First Real-World Driving Study to Test Whether Medical Cannabis Impairs Patients
A two-phase trial will test whether medical cannabis patients are actually impaired while driving at therapeutic doses, comparing their performance to alcohol impairment at the legal limit.
Quick Facts
What This Study Found
Study protocol for the first real-world on-track driving study of prescribed medical cannabis patients (n=72 across pain, anxiety, insomnia) compared to alcohol-impaired healthy controls (n=24 at 0.05% BAC), measuring lateral vehicular control.
Key Numbers
Phase 1: 72 patients (24 each for pain, anxiety, insomnia); Phase 2: 24 healthy controls at 0.05% BAC; repeated on-track driving assessments with cognitive testing and biological sampling.
How They Did This
Two-phase trial: Phase 1 is a semi-naturalistic cohort study of 72 medical cannabis patients completing on-track driving assessments; Phase 2 is a randomized, placebo-controlled crossover study of 24 healthy participants with alcohol.
Why This Research Matters
Australia (and many jurisdictions) prohibit driving with any detectable THC, regardless of actual impairment — this study could provide the evidence needed to shift from zero-tolerance to impairment-based driving laws.
The Bigger Picture
This addresses one of the most contested questions in cannabis policy: are medical cannabis patients who use THC products as prescribed actually unsafe to drive? Current laws assume yes, but evidence is lacking.
What This Study Doesn't Tell Us
Study protocol only (no results yet); on-track driving differs from real-world conditions; single-dose assessment may not capture cumulative or chronic use effects.
Questions This Raises
- ?Will medical cannabis patients show comparable impairment to alcohol at the legal limit?
- ?Should driving laws distinguish between recreational and therapeutic cannabis use?
Trust & Context
- Key Stat:
- Evidence Grade:
- Published study protocol with registered trials, but no results yet — significance lies in the novel design addressing a critical policy gap.
- Study Age:
- Published in 2026, trials registered in 2024, representing the cutting edge of medical cannabis driving research.
- Original Title:
- Effects of prescribed medical cannabis and alcohol on real-world driving performance (CAN-TRACK): a study protocol for a two-phase trial.
- Published In:
- Trials (2026)
- Authors:
- Arkell, Thomas R(10), Hayley, Amie C(8), Aitken, Blair(2), Hu, Xinyun, Manning, Brooke, Downey, Luke A
- Database ID:
- RTHC-08088
Evidence Hierarchy
Frequently Asked Questions
Does medical cannabis impair driving ability?
This is exactly what this study aims to answer — no real-world driving data exists for medical cannabis patients at prescribed doses. Current laws assume impairment at any THC level.
How does this study compare cannabis to alcohol impairment?
Phase 2 directly compares driving performance of cannabis patients to healthy volunteers at the legal alcohol limit (0.05% BAC), providing a meaningful benchmark.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-08088APA
Arkell, Thomas R; Hayley, Amie C; Aitken, Blair; Hu, Xinyun; Manning, Brooke; Downey, Luke A. (2026). Effects of prescribed medical cannabis and alcohol on real-world driving performance (CAN-TRACK): a study protocol for a two-phase trial.. Trials. https://doi.org/10.1186/s13063-026-09512-x
MLA
Arkell, Thomas R, et al. "Effects of prescribed medical cannabis and alcohol on real-world driving performance (CAN-TRACK): a study protocol for a two-phase trial.." Trials, 2026. https://doi.org/10.1186/s13063-026-09512-x
RethinkTHC
RethinkTHC Research Database. "Effects of prescribed medical cannabis and alcohol on real-w..." RTHC-08088. Retrieved from https://rethinkthc.com/research/arkell-2026-effects-of-prescribed-medical
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.