Cannabis drivers 'twice as likely to cause car crash'

BBC News (UK)
Friday, February 10, 2012

Drivers who use cannabis within three hours of driving are twice as likely to cause a collision as those not under the influence of drugs or alcohol, says a Canadian study. This is because cannabis impairs brain and motor functions needed for safe driving, the researchers suggest. The study, Acute cannabis consumption and motor vehicle collision risk: systematic review of observational studies and meta-analysis, reviewed nine studies of 50,000 people worldwide who had been in serious or fatal crashes.