Blood Alcohol Test Results of Motor Vehicle Deaths as an Evaluation Method for the Fairfax Alcohol Safety Action Project

About the report:

The Fairfax Alcohol Safety Action Project (ASAP) was started following the June 1971 approval of the proposal and working plan submitted to the Department of Transportation by the Highway Safety Division of Virginia. A total of $2,123,000 was allocated to the Safety Division. Of the five alcohol countermeasures that constitute the ASAP, one is administration and evaluation. As a part of the evaluation countermeasure, it was decided to determine if the Virginia State Medical Examiner's blood alcohol concentration (BAC) tests of fatally injured motorists could be used in evaluating the project's effectiveness. Three analytical techniques using the BAC test results were defined and evaluated: (a) Difference between mean positive BAC's, (b) expected total (positive and negative) BAC mean and corresponding confidence interval, and (c) significance of a shift in the total BAC distribution. The findings resulting from use of these techniques permitted several conclusions. By employing the techniques, the BAC test results can be useful in evaluating the ASAP project, although the relatively small Fairfax sample requires a sizeable shift in the data before it can be statistically shown that ASAP is having an impact. Further, once ASAP is implemented on a statewide basis, the analytical techniques used here will be much more powerful in detecting its impact. Appendix A is a preliminary evaluation of the alcohol tests on 1972 Fairfax motor vehicle fatalities.

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