How they work
IN-CAR breathalysers are widely used in Australia and the United States.
Known as ‘alcohol interlock devices’, or alcolocks, they are fitted to dashboards and require a clean breath sample before starting up.
The engine will not fire up if the sample is over the limit. Drivers can only take a re-test after a certain amount of time.
In-built chips can notify police when a driver fails a test or if the machine has been tampered with.
Repeat breath tests at random intervals stop the driver from using a sober friend to start the car. They also prevent drinking once the vehicle has started.