What topics does this cannabis study cover?

This study covers research on: Addiction.

Where was this research published?

Published in Traffic injury prevention on May 27, 2026.

Stricter alcohol laws led drivers to cannabis instead

Q: What did this research study find?

This Chilean study examined trends in **impaired driving behavior from 2012 to 2022**, tracking self-reported *driving under the influence of alcohol* (DUIA) and *cannabis* (DUIC) across over 26,000 licensed drivers. The research was designed to test whether stricter alcohol enforcement—introduced b

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

Traffic injury prevention • May 27, 2026 • Moderately Relevant

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AI Summary

This Chilean study examined trends in impaired driving behavior from 2012 to 2022, tracking self-reported driving under the influence of alcohol (DUIA) and cannabis (DUIC) across over 26,000 licensed drivers. The research was designed to test whether stricter alcohol enforcement—introduced by Chile's 2014 Emilia law—would cause drivers to shift to cannabis, or whether both behaviors would decline independently. The findings revealed a striking divergence: DUIA decreased from 12.9% in 2012 to 7.9% in 2022, while DUIC actually increased, rising by approximately 25% after 2014.

The most significant finding was evidence of potential substitution behavior—the phenomenon where stricter regulations on one substance lead people to switch to another. After Chile's 2014 alcohol law strengthened penalties and enforcement for impaired driving, cannabis-impaired driving rose modestly despite weaker cannabis traffic enforcement policies. The researchers found statistically significant divergence between the two trends, with odds of DUIA dropping 40% by 2022 compared to 2012, while odds of DUIC increased by 25% over the same period. Combined use of both substances remained rare (1.2-1.9% across all years).

These findings have important implications for public health policy. They suggest that targeting one substance without comprehensive strategies for others may inadvertently encourage substitution to less-regulated alternatives. The study underscores the need for integrated traffic safety approaches that simultaneously address both alcohol and cannabis impairment, rather than focusing enforcement efforts on a single substance. This is particularly relevant as cannabis legalization spreads globally and the comparative enforcement landscape shifts.

📄 Original Abstract

To examine temporal patterns in self-reported driving under the influence of alcohol (DUIA) and cannabis (DUIC) in Chile between 2012 and 2022, and to assess whether trends are consistent with substitution or complementarity between substances in the context of strengthened alcohol-impaired driving sanctions introduced by the Emilia law (2014), and comparatively weaker cannabis enforcement. We analyzed six waves of repeated cross-sectional data (2012-2022) of the nationally representative Chilean Drugs Population Survey (N = 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. Most respondents reported no impaired driving, ranging from 84.6% in 2012 to 88.8% in 2022. DUIA alone was reported at 12.9% in 2012 and 7.9% in 2022, DUIC alone was measured at 0.8% to 1.6% respectively, and DUIA&C remained rare (1.2-1.9%). Adjusted logistic regression showed that the odds of DUIA, when compared to 2012, went from 0.897 (95% CI: 0.798-1.008) in 2014 to 0.600 (95% CI: 0.526-0.685) in 2022 with the difference between these two years being statistically significant (z = 4.46, p < .05). In contrast, the odds of DUIC increased from 1.345 (95% CI: 1.043-1.736) in 2014 to 1.673 (95% CI: 1.290-2.172) in 2022, with this difference also reaching statistical significance (z = 1.97, p < .05). Multinomial analyses revealed a statistically significant divergence between trends in DUIA and DUIC (difference in slope = 0.132; 95% CI: 0.101-0.164; z = 8.16, p < .001), indicating that while alcohol-impaired driving decreased, cannabis-impaired driving rose. Following the 2014 Emilia 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.