An alcohol ignition interlock is a device installed in an offender’s vehicle that prevents it from starting if the driver’s BAC is above a specified set limit.

Overview

Repeat offenders are a significant portion of the drunk driving problem – about one-third of all DUI arrests each year are of people who have been convicted previously of driving under the influence. (Fell, 1995) Considering that between 50 and 75 percent of those whose licenses are suspended or revoked as the result of driving under the influence continue to drive without their license, (Nichols and Ross, 1990) (Voas and Tippetts, 1994) revoking a license is good, but not always enough.

Alcohol ignition interlocks are proven to be an effective tool in the battle against drunk driving. Ignition interlocks prevent people who have alcohol in their system from driving a car. An operator breathes into an interlock device to determine blood alcohol concentration. If there is measurable alcohol in the blood, the vehicle does not start.

As one might expect, this stops offenders from re-offending while the interlock device is on the vehicle. Studies have shown ignition interlocks are an average of 64 percent effective in reducing repeat drunk driving offenses. (Lybrand, 2004) Interlocks have been shown to be effective in Maryland (Beck, 1999), Alberta (Voas, et al, 1999), California (Tashima and Helander, 1999), and elsewhere (Weinrath, 1997) (Coben, 1999) with results ranging from 50 to 90 percent reductions in subsequent offenses by those offenders who were assigned interlock devices, compared with those who were not.

Take Action

Currently eight states mandate or highly incentivize ignition interlocks for all persons convicted of DUI – New Mexico, Arizona, Louisiana, Illinois, Washington, Nebraska, Alaska and Colorado. If you are from one of the other states, contact your legislators and tell them you support saving lives and eliminating repeat drunk driving offenses by mandating ignition interlocks for all convicted DUI offenders.  

Related Issues

• Repeat offenders
• High-BAC drivers
• Administrative license revocation (ALR)
• Vehicle impoundment
• Mandatory assessment and treatment

Resources

• MADD's Model Ignition Interlock Law Provisions
• Official Position Statement
• Studies
  • MADD's Impaired Driving Summit Report (PDF) 
  • Beck, KH, et al. "Effects of Ignition Interlock License Restrictions on Drivers with Multiple Alcohol Offenses: A Randomized Trial in Maryland." American Journal of Public Health, 89 vol. 11 (1999): 1696-1700.
  • Coben, Jeffrey, and Gregory Larkin. "Effectiveness of Ignition Interlock Devices in Reducing Drunk Driving Recidivism." American Journal of Preventive Medicine 16 vol. 1S (1999): 81-87. 
  • Fell, Jim. "Repeat DWI Offenders in the United States." Washington, DC: National Department of Transportation, National Highway Traffic Safety Administration Traffic Tech No. 85, February 1995.
  • Willis C., Lybrand S., Bellamy N. "Alcohol ignition interlock programmes for reducing drink driving recidivism," Cochrane Database of Systematic Reviews 2004, Issue 4. Art. No.: CD004168. DOI: 10.1002/14651858.CD004168.pub2. This version first published online: October 18. 2004.
  • National Highway Traffic Safety Administration. "Repeat DWI Offenders Are an Elusive Target." Washington, DC: National Department of Transportation, National Highway Traffic Safety Administration Traffic Tech No. 217, March 2000.
  • Nichols, James, and H. Lawrence Ross. "The Effectiveness of Legal Sanctions in Dealing with Drinking Drivers." Alcohol, Drugs and Driving 6(2) (1990): 33-55.
  • Peck, R.C., R. J. Wilson, and L. Sutton. "Driver License Strategies for Controlling the Persistent DUI Offender," Strategies for Dealing with the Persistent Drinking Driver. Transportation Research Board, Transportation Research Circular No. 437. Washington, DC: National Research Council (1995): 48-49.
  • Tashima, H.N., and C.J. Helander. 1999 Annual Report of the California DUI Management Information System. Sacramento, CA: California Department of Motor Vehicles Research and Development Section, 1999.
  • Voas, Robert, et al. "Alberta Interlock Program: The Evaluation of a Province-Wide Program on DUI Recidivism." Addiction 94 vol. 12 (1999): 1849-1859.
  • Voas, Robert and A. Scott Tippetts, A.S. "Unlicensed Driving by DUIs – A Major Safety Problem?" TRB ID No. CR077. Paper presented at the 73up>rd Annual Meeting, Transportation Research Board, Landover, MD, (1994, January 9-13).
  • Weinrath, M. "Ignition Interlock Program for Drunk Drivers: A Multivariate Test." Crime and Delinquency 43 vol. 1 (1997): 42-59.
• Press Releases
  • MADD Applauds Alaska Legislature for Passage of Lifesaving DUI Bill (June 20, 2008)
  • MADD Applauds Florida for Approving Lifesaving Alcohol Ignition Interlocks (June 19, 2008)
  • Colorado Governor Signs into Law Lifesaving Legislation to Expand Use of Alcohol Ignition Interlocks (May 16, 2008)
  • MADD’s Campaign to Eliminate Drunk Driving Leads to Victories in Washington, West Virginia, Virginia and Nebraska (April 22, 2008)
  • MADD Applauds Nebraska Legislature for Approving Lifesaving Drunk Driving Measure (April 8, 2008)
  • Washington State House and Senate Unanimously Pass Lifesaving Drunk Driving Legislation (March 13 2008)
  • MADD Applauds Virginia Senate's Passage of Lifesaving Drunk Driving Legislation (March 5, 2008)
    

States with this law
Alaska, Arkansas, Arizona, California, Colorado, Connecticut, Delaware, Florida, Georgia, Iowa, Idaho, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Minnesota, Missouri, Mississippi, Montana, North Carolina, North Dakota, Nebraska, New Hampshire, New Jersey, New Mexico, Nevada, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, Wisconsin, West Virginia, Wyoming