Marihuana and driving hazards.

Recent research indicates that cannabis use is positively associated with the road toll. In controlled laboratory studies it has also been shown to adversely affect perception skills, coordination, braking time and other motor skills, mood, judgement, and so on. In driving studies (in both controlled areas and ordinary traffic) marihuana adversely affected driving safety. The literature on cannabis is diffused over international journals covering a wide range of specialities--this paper draws together the evidence from 22 scientifically valid reports. A report on a 1975 conference on drugs and driving is described.