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Langham: Pot, Impairment and Car Crashes

By David Langham

Wednesday, July 26, 2017 | 1138 | 0 | min read

I served on a panel at the Colorado workers' compensation conference this spring. It was a tremendous program in an ideal setting at the base of Pikes Peak. Believe it or not, the subject of marijuana came up (in Colorado -- who'd have thought?). Marijuana is a subject about which I have written multiple musings on my blog. A few of those are:

David Langham

David Langham

In another post, Measuring Marijuana Intoxication, I discussed some issues with the way marijuana affects people, and the distinctions it has from alcohol. Alcohol presence can be measured more readily, even if scientists tend to believe that the thresholds such as .08 Blood Alcohol Content (BAC), while convenient, are not necessarily scientifically definitive of impairment. Despite the scientific questions, laws across the country have generally defined presumptions of impairment with that BAC level (.08). 

This spring, NPR reported that "drug-impaired driving is a growing concern." Despite that, "its actual impact is still difficult to measure." There is evidence that drug-impaired driving is even more prevalent than alcohol-impaired driving. But when it comes to determining the cause of accidents, NPR reports that "findings cannot show that drugs are responsible for more deaths on the roadways than alcohol," and the reason is tied to the difficulty with measuring drug impairment. 

A recent insurance study reported on by the Associated Press "links increased car crash claims to legalized recreational marijuana." Keep in mind that there is no such thing as "legal marijuana." Marijuana remains illegal under federal law in this country, and no state can legalize it. The states can elect, and some have elected, not to criminalize possession or use under state law. The states also can elect not to enforce federal law. But states can no more legalize marijuana than they can legalize kidnapping or counterfeiting. Those are also against federal law. 

This insurance study cannot link accidents to drug use or impairment either, perhaps for the same reasons cited by NPR regarding impairment generally. What the insurance study found, however, is that "it would appear, not to anyone's surprise, that the use of marijuana contributes to crashes." And one highway safety industry spokesperson noted that "while we have proven countermeasures, proven strategies for reducing alcohol-impaired driving, there are a lot of unanswered questions about marijuana and driving." 

Some claim impairment can be effectively measured. As The Boston Globe reported, one University of Massachusetts professor has created an app called DRUID, which stands for "driving under the influence of drugs." The app asks users to "tap the screen in certain places when they see different shapes." There are also tests for stopping a stopwatch at 60 seconds and using the finger to follow a moving object on the tablet screen.

Although there are no peer-reviewed studies to validate its efficacy, Professor Milburn recommends the app for those who wish to avoid impaired driving. I wonder as I write this if the app could be adapted to have some kind of fruit or birds involved (gazing into space and pondering).  

A Ph.D. candidate at the University of Akron has recently developed another tool, which operates from a sample of saliva. This device was reported on Cleveland.com (Ohio, a state that has not yet de-criminalized marijuana). It is called a Cannibuster, and it measures the "levels of THC," which the developer notes is "the active ingredient in marijuana." Of course, there is evidence that THC is one of "over 400 chemical entities of which more than 60 are cannabinoid compounds" in cannabis. 

Much remains to be done. There are perceptions that drug use is contributing to accidents. Police who are directed by law to ignore possession and distribution of federally controlled substances may nonetheless have to deal with those who drive under its influence and perhaps contribute to or cause accidents. An effective and reliable method for measuring impairment is perhaps needed in order for there to be consistency. Of course, it is possible that the other debate, on whether such standards are scientifically effective, should be had instead. 

Much to ponder in the world of marijuana, a world that seems to become larger every day.

David Langham is deputy chief judge of the Florida Office of Judges of Compensation Claims. This column is reprinted, with his permission, from his Florida Workers' Comp Adjudication blog.


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