As of this year up to 5000 drivers will be forced to have alcohol interlocks installed in their vehicles, at their own expense.

Road Safety Minister Liza Harvey said this would help reduce the number of drink driving incidents that we see on the road.

The alcohol interlocks are like breathalysers that prevent high risk offenders from driving a car while drunk.

As of the second half of the year, devices will become compulsory for all motorists convicted of driving with a blood alcohol level in excess of 0.15 and those with more than one excess 0.08 offence.  Source: http://www.abc.net.au/news/2016-03-20/interlocks-will-cut-dui-rates-liza-harvey-wa-minister/7261206