A 47-year-old man's 18th drink-driving conviction has sparked calls for a radical law change that would allow judges to sentence the worst offenders to preventive detention - effectively locking them up for life.

Darren Corey Newport, 47, has now racked up 18 convictions for driving over the limit - two of them in back-to-back drink-driving episodes this year alone.

Newport joins four other men who each have 18 drink-driving convictions, sharing the dubious title of New Zealand's worst drink drivers. Newport is the youngest of the bunch.

Statistics from the Ministry of Justice show that while the number of people convicted of drink driving has fallen in the past three years from 27,518 to 23,377, the number of repeat offenders has remained virtually unchanged.

Gary Fryer, whose son Lance was killed by another of New Zealand's worst drink drivers in 2003, believes current penalties are insufficient to stop repeat offenders.

And Malcolm Barnett, whose daughter Krystal, 18, was killed by a driver high on P in 2005, says the law should allow recidivist drink and drugged drivers to be given preventive detention.

He is a spokesman for Cross Roads, a group of families who have had loved ones killed by recidivist drink or drugged drivers, which lobbies for targeted measures to stop them.

The purpose of preventive detention is to "protect the community from those who pose a significant and ongoing risk to the safety of its members".

At the moment only sex and violent offenders qualify if the court is "satisfied" that they are likely to commit a sexual or violent offence again. Barnett said drink drivers were just as much of a menace. "The law of averages says one day they are going to kill someone."

Barnett said the current legislation was not working. "These people do not listen and do not change their ways. You need basically to lock them up and throw away the key."

Drink-driving laws were last toughened just over a year ago. Andy Knackstedt from New Zealand Transport Agency said new sanctions became available to the courts in September 2012 allowing repeat drink-drivers and grossly intoxicated first-time offenders to

be given mandatory driving disqualifications and zero alcohol sanctions.

When allowed back into a car they can be forced to use an alcohol interlock - a device similar to a breathalyser connected to a vehicle's starting system. Before the vehicle can be started, the driver must provide a breath sample. Cars can also be confiscated and jail times have been increased under the get-tough regime while at the same time a softer option is being trialled through a new "booze and drug" court that focuses less on punishment and more on treating a person's alcohol dependency.

As of January 31 this year, 321 interlocks have been ordered by the courts and 158 drivers have served their driving disqualifications and had interlocks installed.

A further 562 zero alcohol sanctions have been imposed, requiring drivers to maintain a zero alcohol limit for three years. "The government is employing a broad strategy to deal with all parts of the drink-driving problem including recidivist and highly impaired drink-drivers," Knackstedt said.

The government is now cracking down on those at the lower end of the scale, lowering the drink-driving limit from 80mg of alcohol per 100ml of blood to 50mg. Knackstedt believes this will have a flow-on effect on the more hardcore drink-drivers. The Ministry of Transport has been asked to review penalties for offences over 80mg, along with the effectiveness of all the new sanctions. That review will take place this year and involve health, police and justice bureaucrats.

None of this deterred Newport. On January 11, he was stopped at a checkpoint in Te Rapa, Hamilton, and blew 979 micrograms of alcohol per litre of breath - nearly two-and-a-half times the legal limit. When questioned he said: "I had been at a mate's place and now I'm heading home."

He was issued a summons to appear in court but on January 30, he was pulled over while driving a different car through Hamilton. Police said he ran inside a house to hide and when they found him he had already cracked open a new bottle of beer and was drinking it.

He pleaded guilty to the two charges in Hamilton District Court on Monday - they add to more than 100 total convictions including his drink-driving rap sheet, going back three decades when he was an unlicensed teenage driver.

His drink driving has been punished with several jail stints, most recently ending in 2011.

Gary Fryer said all the sanctions, including long stints in jail, do not work. "Doesn't matter what you do. You will never teach them," he said, adding repeat drink drivers appear to have no concern for anyone but themselves and any kind of action to stop them seems ineffective.

"Is there a different way of penalising them that actually gets at them? You can crush their cars, but this day and age they can just walk out down the road and get a new one. It is too easy for them to get away without getting a penalty at all; there are millions [of fines] outstanding."

The man who killed Fryer's son in Wairarapa in 2003 after a day drinking beer and bourbon had already killed three others in 1989 in a head-on smash in the Rimutakas after a night of pub and nightclub crawling in Wellington.

A police spokesman said as much as possible was being done to "get these people off the roads". However, the issue was complex and not something police alone could solve. A joint approach across government and within communities was necessary.

Family and friends also played a role in stopping people getting behind the wheel.

"While police have increased their level of activity to reduce alcohol-related harm, we are working in an environment where alcohol has become more accessible and ‘normalised' in society," he said.

Newport will be sentenced next month.