The Ignition Interlock Device is an in-car Breathalyzer that, when used correctly, prevents drunk drivers from driving. The Ignition Interlock system is a device installed near the steering wheel that is about the size of a hand-held calculator and includes a blowing tube. The driver must blow into the tube before starting the vehicle and if the alcohol concentration level after the driver blows into the tube is above a certain limit, the device will prevent the vehicle from starting. The device is installed near the steering wheel and connected to the engine.