JAMA: Drugged-driving fatalities rise by about 12 percent on 4/20

April 20 is a countercultural holiday for marijuana smokers, even in states where cannabis is illegal. The holiday may seem relatively harmless, but it comes at a serious cost: an increase in fatal crashes.

According to a recent research letter in the journal JAMA Internal Medicine, the nationwide fatal accident rate is approximately 12 percent higher between 4:20 p.m. and midnight on April 20. According to the authors’ research, marijuana enthusiasts and activists gather at 4:20 p.m. that day in order to participate in mass consumption of cannabis.

Driving simulation studies have associated higher blood concentrations of THC with a negative impact on driving ability, including decreased reaction times and notable variability in speed and lane position. The researchers noted that previous epidemiologic studies had indicated an increased crash risk, as well.

Therefore, the researchers examined 25 years’ worth of data on fatal accidents in the U.S. recorded in the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS). The FARS system includes data on accidents occurring on U.S. public roadways in which at least one person died within 30 days of the crash.

That included 882,483 fatal crashes involving 1.3 million drivers. These were parsed into subgroups and geographic groups. Overall, the researchers found that the risk of a fatal crash was higher in the evening of April 20 than on control days during the same time interval. Before 4:20 on April 20, the risk was no different than on control days. The risk of fatal crashes was particularly high among drivers under the age of 21.

“The simplest interpretation of our findings is that more drivers are impaired by cannabis on 4/20 and these drivers contribute to fatal crashes,” the study’s author told TIME magazine. He added that the underlying explanation could be more complicated.

Avoid driving after using marijuana

When it comes to alcohol, although there are a number of variables from person to person, it’s generally accepted that having a 0.08 blood alcohol content or higher is indicative of intoxication.

Generally, the effects of THC, the main psychoactive compound in cannabis, wear off after about two hours, but some amount remains in the body for days or even weeks. We can test for THC, but there is no effective test for marijuana intoxication itself.

In Tennessee, cannabis is illegal for all purposes. Testing positive for any amount after driving can get you arrested for driving under the influence of marijuana.

If you have been arrested for DUI involving marijuana, there are defenses that may apply to you. Contact an experienced criminal defense attorney for an evaluation of your case.

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