However, Public Interest Journalism Fund court reporter Guy Williams finds a loophole in the interlock regime is allowing many convicted offenders to ignore their sentences and continue driving drunk.
A breathalyser wired into a vehicle’s ignition system, alcohol interlock devices prevent drivers with alcohol in their system from using their vehicles.
Every year, on average, each interlock device prevents about 100 attempts by such drivers to start their vehicle.
"That just shows why we need to use these things," Automobile Association (AA) road safety spokesman Dylan Thomsen said.
"The people involved in this can have serious drinking problems, and when they’re sober, they genuinely think they wouldn’t drink and drive.
"The problem is when they start drinking, and they drink enough, they lose the ability to have any sort of rational control," Mr Thomsen said.
Four years ago, the devices became mandatory when sentencing repeat drink-drivers, or those caught with very high breath or blood alcohol readings.
Since then, the number of interlock sentences handed down by judges has risen dramatically.
In Otago and Southland last year, 365 drink-drivers received interlock sentences, compared with 16 in 2017.
To drive legally again, they must wait out a minimum 28-day disqualification, apply to Waka Kotahi NZ Transport Agency for an interlock licence then get a local installer to fit the device in their vehicle.
It must stay in for at least 12 months, then they have to drive on a zero-alcohol licence for three years before they can apply for a full licence again.
However, a loophole in the system means about one in three offenders who receive interlock sentences are not getting the devices installed.
Mr Thomsen said no agency had responsibility for following up with offenders to ensure they complied with their sentences.
"We need to be chasing those people up.
"It’s really disappointing and frustrating, because it’s a small number of people across the country, we have all their details from being in court, and so it doesn’t seem like it should be a really challenging task."
In Otago and Southland, the numbers are worse.
In the year to June last year, only 58% of those sentenced to an interlock took the intermediate step of applying for an interlock licence, compared with 74% across the country.
That means there could be as many as 200 recidivist or high-level drink-drivers from that 12-month period alone disobeying their court orders.
Mr Thomsen said although still disqualified, they were "almost certainly" out on the roads.
The AA had been raising the issue with the Government for the past three years, and wanted to see it addressed in its next Road to Zero action plan, for 2023-25.
Compounding the issue was that many recidivist or high-level drink-drivers were not getting interlock sentences in the first place, he said.
An AA study in 2019 found about half of all eligible offenders were exempted from interlock sentences because they met one of the following criteria: not owning a vehicle, not having a driver’s licence, having a qualifying medical condition such as asthma, or living more than 70km from an interlock service centre.
Ministry of Transport mobility and safety manager Matthew Skinner said it was working with Waka Kotahi on ways of strengthening the regime.
That included how it might follow up with offenders sentenced to an interlock, to check they got them installed.
The review would feed into the next Road to Zero action plan, Mr Skinner said.
Smart Start Interlock is one of two companies approved to provide alcohol interlocks in New Zealand, and it has a network of installers throughout the country.
Company founder and owner Gavin Foster said it had been pointing out the loophole to the Government since before the programme started in 2013.
When judges sentenced offenders to prison, they did not say "you can rock up to prison whenever you want", Mr Foster said.
It did not make sense to leave it up to offenders to get interlocks installed, which was why so many "go bush and drive around illegally".
"An interlock is not a birthday present ... it’s not something that people actually want."
However, that attitude usually changed after they had been using them for a while.
"After six months, eight months, they say ‘you know what, this has been the best thing for me ... it’s reset how I think about drink-driving’."
"People think they can just wait 12 months and then get their normal licence back ... 12 months down the track they find they haven’t even started on the alcohol interlock programme, and it comes as a shock to them," Mr Boakes said.
"We would happily follow up people, but there would be a privacy problem with us being given a list of names.
"So it would have to happen from NZTA’s end."
Mr Foster said the cost of interlocks was often cited as a barrier, but his company had not raised its prices since it began providing the service nearly a decade ago.
It charged $175 for a standard installation, and a monthly rental of $183.
Waka Kotahi provided a subsidy for the most hard-up offenders, which covered the cost of installation and removal and lowered the monthly rental to $133.
Mr Boakes said there was a good case for increasing the subsidy.
The direct and indirect costs of a single road fatality was "in the millions", and alcohol was a factor in more than 30% of those crashes.
By spending more on helping genuinely hard-up offenders get interlocks in their vehicles, the Government could save taxpayers money, he said.
Figures given to the Otago Daily Times by Waka Kotahi show it spent $1.25 millon on the subsidy last year, up from about $57,000 in 2018.
