NTSB Report Finds Alcohol and Cannabis Are Primary Drugs Detected in Impaired Drivers


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​​​WASHINGTON, D.C. (January 12, 2023) — Actions from federal and state agencies are needed to address the continuing problem of impaired driving, including from alcohol, cannabis and multiple drug use the National Transportation Safety Board said in a new report released today.

In the Board-approved safety research report, the agency examined the crash risk associated with different drugs — including alcohol, cannabis, prescription, over-the-counter and other drugs — and the prevalence of their use among drivers. The report also makes recommendations aimed at preventing crashes caused by impaired drivers. 

“Impaired driving leads to tragedy every day on our nation’s roads, but it doesn’t have to,” said NTSB Chair Jennifer Homendy. “To create a truly safe system — one where impaired driving is a relic of the past — states and federal agencies must implement our recommendations, and fast. Further complacency is inexcusable.” 

Researchers found alcohol remains the most often detected drug in impaired driving incidents and cannabis is the second most common. They also found that while alcohol is most often detected alone, cannabis was most often detected in combination with alcohol or other drugs. 

The report also highlights that current testing practices and protocols need to be improved to both better detect a driver’s drug use and accurately report the prevalence of drug-impaired driving. For example, many jurisdictions halt testing when a driver’s blood alcohol concentration is over a certain threshold, losing valuable information on other drugs the driver may have used. Additionally, a lack of standardized drug testing and reporting hinders understanding of the issue and the development of policies that can reduce impaired driving, as well as treatment options for those with substance abuse disorders. 

“We’ve long known about the devastating impact of alcohol-impaired driving, but this report shows that impairment from other drugs, especially cannabis, is a growing concern that needs to be addressed,” said NTSB Member Tom Chapman. 

Recommendations in the report include:

  • ​A requirement that cannabis products have a warning label about driving impairment
  • Enhancements to state drug-impaired driving laws 
  • Standardization of toxicology testing for the detection of drug use
  • Research on how to improve compliance with driving-related warnings on potentially impairing prescription and over-the-counter drugs 

The full report is available on the NTSB’s website.


To report an incident/accident or if you are a public safety agency, please call 1-844-373-9922 or 202-314-6290 to speak to a Watch Officer at the NTSB Response Operations Center (ROC) in Washington, DC (24/7).