Citation

Wagenaar AC. HSRI Res. Rev. 1981; 11(4).

Copyright

(Copyright © 1981, University of Michigan Highway Safety Research Institute)

DOI

unavailable

PMID

unavailable

Abstract

Motor vehicle accidents in Michigan during the period 1972-1979 were analyzed to examine whether the change in legal drinking age (from 18 to 21, December, 1978) affected the numbers of 18-to-20-year-old drivers involved in alcohol-related crashes during 1979. Box-Jenkins time-series models were applied to monthly crash data for the years 1972-1979 for alcohol-related and non-alcohol-related accidents involving drivers aged 18-20, 21-24, and 25-45. The study results showed that for drivers aged 18-20, the actual total of alcohol-related crashes for 1979 was 31 percent less than the total expected for 1979, based on the time-series analyses of the 1972-1978 data. In contrast, actual alcohol-related crashes among drivers aged 21-24 were 9 percent higher than expected, and among drivers aged 25-45 were 5 percent higher than expected. The same trends by age were evident in the actual crash totals for 1979 vs. 1978, but differences revealed by use of the time-series models are more valid than comparison of year-to-year changes.