Technical Report Documentation Page

1. Report No. 2. Government Accession No.

3. Recipient's Catalog No.
4. Title and Subtitle

Driver Characteristics and Impairment at Various BACs

5. Report Date

August 2000

6. Performing Organization Code

7. Author(s)

H. Moskowitz, M. Burns, D. Fiorentino, A. Smiley, P. Zador

8. Performing Organization Report No.

9. Performing Organization Name and Adddress

Southern California Research Institute
11914 West Washington Boulevard
Los Angeles, CA 90066

10. Work Unit No. (TRAIS)

11. Contract or Grant No.


12. Sponsoring Agency Name and Address

U.S. Department of Transportation
National Highway Traffic Safety Administration
400 Seventh Street, S.W.
Washington, DC 20590

13. Type of Report and Period Covered

14. Sponsoring Agency Code
15. Supplementary Notes

Paul J. Tremont, Ph.D. was the NHTSA Contracting Officer's Technical Representative for the study.

16. Abstract

The purpose of this experiment was to determine a) the magnitude of alcohol impairment of driving skills as BACs varied from zero to 0.10% and b) whether age, gender, and drinking practice characteristics of the subjects would differentially affect alcohol impairment in a sample of subjects who were broadly representative of the driving population. Using a driving simulator and a divided attention task, 168 subjects were examined at BACs to 0.10% for moderate and heavy drinkers and to 0.08% for light drinkers.

Alcohol significantly impaired performance on some measures at all examined BACs from 0.02% to 0.10%. The magnitude of the impairment increased with increasing BAC. Differences in the magnitude of alcohol impairment between categories of age, gender, and drinking practices were small, inconsistent in direction, and did not reach statistical significance. It is possible that significant differences would have emerged if a wider range of subject characteristics and BACs had been examined. BACs over 0.10% were not tested, and the sample did not include subjects under 19 years and over 70 years, or very light and very heavy drinkers. Within those limits, no significant differences in the magnitude of alcohol impairment within the categories of age, gender, and drinking practice appeared for this diverse sample.

17. Key Words

Age, Alcohol, BAC, Divided Attention, Drinking Practices, Driving, Gender, Impairment, Simulator

18. Distribution Statement

This document is available to the U.S. public through the National Technical Information Service, Springfield, Virginia, 22161.

19. Security Classif. (of this report)


20. Security Classif. (of this page)


21. No. of Pages 22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized