Ignition Interlocks - What You Need to Know: A Toolkit for Policymakers, Highway Safety Professionals and Advocates

Alcohol-impaired driving takes an enormous toll in the United States, killing approximately one person every 40 minutes. Despite continued efforts by enforcement, the judiciary, advocates and governmental agencies, nearly 13,000 people were killed in alcohol-impaired-driving crashes in 2007 (NHTSA 2008a). This number has remained remarkably stable for almost two decades after alcohol-involved fatalities declined significantly in the 1980s and early-to-mid 1990s. Many drivers involved in fatal alcohol-impaired-driving crashes have been arrested previously for driving while intoxicated (DWI). In 2007, drivers with a blood alcohol concentration (BAC) of .08 grams per deciliter or higher in fatal crashes were eight times more likely to have a prior conviction for driving while impaired than were drivers with no alcohol (NHTSA, 2008a). Technology presents exciting possibilities in the area of impaired-driving prevention. One promising strategy is the breath alcohol ignition interlock device (BAIID). A BAIID, or more simply an ignition interlock, is an after-market piece of technology installed in a motor vehicle to prevent a driver from operating the vehicle if the driver has been drinking. Before starting the vehicle, a driver must breathe into the device and if the driver’s BAC is over a pre-set limit, the ignition interlock will not allow the vehicle to start. Research shows that ignition interlocks reduce recidivism among both first-time and repeat DWI offenders, with reductions in subsequent DWI arrests ranging from 50 to 90 percent (Voas & Marques, 2003; Willis et al., 2005; Vezina, 2002; Tippetts & Voas, 1997; Coben & Larkin, 1999). Forty-seven States and the District of Columbia currently allow the use of alcohol ignition interlocks for at least some DWI offenders; only Alabama, South Dakota, and Vermont do not. Some States mandate ignition interlock use; in others, judges, State administrators or even the offenders themselves choose whether or not to apply this promising sanction. Seven States mandate the use of ignition interlocks for all offenders; 22 mandate use for repeat offenders. However, although approximately 1.4 million DWI arrests are made each year, the most recent national estimate reports only 146,000 alcohol ignition interlocks are currently in use with impaired driving offenders (Roth, 2008a). By preventing impaired drivers from starting and operating motor vehicles, the separation of an unsafe driver from a vehicle that has the potential to be a deadly weapon may prevent untold tragedy. This Tool Kit will advance the understanding of ignition interlock technology, improving its application as an effective strategy to save lives and prevent impaired driving.


  • English

Media Info

  • Media Type: Print
  • Features: Appendices; References; Tables;
  • Pagination: 27p

Subject/Index Terms

Filing Info

  • Accession Number: 01156901
  • Record Type: Publication
  • Report/Paper Numbers: HS-811 246
  • Files: HSL, TRIS, USDOT
  • Created Date: Apr 30 2010 3:00PM