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Ignition Interlock Devices

Ignition Interlocks are devices about the size of a cell phone installed in a vehicle's dashboard.  These devices are designed to keep people who have been convicted of driving under the influence (DUI) from starting their vehicle after they have consumed alcohol.  It works like a Breathalyzer -- a convicted drunk driver must blow into the device in order to start their vehicle.  If they have a measurable amount of alcohol in their system, the vehicle will not start.

These devices are a simple and economic way to ensure convicted drunk driving offenders can drive to and from work, but cannot drive under the influence of alcohol.


Drunk_Driving-_The_Facts_1-_for_web.jpgDo ignition interlock devices keep people from having repeat DUI offenses?

The Center for Disease Control (CDC) found repeat drunk driving offenses were reduced by about two-thirds due to interlock devices.

The International Council on Alcohol, Drugs and Traffic Safety's (ICADTS) found ignition interlock devices, as well as monitoring, led to a 40-95% reduction in the conviction rate of people who were previously arrested for DUI. This is important, because the rate of DUI convictions is a good predicator of crash risk involvement.


As of August 2015, 25 states require interlocks for all offenders.

KY_Map_in_green_with_county_outlines_black.pngKentucky's Ignition Interlock Law -- In March 2015, the Kentucky Legislature passed Senate Bill 133 requiring ignition interlock devices for all repeat DUI offenders.  The final version of the bill does not require first-time DUI offenders to have the devices installed unless there's an aggravating circumstance, such as excessive speed or driving drunk with a child in the car. 


How do ignition interlocks prevent tampering? 
  1. Temperature and Air Gauges -- The devices have temperature and air gauges to ensures a person and not a machine is providing the air sample.
  2. Learned Skill -- Blowing into an interlock is a learned skill that requires specific training that would most likely be difficult for an impaired person to administer.
  3. Running Retests -- Running retests require offenders to blow into the device at random intervals once the vehicle has been allowed to start.  It reminds the driver about scheduled checks.  If a check is missed, the device will not allow the car to start.
  4. Alerts Law Enforcement to Failed/ Bypassed Retests -- If a driver drives bypasses or fails a running retest, the horn will honk and the lights will flash to alert law enforcement.  The devices are wired to a vehicle's ignition system not the engine, and for safety reasons will not stop a vehicle while it is in motion.
  5. Car Battery Tampering -- If the driver tampers with the battery, the device will also know if the car’s power has been interrupted.
  6. Tamper-Proof Seals -- There are also tamper-proof seals on interlocks.

The majority of the public supports requiring ignition interlocks for all convicted drunk driving offenders based on the following studies cited from www.madd.org:

Click here for answers to other frequently asked questions about Ignition Interlocks from MADD.org.2014-09-12_Communicare_DUI_Youth_Conference-_DUI_Facts_Image_2.jpg