Too Stoned to Drive?

Colorado's new DUID standard threatens to treat pot smokers as public menaces--even when they're not.


In May, anticipating an increase in marijuana consumption now that the plant is legal for general use in Colorado, the state legislature officially defined "too stoned to drive." The new law allows juries to convict someone of driving under the influence of a drug (DUID) based on nothing more than a test indicating a THC level of at least five nanograms per milliliter of blood.

Addy Norton is a walking (and driving) refutation of that standard. Norton, a 27-year-old who smokes medical marijuana every day, recently participated in an experiment conducted by KIRO, the CBS station in Seattle, where a five-nanogram rule also prevails as a result of I-502, Washington's marijuana legalization initiative. Norton arrived with a THC level of 16 nanograms, more than three times Colorado's new DUID cutoff, but nevertheless completed a driving course satisfactorily, according to the instructor who accompanied her with his foot hovering over a second brake and his hand ready to take the wheel.

After Norton smoked three-tenths of a gram, she tested at 36.7 nanograms, more than seven times the legal limit, but still drove OK. Even after she consumed nine-tenths of a gram, a drug recognition expert from the Thurston County Sheriff's Office said her driving was merely "borderline." Only after consuming a total of 1.4 grams of pot and achieving a THC level of 58.8 nanograms, almost 12 times the legal limit, was Norton clearly too stoned to drive.

The two other participants in KIRO's study, a weekend smoker and an occasional smoker, also drove competently at THC levels far above five nanograms. So did "Justin," a medical marijuana user who volunteered for a study sponsored by KDVR, the Fox affiliate in Denver. Justin's THC level was already 21 nanograms when he arrived, even though he had not consumed any marijuana that day, and it rose to 47 after he smoked some pot. He performed fine on a driving simulator at both levels. "Justin is doing pretty well," a drug recognition expert from the Thornton, Colorado, police department said as he watched the second test. "He's being a safe driver. It's doubtful that I would have pulled him over. He hasn't shown any degree of impairment."

While some people may be noticeably impaired at five nanograms, it is clear that some people are not. The way people react to marijuana is partly a function of pre-existing characteristics, but it also depends on experience. Regular users develop tolerance and learn to adapt to marijuana's effects, so they may be able to drive safely at THC levels that would incapacitate novices.

Because THC is absorbed by fatty tissue, it can linger in the blood of regular users long after the drug's effects have worn off, meaning that daily smokers may never fall below the five-nanogram threshold. "Patients like me," Teri Robnett of the Cannabis Patient Action Network told Colorado legislators in April, "will continually maintain a blood level far above five nanograms and without any impairment." A five-nanogram standard exposes people like Robnett to the risk of being treated as a public menace whenever they get behind the wheel.

Recognizing that a five-nanogram THC level is not a good indicator of impairment, the Colorado General Assembly rejected that standard five times before finally approving it in May, the same week it passed a law regulating pot stores. "It's an arbitrary limit by uninformed people," complains Kayvan Khalatbari, co-owner of a medical marijuana center in Denver. "They just don't know what they're talking about."

The inclusion of a five-nanogram standard in I-502, the Washington initiative, was so controversial that it turned some legalization advocates against the measure. Alison Holcomb, who oversaw the I-502 campaign, points out that police still need "reasonable suspicion" that a driver is impaired to pull him over and seek a blood test. Holcomb says pro-legalization critics of I-502 were never able to cite cases where drivers who tested above five nanograms were acquitted under the old legal standard, which as in Colorado required evidence of impairment, including but not limited to blood tests. She also argues that a five-nanogram standard could help defendants with lower levels who otherwise might have been convicted. She says jurors "might be skeptical that the person was actually impaired if the results were not at that threshold level."

In a concession to critics of the five-nanogram cutoff, Colorado's new law, unlike Washington's, does not make people automatically guilty of DUID if they test above that level. Instead it creates a presumption that defendants can try to rebut by presenting evidence that they were not in fact impaired. But Denver attorney Rob Corry, who frequently represents DUID defendants, thinks that opportunity will not make much difference in practice. With a "permissible inference" of DUID at five nanograms, he says, "A person coming into court is guilty until proven innocent. If you put a number on it, juries are going to latch onto that five-nanogram number, whether it's a permissible inference or a per se [standard], and the effect will be that innocent people are convicted."

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  1. “It’s an arbitrary limit by uninformed people,” complains Kayvan Khalatbari, co-owner of a medical marijuana center in Denver.

    IOW, it is the de facto result of almost all legislation pushed by any sociopathic-intensive group of an organized crime gang (aka “government”).

  2. Alison Holcomb, who oversaw the I-502 campaign, points out that police still need “reasonable suspicion” that a driver is impaired to pull him over and seek a blood test.

    Apparently Alison has not recently been subjected to one of those unconstitutional DUI checkpoints, where everyone is temporarily under arrest despite the police having no articulable suspicion for detaining citizens who happen to be passing by.

  3. We had a little discussion of this a few days ago, but…

    Best album to listen to stoned?

    I go with The Man Who Sold The World.

    “Black Country Rock”

    1. For music noobs, “Dark Side of the Moon” has to be one of the best stoner albums. I used to get blazed and crank up my four speaker system that that in the dark, before I had kids and had to act more responsibly.

      “The Joshua Tree” album is also good, especially the song about heroin use.

      1. I absolutely hate when people say dark side of the moon is good stoner music, pretty much any halfway decent music that you like is awesome when your stoned.

    2. I’m not a fan of rap, but I think Cypress Hill would have to be up there. Dr. Greenthumb, son.

    3. Presence or 2112.

      1. Did you ever read Ready Player One? 2112 is a plot point.

    4. Pink Floyd, Live at Pompeii.

  4. Republicans picking another winning political side: pro drugged driving!

  5. While some people may be noticeably impaired at five nanograms, it is clear that some people are not. The way people react to marijuana is partly a function of pre-existing characteristics, but it also depends on experience. Regular users develop tolerance and learn to adapt to marijuana’s effects, so they may be able to drive safely at THC levels that would incapacitate novices.

    So it’s just like drunk driving; why should we expect any different policy outcome? The law will assume that the offender is a low-tolerance novice with minimal driving skill in order to increase the number offenders and fines.

  6. Five Nanograms is way way way too lowwwwwww.

    THC exists in FAT Cells. Aggresive exercising and weight loss will render THC presents in the blood once the fat cells strink.

    Effectively, pot smokers cannot drive. This is how I read it.

    1. Uh, no. We’re talking about two different things here. There’s THC before it is metabolized. That’s what they are testing a person’s blood for when a person is driving. Then there’s THC metabolites (what’s left after it has been metabolized), which is what is stored in fat and what they look for in urine.

      The metabolites don’t have any psychoactive effect.

      1. Can they tell the diff between metabolized and un-metabolized THC ?

        Either way, if that’s the case, then they can tell if one smoked one hour ago or one day ago. It is my understanding that they have not been able to make that distinction with habitual users.

        1. I believe the blood test to detect active THC (as opposed to metabolites) didn’t come along until fairly recently.

          1. ohhhh…..

            i will make a note of that.

            It was very difficult to obtain a conviction in NY/NJ if the PERP took it all the way to trial.

            The GAS CHROMOTOGRAPHY was performed on Blood and usually, the state, was never able to establish when the drug was used. This was many years go though.

    2. Toxicologists who consulted with Colorado’s CCJJ testified that 5 ng was far too high a standard to protect the public from DUID drivers.

      Laboratories perform a screening test for cannabinoids that is not specific. If the screening test is positive, a confirmatory test is performed that is highly specific for active THC.

      In the Netherlands, where pot is effectively legal, daily users are considered unfit to drive and their licenses are revoked, according to Dr. Ramakers, THC toxicologist and researcher.

  7. Due to the fact that pot remains in your bloodstream without impairing you long after you are stoned, I think if this law ever makes it to a jury, a lawyer will have no problem getting the charges thrown out. Prosecutors will have to prove that the person was impaired at the time of arrest, which is impossible with todays testing.

    1. Not with per se limits. For instance, in most states if you blow above the per se alcohol limit you’re considered intoxicated without regard to impairment. It’s wrong, but that’s how it works. They don’t care if you’re actually a danger to anyone, they care if blatantly ignorant people will vote for them for ‘doing’ something.

  8. I think it’s more about the distractions – reaching for the Doritos, things like that cause most accidents.

  9. And the fact is: When stoned, you tend to avoid driving, but when drunk, you have false confidence and say to yourself, “let’s go!”

  10. Not always harmless, variables much like alcohol:

    Some folks can get slightly stoned and space out into a dangerous menace
    Some chronic pot users can get aware with driving.

    Any teenager stoned on anything is a menace behind the wheel.

  11. I think the crime is scaring people, not necessarily causing harm. The idea of drivers drinking or smoking creates fear of harm. Probably because of the message, they are gambling they can do whatever, either without harm to you in their judgment or because they just can.

    Myself, I don’t mind people gambling even with me, I just want to collect damages when they blow it.

  12. It’s not about making it through a course. It’s about reaction time to unexpected incidents. You know, the MAIN reason accidents happen. Moron.

  13. Let’s get some facts out. Colorado’s law does not allow juries to convict a driver of DUID based on nothing more than a 5 ng THC test. It merely provides a permissible inference of DUID if the level is 5 ng/ml in blood or higher. The blood test is not permitted to be taken unless a law enforcement officer finds probable cause that the driver is DUID.

    Colorado’s law is the weakest DUID law in the nation and may be considered to be a license to driver stoned. That’s because, in 2012, 72% of drivers arrested for DUID who tested positive for cannabinoids, tested below 5 ng/ml THC in blood. In the past those drivers could be prosecuted for DUID based on probable cause. With the new law, that is much more difficult, and perhaps impossible.

  14. All of this is equally true regarding alcohol consumption. The Feds have pushed the .08% standard on the states but every time I read a news article about some horrible DUI accident it seems that the perpetrator was at 2 or 3 times the legal limit. In my opinion the .08% standard has nothing to do with public safety and everything to do with maximizing revenue for the state.

  15. weekend smoker and an occasional smoker, also drove

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