Half of US cannabis consumers feel that driving under the influence of cannabis is a safe thing to do, according to a new survey from PBS Research, Civilized, Burson Cohn & Wolfe, and Buzzfeed News. This is compared to three-quarters of American non-cannabis users who called the action “somewhat unsafe” or “very unsafe.”
When asked if they would be comfortable themselves riding in a car where the driver is under the influence of cannabis, 55 percent of cannabis consumers agreed that they would feel comfortable, compared to just 15 percent of non-consumers.
The Spring 2019 Cannabis Culture Poll was filled out online by a core of 1,000 US adults (aged 21 and up) and 602 Canadian adults (aged 19 and up), with some oversampling of additional cannabis consumers from both countries. Its purpose was to compare and contrast the views and general habits of cannabis consumers and non-consumers in each country.
When posed the same questions on driving safety, 24 percent of Canadian cannabis consumers said that they feel driving under the influence of cannabis is “very safe” or “somewhat safe,” compared to only 5 percent of non-consumers. A whopping 76 percent of non-consumers called the practice “very unsafe,” with an addition 14 percent branding it “somewhat unsafe.”
In response to their personal level of comfort if riding in a car where the driver is under the influence of cannabis, 35 percent of cannabis consumers and 9 percent of non-consumers said that they would feel comfortable in this scenario.
Driving safety also appeared in other places of the survey. When asked to rank a series of statements from the strongest to the weakest argument against legalizing cannabis, the statement “People will be more likely to drive under the influence of cannabis” was ranked the overall strongest argument, with 47 percent of all US respondents and 57 percent of all Canadian respondents giving it priority. This beat out concerns over underage consumption, exacerbation of drug abuse problems, and cannabis as a “gateway” drug, to be the issue of highest concern in this survey.
Driving under the influence
So how dangerous is driving under the influence of cannabis? Unfortunately for would-be marijuana motorists, there doesn’t appear to be a conclusive answer.
One meta-analysis of 60 published experimental studies that looked at behavioral effects following cannabis intake found that cannabis affected all areas that are relevant to safe driving, such as psycho-motor skills, continued attention, visual function, and reaction time.
However, a similar study which compared the effects of cannabis and alcohol on safe driving concluded that while both impair driving ability, the effects of cannabis may be a lot more variable based on individual tolerance and the technique of cannabis consumption. It also found that cannabis affected complex driving tasks much less than the more automatic driving behaviors. This, coupled with an increased awareness that they are impaired, meant that the cannabis users were often able to successfully strategically compensate for their intoxication.
“Although cognitive studies suggest that cannabis use may lead to unsafe driving, experimental studies have suggested that it can have the opposite effect,” the authors summarize in their conclusion. “Marijuana smokers tend to compensate effectively for their impairment by utilizing a variety of behavioral strategies such as driving more slowly, passing less, and leaving more space between themselves and cars in front of them.”
A recent federal report from the National Highway Traffic Safety Administration, which was presented before Congress, also found evidence for this sort of compensation, listing multiple studies in which participants in simulated and real driving tasks were recorded taking fewer risks and driving more cautiously when under the influence of cannabis. Though the report did conclude that this compensation would likely not be enough to mitigate the effects of intoxication when driving on public roads.
Driving safety in the wake of cannabis legalization
Many states, and a small number of countries, have now legalized the recreational use of cannabis, and with this comes renewed concern over whether cannabis is making the roads more dangerous. It has also opened the door for researchers to study real-world trends in road safety in the wake of legalization. So far, this also remains inconclusive.
A study from the Insurance Institute for Highway Safety (IIHS) found a six percent increase in car crashes in states that have legalized cannabis versus their neighbors where cannabis is still prohibited, but emphasized that the study shows only a correlation and that more research would be needed to pinpoint whether cannabis is the main factor behind this increase. At the same time, a study published in the American Journal of Public Health found no statistical differences in fatal car crashes between states with and without legal cannabis.
