There’s a hot story today about some new research by the American Automobile Association on marijuana in fatal accidents.

As usual, media coverage is misleading.

The best example of this media abuse comes from Tom Costello and The Today Show with a headline asserting marijuana is causing a spike in fatal accidents.


However, the AAA never said that as you can see from page 16 of its study:

Drivers who had detectable THC in their blood at the time of the crash were not necessarily experiencing impairment in their ability to drive safely, nor were they necessarily at fault for the crash. Determination of actual impairment or fault status was beyond the scope of the study. Relatedly, many of those who were positive for THC were also positive for alcohol and/or other drugs, which in some cases likely contributed more significantly to the crash than did the THC. Research on the relationship between THC presence and risk of crash involvement has been inconclusive.

In fact, the most recent and thorough study on crash risk from drugs  found that for both marijuana and other illegal drugs: “analyses … did not show a significant increase in levels of crash risk associated with the presence of drugs.”

That study, written by Richard P. Compton and Amy Berning for NHTSA’S Office of Behavioral Safety Research, did initially find a slight increase in crash risk among those who tested positive for illegal drugs and specifically for THC. But then they did what scientists are supposed to do – they looked more carefully at the data. They found that the presence of THC and other drugs were highly correlated with demographic and other statistics (age, gender, ethnicity, and alcohol concentration level) that increase crash risk. When they analyzed the data controlling for those variables they then found that THC and other drugs had no significant effect on crash risk.

For example, if the THC-positive drivers were predominantly young males, their apparent crash risk may have been related to age and gender rather than use of THC.

AAA’s study acknowledged that study, but Tom Costello and The Today Show did not mention it. Did they actually read the article? Or did they deliberately mischaracterize it?



Other news sites are covering marijuana DUI research more accurately, but still misunderstand it.

Ashley Halsey III of the Washington Post and Joan Lowy of the Associated Press both did a somewhat more responsible job by covering a related AAA study  that shows that tests measuring the amount of THC in the blood do not reliably indicate impairment.

What both articles get wrong (thanks to misleading or misquoted statements from AAA’s Jake Nelson) is that using police officers trained as “Drug Recognition Experts” (DRE) will solve the problem.

First of all, the study does not recommend that approach but rather includes it as one of several options:

In the absence of a scientifically based cannabis per se law, there are several options. One is to train officers to detect the signs and symptoms of cannabis use in drivers …. Initial suspicion of cannabis use would lead to a field sobriety test (SFST). This process could be coupled with … oral fluid screening …. The technology to detect certain drugs … at roadside is improving …. The suspect would then be taken for a complete drug evaluation by a DRE.
The … approach, however, does have limitations ….

While the AAA study does discuss some of those limitations, it leaves out the question as to whether police officers with a few hours of training are really qualified to perform neurological and ophthalmological testing and to draw medical conclusions from such testing. They’re not.

It also ignores the evidence mentioned above that marijuana and other illegal drugs do not increase crash risk.

The option not mentioned by any of these journalists is to recognize that DUI laws should focus on alcohol. We should stop wasting time and money – and stop arresting and prosecuting innocent drivers – over things that do not increase crash risk.

An earlier version of this article appeared on Author Warren Redlich has worked with PINAC on DUI checkpoints in the past, and was arrested in a Coral Gables checkpoint while using the PINAC 360 camera. That incident has led to two separate court cases, one in state court and another in federal court.

The Fair DUI book is available on Amazon.