"The percentage of male drivers with a BAC over the current legal limit of 0.08 g/dL was 42% higher than the percentage of female drivers with illegal BACs (Figure 2). A regression analysis showed that males were significantly more likely to have illegal BACs (p < .01). Over 2% of the weekend nighttime drivers had illegal BACs (>0.08g/dL) while only 0.1% of daytime drivers had illegal BACs."

Source

Compton, Richard and Berning, Amy, "Results of the 2007 National Roadside Survey of Alcohol and Drug Use by Drivers" (Washington, DC: Dept. of Transportation, National Highway Traffic Safety Administration, July 2009), DOT HS 811 175, p. 1.
http://www.nhtsa.gov/DOT/NHTS…