Among nearly 1,000 cannabis users in Israel, 23% drove within two hours of use, with male sex, higher use frequency, and medical cannabis licenses associated with riskier driving timing.
Traffic safety researchers, medical cannabis prescribers, public health communicators, cannabis users who drive
What the researchers found
Of 979 cannabis users, 23% drove within 2 hours of use (high risk), 37% waited 3-6 hours (moderate risk), and 40% waited 7+ hours (low risk). Being male (RRR=2.11) and more frequent use (RRR=1.21) predicted moderate risk. Male sex (RRR=1.89) and frequent use (RRR=1.70) also predicted high risk. Medical cannabis license holders had 4x higher odds of moderate-risk driving compared to non-medical users. Cannabis use frequency also predicted driving while feeling cannabis effects.
Why it matters
Nearly a quarter of cannabis users drove shortly after use, and medical cannabis users were more likely to drive at moderate-risk intervals, possibly due to daily dosing schedules. This has implications for how medical cannabis programs counsel patients about driving.
The numbers in context
979 cannabis users; 23% drove within 2 hours; 37% waited 3-6 hours; 40% waited 7+ hours; male sex RRR=2.11 for moderate risk; medical license RRR=4.14 for moderate risk; frequency RRR=1.70 for high risk
How the study worked
Cross-sectional online survey of 979 cannabis users in Israel. Measured reported wait times between cannabis use and driving (categorized as high risk: <2h, moderate: 3-6h, low: 7+h). Logistic and multinomial regression identified correlates.
What this study cannot tell us
Self-report data subject to social desirability bias. Israel-specific sample with different cannabis culture and laws. Cross-sectional design. Wait time does not directly measure actual impairment. Medical cannabis use patterns in Israel may differ from other countries.
How to read the evidence
Moderate: adequate sample size with multivariate analysis, but self-report cross-sectional design in a single country.
When this study was published
2025 publication
The bigger picture
As medical cannabis programs expand, the tension between therapeutic use and driving safety grows. Patients using cannabis daily for medical purposes face practical challenges in maintaining long wait times before driving.
Questions still open
- What wait time adequately reduces impairment risk across different cannabis products?
- Should medical cannabis programs include specific driving guidance as part of treatment plans?
Read the original research
Haven't I waited long enough? The role of wait times and subjective impairment in cannabis-related driving behavior.
The International journal on drug policy, 135, 104654
Citation
Har-Even, Ayelet; Lewis, Nehama; Eliash-Fizik, Hadar; Sznitman, Sharon R. (2025). Haven't I waited long enough? The role of wait times and subjective impairment in cannabis-related driving behavior.. The International journal on drug policy, 135, 104654. https://doi.org/10.1016/j.drugpo.2024.104654