Effects of legal BAC limits on fatal crash involvement: analyses of 28 states from 1976 through 2002.
OBJECTIVE
Hundreds of laws have been implemented in the United States over the past few decades designed to reduce alcohol-impaired driving and the crashes that often result. One approach has been to lower the legally allowable alcohol concentration for drivers. We examined the effects of changes in legal BAC limit in 28 U.S. states from January, 1976 to December, 2002.


METHODS
An interrupted time-series quasi-experimental design was used, incorporating non-alcohol-related crashes as comparisons. Four outcome measures of alcohol-related crash involvement were examined: single-vehicle nighttime, BAC=0.01-0.07, BAC=0.08-0.14, and BAC>/=0.15. Missing BAC test result data were handled by using multiple imputations. Analyses involved estimation of state-specific ARIMA models, controlling for other factors affecting overall crash rates and other major DUI policy changes. Inverse variance weighting methods were used to pool results across states for the most precise underlying estimate of effect of legal BAC limits.


RESULTS
Considerable state by state variability in estimated effects was observed, but results from the pooled analyses were clear and consistent. Changes in legal BAC limits significantly affected alcohol-related fatal crash involvement for both the SVN and BAC test result measures, and the laws affected drivers at all drinking levels.


CONCLUSIONS
An estimated 360 deaths are prevented each year in the United States as a result of the move from a 0.10 to 0.08 legal limit in recent years, and an additional 538 lives could be saved each year if the United States reduced the limit to 0.05, consistent with limits in most countries worldwide.


CONCLUSIONS
Given the significant effects of lower legal BAC limits on fatal crash involvement, businesses should support implementation of laws that further reduce the legal BAC limit for all drivers. Furthermore, all companies should set higher standards for employees, such as a zero allowable BAC limit for driving during work time.
Wagenaar
Alexander C
AC
University of Florida, College of Medicine, Department of Epidemiology & Health Policy Research and Institute for Child Health Policy, 1329 SW 16th St. Rm 5130, Box 100177, Gainesville, FL 32610-0177 USA. wagenaar@ufl.edu
Maldonado-Molina
Mildred M
MM
Ma
Linan
L
Tobler
Amy L
AL
Komro
Kelli A
KA
D000063:Accidents, Traffic / Q000401:mortality* / Q000639:trends; D000428:Alcohol Drinking / Q000331:legislation & jurisprudence*; D001334:Automobile Driving / Q000331:legislation & jurisprudence*; D004651:Employment / Q000331:legislation & jurisprudence; D006801:Humans; D017063:Outcome Assessment, Health Care; D013219:State Government; D014481:United States / Q000453:epidemiology