Ignition Interlock Device (IID)
Definition - What does Ignition Interlock Device (IID) mean?
An ignition interlock device (IID) is a gadget that is installed on the dashboard of a vehicle to prevent the driver from driving under the influence of alcohol. It works much like a breathalyzer. To start the vehicle, the driver first needs to exhale into the device. If the blood alcohol concentration (BAC) level analyzed by the IID is greater than the legal limit, the IID prevents the vehicle from starting.
Justipedia explains Ignition Interlock Device (IID)
The ignition interlock device was invented to prevent drivers, especially those who routinely drive under the influence of alcohol, from driving while intoxicated. The device has similarities to a breathalyzer; however, while a breathalyzer just analyzes the blood alcohol concentration (BAC) level of a driver, an IID prevents a driver with a high BAC level from driving his or her vehicle. Vehicles that have an IID installed on their dashboard require the driver to first exhale in the mouthpiece of the device. The fuel cells present inside the IID device analyze the breath of the driver to estimate the BAC level. All states have laws permitting the use of IID devices as an alternative to sentencing for individuals convicted of drunk driving.