What is an ignition interlock and how does it relate to DWI offenses?

Interlock devices have been used in the United States for more than 20 years. All States have some legislation requiring or permitting the use of breath alcohol ignition devices, or “interlocks.”  An interlock device is installed in a motor vehicle to prevent a driver from operating the vehicle if the driver has been drinking. Before the driver can start the vehicle, the driver must blow into the device.  If the device detects a certain level of alcohol, it will not allow the car to start.

Interlocks are comprised of a breath alcohol sensor, a tamper-proof system, a data-recording system that logs results, and a retest system that is supposed to require the driver to provide another breath sample at varying time intervals.

The primary purpose of the interlock devices is to prevent someone that has been drinking from starting or driving the car.  If the driver gives an alcohol-free sample of their breath and it is verified by the system, the device will provide power to the vehicle. The software in the system logs the test results and records other data, such as the number of times the car is turned off and on, mileage, as well as a picture of who is driving

How long does it take to have an interlock installed?

Generally, interlocks can be installed in about an hour.

Who has to have an interlock installed?

In Texas, the courts mandate an interlock device for certain people.  They may even be required during the pre-trial phase of a DWI charge. Almost all courts in Texas require an interlock device installed with repeat offenders of DWI charges. Also, if the court suspends a person’s license as a result of a DWI conviction, the law mandates an interlock in order to drive. During that suspension period, a person would need to apply for an interlock license which would allow the person to continue to drive any vehicle equipped with an interlock device.

Who pays to have an interlock device installed on my car?

If you are being required by the court to have an interlock on your car, you are responsible for the cost to install and maintain the interlock.

Someone else is going to drive my car.  How do they start the car?

Anyone using a vehicle with an interlock must blow into the device for the vehicle to start.  Most interlocks are now also equipped with a camera to verify who is driving.

Is the use of interlocks common?

Yes.  In 2011, there were approximately 85,000 DWI arrests in Texas.  In 2012, there were over 37,000 interlocks in use. Every year in Texas it seems the laws or the judges themselves are choosing to mandate interlocks in DWI and other alcohol-related offenses. More and more courts are requiring interlocks, even before a person has been convicted of the offense.

It is extremely important to hire a knowledgeable DWI attorney if you are facing charges. Tarrant County Criminal Defense Attorney Stephen Handy represents individuals being accused of DWI and other criminal offenses.  Stephen is a member of the NATIONAL COLLEGE OF DUI DEFENSE and strives to be a leader in DWI defense.

If you have been arrested for DWI, please call criminal defense lawyer Stephen Handy at 817.284.2262 as soon as possible.  Time is of the essence when it comes to defending your rights against a DWI conviction and a driver’s license suspension.  You only have 15 days in most circumstances to contest whether your license will be suspended.

As your attorney in an alcohol-related offense, I certainly understand that having an interlock installed on your vehicle can be a very humiliating and often very unnecessary requirement. I will advocate as hard as I can to avoid that requirement when the law allows for the Judge of the Court to exercise their discretion