Observations Observations [RSS feeds for Observations] Opinion, arguments & analyses from the editors of Scientific American Observations HomeAboutContact Smoke and Mirrors: Driving While High on Marijuana Doubles One’s Chances of a Serious Car Crash

Booze is behind an estimated 2.1 million car accidents each year in the U.S.—which cause almost 11,000 traffic fatalities annually. But many drug users have claimed that a few puffs of pot before getting behind the wheel are perfectly harmless. A new study, however, shows that drivers who smoke marijuana within a few hours of hitting the road are almost twice as likely as stone-sober motorists to be in a crash that results in serious injury or death.