Study: Marijuana Legalization Associated With Reduction in Pedestrian Fatalities

Legalizing marijuana is associated with a reduction in the number of alcohol-related fatalities involving pedestrians, according to a new study published in the journal IATSS (International Association of Traffic and Safety Sciences) Research.

For the study researchers from Florida Polytechnic University examined the relationship between marijuana legalization and rates of pedestrian-involved fatal crashes between the years 1985 and 2019. This is particularly important because “Pedestrian fatality rates in the US began to increase in 2009, after three decades of decline.”

Researchers found that the passage of both medical cannabis laws and laws legalizing recreational marijuana were associated with overall declines in pedestrian fatalities, including declines in alcohol-related fatalities. Researchers believe this may be due to consumers substituting marijuana for alcohol.

“Consistent with the alcohol substitution hypothesis, we find both medical and recreational marijuana laws are followed by a statistically significant reduction in daytime fatalities involving alcohol. Both are also followed by a reduction in nighttime fatalities involving alcohol, but the declines are not statistically significant”, states the study.

The full abstract can be found below.

Abstract

Pedestrian fatality rates in the US began to increase in 2009, after three decades of decline. This increase is occurring at the same time policy makers are encouraging walking as a healthy and sustainable transportation mode. The increase in pedestrian fatalities is also concurrent with the spread of liberalization of marijuana use laws across the US. Has the liberalization of marijuana laws contributed to the increase in pedestrian fatalities?

Using a Poisson regression generalized difference in difference design, we measure the relationship between pedestrian fatalities and liberalization of marijuana laws. We employ randomization inference since persistent idiosyncratic shocks in the state time series may create spurious correlations that inflate type 1 error rates for conventional hypothesis tests. Consistent with the alcohol substitution hypothesis, we find both medical and recreational marijuana laws are followed by a statistically significant reduction in daytime fatalities involving alcohol. Both are also followed by a reduction in nighttime fatalities involving alcohol, but the declines are not statistically significant.

More information on this study can be found by clicking here.