Marijuana, Alcohol, and Driving: "When compared to alcohol, cannabis is detected far less often in accident-involved drivers. Drummer et al. (2003) cited several studies and found that alcohol was detected in 12.5% to 79% of drivers involved in accidents. With regard to crash risk, a large study conducted by Borkenstein, Crowther, Shumate, Zeil and Zylman (1964) compared BAC in approximately 6,000 accident-involved drivers and 7,600 nonaccident controls.
Marijuana, Alcohol, and Driving: "As with cannabis, alcohol use increased variability in lane position and headway (Casswell, 1979; Ramaekers et al., 2000; Smiley et al., 1981; Stein et al., 1983) but caused faster speeds (Casswell, 1977; Krueger & Vollrath, 2000; Peck et al., 1986; Smiley et al., 1987; Stein et al., 1983). Some studies also showed that alcohol use alone and in combination with cannabis affected visual search behavior (Lamers & Ramaekers, 2001; Moskowitz, Ziedman, & Sharma, 1976).
Cannabis and Adolescent Motivation: "The apparent strength of these relationships in cross-sectional studies (e.g. Kandel, 1984) has been exaggerated because those adolescents who are most likely to use cannabis have lower academic aspirations and poorer high school performance prior to using cannabis than their peers who do not (Newcombe and Bentler, 1988). It remains possible that factors other than the marijuana use account for apparent causal relations.
Effects of Decriminalization and Legalization on Adolescent Substance Use: "Most 12th graders felt that they would be little affected personally by the legalization of either the sale or the use of marijuana. Over half (53%) of the respondents said that they would not use the drug even if it were legal to buy and use, while others indicated that they would use it about as often as they do now (14%) or less often (1%). Only 9% said they would use it more often than they do at present, while 13% thought they would try it. Another 11% said they did not know how their behavior would be affected if marijuana were legalized. Still, this amounts to 22% of all 12th graders, or about one in five, who thought that they would try marijuana, or that their use would increase, if marijuana were legalized.
Chart Comparing Addictive Qualities of Popular Drugs