By William Bill Hurst

Indianapolis Personal Injury LawyerMarijuana is the most commonly used illicit drug in the United States.  It’s a dry green and brown mix of stems, seeds and leaves dried from the hemp plant, cannibus sativa.  It is generally smoked but can be mixed in food or brewed as tea.  In its more ­­­­­­­­­­­­­­diluted form, it is called “hashish”.  Scientists have learned a great deal about how marijuana acts on the brain to produce its many effects.  When smoked the active ingredient rapidly passes from the lungs into the blood stream which carries the chemical to the brain and other organs.  The drug acts on the brain’s “canniboid receptors”, setting off a series of cellular reactions that all lead to the “high” that users experience when they smoke marijuana.  The highest effect is in the parts of the brain that influence pleasure, memory, thinking, concentration and time perception.  Research into the effects of long term marijuana use on the structure of a brain has yielded inconsistent results as this article will reveal.

A recent study suggests that legalizing medical marijuana may reduce traffic fatalities.  Indianapolis Personal Injury LawyerThe researchers (Dan Rees Professor at the University of Colorado and Mark Anderson Professor at Montana State University) conclude that legalizing medical marijuana reduces alcohol consumption and reduce traffic deaths.  It is thought that people are more wary of driving when “high” than when drunk on alcohol.  The question is which drug (when one or the other is ingested) is actually more dangerous on the road.  The answer clearly is alcohol.  “Pot” does make drivers less able to complete mindless tasks like staying in a lane, while alcohol undermines behaviors that require more attention like yielding to pedestrians or taking note of stop signs.


Indianapolis Personal Injury Lawyer Yale psychiatrist, Dr. Robert Sewell reviewed academic literature on driving while intoxicated in his 2009 article and found that alcohol is significantly more dangerous.  A drunk driver is approximately 10 times more likely to cause a fatal car accident than a “stoned” driver.  In most studies smoking 1/3 of a joint or less has virtually no impact on a driver’s performance.  A couple of studies even suggest that pot smokers are less likely to cause an accident than sober drivers.

Despite the foregoing, experiments testing the skills required for driving under the influence of “pot” fare significantly worse than sober drivers; but when you put them behind the wheel they perform reasonably well.  Those who have smoked moderate doses of “pot” show minimal impairment; and very experienced “smokers” show almost no deficit at all (interestingly, habitual stoners are also better at driving drunk than non-smokers).        No one is sure how to explain these results!  Participants in one study who smoked 1/3 of a “joint” perceived themselves as being impaired even though the experiments suggest they were not.  By contrast, people who had two alcohol drinks thought they were fine despite performing poorly in driving tests.  Drunk drivers drive faster, tailgate and are more reckless.  Experiments using larger doses of marijuana indicate very “high” drivers can’t stay in a lane, react slowly to yellow lights and unexpected obstacles, and are unaware of speed.  The most consistent result found in these driving studies is that using marijuana and alcohol together creates a greater hazard than taking either one alone.  Drivers who are drunk and high seem to suffer from the worst effects of both drugs.  They meander, pass recklessly, drive too fast, take unnecessary risks, and are unaware of their incapacity and put pedestrians at risk.

Recently the Department of National Highway Safety; and, as well, the White House Director of the National Drug Control Policy have made public statements that marijuana is a significant and important contributing factor in the growing number of fatal accidents.  Despite this warning some States (for example California) argue the possibility that relaxed marijuana laws have created more drivers who are driving under the influence of pot than previously occurring; and that this is a safety benefit.  While it is an established fact that alcohol increases a driver’s accident risk but apparently the issue as to whether pot or marijuana places drivers at risk is still a matter of controversy in the literature.  There is no question that marijuana has a measurable effect on psychomotor skills, but despite this there is a significant question as to whether or not it plays a significant role in vehicle crashes.  As noted below there is an argument that marijuana use replacing alcohol use may make the highways safer.
The United States Department of Transportation’s 1993 report is one of the first studies where the driving performance under the influence of marijuana (THC) was studied.  This study is often cited in support of marijuana usage.  In this study, subjects under high doses were seen to complete every ride without a major intervention by driving instructors and their safety was never compromised.  These tests are “set forth” in the U.S. Department of Transportation National Highway Traffic Safety Administration, DOTHS808078, November 1993 study.

It would seem that when it comes to speed and focus,  “high” and“drunk” drivers actually have the exact opposite reactions.  Drivers under the influence of marijuana are more aware of their impairment and generally compensate for it by slowing down and increasing focus, while drunk drivers tend to drive in a more risky manner proportional to their level of intoxication, e.i., the more drunk, the more reckless the driving becomes.

While driving “stoned” is difficult to regulate by law enforcement, it should be kept in mind that it is a crime in most States; and being “stoned” does cause impairment which can lead to mistakes while operating  a motor vehicle under the influence of marijuana.  You are more likely to pull out in front of someone or run a red light.   And by the way, if you get caught, you could go to jail.