Should We Lower Blood Alcohol Concentration's Legal Limit?

Over 15 years, from 2000 to 2015, there were 612,030 motor vehicle fatalities, 37% involved one or more drivers with a positive BAC. While the majority, 85%, involved a legally impaired level, roughly 34,000 deaths involved lower amounts. [1] That ratio remained reasonably constant throughout the reporting period. The researchers made three significant findings:

• Crash fatalities for lower BACs were a significant, meaningful number.
• When compared to accidents involving BACs >0.08%, deaths “were likely to be individuals other than a drinking driver,” and were more frequently the young.
• “More restrictive state alcohol policies,” were associated with fewer fatalities involving a BAC <0.08%. [2]

There are several takeaways in the data. Drinking drivers are not the individuals primarily impacted; in many instances, it is their companions, so getting in the car with someone who has been drinking, and only a little, may actually be putting your life in their hands. It is interesting to speculate why smaller amounts of alcohol are more problematic for young drivers. I would suggest, as a first-order consideration, that it involves a lack of experience and judgment over and above the degree of impairment. Buzzed driving may be “safer” when the driver has more road experience and avoids situations that can escalate into accidents. But the real message, as is stated in those public service announcements is that buzzed driving is drunk driving.

Both the National Academies of Science, Engineering, and Medicine, and the National Transportation Safety Board have recommended lowering the legal definition of impaired driving to 0.05%; only Utah has enacted the legislation. As a thought experiment, put yourself in the shoes of those policymakers. Lowering the BAC is going to result in pushback from alcohol’s vested interests, manufacturers, distributors, and retailers, if for no other reason than it will impact sales. What are the lives of those 2000 annual deaths resulting from drinking drivers below the legal limit worth? Would you be willing to stand behind your recommendation in the face of angry lobbyists as well as devastated parents and family? Where would you draw the line?

[1] Data was obtained from the National Highway Traffic Administration’s Fatality Analysis Reporting System (FARS). Based on how the data is collected, measured BAC’s are not always obtained and, therefore, under-reported. FARS does allow “imputation” of BAC levels. The bottom line is the best data we have but not wholly accurate.

[2] 10 experts judged 29 various alcohol policies to assess their impact on binge drinking and impaired driving in adults and underage youth. Among the more effective include revocation of licenses, restriction of sale by age, location, and time. Other policies included liability on the part of the server or social host, and of course, cost increases due to alcohol taxes.

Source: Alcohol Policies and Motor Vehicle Crash Deaths Involving Blood Alcohol Concentrations Below 0.08% American Journal of Preventive Medicine DOI: 10.1016/jamepre.2019.12.015