The Problem: Alcohol consumption is a risk factor for many public health harms. Impaired driving is one of the largest contributors to motor vehicle crashes. Each year in the United States roughly 10,500people die in motor vehicle crashes involving an alcohol-impaired driver. In 2016, over one million people were arrested for driving under the influence of alcohol or narcotics. CDC: Impaired Driving Factsheet. Alcohol consumption is also a risk factor for cancer and other chronic conditions such as cirrhosis. One established risk factor for excessive alcohol consumption is high density of outlets that sell alcohol. CDC: Alcohol Use Factsheet.
The Law: Blood alcohol per se laws set a blood alcohol limit at which an individual is considered legally impaired (i.e., impairment is “per se” because actual inability to function need not be established). Currently, all states set their BAC limit at 0.08 percent; some previously set the BAC levels at 0.10 percent. For examples of BAC per se laws, see Cal. Veh. Code §23152 (California), Fla. Stat. §316.193 (Florida), K.S.A. §8-1567 (Kansas), M.R.S. §2411 (Maine), N.M. Stat. Ann. §66-8-102 (New Mexico), N.C. Gen. Stat. §20-138.1 (North Carolina), O.R.S. 813.010 (Oregon), Utah Code §41-6a-502 (Utah), 23 V.S.A. §1201 (Vermont), and Va. Code Ann. §18.2-266 (Virginia).
The Evidence: In a Community Guide systematic review, Shults et al. reviewed nine studies that examined the impact of lowering the BAC limit to 0.08 percent on the rate of alcohol-related motor-vehicle deaths. Shults, et al. Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving. Am J Prev Med. 2001;21(4S):66-88. According to the reviewers, the underlying studies reveal a considerable association between the adoption of 0.08 percent BAC laws and a decline in alcohol-related motor-vehicle deaths; the median reduction in motor vehicle fatalities after the laws were adopted was 7 percent. Shults et al view these studies as strong evidence of the effectiveness of 0.08 BAC laws as a public health intervention. However, they caution that most of the BAC laws analyzed were enacted along with, or were supplemented by, other preventive drunk-driving laws, such as Administrative License Revocation (ALR) laws, making it difficult to isolate the exact magnitude of the impact of BAC laws.
The Bottom Line: According to the reviewers of a Community Guide Systematic Review, there is strong evidence that laws adopting zero tolerance BAC levels effectively reduce alcohol-related motor-vehicle deaths.
Impact: Effective