Marijuana Law, Policy & Reform

Editor: Douglas A. Berman
Moritz College of Law

Thursday, May 15, 2014

Drugged driving is a real concern, but it has little to do with marijuana legalization

Yesterday, Westword reported on the results of a weekend DUI checkpoint in Colorado.  The police caught 21 people driving under the influence of alcohol and none driving while high (or on other drugs.)  The cops did make one marijuana possession arrest, however: a minor in possession.  

Since these figures are from a single checkpoint, they can't be more broadly extrapolated; they qualify as anecdotal. But in this case, alcohol arrests led marijuana busts 21 to one -- and the single exception involved underage possession, not driving under the influence of cannabis.

As Westword notes, data from a single checkpoint means very little.  But it did get me to thinking more about the connection between marijuana legalization and driving under the influence.  

It's always struck me as a bit odd that anytime a marijuana legalization law is proposed, driving under the influence is one of the first areas of concern.  This isn't because I think people should be driving while high.  Far from it.  

What is odd to me about the connection is that it seems to imply that drug imparied driving isn't a big problem already.  And I'm not just talking about marijuana.  I'm talking about all drugs.  

Breathalyzers test for only one mind-altering substance: alcohol.  But Americans use a range of other substances--legal and illegal--that could impair driving.  From prescription medications to cocaine to marijuana.  

Regardless of whether marijuana is legalized, we should be thinking a lot more about how to prevent impaired driving.  We should make sure more officers are trained in conducting road-side testing for impairment (which is currently the only way to catch people who are driving while high on anything other than alcohol.)  We should be putting more research dollars into developing impairment testing devices for prescription drugs, marijuana, etc.  

It shouldn't take a marijuana legalization ballot measure to get people concerned about drug impaired driving.  

The other thing I find odd about this part of the legalization debate is that it seems to assume legalization will result in a dramatic increase in marijuana-impaired driving.  I'm not so sure that legalization is likely to lead to much of an increase in stoned driving, however.  At least not the way it is currently being implemented.  

One of the reasons we have so many DUIs is that alcohol is so often consumed outside the home, in settings like sporting events, restaurants, family gatherings, etc.  We allow alcohol to be sold and publicly consumed in places that we know many people are driving to and from.  

By contrast, Colorado doesn't license "marijuana bars."  Users buy their marijuana to go.  

So, even if marijuana legalization significantly increases the total amount of marijuana use (something that itself remains to be seen), that doesn't mean driving while high will necessarily increase at the same rate.  If most new use incidents occur in the user's home--e.g., a person smoking a joint after work at home--then increases in use may not result in much of an increase in stoned driving at all.  

If states were to start licensing marijuana bars or selling marijuana at suburban sports stadiums, then it would be a different story.  But so long as marijuana is being sold exclusively on a "to go" basis, I'm not sure that legalization will result in noticeable increases in impaired driving.

Again, this doesn't mean stoned driving isn't an issue of concern.  I think we should all be more concerned about the dangers of impaired driving (including alcohol, an area where we can certainly still do far more than we are doing.)  But it shouldn't take a proposal to legalize marijuana to put drug impaired driving on the public policy agenda.

Current Affairs, Recreational Marijuana State Laws and Reforms | Permalink


Or it does:

| Marijuana-Impaired Driving a Growing Threat|
Weed-Involved Auto Fatalities Triple in 10 Years
By Buddy T / February 06, 2014/

[A study conducted by Columbia University's Mailman School of Public Health]
found that alcohol involvement in deadly auto crashes remained stable from 1999 to 2010
Drug involvement in fatal crashes, however, increased
from 16.6% in 1999
to 28.3% in 2010.

Rates of marijuana involvement in fatal crashes during the same time period went
from 4.2%
to 12.2%.

The researchers believe the decriminalization of marijuana use, for medical and recreational purposes, is a significant contributor to the increase in driving deaths
involving marijuana.
"The marked increase in its prevalence as reported in the present study is likely germane to the growing decriminalization of marijuana," said lead author Joanne Brady
Another study found that smoking marijuana doubles the risk of having an auto crash.

Posted by: Adamakis | May 15, 2014 6:39:00 PM

Thank you for your comment, but the authors of that study said it does not tell us whether there was an increased in impaired driving. From an article by Jacob Sullum:

>>As Columbia University researchers Guohua Li and Joanne E. Brady pointed out a few months ago in the American Journal of Epidemiology, this increase in marijuana consumption has been accompanied by an increase in the percentage of drivers killed in car crashes who test positive for cannabinol, a marijuana metabolite.

But as with the increase in DUID arrestees who test positive for THC, this trend does not necessarily mean marijuana is causing more crashes. A test for cannabinol, which is not psychoactive and can be detected in blood for up to a week after use, does not show the driver was under the influence of marijuana at the time of the crash, let alone that he was responsible for it. “Thus,” Li and Brady write, “the prevalence of nonalcohol drugs reported in this study should be interpreted as an indicator of drug use, not necessarily a measurement of drug impairment.”

Another reason to doubt the premise that more pot smoking means more deadly crashes: Total traffic fatalities have fallen as marijuana consumption has risen; there were about 20 percent fewer in 2012 than in 2002. Perhaps fatalities would have fallen faster if it weren’t for all those new pot smokers. But there is reason to believe the opposite may be true, that there would have been more fatalities if marijuana consumption had remained level or declined.>>

The article is at:

Posted by: Alex Kreit | May 15, 2014 7:39:16 PM

Again, I firmly believe that drug impaired driving (for any drug, marijuana included) is a big concern and too often overlooked. But I think it is strange to believe the issue is uniquely connected to marijuana legalization (particularly since the first states to legalize marijuana were Colorado and Washington in 2012).

Posted by: Alex Kreit | May 15, 2014 7:45:12 PM

I think the post about Dr. Oz explains the reason for the focus on impaired driving: as Dr. Oz is quoted, a lot of people think MJ is Satan's doing. Many of those same people are now grasping at straws.

Posted by: anon | May 16, 2014 12:33:34 PM

If we were really concerned about automobile deaths, we would be doing everything possible to facilitate and hasten the adoption of autonomous ("driverless") cars. They already do a far better job at avoiding road accidents than human beings.

Posted by: Fallibilist | May 21, 2014 1:04:58 PM

In August 2012, the team announced that they have completed over 300,000 autonomous-driving miles (500,000 km) accident-free, typically have about a dozen cars on the road at any given time, and are starting to test them with single drivers instead of in pairs.[17] Four U.S. states have passed laws permitting autonomous cars as of December 2013: Nevada, Florida, California, and Michigan.[18] A law proposed in Texas would establish criteria for allowing "autonomous motor vehicles".[19][20]

In April 2014, the team announced that their vehicles have now logged nearly 700,000 autonomous miles (1.1 million km).[21]

In August 2011, a human-controlled Google driverless car was involved in a crash near Google headquarters in Mountain View, CA. Google has stated that the car was being driven manually at the time of the accident.[22] A previous incident involved a Google driverless car being rear-ended while stopped at a traffic light.[23] Google says that neither of these incidents were the fault of Google's car but the fault of other humans operating the car.

Posted by: Fallibilist | May 21, 2014 1:07:38 PM

Meanwhile, alcohol abusers visit bars every day of the year. They frequently leave the pub impaired with BAC above the legal limit and happily take to our roads. They are subject to little harassment or social opprobrium.

While limiting the use of cannabis is unjustifiable, repealing the Prohibition of alcohol is looking sillier every day.

Posted by: Fallibilist | May 21, 2014 1:10:04 PM

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