Patterns of Traffic Accidents and Violations Related to Drinking and to Some Medical Conditions

A comparison was made of the types of accidents and violations incurred by 256 drivers with alcoholism as a primary diagnosis, 126 drivers with another medical condition and a drinking problem as a secondary diagnosis, 1,319 drivers with other medical conditions and no drinking problem, and 921 drivers with no known medical condition, all of California. Alcohol impairment was measured in 33% by blood or breath alcohol determination and in the remainder by a “sobriety field test.” The following differences in accident and violation patterns were found: (1) 60% of accidents involving persons with primary alcoholism, 30% involving persons with a secondary drinking problem, and 10% involving persons with other medical conditions or none occurred after drinking. (2) It is estimated that alcoholic drivers, representing 6.5% of the drivers in California, are responsible for between 41 and 62% of accidents after drinking in the State. (3) Alcoholic drivers were innocent victims in only 1 out of 8 of their accidents, those with another medical condition in 1 out of 3, and drivers with none in 1 out of 2 of their accidents. (4) Accidents in which the driver was drinking but was thought not to be impaired resembled accidents in which the driver was known to be impaired more than accidents in which he was sober, suggesting significant impainnent without overt intoxication and, if drinking can be identified, impairment may also be assumed. The need for implied-consent legislation suggests itself. (5) Accidents involving alcohol were more likely to be single-vehicle accidents, or collisions with parked or stopped cars, than accidents during sobriety. Drivers with alcoholism and other medical conditions had a greater proportion of such accidents when sober than drivers in the comparison group. (6) Though no appreciable difference between alcohol and nonalcohol accidents appeared in the number of people injured per accident, fewer were at risk in alcohol accidents because more of them involve a single vehicle or a parked car. Injuries per number of people exposed would therefore be more. (7) Drinking accidents of alcoholic drivers were distributed throughout the day more evenly than accidents of nonalcoholic drivers, and they were more likely to occur between 6 am and noon. (8) 20% of nonaccident violations by alcoholic drivers were for drunken or reckless driving in comparison with 2% by the other groups. (9) Persons with alcoholism and other psychosocial disorders had 1 1/2 times as many violations for vehicle defects as persons with organic medical conditions and persons with none. (10) The proportion of convictions for driving with a suspended or revoked license or without a license in possession was twice as great for drivers with alcoholism as for drivers with other medical conditions.