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Drink Driving and Interlock Devices: When Am I Required to Install One?

Drink Driving and Interlock Devices: When Am I Required to Instal One?

Despite the introduction of random breath testing and multiple public safety campaigns, drink driving remains a scourge on Australian roads with around one in four accidents on the road counting alcohol or drugs as a factor.

One survey also discovered that around 50 per cent of Australians support the use of a device that would prevent them starting their car if they were over the legal blood alcohol limit.

An alcohol interlock device records the amount of alcohol on a person’s breath and prevents the driver from starting the vehicle if alcohol is detected. An interlock can also request a breath test from a driver during a trip, activating a vehicle’s horn and lights if the test is not taken. Modern versions of the device use sophisticated technology to prevent a driver trying to bypass its functions.

In Queensland, the Alcohol Ignition Interlock Program applying to repeat and high range drink drivers started in 2010 and is governed by the Transport Operations (Road Use Management) Act 1995. In this article we’ll look in more detail at the circumstances in which a driver is subject to use of an interlock device.

Offences which result in a person becoming an interlock driver

A person will be required to enter the interlock program, at the end of their period of disqualification, if they commit and are convicted of any of the following offences:

  • drive, or attempt to put in motion, or be in charge of a vehicle under the influence of alcohol;
  • drive, or attempt to put in motion, or be in charge of a vehicle with a blood/breath alcohol concentration of: 0.15 or more (after September 10, 2021, all drivers convicted of driving over the middle alcohol limit – a BAC equal to or greater than 0.10 – will also be required to participate in the alcohol ignition interlock program;
  • failing to provide a blood/breath specimen for analysis;
  • dangerous driving while affected by alcohol;
  • two or more drink driving offences within a five-year period.

Before changes made to the program in September 2021, those offenders subject to an interlock requirement were required to either have the device installed for 12 months from the time their licence was reinstated, or refrain from driving for a further two years after their disqualification ended under the Time-based Alcohol Ignition Interlock Program.

Once a licence has been reissued to an offender, it will be marked with an ‘I’ condition meaning the holder can only drive or ride a vehicle fitted with an alcohol interlock device and must drive with zero BAC.

As a result of the law change in September 2021, a performance-based interlock program was introduced for those who were convicted of a high-risk drink driving offence before September 9, 2021 and whose licence disqualification ended on or after that date,
or drivers who were convicted of a high-risk drink driving offence on or after September 9, 2021. Those who choose not to participate in this program are unable to drive for five years from the end of their disqualification period (or the date they were issued a work licence).

In the performance-based program, interlock use and data is sent to the Department of Transport and Main Roads (DTMR) for assessment. Data from the device is required to show that all breath tests have been provided and returned ‘no alcohol’ readings, and that all scheduled interlock services have been attended – otherwise the driver’s time in the program will be extended.

The program comprises a 12-month period beginning the day after your driving disqualification ends, or the day a court grants you a restricted licence (work licence). There are two parts to the program to complete – the ‘learning period’ in the first eight months of the program and the ‘performance period’ for the last four months Participants must:

  • hold a current licence with an interlock condition (the licence must not be expired, cancelled or suspended);
  • only drive a nominated vehicle with an interlock installed;
  • have a ‘no alcohol’ limit when driving;
  • attend all interlock service appointments;
  • not attempt to tamper with or bypass the interlock.

During the performance period use of the interlock is monitored and if alcohol is detected, or there is a permanent lockout due to a missed scheduled interlock service, the four-month performance period will restart and time in the interlock program will be extended.

The device

The interlock device can be fitted to most vehicles with an ignition, including motorcycles, and records actions including blowing into the device and the engine being turned on and off. The data is downloaded by the supplier of the device at scheduled services and provided to the DTMR. All alcohol interlock devices also include a camera to ensure the program participant is the person driving the vehicle. The supplier of the device charges the participant for installation, monthly leasing and servicing and removal, with financial assistance for those who qualify.

A driver required to install an interlock faces a penalty of $3859.80 if they drive a vehicle that does not have the device installed. A driver convicted of this same offence within five years will attract a maximum penalty of a fine of 60 penalty units ($8271), and driver’s licence disqualification will be extended up to six months.


Limited exemptions exist to the requirement for a high-risk drink driver to have an interlock installed, including where the driver:

  • lives in a remote location;
  • lives on an island;
  • has a medical condition which prevents them from providing enough breath for a sample to operate the device, or;
  • where their family will experience severe financial hardship if an exemption is not granted.

Unsure? Call our experienced legal team

If you are – or believe you will be subject to – an alcohol interlock device and need more detail on your rights and obligations under the program, contact our experienced legal professionals today. We regularly advise clients on the implications of having to install an interlock device as part of a drink driving penalty and can provide timely and relevant advice to help you through this difficult period.