The analytic essay by Morain and Largent (p. 709) presents a very different, yet important, approach to evaluating a law in the United States that would reduce the blood alcohol concentration (BAC) limit for driving from the current level of 0.08 grams per deciliter (g/dL) to 0.05 g/dL. A 0.08 BAC limit currently exists in 49 states and the District of Columbia. Utah became the first state to lower the BAC limit to 0.05 g/dL, which became effective on December 30, 2018. The authors expound an ethical argument to support a 0.05 BAC that includes preventing harm both to the drinking drivers and to others affected by impaired drivers. They go on to describe objections to a 0.05 BAC law as restricting individual liberty and failing to consider the value that people derive from social drinking, but they reject those arguments in an analytical and evidence-based manner.
The authors initially accomplish this by briefly describing the history of BAC limit laws in the United States where states gradually reduced the BAC limit from 0.15 g/dL in the 1960s and 1970s to 0.10 g/dL in the 1980s and then to 0.08 g/dL in the 1990s and 2000s. They describe, with strong evidence, the arguments in favor of a 0.05 BAC limit: preventing harm to drinking drivers and preventing harm to others. Finally, they assess the objections to a 0.05 BAC limit by critics and reject those arguments with empirical data. The essay provides even more support for lowering the BAC limit to 0.05 g/dL than heretofore has been presented.
RATIONALE FOR LOWERING THE LIMIT
It is fairly well-known that a 0.05 BAC limit has the science behind it to support such a measure. In summary, here are some of the key reasons:
Driving is impaired at 0.05 BAC. Research conducted over the past 30 years clearly indicates that most drivers are impaired at 0.05 BAC and higher with regard to driving performance. Regardless of age, gender, ethnicity, and drinking experience, laboratory, driving simulator, and test track experiments indicate impairment for most participants at 0.05 BAC.1,2
The risk of a crash is significant at 0.05 BAC. In case–control experimental research, the risk of being in a crash begins to rise substantially at 0.05 BAC and higher when compared with drivers with 0.00 BAC.3
Evaluation studies show that when countries lower their BAC limit to 0.05 g/dL, decreases in crashes occur. Lowering their BAC limit for driving to 0.05 g/dL has reduced alcohol-related traffic fatalities in several countries, most notably Australia. A recent meta-analysis of international studies on lowering the BAC limit found a 5.0% decline in nonfatal alcohol-related crashes associated with lowering the BAC from 0.10 g/dL to 0.08 g/dL, and an additional 9.2% decline in fatal alcohol-related crashes. When countries lowered their BAC limit to 0.05 BAC or lower, there was an 11.1% decline in fatal alcohol-related crashes associated with that countermeasure according to the meta-analysis.4
A 0.05 BAC is not typically just one or two drinks. For the average 170-pound man, it would take at least four alcoholic drinks in two hours on an empty stomach to exceed a 0.05 BAC. The average 137-pound woman would have to drink three glasses of wine on an empty stomach in two hours to reach or exceed a 0.05 BAC.
Surveys show that the public supports levels below 0.08 BAC. A survey conducted by the AAA Foundation for Traffic Safety indicated that 63% of a representative sample of drivers in the United States are in favor of lowering the illegal BAC from 0.08 g/dL to 0.05 g/dL.5
Close to 100 countries around the world have set BAC limits at 0.05 BAC or lower. All states and territories in Australia have a 0.05 BAC limit, and their per-capita alcohol consumption is higher than that in the United States. Most of Europe, including Spain, France, Austria, Italy, and Germany have established their limit at 0.05 g/dL, while Sweden, Norway, Japan, and Russia have enacted their BAC limit at 0.02 g/dL.
Progress in reducing alcohol-impaired driving has stalled. The percentage of US traffic fatalities involving an alcohol-impaired driver has been around 30% for more than 20 years. If states lowered their BAC limit from 0.08 g/dL to 0.05 g/dL, studies show that hundreds of lives could be saved. A 0.05 BAC limit has the potential to serve as a general deterrent to all those who drink and drive.
FURTHER EVIDENCE FOR 0.05
The essay provides another major reason to lower the BAC limit to 0.05 g/dL by describing the ethical acceptability of the strategy. There is a growing body of research on alcohol harm to others documenting the prevalence of a wide range of harms to others attributable to alcohol. These harms to communities include noise, vandalism, property damage, spousal abuse, child neglect, and work-related problems. This enhances the position in the essay on alcohol’s harm to others. See Greenfield et al.6 and Karriker-Jaffe et al.7 for more detailed evidence.
CONCLUSION
In summary, despite the critics, there is strong scientific evidence for states to consider lowering their BAC limit for driving to 0.05 g/dL. Laboratory studies indicate that most drivers are impaired at BAC levels at 0.05 g/dL and higher, the risk of being involved in a crash is significant at BACs of 0.05 g/dL and higher, evaluations of the effectiveness of lowering the BAC limit to 0.05 g/dL or lower indicate it is a proven effective countermeasure, a 0.05 BAC is a reasonable limit to set, and the majority of the public favors the strategy. Now, with this analytic essay and other studies, there is strong evidence of ethical acceptability of the measure.
Most of the industrialized nations in the world have a 0.05 BAC limit for driving, and progress in the United States in reducing impaired driving fatalities has stagnated for more than 20 years. The National Academy of Sciences, Engineering, and Medicine; the National Transportation Safety Board; the American Medical Association; the National Safety Council; the Association for the Advancement of Automotive Medicine; and numerous other public health organizations all recommend lowering the BAC limit to 0.05 g/dL.
The analytic essay by Morain and Largent adds another argument: the harm to others is a major ethical reason to lower the BAC limit.
CONFLICTS OF INTEREST
I have no conflicts of interest concerning this editorial.
Footnotes
See also Morain and Largent, p. 709.
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