The relationship between blood alcohol concentration (BAC), age, and crash risk
Section snippets
Problem
Both age (youth) and alcohol-impairment are strong independent correlates of increased crash risk. This fact has been demonstrated by innumerable studies of traffic crash causation and driver performance over the past 50 years.
In a study of California drivers, Janke, Masten, McKenzie, Gebers, and Kelsey (2003) reported that crash rates were highest for drivers under 21 years of age and declined to age 50–54 for crashes per mile driven and to age 65–69 for crashes per licensed drivers. Drivers
Data
All data used in this study were collected by Blomberg et al. (2005) in connection with a case control study of the relationship between blood alcohol concentration (BAC) and crash risk. Prior to initiating the present analysis, the data were re-edited for accuracy and internal consistency. Five errors or highly questionable values were found, four of which affected BAC scores and one that affected a passive alcohol sensor (PAS) value. Two of the BAC errors were due to decimal misplacement on
Results
The number of drivers in each of the four age groups used in the logistic regressions is tabulated by outcome, BAC, and relative risk in Table 1. The same tabulation for gender is shown in Table 2. The tabulations illustrate simple bivariate relationships that have not been adjusted for other covariates. These relative risks represent the simple odds of crash involvement of each positive BAC group (number with crashes/number in control) compared to odds of crash involvement of 0-BAC drivers.
Discussion
Taken together, the results provide strong support for the hypothesis that the association between BAC and crash risk is higher in young drivers than older drivers. The results also indicate that the interaction is largely confined to a single age group, drivers under 21. None of the interaction contrasts involving the 21 and over sub-groups approached significance.
There are a number of reasons for believing that young and inexperienced drivers would be more vulnerable to the effects of
Acknowledgement
We thank the National Institute on Alcohol Abuse and Alcoholism, which provided support for this work (grant number R21AA015093). The authors also wish to thank Ellie Enriquez Peck for her assistance in typing drafts of the manuscript.
Raymond C. Peck is President of R.C. Peck & Associates, Folsom, CA and Senior Project Analyst at Pacific Institute for Research and Evaluation, Calverton, MD. He holds a M.A. in Experimental Psychology from California State University.
References (33)
- et al.
Correlation between modes of drinking and modes of driving as reported by students at two American universities
Accident Analysis & Prevention
(2003) The young driver follow-up study: An evaluation of the role of human factors in the first four years of driving
Accident Analysis & Prevention
(1972)- et al.
The influence of alcohol, age, and number of passengers on the night-time risk of driver fatal injury in New Zealand
Accident Analysis & Prevention
(2004) - et al.
Traffic accident involvement rates by driver age and gender
Accident, Analysis and Prevention
(1995) - et al.
Youth alcohol and relative risk of crash involvement
Accident Analysis and Prevention
(1986) - et al.
Traffic safety in the U.S.: Re-examining major opportunities
Journal of Safety Research
(2007) Night-time driving and fatal crash involvement of teenagers
Accident Analysis & Prevention
(1985)Logistic Regression Using the SAS System
Theory and Applications
(1999)Alcohol and Road Accidents. (Road Research Laboratory Report No. 6)
(1966)- et al.
Crash risk of alcohol involved driving: A case-control study
(2005)
The role of the drinking driver in traffic accidents
Blutalkohol
General relative-risk function for case-control studies
American Journal of Epidemology
Two studies examining environmental predictors of heavy drinking by college students
Prevention Science
The Analysis of Binary Data
Regression and Linear Models
Traffic Safety
Cited by (0)
Raymond C. Peck is President of R.C. Peck & Associates, Folsom, CA and Senior Project Analyst at Pacific Institute for Research and Evaluation, Calverton, MD. He holds a M.A. in Experimental Psychology from California State University.
Michael Gebers is a Research Program Specialist at the California Department of Motors, Sacramento and a Statistical Consultant with R.C. Peck & Associates. He holds an M.A. in Experimental Psychology from California State University.
Robert Voas is a Senior Research Scientist with Pacific Institute for Research and Evaluation; Vice President and Director of Alcohol Programs at the National Public Services Research Institute, Landover, MD; and Consulting Senior Scientist with the Vermont Alcohol Research Center, Burlington, VT. He holds a Ph.D, M.A., and B.A. from UCLA and a Ph.B from the University of Chicago.
Eduardo O. Romano is Associate Research Scientist at the Pacific Institute for Research and Evaluation. He holds a Ph.D. and M.S. from Virginia Polytechnic Institute and State University and an Ing. Agr. from University of Buenos Aires.