Can Someone Else Drive My Car with an Ignition Interlock Device Installed?

Blowing into an ignition interlock device (IID) can be intimidating – just ask anyone who is required to prove his or her sobriety before, and while driving. Chances are, because of the intimidation factor, you’ll never have someone ask to borrow your vehicle if you have an ignition interlock device installed. But, if your spouse or neighbor asks to drive your car, there is no reason to deny the favor. In fact, there are only two reasons another person should not drive your car if you have an ignition interlock: they’re drunk, or they can’t operate the IID correctly.

An IID requirement is attached to any vehicle a DUI offender operates, which can impact other family members or anyone who needs to drive the car. The breath tests from the ignition interlock device test the driver’s blood alcohol content (BAC), and as long as the person driving is sober, he or she can drive the car. If that person has been drinking then the test failure is recorded, and any failed IID test is attributed to the person with the ignition interlock device requirement until proven otherwise. So, by letting someone else drive your car with an ignition interlock, you are responsible for his or her sobriety, as well as your own.

Since an IID relies on specific steps in testing the BAC of a driver, anyone operating the vehicle should be taught how to use the device properly. Make sure any other driver understands the ignition interlock test procedure before driving and what to expect during the rolling re-tests that occur periodically.

Despite any intimidation, there is no reason a sober person cannot drive a car with an ignition interlock. The devices are effective because they allow a person the freedom to keep driving, while ensuring his or her sobriety on the road, no matter who the driver may be.