Danger of driving after smoking marijuana

According to a new study, one in every 25 people in the United States reports having driven while under the influence of a drug other than alcohol. For the vast majority of these people the drug in question was marijuana. We often see public education programs related to the dangers of getting behind the wheel after having drunk alcohol, it is much less frequent that the danger of driving on other intoxicants is addressed.

Despite the relative absence of public awareness of the risks, the new report indicates that a driver who has smoke marijuana within three hours before getting behind the wheel is about twice as likely as a sober driver to be involved in a serious accident that results in injury or death.

Researchers reviewed a number of different studies and combined the findings to generate their findings. While the 92 percent increase in the likelihood of a driver being involved in a serious accident after smoking marijuana is startling, it is still a smaller increase in risk than for drivers who are drunk. The study found that drivers who have a blood alcohol concentration of 0.08 are three times as likely to be in a serious accident. One difficulty in determining the effects of marijuana on driving is that the level of concentration of the active ingredient in the bloodstream does not does not always correlate to the level of impairment as an alcohol concentration does.

It is certainly interesting to consider the differences in risk associated with driving while under the influence of marijuana as compared to driving under the influence of alcohol. But the bottom line is that driving is dangerous enough even if everyone on the road is completely sober, and impairment creates a completely unnecessary increase in the risk that an innocent person will be injured or killed in a car accident.

Source: Time, "Stoned Driving Nearly Doubles the Risk of a Fatal Crash," Maia, Szalavitz, Feb. 10, 2012