Drivers involved in fatal and serious injury highway crashes were compared With drivers:​ (1) using the same roads at similar times, but without crash involvement;​ (2) With recent drunken driving arrests;​ (3) with arrests for other serious traffic Violations;​ and (4) with no crashes or citations in prior 5 years. Variables studied included presence of alcohol, drinking patterns, driving patterns, and social problems;​

Among driver fatalities, 54% had alcohol, and 42% had 100 mg% or greater. Those with alcohol tended to be young to middle-aged males with histories of medium to heavy drinking and with fatty degeneration of the liver. Those without alcohol tended to be older and to be light drinkers. Regulated drugs were almost never found. 23% died of Survivable injuries due to problems throughout the emergency care system.

Among roadblock drivers, 14% had alcohol, and 2% had 100 mg% or greater. 12% were heavy drinkers and were over-represented among those who had alcohol when stopped, and who had prior crashes or citations. At BACs of 100 mg%, risk of responsibility for a fatal crash was 7 times that without alcohol, and at 150 mg%, was 25 times greater.

Among clear-record drivers, 2% had alcohol, and 0% had 100 mg% or greater.

Almost all drunken drivers were males;​ most were heavy drinkers with excessive numbers of prior crashes and citations;​ many were laborers;​ and many were unmarried. A

discriminant function analysis correctly classified 95% of clear-record drivers and 87% of drunken drivers using four significant variables:​ lifetime citations, occupational level, beer frequency, and liquor quantity.

Three types of induced-intoxication experiments were conducted to study influences of alcohol upon driving-related behavior:​ small-group studies, laboratory experiments, and a closed-course pilot study using an instrumented car.