The continuing saga of stoned driving

The science has long been clear. Marijuana can cause impairment and driving while impaired by anything (lack of sleep, alcohol, texting, being angry) is not a good idea. However, the impairment caused my marijuana is only a fraction of the impairment caused by alcohol, and, while alcohol releases inhibitions and can make drivers more reckless, those who are stoned are more likely to be aware of their limitations and exercise additional caution. Treating the issue of marijuana impairment in driving as the same kind of problem as alcohol impairment is a disservice to safety on the highways. All this we know.

That doesn’t prevent people from still trying to pretend that legalization is going to cause a cataclysm on the highways.

So here’s yet another study that shows, once again, that marijuana isn’t the stuff of disaster films. The Real but Exaggerated Danger of Stoned Driving by Jacob Sullum.

But according to an analysis that’s about to be published by the journal Addiction, the increase in crash risk associated with marijuana use is roughly 20 percent to 30 percent, as opposed to the widely cited estimate of 92 percent.

That doesn’t stop lawmakers from going crazy.

Politicians are in such a panic about stoned driving that they are willing to endorse legislation they concede has no scientific basis—legislation that is bound to result in the conviction of innocent drivers who pose no threat to the public. Advocates of that policy simply assume that requiring proof of actual impairment, as Massachusetts currently does, is too demanding in the face of the increase in cannabis consumption they anticipate as a result of legalization. This response is unfair, premature, and disproportionate given what we actually know about marijuana’s impact on traffic safety.

And, of course, science doesn’t stop the absurd reefer madness theatre that constantly shows up.

Drugged driving suit aims to curb impaired driving

Being simultaneously high on pot, cocaine, heroin, MDMA and LSD is never a good combination, but the Ford Motor Company wants you to know that it’s particularly bad if you plan to get behind the wheel.

That’s the idea behind the automaker’s new “drugged driving suit,” an elaborate collection of weights, bandages, goggles and noisemakers that claims to simulate the physical effects of taking a variety of drugs. […]

But why show teen drivers the effects of so many different drugs at once instead of making a suit that focuses on one popular drug like marijuana or MDMA?

Drennan-Scace explained that it was all about logistics.

“If we’re showing just one drug, we would need to make a suit for every different type of drug,” he said.

“The research team decided it would be better to show (new drivers) the effects of different types of drugs in one suit, to get a feel for what it’s like.”


And once again, we see bad use of science used to justify that alcohol impairment is the same as other drug impairment.

“It shows them that getting behind the wheel, whether you’re drunk or you’re drugged, is a terrible idea,” said Ford of Canada spokesman Matt Drennan-Scace.

“Here in Canada in 2010, research showed that in 34 per cent of all accidents drugs were part of that accident. Thirty-nine per cent were alcohol, so it’s not that far off.”

Ah, that scientific term “part of.” Yeah, good stuff there, Matt.

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16 Responses to The continuing saga of stoned driving

  1. Krymsun says:

    Why does most everyone jump to the automatic, knee-jerk, and FALSE assumption that cannabis impairs drivers much the same as does alcohol? Why let uninformed opinions be the basis of new laws? It took me very little time to do a search, and find actual scientific studies which indicate just how incorrect such an assumption is. Examples follow.

    Studies Show Marijuana Consumption Not Associated With Dangerous Driving, May Lead to Safer Drivers
    Anyone who consumes cannabis on a regular basis knows that it doesn’t make you a dangerous driver. Many people find that it makes them a safer, more focused driver; one that’s more aware of their surroundings and the dangers associated with controlling tons of gasoline-filled metal. Not only has this been an anecdotal truth for as long as cars and cannabis have been paired, science has also been clear that consuming marijuana doesn’t make you a dangerous driver, and may make some people safer drivers. More research is needed, but it’s hard to deny that of the research we have, marijuana hasn’t been found to increase a person’s risk of an accident. To back this claim up, here’s a list of studies and research conducted on this very topic, some of which were funded by national governments in hopes of different results.

    Marijuana and Driving: A Review of the Scientific Evidence
    “Marijuana has a measurable yet relatively mild effect on psychomotor skills, yet it does not appear to play a significant role in vehicle crashes, particularly when compared to alcohol. Below is a summary of some of the existing data.”

    The incidence and role of drugs in fatally injured drivers
    “There was no indication that cannabis by itself was a cause of fatal crashes.”
    REFERENCE: Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration,
    Report No. DOT HS 808 065, K. Terhune. 1992.

    Marijuana’s effects on actual driving performance
    “Evidence from the present and previous studies strongly suggests that alcohol encourages risky driving whereas THC encourages greater caution. .. Drivers under the influence of marijuana retain insight in their performance and will compensate when they can, for example, by slowing down or increasing effort. As a consequence, THC’s adverse effects on driving performance appear relatively small.”
    REFERENCE: University of Adelaide study, 1995

    Role of cannabis in motor vehicle crashes
    “There is no evidence that consumption of cannabis alone increases the risk of culpability for traffic crash fatalities or injuries for which hospitalization occurs, and may reduce those risks.. The more cautious behavior of subjects who have received marijuana decreases the impact of the drug on performance, whereas the opposite holds true for alcohol.”
    REFERENCE: Marijuana: On-Road and Driving-Simulator Studies; Epidemiologic Reviews 21: 222-232, A. Smiley. 1999.

    “Both simulation and road trials generally find that driving behaviour shortly after consumption of larger doses of cannabis results in (i) a more cautious driving style; (ii) increased variability in lane position (and headway); and (iii) longer decision times. Whereas these results indicate a ‘change’ from normal conditions, they do not necessarily reflect ‘impairment’ in terms of performance effectiveness since few studies report increased accident risk.”
    REFERENCE: UK Department of Environment, Transport and the Regions (Road Safety Division). 2000.

    Cannabis And Cannabinoids – Pharmacology, Toxicology And Therapy
    “At the present time, the evidence to suggest an involvement of cannabis in road crashes is scientifically unproven”.
    REFERENCE: G. Chesher and M. Longo. 2002.

    Cannabis: Our position for a Canadian Public Policy
    “Cannabis alone, particularly in low doses, has little effect on the skills involved in automobile driving. Cannabis leads to a more cautious style of driving. However it has a negative impact on decision time and trajectory. This in itself does not mean that drivers under the influence of cannabis represent a traffic safety risk”
    REFERENCE: Canadian Senate Special Committee on Illegal Drugs. 2002.

    “The evidence to suggest an involvement of cannabis in road crashes is scientifically unproven.”
    REFERENCE: Cannabis and Cannabinoids: Pharmacology, Toxicology, and Therapeutic Potential, 2002
    Cannabis and Cannabinoids: Pharmacology, Toxicology, and Therapeutic Potential, edited by Franjo Grotenhermen, MD and Ethan Russo, MD (Haworth Press 2002).

    The Prevalence of Drug Use in Drivers, and Characteristics of the Drug-Positive Group
    “There was a clear relationship between alcohol and culpability. In contrast, there was no significant increase in culpability for cannabinoids alone.”
    REFERENCE: Accident Analysis and Prevention 32(5): 613-622. Longo, MC; Hunter, CE; Lokan, RJ; White, JM; and White, MA. (2000a).

    In a 2008 case study published by the International Association for Cannabis as Medicine that explored the potential for THC to have positive effects on attention-deficit disorder, the report’s authors concluded that cannabis use could mitigate problems with inattention and lead to “enhanced driving related performance.”

    The Effect Of Cannabis Compared With Alcohol On Driving
    “Although cognitive studies suggest that cannabis use may lead to unsafe driving, experimental studies have suggested that it can have the opposite effect.” U.S. National Library of Medicine, 2009

    Why Medical Marijuana Laws Reduce Traffic Deaths
    “No differences were found during the baseline driving segment (and the) collision avoidance scenarios,”
    REFERENCE: Research published in the Journal of Psychoactive Drugs, 2010

    Top 10 Reasons Marijuana Users Are Safer Drivers
    “20 years of study has concluded that marijuana smokers may actually have fewer accidents than other drivers.”

    Risk of severe driver injury by driving with psychoactive substances
    “The study found that those with a blood alcohol level of 0.12% were over 30 times more likely to get into a serious accident than someone who’s consumed any amount of cannabis. .. The least risky drug seemed to be cannabis and benzodiazepines and Z-drugs.”
    REFERENCE: Accident Analysis & Prevention; Volume 59, October 2013, Pages 346–356

    Cannabis: Summary Report
    “Cannabis alone, particularly in low doses, has little effect on the skills involved in automobile driving.”
    REFERENCE: Canadian Senate Special Committee on Illegal Drugs

    Acute cannabis consumption and motor vehicle collision risk
    “There is no evidence that consumption of cannabis alone increases the risk of culpability for traffic crash fatalities or injuries for which hospitalization occurs, and may reduce those risks.”
    REFERENCE: British Medical Journal, 1999; M. Bates and T. Blakely

    Marijuana-DUI Case Tossed by Arizona Supreme Court in Metabolite Ruling
    “Because the legislature intended to prevent impaired driving, we hold that the ‘metabolite’ reference in [the law] is limited to any of a proscribed substance’s metabolites that are capable of causing impairment . . . Drivers cannot be convicted of the . . . offense based merely on the presence of a non-impairing metabolite that may reflect the prior usage of marijuana.”

    Landmark Study Finds Marijuana Is Not Linked to Car Crashes

    Stoned drivers are a lot safer than drunk ones, new federal data show

    “Stick all *that* in your pipe and smoke it!”

    Update: In “Preventing Drugged Driving Must Become a National Priority Equivalent to Preventing Drunk Driving,” 2015 National Drug Control Strategy ended up admitting that “The study found that marijuana users are more likely to be involved in accidents, but that the increased risk may be due in part because marijuana users are more likely to be in high-risk groups for becoming involved in crashes (e.g., young males).”

    Update 2: “Study: Driving Stoned Won’t Make You Much More Likely to Crash”
    A new study from the National Highway Traffic Safety Administration says smoking pot does not have a significant effect on a person’s ability to drive.

    Researchers in Norway say past studies about THC-positive drivers involved in motor vehicle accidents have failed to adequately control for other variables. In other words, authors have been quick to jump on cannabis as the cause – even when it may not have been. The researchers, who are set to publish their findings in the journal Addiction, reviewed more than 20 driving culpability studies and two meta-analyses published between 1982 and 2015. They adjusted the numbers and found “acute cannabis intoxication” increased crash risk only moderately – by about 20 to 40 percent, or an “odds ratio” of between 1.2 and 1.4.
    By comparison, the U.S. National Highway Traffic Safety Administration reported that driving with legal amounts of alcohol in one’s system increases crash risk almost fourfold (an odds ratio of 3.93). Fun fact: Even the National Highway Traffic Safety Administration, a federal agency, acknowledges it’s “difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects.”

    • DdC says:

      Nice list Krymsun,
      now if we can teach Congress how to read, we’re home free…

      They treat misery, that they create.
      Never cure or prevent, taking profits treating.
      Cannabis isn’t a schedule#1 narcotic by definition… for 45 years.
      So a little non factual enhancement to profit on a law is absolutely nermile.

      Why does most everyone jump to the automatic, knee-jerk, and FALSE assumption that cannabis impairs drivers much the same as does alcohol?

      “President Ronald Reagan, at the urging of then Vice President George Bush, appointed Carlton Turner as the White House Drug (czar) Advisor in 1981. Soon after Drugczar Carlton Turner left office, Nancy Reagan recommended that no corporation be permitted to do business with the Federal government without having a urine purity policy in place to show their loyalty. Carlton Turner became a rich man in what has now become a huge growth industry: urine-testing.”
      Corruption/Carlton Turner

      “Like the RED MENACE of the early 1950s
      the current drug hysteria has led to a loyalty oath
      this time, the urine test.
      ~ Abbie Hoffman, the Nation, 11.21.87
      “Steal This Urine Test!”

      Apr 12 12
      ~ DEAth Merchants
      ~ Who’s going to stop the thieves?
      ~ Why Police Officers Lie Under Oath
      ~ Drug mishandling may have tainted 40,000 cases
      ~ Rackets Driven by this Drug War
      ~ AÊ‚Ê‚hole police
      ~ Second Probe Raises Stink
      ~ WTF’s Up with New Mexico?
      Have they been annexed by Texas?
      ~ How to Prosecute Abusive Prosecutors
      ~ Money, Not Morals, Drives Marijuana Prohibition Movement

      U.S. Lawmakers consider ‘Piss Tasting Gritty Act of 2005’
      On June 8, 2005 U.S. Representative Eliot L. Engel(D) NY, introduced into congress a bill that proposes a prohibition on the “manufacture, marketing, sale, or shipment in interstate commerce of products designed to assist in defrauding a drug test”.

      Cannabis use and Driving Mar 22 00
      ~ Do Medical-Marijuana Laws Save Lives on The Road?
      ~ Kinkykerli’s back and wants to taste more of your piss…
      ~ Employers Can Fire You For Using Marijuana
      ~ NHTSA study: No evidence marijuana leads to higher crash risk

      The Reagans Speak Out On Drugs (satire) dwr11

    • Aim High in Steering says:

      Nice effort dude, take a few hits off this and pass it around.

    • Canabuzz says:

      Excellent point shared. Keep it up!

  2. Servetus says:

    One characteristic of police states is the need to possess something incriminating on nearly everyone in case a need arises to arrest a person for political or other purposes, such as in a public revolt. Thom Hartmann talks about the practice in a video, “How to Turn the US into a Police State”.

    With that paradigm in mind, the race is on to find an accurate and reliable technical means of testing for marijuana consumption in drivers on-the-go. Justification is based on an unsubstantiated presumption that any altered state of consciousness must necessarily result in physical or mental driving dysfunctions of some kind. Yet, we see a different attitude applied toward driving while on meth, cocaine, codeine, or heroin. Why no instant analyzer technology for these drugs?

    One reason is the other drugs aren’t common enough. Marijuana and alcohol reign supreme on the hit list of revolts against Puritanism, the morbid fear that someone, somewhere, might be having a good time. This is where the highest number of arrests for DUI are to be expected. Alcohol and other downers, justifiably so, but also marijuana because it challenges an arcane culture’s assumptions about free will and authority.

    The wild card in the whole stoned driving hysteria is that the government is proposing all vehicles built a few years from now have collision avoidance systems, using infrared and Doppler radar systems tied to computerized tracking, acceleration, and braking. Legally, it seems a moot point if the car functions without the driver necessarily being tip-top, as if that person were riding on a train, or a subway car.

    Technology will solve this one, not authoritarianism, nor totalitarianism. The government will just have to grit its teeth and find some other way to victimize and antagonize its citizens.

    • Chris says:

      It’s exciting to know that within my lifetime I will be able to sit in a self-driving car and arrive at my destination safely, regardless of my level of impairment.

    • Windy says:

      The problem with that (for US, not for government) is that even at this point in tech, cars can be hacked. Once they are ALL computerized in that manner, anytime someone with authority (or talent) wants to get rid of a human thorn they’ll hack the person’s car and create a fatal “accident” then blame it on a momentary glitch in the car’s computerized system. For a visual on one way of doing this, see the clip from the episode of EXTANT where they killed off Molly’s husband (Goran Visnjic).

      • Servetus says:

        The death of journalist Michael Hastings and a James Bond film raised awareness of car hacking. No doubt about it. If the new technology is to meet with public approval and confidence, it must be made CIA-proof.

  3. jean valjean says:

    Bernie’s back! 81% in Alaska, 72% in Washington. Time I reached for my credit card again.
    Even nature is endorsing him:

  4. darkcycle says:

    Don’t expect self driving cars to be that much safer. Remember, they will have to contend with cars driven by humans on the same roadways. Also, they will have to operate on roads built to be negotiated by humans, as well as rules likewise developed by and for humans. Lots of vagueness and uncertainties in traffic where we rely on judgement rather than rules. The cars can only follow rules.

    • Servetus says:

      A finite probability of failure always exists in a system. The idea is to make failure as finite or small as possible. That’s why it’s called assisted driving, rather than automatic driving. Estimates are that a working proximity sensor system in all cars could save 40,000 lives per year, justifying its cost.

      An auto-driving-automobile, a more advanced technology, is made more reliable by running detectable cables on both sides of the road, and maybe one through the underground center of a highway, starting with construction on major urban thoroughfares, and working outward through rural areas.

      It’s the equivalent of a running a massive transatlantic cable, but in three dimensions on land areas instead of just linearly along a sea bottom. It would involve a national undertaking comparable to the interstate highway project in the 50s, using equipment built specifically for installing cable on-the-go along highways and bypasses.

      Ancillary technology is developing in leaps and bounds as I blog, including this bit of infrared technology. Combining technologies and multiple backups will create an effective system that is both automatic and driver actuated as necessary.

      Otherwise, off-road at your own risk and pleasure. I don’t see a system like this winning endurance races in Baja, even though robotics based vehicles are tested there; nor easily negotiating old mining roads and steep passes in the Mohave Desert. Mars is difficult enough. Human pilots of equipment on remote planets remain necessary. Also, some decisions are too scary or important to hand over to a machine. With all the sophistication of drones, humans still pilot killer drones and fighter jets.

  5. Mouth says:

    OT: Would any of you buy shares in Bruce Perlowin’s Hemp inc? Because he’s been in the activist spotlight scene for quite some time, I don’t picture him being a Pump and Dump guy. And (relying on his word and his Hemp Inc website’s word) he’s building a giant hemp processing plant in Carolina, which could lead to more. What about Medical Marijuana inc? I’ve always believed in diluting the system to win and if legal hemp, legal cannabis based meds and legal recreational marijuana is worth anything on the market, it would be a good way to make some money in the future too. I’m not looking for short term gains anytime soon, but I do beleive in the power of hemp/cannabis, which makes me think of future dividends since legal hemp/cannabis is a win/win. I’d rather have big marijuana than big DEA/Cartel.

  6. jean valjean says:

    ‘Dump Trump’: Artist Hanksy on the ‘grassroots (bowel) movement’ that is defining the 2016 US presidential race

  7. claygooding says:


    I looked at the study long enough to find the rest of the story

    The Dunedin Multidisciplinary Health and Development
    Research Unit is supported by the New Zealand Health Research
    Council (NZ NIDA???). This research received support from the U.S. National
    Institute on Aging (Grant AG032282), the UK Medical Research
    Council (UK’s NIDA??? )(Grant MR/K00381X), and the Jacobs Foundation. M. Cerdá ( ) was supported by a grant from the U.S. National Institute
    on Drug Abuse (DA030449).

    Put a fucking warning label on pot and move on.

  8. Freedom revolution now!

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