Review Paper: Marijuana’s Driving Impact Less Than That Of Alcohol

CALIFORNIA: Cannabis’ impact on driving performance is generally less pronounced than that of alcohol, according to a review paper published by a pair of New York University researchers and BOTEC Analysis, LLC.

Authors reported that the use of cannabis, absent the simultaneous use of other drugs or alcohol, creates “only a fraction of the risks associated with driving at the legal 0.08 BAC threshold, let alone the much higher risks associated with higher levels of alcohol.” By contrast, they report that “the simultaneous use of alcohol and cannabis is linked to higher levels of driver impairment than either alone” – a finding that is consistent with much of the available literature.

They conclude, “The maximum risk for cannabis intoxication alone, unmixed with alcohol or other drugs, appears to be more comparable to risks such as talking on a hands-free cellphone (legal in all states) than to driving with a BAC above 0.08.” As a result, they suggest that as a matter of policy, “stoned driving alone (not involving alcohol or other drugs), should be treated as a traffic infraction rather than as a crime, unless aggravated by recklessness, aggressiveness, or high speed.”

In virtually all instances, cannabis-influenced driving is classified as a criminal rather than an administrative offense.

Investigators also argued against the imposition of per se limits which criminalize the act of operating a vehicle with trace levels of either THC or THC metabolites in one’s blood or urine. They determined: “Blood THC is not a good proxy either for recency of use or for impairment, and the dose-effect curve for fatality risk remains a matter of sharp controversy. … Moreover, the lipid-solubility of THC means that a frequent cannabis user will always have measurable THC in his or her blood, even when that person has not used recently and is neither subjectively intoxicated nor objectively impaired.”

The US National Highway Traffic Safety Administration (NHTSA) and the American Automobile Association(AAA) take a similar stance against the use of blood/THC concentrations as per se evidence of psychomotor impairment. NORML has long articulated similar opposition, stating, “Per se limits and zero tolerant per se thresholds … are not based upon scientific evidence or consensus. … [T]he enforcement of these strict liability standards risks inappropriately convicting unimpaired subjects of traffic safety violations, including those persons who are consuming cannabis legally in accordance with other state statutes.”


Full text of the paper, “Driving While Stoned: Issues and Policy Options,” is available online. NORML’s fact-sheet, “Marijuana and Psychomotor Performance,” is online.

Study: THC/CBD Administration Not Associated With Driving Impairment

NORWAY: The administration of an oral spray containing equal ratios of THC and CBD is not associated with either driving impairment or an increased risk of motor vehicle accident, according to a literature review published in the journal Brain and Behavior.

Norwegian and Spanish researchers reviewed the results from several driving performance studies that assessed subjects’ abilities following the use of THC:CBD oromucosal spray.

“Real-world registries did not show any evidence of an increase in motor vehicle accidents associated with THC:CBD oromucosal spray,” they reported. “The majority of patients reported an improvement in driving ability after starting THC:CBD oromucosal spray.” The spray, marketed in several countries throughout the world as the prescription drug Sativex, relieves spasticity in patients with multiple sclerosis.

Authors concluded, “THC:CBD oromucosal spray was shown not to impair driving performance.”

By contrast, the results of a recent series of driving studies conducted by a team of French researchers reported that the administration of 20mg of THC in occasional marijuana users can influence both subjective (e.g., subjects’ self-confidence) and objective measurements (e.g., changes in standard deviation in lateral performance) of driving performance. Authors reported that changes in participants’ driving behavior following THC dosing were more pronounced during simulated driving conditions versus real-world conditions – a finding that is consistent with those of previous studies.


For more information, contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “The influence of THC:CBD oromucosal spray on driving ability in patients with multiple sclerosis-related spasticity,” appears in Brain and Behavior. Full text of the study, “Cannabis smoking impairs driving performance on simulator and real driving: A randomized, double-blind, placebo-controlled, crossover trial,” appears in Fundamental & Clinical Pharmacology. NORML’s fact-sheet on cannabinoids’ influence on psychomotor performance is online.

How Much Does Marijuana Impact Your Driving?

DISTRICT OF COLUMBIA: A rigorous federal research study by the National Institute on Drug Abuse offers new data on the effects of marijuana on driving performance.

The exact impact of marijuana on driving ability is a controversial subject—and it’s become more important states continue to loosen their drug laws. And, while drunk driving is on the decline in the U.S., driving after having smoked or otherwise consumer marijuana has become more common. According to the most recent national roadside survey from the National Highway Traffic Safety Administration of weekend nighttime drivers, 8.3 percent had some alcohol in their system and 12.6 percent tested positive for THC—up from 8.6 percent in 2007.

It is illegal in all states to drive under the influence of anything, but years of work went in to establishing the .08 breathe alcohol limit that exists in most states. The question is whether we can establish a similar threshold for pot.

Colorado State Patrol: Legal Marijuana Brought ‘New Era’ Of DUI Arrests In 2014

COLORADO:   The legalization of marijuana in Colorado brought with it a “new era” of impaired driving, the Colorado State Patrol said Thursday.

Of more than 5,500 drug- and alcohol-related tickets served to impaired drivers in 2014, 354 of them involved only marijuana.

CSP released statewide data late Thursday; no county or city breakdown was available.

Overall, 18.5 percent of citations for driving under the influence, or DUI, and driving under the influence of drugs, DUID, involved marijuana.

 

Ontario To Bring In Stronger Punishment For Driving Under Influence Of Drugs

CANADA:  Canada’s stance on the legal use of marijuana remains somewhat ambiguous, with rules and their implementation varying on a case-by-case basis.

Certain parts of the marijuana debate, most notably the legality of medical marijuana, the recreational use of pot and the hesitance of some law enforcement agencies to crack down on it, continue to be discussed at length. But there has been little argument about what users can and should do while under the influence – most notably, refrain from operating motor vehicles.

Driving under the influence of drugs is illegal across Canada, and several provinces have already laid out strict punishments for the action. Ontario will soon strengthen its own, when the government approves a new set of amendments for traffic laws in the province.

Bill 31, unambiguously called the Transportation Statue Law Amendment Act, was introduced before the previous provincial election and will soon return to Queen’s Park.

 

Washington State Looks To Ban Pot In Vehicles

WASHINGTON:  When it comes to setting limits on driving while under the influence, the architects of Washington’s legal marijuana law largely aimed to imitate the state’s rules for alcohol.

In one crucial respect, though, state officials say the legal pot law is different: There’s no explicit language saying that you can’t smoke marijuana in a car.

The Washington Traffic Safety Commission wants state lawmakers to fix that oversight when they reconvene in January. The commission plans to ask the Legislature to create a clear rule stating that neither drivers nor their passengers can smoke or have open packages of marijuana inside a vehicle, said Darrin Grondel, director of the Washington Traffic Safety Commission.

Grondel said the goal is to mirror the state’s open container law, which says drivers can’t have open, partially consumed or unsealed containers of alcohol inside the passenger cabin of a car. An opened and recorked bottle of wine, for instance, should go in the trunk or a locked vehicle compartment, according to state law.

Initiative 502, which Washington state voters approved in 2012 to legalize recreational pot use, contained no language setting up the same rule for marijuana, Grondel said.