This is the third part in an occasional series I've titled,
Do It For The Children (Mending the Drug War)
This installment is about driving under the influence of marijuana. This issue will likely be more widely discussed over the next few years. As the prospects for legalization begin to look up we can expect this concern to be raised, even by many who also support removing legal penalties for possession of marijuana.
For many who have never experienced the drug it may be difficult to conceptualize the difference between marijuana and alcohol as it relates to driving performance. In this diary I will present various studies which establish that significant marijuana intoxication results in less driver impairment than alcohol at the .08 BAC level - the most stringent DUI criteria is use. I will also discuss a number of social factors regarding stoned drivers, and also the wide range of legal sanctions currently in place from state to state.
Jump with me ...
I've driven stoned on marijuana. There I said it. I confess. In fact, I've driven stoned on marijuana, legally - at least the driving part, for longer than I've had a driver's license. Back when I was 16 you could drive on a Learner's Permit as long as you were accompanied by a licensed driver. There was no age requirement for that person.
I had a car, knew how to drive, and just needed to finish the state required driver's education class to be able to get my license. I had a few friends who already had their licenses but didn't have a car available to drive. So they would walk or bicycle to my house and then I'd drive us wherever we planned to go. On one of these drives me and my buddy Bob went to visit our local "hippie with the cool parents and the party room with the kick-ass stereo and blacklight posters" friend, Glenn. He had just recently gotten a bong, something which I'd never seen/experienced before.
I was hesitant to get high because I needed to drive. Bob assured me that it was no big deal, nothing like drinking and driving. Given our long friendship and the trust I had in him I went ahead and tried my first bong hits. And when it was time to drive home I found that Bob was right, it was no big deal. I found that just by choosing to focus on driving I could shake my sense of spaciness and drive perfectly well. Another marijuana myth-based belief busted as a result of personal experience.
Over the years I've come to recognize that the biggest concern regarding driving and marijuana is not about being stoned, but rather about divided attention while getting stoned. More on this later. But first, as promised, science and stuff ...
article
May 15, 2008 - Jerusalem, Israel
Jerusalem, Israel: Low doses of cannabis and alcohol have contrasting effects upon psychomotor performance, according to clinical trial data published in the current issue of the journal Accident Analysis and Prevention.
Abstract from study
[snip ...]
Both alcohol and low doses of cannabis impaired drivers’ ability to maintain lane position and significantly increased subjects’ reaction time. Neither low doses of alcohol nor THC significantly increased subjects’ total number of collisions.
In terms of overall driving performance, subjects administered cannabis performed in a manner similar to drivers with a blood alcohol concentration of 0.05, authors determined.
[snip ...]
Two recent examinations of fatal accident crash data indicate that alcohol, even at low doses, greatly increases drivers’ crash risk compared to cannabis. A 2007 case-control study published in the Canadian Journal of Public Health reported that US drivers with blood alcohol levels of 0.05 percent were three times as likely to have engaged in unsafe driving activities prior to a fatal crash as compared to individuals who tested positive for marijuana. Similarly, a 2005 review of French auto accident data reported that drivers who tested positive for any amount of alcohol had a four times greater risk of having a fatal accident than did drivers who tested positive for marijuana in their blood.
So from this it appears that not only is the level of physical impairment for marijuana akin to levels deemed legally acceptable for alcohol impairment, but also that the real world number of serious accidents on the highways are dramatically lower for marijuana than for alcohol - even at the .05 BAC equivalence level.
This is not startling new information by any means. US government studies as far back as 1993 have found similar results:
DOT study
The major conclusions from the present program are summarized as follows:
Current users of marijuana prefer THC doses of about 300 ug/kg to achieve their desired "high".
It is possible to safely study the effects of marijuana on driving on highways or city streets in the presence of other traffic.
Marijuana smoking impairs fundamental road tracking ability with the degree if impairment increasing as a function of the consumed THC dose.
Marijuana smoking which delivers THC up to a 300 ug/kg dose slightly impairs the ability to maintain a constant headway while following another car.
A low THC dose (100 ug/kg) does not impair driving ability in urban traffic to the same extent as a blood alcohol concentration (BAC) of 0.04g%.
Drivers under the influence of marijuana tend to over-estimate the adverse effects of the drug on their driving quality and compensate when they can; e.g. by increasing effort to accomplish the task, increasing headway or slowing down, or a combination of these.
Drivers under the influence of alcohol tend to under-estimate the adverse effects of the drug on their driving quality and do not invest compensatory effort.
The maximum road tracking impairment after the highest THC dose (300 ug/kg) was within a range of effects produced by many commonly used medicinal drugs and less than that associated with a blood alcohol concentration (BAC) of 0.08g% in previous studies employing the same test.
It is not possible to conclude anything about a driver's impairment on the basis of his/her plasma concentrations of THC and THC-COOH determined in a single sample.
But despite the reality of the relative effects on driving, there are widely varying laws in place regarding driving under the influence of marijuana. Some states have very strict zero tolerance per se drugged driving laws under which one is presumed impaired if there is any detectable illegal drug present in the blood.
from NORML
To date, ten states have enacted "zero tolerance" per se laws: Arizona,6 Georgia,7 Illinois, Indiana, Iowa,8 Michigan,9 Minnesota,10 Rhode Island, Utah,12 and Wisconsin.13 Among these, Arizona, Georgia, Illinois, Indiana, and Utah forbid drivers from operating a motor vehicle with any detectable level of a controlled substance or its metabolites in one's bodily fluids.
The metabolites part is important with respect to marijuana as its metabolites remain in one's system for days to weeks after consumption. This is really just a backdoor way for busting people for having smoked marijuana in the recent past, regardless of their fitness to drive.
Other states are at the opposite end of the spectrum, focusing on how the driver is actually able to perform in a roadside sobriety test, or focusing on their actual driving performance. These factors are rarely if ever an issue for a driver who has only consumed marijuana.
The middle ground is found in threshold-based per se laws such as the familiar .08 BAC threshold for DWI. It is debatable whether this level is based more in science or politics, but what is not debatable is that by law, those who have consumed less than this limit are deemed OK to drive. And this, combined with the results of the studies above, suggest there is no reason that any special laws be written or tests be devised to detect and punish stoned drivers. The added risk they represent on the road is minimal and well below the already accepted risk posed by drivers who have consumed moderate amounts of alcohol.
This is a good thing too, because of the millions of Americans who regularly consume marijuana either recreationally or medicinally, there are millions of Americans who drive under the influence of marijuana. In my entire life I've heard exactly one instance of a person claim that they were too stoned to drive. That was my cousin the first time he experienced a good marijuana high. I think he had a panic attack as he turned very pale and started to sweat. Within twenty minutes he was fine though, and shortly thereafter ready to take the wheel and drive home.
A recent, (last two weeks), story provides some anecdotal evidence that this aspect of stoned driving is understood in California - a state where the police have a good deal of experience with marijuana culture. This is purely second-hand information, hearsay, whatever you want to call it. A friend claims that someone he knows personally was driving in a car on I-5 in California with a group of friends. While they were smoking a joint they were directed to pull over by a CHP officer. The driver received a ticket for a moving violation ... period. There was no mention, no acknowledgment, that the car just happened to reek with fresh pot smoke.
And this story conveniently brings us to the next point I'd like to discuss, driver distraction when getting high while driving. Anything that divides the driver's attention raises the risk of having an accident. Events can transpire quickly when you're hurtling down the road at 80 70 60 50 miles an hour. And while pot smokers' general tendency to drive slower than they otherwise might helps somewhat, a distraction is still a distraction - just like a cell phone, an involved conversation, or even good music. I'm sure there have been accidents caused by persons attempting to pass joints, pipes, etc. while driving. This is a stupid and unsafe practice.
Unfortunately, it is a practice which is made more prevalent by the continued prohibition of marijuana. Some of you already know exactly where I am going with this because you have been there before. Others know because they always knew why we were all heading out in a group. Then there are the rest of you who may only now be realizing what was happening at Jim and Sue's cookout last summer. Remember when 4 or 5 people disappeared for a while and nobody seemed to know where they were? They were out riding around catching a buzz. Now most likely they confined themselves to lower speed limit streets and were ultra-paranoid about being careful. But that's where they went and what they were doing.
If society wasn't so head-up-its-ass foolish about the laws and social mores on marijuana these folks could have discreetly fired one up in the backyard without raising a stink. (Sorry, couldn't resist :)
Another aspect of driving while stoned involves long distance driving. Contrary to what one might expect, I have found marijuana to be quite helpful when driving long distances. During the drive from Baltimore to the Wilmington, North Carolina region for our annual family reunions I discovered that I generally needed about a joint every two hours or so to help keep me from being too bored with the highway and also to keep me from going more than my nominal 5-10 mph above the posted limit. Knowing this I prepared my materials in advance to minimize the distractions to where it was about the same as if I were smoking a tobacco cigarette.
For all of these reasons I believe that policing stoned drivers should be a non-issue in the overall debate about legalizing marijuana. And while we can be relatively certain that it will be raised, the studies have been performed and the facts ascertained. If it is OK for people to drive with a BAC up to .08 then there should be no legal impediment to driving while under the influence of marijuana.