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 (NTSB) said in a recently released report.

In the NTSB-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 Jennifer Homendy, chair of the NTSB. “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 that 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 Tom Chapman, member of the NTSB.

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.