Driving Me Crazy

NORML, one of the oldest and most respected marijuana law reform organizations in the United States, has officially endorsed I-502. As expected, this has created another backlash from those within the reform community who think the bad parts of the bill outweigh any good that comes from having a statewide vote in favor of ending prohibition. In particular, the DUI provisions are what drive much of the opposition, and even though NORML expressed their opposition to its inclusion in the bill, they still support its passage.

My personal position isn’t too much different from NORML’s. I’m pained by the inclusion of the DUI provision, but I-502 is still likely to get my vote. But what’s been troubling to me is how much of the debate over the DUI provision seems to have very little scientific backing and how much of the “science” surrounding this topic appears to be contradictory or just pure nonsense.

To begin to wade through this debate, I want to post a video that illustrates how difficult all of this is to understand:

The video was taken during last year’s Cannabis Freedom March in May. It was during the signature gathering drive and Sensible Washington volunteer Mimi Meiwes was driving her RV around the state rallying support for the effort. Meiwes had driven the vehicle (dubbed the “Canna-bus”) up to Seattle from Kelso, and if you click ahead to 1:30 in the video, you’ll see her driving from Capital Hill to SoDo while being interviewed by the cameraman. I was actually a passenger in the vehicle at the time.

Meiwes is a medical marijuana patient (as she discusses in the video). She uses it throughout the day every day. However, as you can clearly see from the video, despite consuming marijuana that frequently, she’s not impaired at all as she navigates a gigantic RV through Seattle while being interviewed on camera. She continued to drive the Canna-bus across the state several times that spring, and despite using medical marijuana throughout that entire time, her driving ability was never impaired at any point.

I recognize that this is difficult for a lot of people to understand. There’s a strong desire to merely equate alcohol to marijuana in terms of drawing parallels, but the comparison doesn’t hold up. Even an alcoholic who consumes large amounts of booze all the time still gets drunk (even if their tolerance goes up). But individuals who consume large amount of marijuana (usually for medicinal reasons) stop feeling the typical intense psychoactive response that recreational users enjoy.

Taking an objective look at this, there are two main questions and neither one seems to have an easy answer:
– How much active THC does a person like Meiwes have in her system at any one time?
– How much do non-impaired drivers like Meiwes have to fear from a per se DUI?

I was intending only to write about the latter question in this post, but after reading this post from Russ Belville at the NORML blog, I want to start with the former question*.

Before reading Belville’s post, I’d been under the impression that folks who consume large amounts of marijuana will be well over the 5ng/ml active-THC DUI threshold even for many hours after last use. This was based upon what happened when Denver columnist William Breathes had his THC levels checked and discovered that even after 15 hours of abstinence, he still tested at a whopping 13.5ng/ml. But Belville points to a different study that shows something quite the opposite:

For comparison’s sake, Participant N is a 21-year-old obese African-American woman who admits to smoking pot starting at age 9. She admits to smoking a half-ounce per day and had done so that day. She didn’t even have detectable ng/mL when she checked in. Participant L, a man who’d smoked an ounce that day tested at only 0.4ng.

Obviously, something isn’t right here. For those who aren’t up on the measurements, an ounce of marijuana is a lot. A whole lot. Even when I was a 2-3 times a week marijuana user, it would take me about a year to use that much. So this study is saying that someone who smoked several hundred dollars worth of marijuana in a single day only tested at 0.4ng/ml, and another person who smoked half as much had no active-THC in their system at all.

What this study suggests (if it’s accurate) is one of two things. Either the existence of active-THC in one’s system really does fall to near-zero levels quickly after use – or someone has to smoke pounds of marijuana every day to be at 5ng/ml for several hours. Either way, this is clearly not compatible with the data point from Breathes in Denver. Something clearly isn’t correct and I have no way on knowing what it is.

If the study that Belville points to is accurate, though, then the concerns over the DUI provision are totally unwarranted. In fact, people would still be totally free to get baked and drive since most people consume far, far less than the remarkably prolific pot consumers they managed to find for this study. If a person can process an ounce of active-THC within a short period of time, they can easily process a gram or two faster than the officer can take you to the hospital for a blood draw.

But I obviously have my doubts about the accuracy of that study, and I’d love to get some feedback from the comments on what other studies have found. While a lot of people are merely interested in advocacy and propaganda as we approach this historic vote, I want to make sure we have the facts straight. If the DUI provision really does make drivers like Meiwes sitting ducks for the police to saddle with DUI’s, it certainly gives me pause.

* This post is too unweildy to explore the second question, but hopefully in a later post…


  1. 2

    Mimi spews:

    You will need to understand tolerance and cannabis. Here are some reference materials. ;)




    Let me know if you need any more or if you need help understanding some of the more technical portions of the study.

    Unfortunately, all of these folks spewing out numbers need this information to be able to rationally understand the in’s and outs of thc impairment.

    The next thing you will want to look at is the variation of the testing. You can test the same blood using different labs and machines, and the results vary significantly.

    Also, what many do not take into consideration is the proportion of thc to cbd, etc. because that could have some correlation in regards to impairment.

    Essentially, the 5ng limit is bunk. Most of the studies do not test those who ingest cannabis, and that is noted in a number of the studies. This is a confounding factor for basing blood levels on impairment, as ingested cannabis can further heighten tolerance.

    It is a subject that certainly needs more research, and folks in Washington State really don’t want to be the guinea pigs who have to further suffer yet more Reefer Madness perpetuated by a greedy and power hungry government that clearly does not have the best interests of it’s citizens in mind at the current time.

    Legalization via criminalization is not the answer. Please vote NO on I-502.

  2. 4


    We do have a perfectly good set of tests that a police officer can administer to determine the level of impairment of any driver, irrespective of what substance is used. I think the sophistication of the THC tests will make them beyond the capacity of most police departments. This will work itself out and the legislature and courts will be able to work out the kinks. I don’t want the guy or gal in the oncoming traffic wasted on anything.

  3. 6

    Mimi spews:

    @5 Please clarify. I own nothing but my own soul, and that’s questionable as well.

  4. 7

    Politically Incorrect spews:


    Clarification: do you have the right to ingest what you will if it harms no one else? Do you have the right to drink alcohol if you choose to do so? Do you have the right to eat rare roast beef 10 times per week if you choose to do so? Do you have the right to smoke the buds of a naturally-occurring weed if you choose to do so?

    Do you have a problem with personal rights or just personal responsibility?