Ignition Interlock Laws: Effects on Fatal Motor Vehicle Crashes, 1982–2013

• Published in: American journal of preventive medicine Vol. 52; no. 4; pp. 417 - 423
• Main Authors: McGinty, Emma E., PhD, MS, Tung, Gregory, PhD, MPH, Shulman-Laniel, Juliana, MPH, Hardy, Rose, MPH, Rutkow, Lainie, JD, PhD, MPH, Frattaroli, Shannon, PhD, MPH, Vernick, Jon S., JD, MPH
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01-04-2017; Elsevier Science Ltd
• Subjects: Accidents, Traffic - mortality; Accidents, Traffic - prevention & control; Accidents, Traffic - trends; Alcohol content; Analysis; Blood; Driving; Driving Under the Influence - legislation & jurisprudence; Driving Under the Influence - prevention & control; Drunk driving; Fatalities; High risk; Humans; Internal Medicine; Mortality; Offenders; Preventive medicine; Protective Devices - utilization; Public health; Recidivists; Risk reduction; Traffic; Traffic accidents & safety; United States; United States > US
• ISSN: 0749-3797; 1873-2607
• DOI: 10.1016/j.amepre.2016.10.043

Introduction Alcohol-involved motor vehicle crashes are a major cause of preventable mortality in the U.S., leading to more than 10,000 fatalities in 2013. Ignition interlocks, or alcohol-sensing devices connected to a vehicle’s ignition to prevent it from starting if a driver has a predetermined blood alcohol content (BAC) level, are a promising avenue for preventing alcohol-involved driving. This study sought to assess the effects of laws requiring ignition interlocks for some or all drunk driving offenders on alcohol-involved fatal crashes. Methods A multilevel modeling approach assessed the effects of state interlock laws on alcohol-involved fatal crashes in the U.S. from 1982 to 2013. Monthly data on alcohol-involved crashes in each of the 50 states was collected in 2014 from the National Highway Traffic Safety Administration Fatality Analysis Reporting System. Random-intercept models accounted for between-state variation in alcohol-involved fatal crash rates and autocorrelation of within-state crash rates over time. Analysis was conducted in 2015. Results State laws requiring interlocks for all drunk driving offenders were associated with a 7% decrease in the rate of BAC >0.08 fatal crashes and an 8% decrease in the rate of BAC ≥0.15 fatal crashes, translating into an estimated 1,250 prevented BAC >0.08 fatal crashes. Laws requiring interlocks for segments of high-risk drunk driving offenders, such as repeat offenders, may reduce alcohol-involved fatal crashes after 2 years of implementation. Conclusions Ignition interlock laws reduce alcohol-involved fatal crashes. Increasing the spread of interlock laws that are mandatory for all offenders would have significant public health benefit.