Alcohol Interlock Scheme

drink driving charge

Alcohol Interlock Scheme

The Alcohol Interlock Scheme came into force in Western Australia on 24 October 2016 and follows similar schemes in other states.  The Alcohol Interlock Scheme applies to ‘alcohol offenders’, being any person who is convicted of an ‘alcohol interlock offence’.

An offender who is subsequently granted a driver’s licence will have conditions attached to their licence their licence and will be deemed to be an ‘interlock-restricted driver’ until the conditions are removed. An interlock-restricted driver may only drive a vehicle fitted with an approved alcohol interlock device.

Alcohol interlocks are devices installed in vehicles that prevent the vehicle from being started unless a breath sample is provided for analysis. The device will prevent the vehicle from being started if it detects a reading equal to or greater than 0.02%.  The interlock device also requires randomly timed breath samples to be provided when prompted whilst driving the vehicle.

Alcohol Offences

An ‘alcohol interlock offence’  is defined in reg 3 Road Traffic (Authorisation to Drive) Regulations as:

  • Driving Under the Influence (DUI).
  • Fail to comply with requirement to provide sample of breath.
  • Dangerous driving causing death, GBH or bodily harm where the offender is under influence of alcohol, or alcohol and drugs, to such an extent as to be incapable of having proper control of the vehicle.
  • Excess 0.08 or 0.05 or 0.02 where in 5 years preceding conviction the offender has a prior conviction for excess 0.08, excess 0.05, excess 0.02, DUI, Fail to comply, Dang driving causing death, Dang driving causing GBH or Dang driving causing bodily harm.*

*Only applies to prior convictions recorded after 24 October 2016

Effect on Provisional and Extraordinary Licences

Provisional licences (including EDL or provisional) or learner’s permit  are automatically cancelled when convicted and disqualified for an alcohol interlock offence listed above.

Offenders may apply to get their provisional licence back after the disqualification period, or they may apply for an EDL during the disqualification period. If the provisional/extraordinary licence is granted: it will be subject to conditions of the Alcohol Interlock Scheme unless an exemption applies.

The holder of a learner’s permit cannot be subject to the Alcohol Interlock Scheme.

Removal of the Alcohol Interlock Conditions

drink driving lawyers perthThe interlock condition will only be removed from an alcohol offender’s licence when the offender has successfully completed the minimum participation period as well as any mandated assessment and treatment. The minimum participation period varies depending on the circumstances of the alcohol offender.

  • Alcohol offenders with a lifetime disqualification who have been granted an extraordinary licence: 3 years.
  • Alcohol offenders serving a finite disqualification who have been granted an extraordinary licence: the duration of the extraordinary licence.
  • An offender who serves their finite disqualification period and is subsequently granted a driver’s licence – a continuous 180 days immediately after being granted their licence.

The offender must also demonstrate “separation of drinking and driving behaviour” for a continuous 180-day period immediately prior to exiting the scheme.

Condition of the Alcohol Interlock Scheme

Standard conditions of the Alcohol Interlock Scheme are:

  • Alcohol interlock fitted and maintained and removed at offender’s
  • Must provide randomly timed breath tests during journey.
  • If the vehicle is shared by more than one person: all data attributed to the offender.
  • Participation terminates if the offender is convicted of another alcohol interlock offence or any offence that results in cancellation of licence.

Exemptions from the Alcohol Interlock Scheme

An offender by be exempt from the scheme if:

  • They reside more than 150km from any premises from which the services of an accredited service provider are located; or
  • They have a medical condition which prevents them from providing the minimum required volume of breath for analysis by the alcohol interlock


There are several offences created offence under the scheme. It is an offence to:

  • tamper with or circumvent operation of alcohol interlock
  • drive when still under cancellation.
  • drive contrary to “I” conditions (eg drive a vehicle not fitted with interlock).


The cost of having an alcohol interlock installed is around $1,600. There are concessions available for holders of certain benefit cards.

Paxman & Paxman are firm of criminal defence lawyers in the Perth CBD specialising in traffic law, extraordinary licences and criminal law.  If you need a traffic lawyer in Perth, give us a call on 1300 274 692 or fill out an online enquiry form today and one of our criminal barristers & solicitors will gladly provide you with legal advice on your matter. Our firm of criminal lawyers and barristers is one of the top firms in Perth providing representation on all types of criminal law matters including traffic law, assaults and drug cases.