Crashes among male drivers are much more likely to involve alcohol than those among female drivers. Among fatally injured male drivers of passenger vehicles in 2007, 40 percent had BACs at or above 0.08 percent. The corresponding proportion among female drivers was 21 percent. Alcohol involvement in fatal crashes was highest for males ages 21-40. Between 1982 and 2007, the proportion of fatally injured passenger vehicle drivers with BACs at or above 0.08 percent declined from 56 to 40 percent among males and from 33 to 21 percent among females. According to national roadside breath surveys, females are increasingly driving at night. The proportion of females in weekend nighttime samples of drivers increased from 16 percent in 1973 to 26 percent in 1986 and 31 percent in 1996.10 The increase between 1973 and 1986 was accompanied by a reduction from 3 to 1.3 percent in the proportion of female drivers with BACs at or above 0.10 percent. However, between 1986 and 1996, the percentage of female drivers with high BACs increased slightly from 1.3 to 1.5 percent, compared with a decline from 3.9 to 3.5 percent for male drivers.