can anyone drive a car that has an interlock

[DiJuliana]

Yes, but with significant restrictions. Only individuals specifically authorized by a court or state DMV can legally drive a vehicle equipped with an interlock device. This authorization is almost always limited to the person convicted of the DUI/DWI offense who is required to have the device installed as a condition of having their driving privileges restored. If you are not the offender and you blow into the device, you will likely trigger a violation for the primary user. The system is designed to prevent unauthorized operation, making it illegal and practically difficult for anyone else to drive the car.

The core function of an interlock, or Ignition Interlock Device (IID), is to prevent a vehicle from starting if it detects a Blood Alcohol Concentration (BAC) above a pre-set limit, usually 0.02%. This isn't just a one-time check at startup. The device requires "rolling retests" at random intervals while driving to ensure the driver remains sober. This means even if an authorized driver starts the car, a passenger cannot take over the wheel midway because a retest would be failed by the unauthorized user, resulting in a violation.

The legal and practical consequences for allowing an unauthorized person to drive an interlock-equipped car are severe. For the primary user, it can be considered a violation of their probation or driving restrictions, potentially leading to extended IID requirements, license revocation, fines, or even jail time. The unauthorized driver could also face charges for driving without a valid license or for circumventing a court order.

Before anyone else drives the car, even in an emergency, you must understand your state's specific laws. Some states have a formal process for adding a "non-violator" user to the IID agreement, which often involves notifying the monitoring authority and the device provider. Always consult with your legal counsel or IID provider to understand the exact protocols and avoid serious legal trouble.

[OwenAnn]

Nope, not really. My buddy had one in his truck after his DUI. That thing is basically keyed to him. I tried to move it out of the way once when he was at work, and it wouldn't even start because it wanted a breath sample right away. It's a huge hassle for him, but it's also a major violation if someone else uses it. The company that installed it monitors everything. It's just not worth the risk to try and get around it.

[MacDerek]

As an attorney who handles traffic cases, I must emphasize that this is a serious legal matter. The court order mandating the interlock is specific to the offender. Allowing an unauthorized individual to operate the vehicle constitutes a violation of that court order. This can result in the offender facing contempt of court, extension of their probation, and immediate suspension of their driving privileges. The unauthorized driver may also be charged with driving without a valid license.

[MichaelMarie]

Think of it like a personalized security system for the car. The device is calibrated and programmed for the specific person who is required to use it. The monitoring authority receives data from every test—starts, passes, fails, and retests. If a test is missed or failed during a drive, it's flagged. If the breathing pattern or volume is consistently different, it could indicate someone else is attempting to use the device. It’s not a simple piece of equipment; it’s a sophisticated monitoring tool designed for accountability.