Straightforward and powerful reasons exist for lowering the legal limit of blood alcohol concentration (BAC) from 0.1 0 to 0.08. In 1964, Borkenstein et al. showed that drivers who had been drinking were more likely to be involved in a crash than sober drivers, and that beginning with low BACs, the greater the level of intoxication, the higher the probability of being in a crash. Other investigators have replicated and refined Borkenstein et al.'s original findings. More recently, Mounce and Pendleton (1992) extended this line of research by showing that driver BAC is associated with the probability of being responsible for a crash in which they were involved. The objective of the current study was to review the fatal crash experience of all of the states that have lowered BAC limits to 0.08; however, many of these states have not had sufficient experience with the lower BAC limit to provide meaningful statistical inferences. At the time this study was begun, 11 states had sufficient experience with 0.08 BAC laws to conduct a statistical analysis. In summary, the analysis of the impact of 0.08 BAC laws found that 5 of the 11 states that implemented such laws experienced significantly lower rates of alcohol involvement among fatalities, and that five of these states experienced significantly fewer high-BAC and alcohol related fatalities during the period after implementation. While some of these states were apparently already experiencing either a long-term or short-term downward trend in alcohol involvement, due possibly to other factors such as the presence of laws (ALR), the use of sobriety checkpoints, or a general societal trend for reduced alcohol consumption this alone does not account for the reductions observed. Each and every state in the group exhibiting a significant association between 0.08 and reductions in alcohol involvement already had an administrative license revocation law in effect (Vermont, Kansas, North Carolina, Florida and New Mexico). An additional 2 states (California and Virginia) experienced significant reductions after ALR was in place, when the effects of 0.08 and ALR (implemented about 6 months apart) were considered as a single intervention. Clearly, other factors may be at work, as evidenced by the presence of declines in alcohol involvement that began around 1992, which coincided with the implementation of neither 0.08 nor ALR. While it is difficult to pinpoint exactly what factors may be responsible, the data and analyses are clearly suggestive that 0.08 BAC laws have some deterrent effect leading to reductions in drinking and driving, most notably in conjunction with the presence of other drunk-driving laws and practices, especially administrative license revocation. (A)
Abstract