Ignition Interlock Systems

Smart Start Ignition Interlock DeviceWhat Is an Ignition Interlock System?
An ignition interlock is a sophisticated system that tests for alcohol on a driver's breath. It is a device that requires a vehicle operator to blow into a small handheld alcohol sensor unit that is attached to a vehicle's dashboard. The car cannot be started if a BAC is above a preset level (usually .02 to .04 BAC). Alcohol safety interlocks that meet the standards issued by NHTSA (see the See NHTSA Conforming Products List and Technical Information Regarding Alcohol and Drug Law Enforcement Technology) not only require a test to start the engine, but also require a test every few minutes while driving. Called the "rolling or running retest," it prevents a friend from starting the car and then allowing an impaired driver from taking over the wheel (NHTSA guidelines call for only one subsequent test and the Alberta, Canada standard calls for multiple running retests). With modern safeguards, alcohol safety interlocks are extremely difficult to circumvent when properly installed and monitored every 30 to 60 days.

When used by the courts or state motor vehicle departments in conjunction with a monitoring, reporting, and support program, the ignition interlock system provides DWI offenders with an alternative to full license suspension. Its use has spread rapidly across the country and as of late 1999, 37 states have enacted legislation providing for its integration into the DWI adjudication and sentencing process.


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Does This Technology Work?

Yes. Not only can ignition interlocks reduce recidivism while they are installed, but the data that is recorded by them can also be used to predict future behaviors of DUI offenders - their recording devices can show patterns of abuse that can lead to DWI/DUIs (offers insight into offender behaviors).

For example, the most frequent time of day for recording elevated BAC levels is 7AM. This figure indicates a night of heavy drinking. Additionally, their use can stop individuals from driving drunk during high-risk time periods - from 12AM-3AM.

Who Uses This Technology?

All DUI offenders have the potential to benefit from the use of the ignition interlock - it's installation allows offenders to maintain their responsibilities while also reminding them that their behavior has a direct impact on their right to drive. Court systems and motor vehicle administrations agree that it is a valuable tool because it deters individuals from driving while intoxicated while the device is installed. Additionally, when its use is required as a provision of probation/parole, the threat of doing jail time better ensures that DUI offenders will correctly use the device each and every time he/she gets behind the wheel.

DUI offenders benefit from the device as well. Their lives, and those of family members who share the use of the car, can remain relatively undisrupted-individuals can go to work, pick up children, run errands, etc.

Legislators and government officials like this program because in most cases, the installation and maintenance fees, which run about $60 per month, are paid for by the DUI offenders. Thus, the program can be self-sustaining and does not necessarily affect taxpayers.

The Federal government, in the Transportation Equity Act for the 21st Century (TEA-21), supports the use of the ignition interlock. Section 164 of the TEA-21 Restoration Act indicates that state laws regarding second and subsequent convictions for driving while intoxicated or driving under the influence of alcohol (DWI/DUI) must, among other provisions, "Require that all motor vehicles of repeat intoxicated drivers be impounded or immobilized for some period of time during the license suspension period, or require the installation of an ignition interlock system on all motor vehicles of such drivers for some period of time after the end of the suspension." TEA-21 requires that states have such repeat intoxicated driver laws in place by October 1, 2000. States without these laws will have a portion of their Federal-aid highway construction funds redirected into other state safety activities, beginning in Fiscal Year 2001.

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Are There Major Stumbling Blocks to Technology Integration?

Yes. While "breath alcohol ignition interlock devices, when embedded in a comprehensive monitoring program, lead to 40-95 percent reductions in the rate of repeat DWI offenses of convicted DWI offenders," the technology has not been widely integrated into the field. According to Dr. Paul Marques in his position paper, Alcohol Ignition Interlock Devices, published for the International Council on Alcohol, Drugs and Traffic Safety, a number of stumbling blocks are present, including:

  • The protective effect of the interlock lasts only as long as it remains installed on the vehicle. The likelihood of repeat DUI offenses rises back to previous levels once it is removed from the car.
  • Only a small percentage of eligible offenders ever enter an interlock program. As a result, interlocks have not yet made a large contribution to highway safety (at the population level). This may change when many more states, provinces, and nations adopt interlock programs.
  • The most dangerous repeat DWI offenders only rarely become eligible for an interlock and then only for a brief period of time because of the manner in which interlocks are assigned to prior DWI offenders (interlock use is not necessarily widespread and sentencing procedures are inconsistent). Research is called for that would evaluate the impact of lowering the threshold for entry into an interlock program and raising the threshold for exit from an interlock program. If such an approach was successful, it could put more of the most dangerous repeat offenders under the control of a program and retain them until evidence was available documenting their readiness to drive without an external monitor.
  • Not all drivers of interlock-equipped vehicles will be equally motivated to comply with interlock restriction and monitoring requirements. Authorities need to be attentive to these differences. The evidence base for interlock effectiveness in reducing DWI is strong but most studies to date have evaluated the effects of interlocks on offenders who are motivated to be compliant with the law.
  • The majority of convicted DWI offenders whose licenses are suspended choose to drive anyway, and since an alcohol interlock program can improve monitoring and prevent impaired driving, it is worth evaluating the public safety impact of an early or immediate post-conviction interlock requirement relative to simply suspending the driver's license.
  • It is impractical to require that an interlock system be installed on every vehicle owned by someone who will be required to use an interlock device. As an alternative the driver license of such drivers should be clearly marked showing that the driving privilege is exclusively contingent upon use of interlock vehicles.
  • In the future, the interlock may become an integral part of advanced driver recognition and control systems. In the meantime it is very easy for a driver to circumvent the interlock by using a different vehicle without the interlock. Accordingly, at the current stage of technological development, an offender's motivation for compliance with the interlock restriction is expected to be a prime factor in determining effectiveness. Brief motivational interventions delivered while drivers are captive in the interlock program may help improve motivation for making lasting behavior changes.

Click HERE to link to Smart Start Interlock Systems with locations throughout the U.S.

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