Editorial: Car interlocks welcome gain for road safety

The devices are going to be available to courts dealing with serious drink-drive offenders. Photo / Thinkstock

The day may come when all motor vehicles are equipped with a breathalyser that can jam the ignition if the driver has been drinking beyond a set limit. Considering the risk of meeting a drunken driver head-on, the day cannot come too soon. In the meantime, the devices are going to be available to the courts dealing with serious offenders. It is a start.

From September 10, repeat offenders, or those convicted for the first time with twice the permitted alcohol level, could opt for an "interlock" disqualification. This will mean that after a mandatory three-month disqualification they will be restricted to driving a vehicle fitted with the interlock device for at least the next 12 months.

The device will have to be installed by a court-approved provider at the offender's expense and will be checked monthly, again at the offender's expense. The cost, perhaps $1800 over the year, might seem a light fine in the circumstances, but it should be infinitely better than a fine from the point of view of public safety and the possibility of reforming the repeat offender.

For them the permitted level of breath alcohol will be set at zero and the interlock will keep a record of breath tests to be downloaded by the installer at the monthly servicing. If the device misses a servicing it will incapacitate the vehicle until the servicing is done. Any attempt to tamper with the interlock, or to start the engine by bypassing it, will be recorded in the device as a violation, as will any readings of excess alcohol.

To be released from the interlock after 12 months the record will need to show no violations for the last six months, or three months if the driver has also completed a drug and alcohol assessment. It seems a thoroughly rigorous regime that ought to be salutary for those caught driving repeatedly over the limit.

The only criticism of interlock devices is coming from driver education providers, who say that once drivers are released from the device after 12 months they are likely to relapse. But the same may be said of mandatory counselling and the like. At present a fifth of those appearing before the courts on drink-driving charges are recidivists, according to the Automobile Association, which supports the interlock.

The AA wanted the device to be mandatory for those convicted of drink-driving more than twice and it would prefer that it be installed immediately rather than after a three-month disqualification. Its international research suggests many disqualified drivers will drink and drive regardless within that period.

Obviously the interlock will not be foolproof. Determined offenders will sometimes have access to another car, or have a companion willing to breathe into their device. But the companion will need to go along for the ride because the device can ask for a random test while the engine is running. All things considered, the companion might decide it is wiser to drive.

It is not often that technology provides justice with such a constructive response to crime. The interlock looks likely to be not only punitive but instructive. Offenders will work out how long, after drinking, the device will let them safely drive and that is a lesson they might not forget.

By the AA's count about a third of the 35,000 drunk drivers caught every year have a blood-alcohol reading more than twice the legal limit. That suggests there could be 10,000 cars with interlocks in operation by this time next year. When we see them in operation they might come to seem a sensible precaution for all drivers - as sensible as seatbelts. They could save lives.