Alcohol Ignition Interlock Fact Sheet
Alcohol ignition interlocks save lives.
• The breath alcohol ignition interlock prevents a vehicle from being driven by a drunk driver. If
used correctly, the device can substantially reduce repeat offenses.
If properly administered, alcohol ignition interlocks could save thousands of lives and give
offenders the ability to drive while not endangering the public.
Studies clearly show alcohol ignition interlocks are effective.
• Multiple studies on interlocks for both firsttime and repeat offenders show that Interlocks reduce
repeat drunk driving offenses by an average of 64 percent.
• Most of the failures of interlocks are legal system failures, where mandatory interlock laws are not
enforced and offenders who are sentenced to receive interlocks either do not have them installed
or receive little oversight. MADD’s proposed model interlock law will alleviate many of these
The public supports the implementation of alcohol ignition interlocks.
• Sixtyfive percent of the public supports the mandatory installation of alcohol ignition interlocks for
all convicted drunk drivers. v
First offenders are likely to become repeat offenders.
• Firsttime arrestees have driven drunk an average of 87 times before they are arrested. vi
• Firsttime arrestees are likely to have committed the crime before and will commit the crime again
unless significant intervention is taken.
Current sanctions alone are not effective in stopping repeat offenses.
• Currently, the most common sanctions for firsttime offenders in the United States are fines,
license suspensions and assessment and treatment for problems with alcohol. vii
• Studies estimate that 50 to 75 percent of drunk drivers whose licenses are suspended continue to
drive anyway. A strong alcohol ignition interlock program will prevent the suspended offender
from driving. viii,ix
How interlock technology works
• An alcohol ignition interlock is a breath test device linked to a vehicle’s i