Is Marijuana Legalization Fueling More Car Crashes? Utah Weighs the Risks

Utah has not legalized recreational marijuana—only medical cannabis, approved via ballot in November 2018. Recreational use remains illegal, punishable as a misdemeanor. Recent debacles in other states naturally raise concerns: if legalizing cannabis elsewhere has changed crash rates, could a shift come to Utah?

What the National Research Shows

Across the U.S., multiple studies point to a modest but measurable rise in car accidents and fatalities in states that legalized recreational cannabis:

• A Canadian-led study of 11 U.S. jurisdictions found a 15% increase in fatal crashes after legalization and when commercial dispensaries opened.
• Another study covering 2009–2019 found legalization correlated with a 2.3% increase in fatal crash rates and a 6.5% rise in injury crashes.
• In a 5‑state comparison (legal vs non‑legal jurisdictions), researchers reported a 5.8% uptick in injury crashes and a 4.1% jump in fatal crashes post-legalization.
• The Insurance Institute for Highway Safety (IIHS) and Highway Loss Data Institute (HLDI) observed a 6% increase in crashes in legalized states (Colorado, Washington, Oregon) compared to neighboring non-legal states like Utah.

Still, findings vary by state. For instance, Colorado saw a spike, while Washington recorded no net increase in fatalities post-legalization.

Why the Discrepancies? The Complexities of THC and Driving

Interpreting these results requires caution, especially since:

• THC detection ≠ impairment: THC can linger in the body long after the “high” wears off.
• Study variables differ: Some controlled THC blood levels; others used self-reports. Findings vary significantly depending on methodology.
• Behavioral nuances: Cannabis-impaired drivers often drive slower or keep their distance, possibly increasing minor crashes but not necessarily fatal ones.
• Co-use with alcohol: Marijuana is often used alongside alcohol, which amplifies risk.

Lessons from States Like Colorado and Washington

In regions with legalization:

• Colorado saw one additional fatal crash per million residents post-legalization.
• Washington observed a doubling—from about 9% to 19%—in the share of fatal-crash drivers testing positive for THC.
• Neighbor spillover: An examined triad—Colorado, Washington, Oregon—showed increases in serious crashes in both legal states and adjacent ones.

What This Means for Utah

Even though Utah hasn’t legalized recreational cannabis, it serves as a crucial benchmark:

• The IIHS study directly compared Utah (non-legal) with legal states, finding that accident rates in legal states were ~6% higher.
• As nationwide cannabis regulations evolve, Utah could face a spillover effect—either via tourists, online purchases, or cross-border travel.

How Near-Future Legalization Might Affect Utah Roads

If Utah reconsidered recreational cannabis, expect similar patterns:

• Increased crash risk: Most studies suggest a 2–6% rise in crashes and a modest absolute jump in fatal collisions.
• Need for public safety measures: As legalization unfolds, educating drivers about delayed impairment—recent research warns THC’s effects can linger 5.5 hours or more.
• Robust enforcement: Zero‑tolerance per se laws, similar to Utah’s .05 BAC rule, might present an effective deterrent.

Alternative Views and Limitations

Not everyone agrees:

• Some controlled studies found no statistical increase in accident risk after adjusting for confounding factors.
• Meta‑analyses show about double crash risk among marijuana users in general, but causality remains debated.
• Critics argue elevated crash rates might stem from greater THC testing, not actual increases in impaired driving.

Policy Recommendations for Utah

Should recreational cannabis be legalized in Utah, proactive steps could help mitigate risks:

1. THC impairment laws: Invest in accurate roadside testing that reflects real impairment, not just presence.
2. Public education: Emphasize that impairment can last well past the “high”—sometimes over five hours .
3. Strict DUI enforcement: Consider per se laws like those for alcohol, alongside training for police in drug recognition.
4. Continuous monitoring: Track accident and fatality rates post-legalization to adapt regulation and enforcement.

Conclusion

While Utah hasn’t introduced recreational cannabis, data from other states consistently show moderate rises in crashes and fatalities after legalization. If Utah shifts course, it should do so with evidence-based policies, strong enforcement, and public education to keep its roads safe.

Drawing from diverse U.S. studies, the consensus suggests legalization often brings a 2–6% increase in crashes, often minor, with a small but measurable uptick in fatalities. By learning from others—and tailoring responses like impairment testing and public campaigns—Utah can hopefully avoid pitfalls while managing any future regulatory changes.