Weed is Becoming Legal... Are Crash Rates Going Up?


Marijuana plant
Photo by Jeff W on Unsplash

In North America, the legalization of marijuana is an increasing trend, one that is expected to continue. In Canada, the recreational use of marijuana became legal in 2018. In the U.S., a number of states have legalized the drug, including Colorado, California, and New York, while others are moving in that direction or have decriminalized marijuana use.


The reality is that the legalization of marijuana is here to stay and will likely become more common in the upcoming years. In the U.S., where not all states have legalized marijuana use, the majority of Americans support its legalization, and individual states have a lot to gain by pressing forward with legalization, most notably where taxation of the plant is concerned.


If legalization is the new norm, however, there are some questions that will need answers. One of these is, what does the legalization of marijuana mean for road safety? In an article for Globe News Wire, the Insurance Institute for Highway Safety (IIHS) tackles exactly this question, while also looking at new research on what happens in states immediately after legalization.


It should go without saying that it remains illegal to drive under the influence of any narcotic, and that you should never drive while under the influence of marijuana. Driving is an activity that should always be done with a clear head. Anything less is a recipe of disaster. And research shows that marijuana absolutely does have an influence on the way that you drive.


"Driving stimulator tests have shown that drivers who are high on marijuana react more slowly, find it harder to pay attention, have more difficulty maintaining their car's position in the lane and make more errors when something goes wrong than they do when they're sober."

Aside from whether you should drive while high (you should not), the IIHS was interested in whether or not states that have legalized marijuana have seen an increase in vehicle crashes. Attempting to get an answer to this question, the IIHS have conducted, "a series of studies since 2014 examining how legalization has affected crash rates and insurance claims in the first states to legalize recreational use."


The results were... mixed. On the one hand, the five states that the study looked at saw a 6% increase in crashes resulting in injury and a 4% increase in crashes resulting in a fatality, with only the injury crash rate considered statistically significant. While these increases were measured against states where marijuana has not been legalized, verifying that marijuana use on its own is responsible for the increase has been more difficult.


"Despite those increases in crash rates, studies of whether marijuana itself makes drivers more likely to crash have been inconsistent. The latest one from IIHS... showed no increased crash risk associated with the drug, except when combined with alcohol."

Researchers have speculated that the legalization of marijuana may be providing encouragement to people to drink and use marijuana together, a combination that is not advisable and that is certainly dangerous for driving.


In an effort to understand how crash rates could rise following legalization while research suggests no increased crash risk associated with marijuana has led some to other possible explanations.


One of these is that the novelty of legalization can lead to temporary increases that don't reflect the real impact marijuana legalization has, or will have, on road safety.


"Other factors related to how legalization has affected the way people use marijuana, rather than the psychological effects of the drug, may also be at play. For example, the larger spike in crash rates in Colorado... suggests a burst of enthusiasm that leveled [sic] off as the drug's new status became more commonplace."

Another possible explanation is that more people are traveling to states where marijuana has been legalized from states where it hasn't, and that the increased crash rates reflect this increased amount of traffic.


The reality is that the full impact of legalization is likely to be understood better as time goes on. Legalization is still very new in most places, and as a result the studies that have been conducted thus far are working off a limited amount of data. With North America trending towards total legalization within the next generation, there will be plenty more research to come, research that will better be able to answer questions of road safety. Until then, stay safe and don't drive while are under the influence of marijuana!


For more on the research being done by the IIHS, check out the original article in Globe News Wire.