Roll Call: Latest News on Capitol Hill, Congress, Politics and Elections
October 23, 2014

Driving While Stoned Risky, but No Federal Standard Yet

More stoned drivers on the road because of marijuana legalization could be a serious risk, at least according to some lawmakers.

At a hearing Thursday on driving and operating other vehicles while impaired by marijuana, House Subcommittee on Government Operations chairman Rep. John L. Mica, R- Fla., said “we’re going to have more people stoned on the highways and there will be consequences.”

National Highway Traffic Safety Administration official Dr. Jeff Michael told the subcommittee that right now there’s too little data to devise a federal impairment standard. His agency is working with the state of Washington to assess the change in marijuana use by drivers before and after the state’s legalization of the drug.

Mica urged Patrice Kelly, the acting director of the Department of Transportation’s Office of Drug and Alcohol Policy and Compliance to focus more intensely on states that have legalized marijuana to see if the wider availability of the drug is affecting drivers of trucks and buses and pilots of planes, complaining that DOT’s current approach is “same old same old.”

Kelly emphasized that her agency still oversees drug and alcohol testing of 5 million drivers and other transportation employees. No matter what state law might permit, it’s still illegal for them to use marijuana and operate vehicles such as buses or trucks.

But Mica said, “We need to be a little bit pre-emptive” in order to protect passengers from marijuana-impaired drivers.

Once federal agencies come up with a standard to determine the level for driving while impaired by marijuana, would Mica favor withholding federal transportation funds from states that don’t enforce the standard?

“I don’t know,” he told The Container in an interview after the hearing. “We penalize them now if they don’t comply with our standards on alcohol. Certainly there’s plenty of merit in looking at the same types of standard if they don’t comply with the marijuana standards.”

Subcommittee ranking Democrat, Rep. Gerald E. Connolly, D- Va. asked Michael how many traffic deaths can be attributed to THC, the active ingredient in marijuana, being in the bloodstream of a driver.

“Currently, that’s difficult to say,” replied Michael. He explained that individuals response to increasing amounts of THC “is much more variable than it is for alcohol.”

The number of THC-related traffic deaths is “probably not zero,” Connolly said, but he added the lack of data to determine the impairment level is “amazing” even though marijuana has been classified a Schedule I drug under federal law for many decades.

“No one is arguing that it is a good idea” to drive after having smoked marijuana, the Virginia Democrat said, but the scarcity of data is “not a good recipe for rational public policy.”

Connolly voiced concern that Colorado and Washington have legalized marijuana for recreational use and other states are moving in that direction even though reliable driver safety data don’t exist.

“There’s a danger in that too, because they’re going in a direction also without good science,” he said.

He said one part of the research problem is that all federal drug research must go through the National Institute on Drug Abuse. “By its very name, its mission is to prevent drug abuse. Ninety percent plus of all the research it approves is to prove the harmful effects of marijuana and THC. That’s not objective science.”

  • Stephen Weber

    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.
    http://tinyurl.com/kwz5bz2

    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.”
    http://tinyurl.com/8xa862z

    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.
    http://tinyurl.com/qfg9ruf

    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
    http://www.druglibrary.org/schaffer/Misc/driving/s1p2.htm

    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.
    http://www.ncbi.nlm.nih.gov/pubmed/10682259

    “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.
    http://tinyurl.com/og89wrm

    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.
    http://tinyurl.com/o7dmm2g

    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.
    http://www.parl.gc.ca/content/sen/committee/371/ille/rep/summary-e.htm

    “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).
    http://tinyurl.com/o7dmm2g

    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).
    http://www.grotenhermen.com/driving/longo1.pdf

    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
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722956/

    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
    http://healthland.time.com/2011/12/02/why-medical-marijuana-laws-reduce-traffic-deaths/

    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.”
    http://www.4autoinsurancequote.com/uncategorized/reasons-why-marijuana-users-are-safe-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
    http://www.sciencedirect.com/science/article/pii/S0001457513002315

    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
    http://tinyurl.com/o7dmm2g

    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.”
    http://tinyurl.com/msq7umr

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

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