| The association between the blood alcohol concentration (BAC) law and the incidence of alcohol-related traffic crashes and fatalities is evaluated in this study. On September 1, 1999, Texas passed legislation to lower the legal BAC level from its previous level of 0.10% to 0.08%. We are interested in whether the Texas 0.08% BAC law is effective in reducing alcohol-related traffic fatalities. Our study design focused on identifying the trends of alcohol-related traffic crashes and fatalities and explaining the observed trends that have occurred since 1995. We used the Texas Fatal Accident Reporting System (FARS) dataset and we did analyses on the trends of the proportion of alcohol-related fatalities in all traffic fatalities, both before and after the 0.08% BAC law. Linear regression models were used to evaluate the slope of trends for fatal crashes, and the correlation structure of the sequences of alcohol-related traffic fatalities.; By the statistical analyses, we evaluated the impact of different variables on the trends in fatal crashes (alcohol-related and non-alcohol related). We identified the two most statistically significant variables in the observed declining trend of the proportion of accidents involving alcohol. They were blood alcohol concentration and implementation of the 0.08% BAC law. The law indicator variable and blood alcohol concentration were significant at the 0.05 level in the final model. From our analyses, we conclude that the 0.08% BAC law had a significant impact on the trend of alcohol-related traffic fatalities. |
