The real truth about drugged driving, by Robyn Robertson, President, TIRF

June, 2007 – Bill C-32, the hotly debated drugged driving legislation proposed by the Tory government continues to spawn opposing views from proponents on both sides. Some argue stronger measures are needed to protect the public; others believe the legislation violates civil liberties.

In the midst of this controversy, researchers at the Traffic Injury Research Foundation (TIRF) are baffled by the unfounded accusations in an April 30th Ottawa Citizen article by Lawrence Greenspon, an Ottawa defence attorney, and fellow colleague, David D’Intino who both suggest the articles referenced in TIRF’s research are “marred by poor methodology, frequent misquotes, and provides conclusions that are unsupported by the evidence.”

A closer examination of TIRF’s research on drugged driving reveals that Greenspon and D’Intino are guilty of failing to consider all the evidence and misinterpreting the facts.

The research in question is the Road Safety Monitor, an annual public opinion poll that is funded by government and industry and developed by highly-experienced researchers. The poll is administered by a reputable, well-established polling firm according to scientific standards. Although neither the way the poll was conducted, nor the findings of the poll are questioned, Greenspon and D’Intino dismiss the research as being based “largely on public opinion” – a perplexing criticism of a public opinion poll.

Greenspon and D’Intino also take issue with the articles used to compile the Road Safety Monitor. In fact, the articles referenced in the report as background material are based on a thorough review of the current drugged driving literature and the limitations of the research are clearly noted.

These articles also formed the basis for proceedings from a 2005 workshop hosted by a committee of the prestigious U.S. Transportation Research Board – a workshop attended by leading researchers worldwide.

TIRF summarized several articles based on the proceedings, one of which notes that the evidence is mixed regarding the role of marijuana in road crashes. Some studies reported a reduced crash risk for drivers, whereas others cite an increased risk. TIRF also noted that some of the suggestive evidence has been questioned on methodological grounds – a claim in direct contradiction to those made by Greenspon and D’Intino.

Greenspon and D’Intino also suggest that Bill C-32 is based on the Road Safety Monitor. Although a flattering portrayal, it is one that is chronologically impossible. Drug legislation was in development long before the 2005 TIRF report.

Of some interest, the Road Safety Monitor reports that:

  • 2.4 per cent of drivers in the survey indicated they had driven within two hours of using marijuana or hashish – Greenspon and D’Intino claim the figure is less than two percent, apparently overlooking the recent findings which reflect a significant increase over the past three years. Indeed, a similar survey by the Canadian Centre on Substance Abuse now puts the estimate at over four per cent.
  • Contrary to the concerns cited by Greenspon and D’Intino, the poll emphasizes almost 70 per cent of those who admitted to using drugs within two hours of driving also admitted to using alcohol, echoing concerns that “it is difficult to separate those who drive stoned from those who drive stoned and drunk.”

It appears Greenspon and D’Intino’s frustrations stem largely from the testing procedures and protocols imposed by Bill C-32, particularly those that they feel may infringe on rights and civil liberties. These issues are complex and are clearly beyond the scope of TIRF’s public opinion poll, which was merely designed to report objectively and without bias the perceptions, opinions, and practices of Canadian drivers with regards to drugged driving.

All this brings into question the true motivations for Greenspon and D’Intino’s misdirected attack on TIRF, an organization which has produced award-winning research.

TIRF’s public opinion poll reports the facts. Not only is the public concerned about drugged driving, they are also supportive of enforcement action – including physical coordination tests if drugs are suspected, as well as the use of blood, urine, and saliva tests. Not surprisingly, it also found that marijuana and hashish users are less supportive of these actions than non-users. That’s the truth, the whole truth, and nothing but the truth.

  • Robyn Robertson is a criminologist and accomplished researcher. In addition to being president and CEO of TIRF, she also serves as part-time faculty at the criminology department of the University of Ottawa, and the National Judicial College in the US.
  • The Road Safety Monitor: Drugs and Driving is available at:

About TIRF:

Established in 1964, TIRF’s mission is to reduce traffic-related deaths and injuries. As a national, independent, charitable road safety institute — TIRF designs, promotes, and implements effective programs and policies, based on sound research. TIRF is a registered charity and depends on grants, contracts, and donations to provide services for the public. More information about TIRF can be found at: