Because a growing number of states and the District of Columbia have legalized marijuana, it’s important for parents to be aware of the impact of marijuana to their teen and young adult children, especially if they drive.

Parents should know that marijuana affects judgement and many other skills that are critical to safe driving including concentration and alertness, coordination, perception, and reaction time (NIDA). Combine this with the fact that younger drivers are also less experienced behind the wheel and a perfect storm is created with the high potential for tragic results.

We now know that marijuana is the most commonly identified illegal drug in deadly crashes, sometimes in combination with alcohol or other drugs. On its own, marijuana can double the risk of a driver being in a crash. Include alcohol, even in small amounts, and the risk becomes even greater. (NIDA)

A recent analysis of nine epidemiological studies conducted by researchers at Columbia University’s College of Physicians and Department of Public Health concluded that drivers that test positive for marijuana are more than twice as likely as other drivers to be involved in a collision. Another study found that they are three to seven times more likely to have caused the crash (Li, Mu-Chen, et al, 2012). Research has further supported this dangerous effect following legalization of medical marijuana:

• In 2009, Colorado marijuana‐related traffic deaths involving operators testing positive for marijuana represented 10 percent of all traffic fatalities. By 2015, that number doubled to 21 percent (NHTSA).
• There was an 87 percent increase in drivers testing positive for marijuana who were involved in fatal crashes from 2013 to 2015 (CO Department of Public Safety).

Parents should make firm rules for vehicle use and communicate with young drivers to educate them on the harms of marijuana, alcohol and other drugs and driving.