre-legalization Canadian data.
The bigger picture
This population-level data complements simulator studies by showing that cannabis use is associated with real-world driving outcomes, not just laboratory measures of impairment.
Questions still open
- Are these traffic violations directly related to cannabis impairment or to broader risk-taking behavior? Has legalization changed the association between cannabis use and traffic violations?
Common questions
Does cannabis use increase traffic violations?
Are casual cannabis users also at risk?
Read the original research
Steering clear: Traffic violations among emerging adults who engage in habitual or casual cannabis use.
Accident; analysis and prevention, 153, 106059
Citation
Ciccarelli, Tiana M; Leatherdale, Scott T; Perlman, Chris; Thompson, Kara; Ferro, Mark A. (2021). Steering clear: Traffic violations among emerging adults who engage in habitual or casual cannabis use.. Accident; analysis and prevention, 153, 106059. https://doi.org/10.1016/j.aap.2021.106059