Commentary on Yao et al. (2016): Enforcement uniquely predicts reductions in alcohol-impaired crash fatalitiesYao et al. demonstrate that increases in arrests are associated with decreases in the percentage of fatal crashes involving impaired drivers. We argue that to have a substantial impact on impaired driving fatalities high visibility enforcement methods that require substantial public support must be implemented.
RELATIONSHIP OF ARRESTS TO IMPAIRED DRIVING CRASHESMothers Against Drunk Driving (MADD) has been successful in educating the American public of the tragedies that occur on our highways because of alcohol-impaired driving. They helped produce a cultural change in attitude towards drunk driving [1]. Within 2 years of MADD's founding in 1980, driving while intoxicated (DWI) arrests rose from 1.4 to 1.8 million a year (a 29% increase) and remained at that higher level for a decade before returning to the 1.4 million base in 1994 [2]. While DWI arrests remained at 1.8 million, the percentage of alcohol-impaired fatal crashes [defined as a fatal crash involving a driver with a blood alcohol concentration (BAC) of 0.08 or higher-the current illegal limit in all 50 states and the District of Columbia] declined 1.5% per year. However, with the diversion of public attention to other national problems in 1997 and beyond, DWI arrests returned to 1.4 million annually, the decline in the percentage of all alcohol-impaired fatal crashes ended and both DWI arrests and the percentage of fatal crashes involving an impaired driver have remained unchanged for 15 years.This lack of progress does not seem to be due to a reduction in the potency of DWI arrests, as recent studies continue to show that increases in DWI arrests are associated with reductions in alcohol-impaired crashes. In a nationally representative study, Fell et al. [3] found that a 10% increase in the DWI arrest rate per capita in a community was associated with a 1% decrease in alcohol-impaired driving crashes in that locality. Using a 11-year sample (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) of state data from the Fatality Analysis Reporting System, Yao et al.[4]-in a paper in this issue-studied states with increases and decreases in the percentage of alcohol-impaired fatal crashes during that 11-year period and found that states that had higher DWI arrest rates per capita had reductions in the percentage of fatal crashes involving an alcohol-impaired driver.
ENFORCEMENT INTENSITYThese studies appear to suggest that a return to 1.8 million annual DWI arrests would restore the downward trend in the percentage of alcohol-impaired fatal crashes experienced between 1982 and 1997 (Fig. 1). However, the relationship of DWI arrest rates to alcohol-impaired crashes can be misleading if it suggests that increasing arrests alone will reduce alcohol-impaired driving fatal crashes strongly. The Yao et al. paper noted that the effect size of arrests on crashes was small, and research suggests that DWI arrest rate is only a limited indicato...