Cannabis and Driving: Data and Research

Driving high is dangerous, and we want cannabis users and the general public to have the facts on the impacts of cannabis-impaired driving. There is a growing body of state data and academic research that shows cannabis does have physiological effects that impair driving – and that people are being injured and killed as a result.

State and National Data Resources on Cannabis-Impaired Driving

Bar chart showing 2019–2024 data on cannabis users who reported driving within 2–3 hours after use, ranging from 15% to 18.6%.
Driving After Using Cannabis (2019–2024): Percentage of past-30-day cannabis users who reported driving within 2–3 hours of use: 2019: 18.6%, 2020: 17.5%, 2021: 17.5%, 2022: 15.0%, 2023: 18.4%, 2024: 16.3%. Source: CDPHE Behavioral Risk Factor Surveillance System (BRFSS) database.

Bar chart titled "Fatalities in Crashes with Cannabis-Impaired Driver"
Fatalities in Crashes with Cannabis-Impaired Driver. Number of Colorado roadway fatalities in which the at-fault driver was suspected to be impaired by cannabis at the time of the crash: 2021: 82, 2022: 58, 2023: 52, 2024: 45. Source: Motor Vehicle Problem ID Dashboard, Colorado Department of Transportation and Colorado Department of Public Health and Environment.

Line graph showing a rise in polydrug involvement in fatal crashes from 26% in 2017 to 32% in 2024 in Colorado.
Polydrug Involvement in Fatal Crashes (2017–2024): Percentage of Colorado drivers in fatal crashes who tested positive for multiple impairing substances, including alcohol: 2017: 26%, 2018: 24%, 2019: 19%, 2020: 20%, 2021: 25%, 2022: 29%, 2023: 33%, 2024: 32%. Source: CDOT Data Intelligence Group, Toxicology Data (2024). Note: Includes drivers who tested positive for two or more categories of impairing substances such as alcohol, cannabinoids, stimulants, depressants, hallucinogens, narcotics, dissociative anesthetics, and inhalants.

Links to state and federal impaired driving data resources

Links to Academic Research on Cannabis and Driving Impairment

There are many misconceptions about marijuana use, including rumors that it can’t impair your ability to drive or that it can actually make you a safer driver. Several scientific studies indicate that this is false. Research shows that marijuana impairs motor skills, reaction time, lane tracking and cognitive functions.