ALCOHOL INVOLVEMENT IN TEXAS DRIVER FATALITIES: ACCIDENT REPORTS VERSUS BLOOD ALCOHOL CONCENTRATION

The extent of alcohol involvement among driver fatalities has been difficult to estimate from subjective, nonquantitative sources such as accident reports. Compared in this paper are estimates from two data sources of the proportion of driver fatalities in which the driver is legally intoxicated: accident reports and toxicological reports, i.e., reports of blood alcohol concentration (BAC). On the basis of 1,260 driver fatalities in Texas for which BAC test results were available, 51 percent of the drivers were legally intoxicated as defined by a BAC greater than or equal to 0.10 percent blood alcohol by volume. Accident reports for these same driver fatalities reported alcohol as a contributing factor in the accident in only 20 percent of the fatalities. Of the legally intoxicated driver fatalities identified by the BAC tests, 68 percent of the corresponding accident reports did not indicate alcohol as a contributing factor in the accident. Descriptive statistics based on BAC results by age and sex of the driver and time and date of the accident are reported. The underreporting rate of alcohol involvement is also described by age and sex of the fatally injured driver and by investigating officer, i.e., local police versus department of public safety (DPS). The findings emphasize the need for better quality data on alcohol involvement in traffic accidents.