Opening cannabis dispensaries in Colorado did not increase traffic crashes
While recreational dispensary openings in Colorado counties led to increased marijuana-related hospital visits, they were not associated with increases in traffic crash incidents.
Quick Facts
What This Study Found
Using county-level variation in when recreational dispensaries opened across Colorado, the entry of cannabis retail stores was associated with a significant increase in marijuana-related hospital discharges but no increase in traffic crash incidents. At 90% confidence, a large increase in crashes (>5%) could be ruled out.
Key Numbers
Significant increase in marijuana-related hospital discharges after dispensary entry. No significant increase in traffic crashes. Upper bound of 5% increase can be ruled out at 90% confidence.
How They Did This
Difference-in-differences analysis exploiting variation in the timing of recreational dispensary entry across Colorado counties. Used marijuana-related hospital discharges as a measure of cannabis use intensity. County-level traffic crash data.
Why This Research Matters
Traffic safety is one of the most cited concerns about cannabis legalization. This county-level analysis finds no evidence that dispensary openings increased crashes, despite confirming increased cannabis use.
The Bigger Picture
The dissociation between increased cannabis use (confirmed by hospital data) and stable crash rates suggests that factors like substitution away from alcohol or increased awareness of impairment may offset driving risks.
What This Study Doesn't Tell Us
County-level analysis cannot capture individual-level behavior. Hospital discharges may not perfectly proxy cannabis use. Short post-entry periods in some counties.
Questions This Raises
- ?Are cannabis users substituting away from alcohol (which is more strongly linked to crashes)?
- ?Would effects differ in the long term as dispensary density increases?
Trust & Context
- Key Stat:
- No traffic crash increase despite confirmed rise in cannabis use
- Evidence Grade:
- Rigorous econometric design using natural variation, though county-level ecological analysis has inherent limitations.
- Study Age:
- Published in 2022.
- Original Title:
- Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado.
- Published In:
- Health economics, 31(10), 2244-2268 (2022)
- Authors:
- Gunadi, Christian(4)
- Database ID:
- RTHC-03889
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Did cannabis dispensaries increase traffic crashes?
No. Despite a confirmed increase in cannabis use (measured by marijuana-related hospitalizations), traffic crash rates did not increase when dispensaries opened in Colorado counties.
Why might crashes not increase?
Possible explanations include cannabis users substituting away from alcohol, increased awareness of impairment, or use of delivery and ride-share services in legal markets.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-03889APA
Gunadi, Christian. (2022). Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado.. Health economics, 31(10), 2244-2268. https://doi.org/10.1002/hec.4573
MLA
Gunadi, Christian. "Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado.." Health economics, 2022. https://doi.org/10.1002/hec.4573
RethinkTHC
RethinkTHC Research Database. "Does expanding access to cannabis affect traffic crashes? Co..." RTHC-03889. Retrieved from https://rethinkthc.com/research/gunadi-2022-does-expanding-access-to
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.