An introduction to ignition interlock devices in Texas

When a Texas driver is the subject of a court order involving certain kinds of DWI charges, they may be required to obtain an interlock license to prevent their driving privileges from being canceled. An interlock license limits the holder to operating motor vehicles equipped with an ignition interlock device. What does this mean for a Texas driver facing this restriction?

Ignition interlock devices, also called IIDs, are instruments that prevent the operation of a vehicle when the driver has alcohol on their breath. An IID is installed on the driver’s side of the passenger compartment. In order to start the car, the driver is required to blow into a tube connected to the IID. If a threshold amount of alcohol is detected on the driver’s breath, the car will not start. Otherwise, the car will start as normal.

IIDs are usually programmed to require rolling retests. The driver is required to blow into the tube from time to time in order to continue operating the car after the engine has been started. This is to discourage the driver from using another individual’s breath to start the car. If the driver fails the test, an audible alarm may go off to inform the driver to turn off the car’s engine. IIDs are installed at service centers authorized by the Texas Department of Public Safety.

Having an interlock license and an IID installed is better than not having driving privileges at all. However, it can be a major inconvenience and a possible source of embarrassment. There are also other possible penalties associated with DWI offenses, including fines, license suspension and even possibly a jail sentence. Texas motorists accused of DWI should take steps quickly to inform themselves about their full range of legal options.

Source: Texas Department of Public Safety, “Ignition Interlock Devices,” accessed on March 21, 2016