Texas DWI and Understanding Ignition Interlock Devices


An ignition interlock device is a device that you blow into which detects your blood alcohol content (BAC). It is essentially a breath test that is installed in your vehicle, and your car will not start until after you have blown into the device and had your blood-alcohol level tested. In Texas, a person with a DWI charge who has a prior DWI conviction on his record can be required to have an ignition interlock device installed in vehicles that he owns or leases. A person with a commercial driver’s license and a DWI conviction can also be required to use an ignition interlock device.¬†

Our Texas DWI attorneys know it’s important to understand these devices if you are facing a potential DWI conviction and may need to have a device installed in your vehicle.

Understanding Ignition Interlock Devices

Ignition interlock devices are intended to make sure that you cannot drive when you are intoxicated. When you are ordered to have an ignition interlock device installed in your vehicle as a result of a DWI conviction, you will be responsible for paying for the cost of the installation of the device. You must have a device installed on any car that you own or lease, even if the vehicle is shared with someone else in your family or co-owned by someone else in your household.

Once the ignition interlock device has been installed in your vehicle, you must blow into the device every single time you start the car. This means that if there are others in your family who share your vehicle, they too will have to blow into the ignition interlock device before driving. This can be a minor inconvenience for family members, but it is an unfortunate necessity based on the way ignition interlock devices work.

The device will take a reading of your blood-alcohol content, just as a breath test does when police administer the test to a suspected drunk driver. If your blood-alcohol content has exceeded the legal limit based on the test results, then you will be unable to drive your vehicle as the car will not start. The hope, therefore, is that the device will prevent drivers from driving drunk.

The ignition interlock device can also require rolling breath checks as well as a test after you start the car. This means that as you are driving or operating your vehicle, you can be required to blow into the breath test to have your blood-alcohol content rechecked. The test allows plenty of time for you to pull over so you can be tested safely, and you won’t have to worry about taking the test as you drive in traffic. If you fail to blow into the breath test or if your test reveals that your BAC is too high and you fail the rolling re-test, then the horn will go off and the lights will start flashing. You also cannot turn off the car. You must take the rolling retest.

When you blow into the ignition interlock and fail the test, either initially or in a rolling retest, the failure is recorded and can be a violation of your probation. The best way to ensure you are not paying for one of these devices to monitor your every move behind the wheel is to fight the drunk-driving charge in the first place.

You need an experienced, aggressive Texas DWI lawyer.  Call 1-800-395-5951 today for your free consultation. More than 20 years experience.

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