A new study in the American Journal of Public Health, analyzing National Highway Traffic Safety Administration data, shows that states with mandatory interlock laws see a 15 percent reduction in drunk driving-related deaths compared to states without legislation requiring DUI offenders to use “mandatory ignition interlock.” According to the study, state laws that require drivers who’ve been convicted of drunk driving to pass a breathalyzer-type test before starting their cars saved an estimated 915 lives between 2004 and 2013.
“Although crashes and crash fatalities decline, we’re not seeing a significant reduction in those involving alcohol,” said the study’s senior author, Douglas J. Wiebe, PhD, an associate professor of epidemiology in the department of Biostatistics and Epidemiology, a senior scholar in the Center for Clinical Epidemiology and Biostatistics and UPenn PRC Training Core Lead. “We’re encouraged by the increasing number of states enacting mandatory interlock laws since 2013 and hope these findings advance public health conversations aimed at saving more lives.”
Car crashes involving alcohol make up 30 percent of vehicular fatalities, resulting in 11,000 deaths each year. The National Highway Traffic and Safety Administration estimates that for each of the million drunk driving convictions each year, there are 88 previous instances of drunk driving. Previous research on mandatory interlock laws focused on recidivism rates, but the new Penn study serves as the first national analysis of the impact of a universal interlock requirement on alcohol-involved crash deaths.