The ignition interlock system was designed to check a person’s breath for alcohol before allowing a motor vehicle to start. Every time he or she wants to use the car—regardless of the time of day—the person has to blow into the device. Only when he or she is cleared will the vehicle start.

So, do you have to use this system if you get a DUI in Pennsylvania? As you’ll see, the answer can be both yes and no, depending on the circumstances.

If you have just been given your first DUI, you are most likely not going to be ordered to use the ignition interlock device. It is not mandatory at that time.

If you have been given a second DUI, though, you qualify as a repeat offender and you do have to use the device. Your suspension has to be served first, as you are not allowed to drive at all without a license. After the suspension ends, you then have to have the device on your car for the next year.

This is also true if you get any subsequent DUI charges. This applies for charges starting on the first of October in 2003, when the new law went into effect.

For most recent DUI offenses—those after 6/30/2007—it is worth noting that a second DUI only counts as a repeat offense if you’ve had another one within the last 10 years. After that, you can get another DUI and it will not make the ignition interlock mandatory.

If you have been injured by a drunk driver, you may have a right to compensation for your injuries.

Source: Pennsylvania Department of Transportation, “IgnItIon Interlock “The Law” Frequently Asked Questions,” accessed July 31, 2015