What is the purpose of an Ignition Interlock Device?

The primary function of an Ignition Interlock Device is to prevent a driver from operating a vehicle if their blood alcohol concentration (BAC) is over a predetermined limit. This device requires the driver to provide a breath sample before starting the vehicle. If the breath sample indicates that the driver's BAC exceeds the set limit, the vehicle will not start. This mechanism is designed to deter individuals who may be tempted to drive under the influence of alcohol, thereby enhancing road safety and reducing the incidence of DUI-related accidents.

The other options presented do not reflect the role of an Ignition Interlock Device. Tracking a driver's speed is unrelated to the device's design and intent, as this is typically handled by other systems or devices. Fuel efficiency improvement is also outside the scope of what an Ignition Interlock Device does, since its focus is solely on preventing intoxicated driving. Lastly, monitoring road conditions is not a function of this device, which is instead solely concerned with ensuring that a driver is sober before they can operate a vehicle.