Alcohol- and cannabis-impaired driving in Chile, 2012–2022: trends in the context of alcohol policy changes and substitution theory

OBJECTIVE: law (2014), and comparatively weaker cannabis enforcement. METHODS: = 26,242 licensed drivers). Outcomes were self-reported DUIA and DUIC, analyzed separately and jointly. Survey year served as a proxy for exposure to Chile's traffic laws. Descriptive prevalence estimates were calculated across waves. Temporal patterns were examined using survey-weighted logistic regression models for DUIA and DUIC and multinomial logistic regression models comparing DUIA only, DUIC only, and combined DUIA and DUIC (DUIA&C) relative to no impaired driving. Models were adjusted for sex, age, age at alcohol onset, household income, and administrative region. RESULTS: < .001), indicating that while alcohol-impaired driving decreased, cannabis-impaired driving rose. CONCLUSIONS: laws, DUIA in Chile declined substantially, suggesting the contribution of strengthened alcohol-focused interventions. In contrast, DUIC increased modestly, suggesting potential substitution behaviors in response to stricter alcohol regulations and weaker cannabis enforcement. These findings highlight the importance of considering cross-substance dynamics in road safety policies and underscore the need for integrated strategies that target both alcohol and cannabis, to prevent unintended behavioral adaptations and enhance overall traffic safety.