These are breathalyzer machines that are required by law to start your vehicle. The IID is connected to the vehicle dashboard or a location of similar advantage. The device requires the driver to breathe into it prior to starting the vehicle. Should it detect any alcohol in the BAC, the ignition will not engage.

How an Ignition Interlock Device Works

1. The driver blows into the mouthpiece.
2. The fuel cell inside the IID analyzes the blood alcohol concentration (BAC).
3. If the BAC is above the pre-determined limit, the fuel cell triggers a relay to close and the car will start.
4. If the BAC is within the pre-determined limits, the fuel call triggers a relay to close and the car will start.

Recent Legislation Proposed to Close IID Loopholes

A recent proposed bill would tie ignition interlock requirements to a person instead of a vehicle. The proposal would create a new type of license for drivers subject to IIDs, and make violations a criminal offense rather than only a citation as they currently are.

Can a Driver "Trick" the IID?

While it is possible, the IID systems meet strict government requirements and are designed with security and safety in mind. Even if a driver is able to circumvent the breathalyzer by having a sober passenger, the penalties for doing so are severe. Keep in mind all events on an ignition interlock system are recorded and a "rolling retest" is periodically required.

Is a "Rolling Retest" Dangerous?

The driver should pull over to safely complete this requirement. The IID will allow ample time to do so.

Who Pays for the IID and How Much Does it Cost?

In almost all cases the driver convicted of the DUI/DWI pays for the installation and lease of the Ignition Interlock Device. You can expect to pay up to $100 for installation and between $50-$100 for the monthly lease. This is only a rough estimate based on an average cost across geographic locations.

Frequently Asked Questions

Q: My interlock device screen says "Service in X Days". What does this mean?

A: That means your required recalibration service is due soon. Make sure you get in for an appointment before the countdown expires. If you go past the last day on this service countdown, you will be charged a $50 late fee.

Q: I blew in my device and it is reading that I failed. I haven't been drinking, what does this mean?

A: "Test Failed" means alcohol was detected during your test. This does not mean you were drinking, but common culprits are mouthwash, perfume, aftershave, hand sanitizer, air fresheners and fermented teas, for example. Avoid using any of these products for 15 minutes before driving. Too many failed tests from alcohol detection will cause a violation. Do not test again after failure until you are sure the alcohol source has been eliminated.

Q: Will the interlock turn my engine off if I fail a test while driving?

A: The interlock will never shut your engine off. If you fail a test or do not take it properly, the horn will start honking and the hazard lights will start flashing. This will continue until you pass the test or shut the car off.