Examining driving under the influence: New study makes recommendations for a ‘drugged driving’ policy

Following the passing of ballot measures to regulate cannabis sales and consumption in Washington and Colorado this past November, many wondered what a regulatory system could and would look like.

While the ballot measures outlined where tax revenues would be directed (including drug treatment and education programs), questions remain on what the social impacts of legalized cannabis might be on other health and social indicators.

A new study published in Drug Testing and Analysis addresses one of these primary issues: driving under the influence of cannabis. (See: Armentano, P. (2013), Cannabis and psychomotor performance: A rational review of the evidence and implications for public policy. Drug Test Analysis, 5: 52–56. doi: 10.1002/dta.1404)

Study author Paul Armentano is the deputy director of National Organization for the Reform of Cannabis Laws (NORML). Founded in 1970, NORML has played a central role in the cannabis legalization movement, operating a large grassroots network with 135 chapters and over 550 lawyers internationally, and Armentano is widely regarded as an expert in the field of marijuana policy, health, and pharmacology.

Armentano opens his paper by asking: “How does society address the public’s growing concerns about cannabis consumption and driving?”

Using data compiled in the US-based Substance Abuse and Mental Health Services Association 2010 National Survey on Drug Use and Health, Armentano found that 10.6 million Americans, or 4.2% of the population age 12 or older, reported driving under the influence of an illicit drug during the past year. He also cites another survey by the association that estimated that among those who acknowledge having driven following the consumption of an illicit substance, a majority of respondents, 70%, confirmed having done so following the ingestion of cannabis.

While this number is far from negligible, Armentano points out that it is far fewer than the number of respondents who acknowledge having driven while under the influence of alcohol.

While it is well established that alcohol consumption increases accident risk, Armentano presents evidence that cannabis’s role in increasing the risk of on-road driving accidents and injury is far less clear. What is clear, he finds, is that cannabis does impair cognitive and psychomotor performance. Put simply, driving under the influence of cannabis can be dangerous.

As a result, Armentano comes to a decisive conclusion: motorists should never operate a vehicle while after inhaling cannabis.

Among the other key findings from the study:

  • Less experienced drivers are more likely to be negatively affected by the consumption of cannabis
  • Less experienced cannabis consumers are also less tolerant of cannabis’ effects and also more likely to be impaired as a result
  • Cannabis’ influence on driving skills is arguably less severe than that induced by the consumption of alcohol, including relatively low doses of alcohol
  • Simultaneous use of both cannabis and alcohol further compounds the risk of accident

Armentano suggests that public education campaigns directed at young adult drivers (those aged 18-25) to warn them of the harms of driving under the influence of cannabis are particularly important, given that demographic’s inexperience with driving and their increased level of cannabis use relative to the general population.

In addition, Armentano makes clear recommendations for increasing law enforcement efforts to address cannabis-influenced driving, which include encouraging police officers to engage in drug recognition expert training and increasing the number of field sobriety tests, both of which would help police officers identify drivers who may be operating a vehicle while under the influence of cannabis.

Armentano also recommends the provisional use of point-of-collection cannabis-sensitive technology, such as a roadside saliva test, to rapidly identify the presence of THC in drivers.

Past research has demonstrated that the legalization and regulation of adult cannabis use will likely improve community health and safety and reduce many of the social harms associated with cannabis prohibition. Creating clear drugged driving policy is one important piece in ensuring that a regulatory system effectively minimizes the societal harms of cannabis use.

Media: to speak with a member of the Stop the Violence BC Coalition, please contact:

Kevin Hollett
BC Centre for Excellence in HIV/AIDS
604 682 2344 ext. 66536