How Eating Cannabis Edibles Affects Simulated Driving Performance | Research

The takeaway

In 88 adults, edible cannabis impaired driving simulator performance, with effects varying by usage frequency, THC dose, and whether driving was in urban or rural settings.

Cannabis consumers, traffic safety researchers, policymakers, and anyone interested in how edibles specifically affect driving ability.

What the researchers found

Edible cannabis impaired simulated driving performance across speed control and lane maintenance measures, with daily users showing different patterns than occasional users, and effects varying between rural and urban driving scenarios.

Why it matters

Edibles are increasingly popular but their driving impairment profile differs from smoked cannabis — slower onset, longer duration, and harder to self-regulate dosing. This creates unique road safety concerns.

The numbers in context

88 adults: 29 daily users, 30 occasional users, 29 non-users. Denver, Colorado, recruited November 2023 to July 2024. Measured speed, lane departure, and other driving metrics.

How the study worked

Within-subjects driving simulator study in Denver, Colorado with 88 adults (25-55 years) in three groups: daily users (n=29), occasional users (n=30), and non-users/comparison (n=29), assessing driving after edible cannabis consumption.

What this study cannot tell us

Simulator driving doesn't perfectly replicate real-world driving. Denver population in a legal state may not represent all drivers. Within-subjects design may have practice effects.

How to read the evidence

Well-designed within-subjects simulator study with appropriate comparison groups, though simulated driving has inherent limitations.

When this study was published

Very recent study (2023-2024 recruitment) addressing the timely issue of edible cannabis and driving safety.

The bigger picture

Most cannabis-impaired driving research focuses on smoked cannabis. As edibles gain market share, understanding their specific impairment profile is critical for public safety messaging and policy.

Questions still open

How long after consuming edibles should people wait before driving? Should impaired driving laws differentiate between edible and smoked cannabis consumption?

Common questions

Are edibles worse for driving than smoking cannabis?

This study focused on edibles specifically. Edibles have delayed onset and longer duration, potentially making it harder for users to judge when they're impaired compared to smoked cannabis.

Did daily cannabis users drive better than occasional users after edibles?

The study found different patterns between daily and occasional users, which is consistent with research showing some tolerance development, though impairment was still observed.

Read the original research

Edible cannabis use on simulated driving performance.

Traffic injury prevention, 1-9

View on PubMed ↗Publisher’s paper ↗

Citation

Won, Nae Y; Bird, Sarah; Wrobel, Julia; Brown, Timothy; Brooks-Russell, Ashley. (2025). Edible cannabis use on simulated driving performance.. Traffic injury prevention, 1-9. https://doi.org/10.1080/15389588.2025.2574271