The dilly-dallying over proposals to lower the legal driving limit from 80mg of alcohol per 100ml of blood to 50mg has gone on far too long.
The change should be enacted as soon as practicable.
The case was clearly laid out in a Ministry of Transport document as long ago as March 2010.
But the Government put off action, citing the need for more research.
That has been carried out, and Cabinet is due to make a decision on the matter later this year.
Embarrassingly for the Government, Labour MP Iain Lees-Galloway has had his member's Bill to reduce the limit to 50mg drawn from the ballot.
Senior police officers have also come out strongly in support of the lower limit as has, this week, even the AA which has been timid on this issue.
Meanwhile, according to Ministry of Transport figures, two-thirds of New Zealanders want the change.
Its poll, with 1667 respondents and carried out last year and released last month, found 40% favoured the drop in the legal level, while 20% supported the limit being lowered to zero.
The narrow method to evaluate the value of lowering the limit would be to examine crashes caused by drivers in the 50mg to 80mg range.
The 2010 report said they were responsible for at least seven deaths, 45 serious injuries and 102 minor injuries.
The social cost of this is tallied to $56.5 million.
But Australian and Danish experience suggests lowering to 50mg actually also lowers the number driving with very high levels, 100mg and over.
Why?
A limit of 50mg requires people to make responsible decisions when they still can.
Get to 80mg, and they are becoming so drunk they cannot think straight.
They are less able to recognise driving drunk is a very bad idea.
Lowering the under-20 level to zero is credited with lowering young driving crashes substantially, in part through improving attitudes.
Lowering the adult limit would also strengthen the anti drink-driving message.
All in all, lowering the limit to 50mg has been estimated to save between 15 and 33 lives and prevent 320 to 686 injuries each year.
Alcohol begins to affect driving at even the lowest of levels.
At 20mg, peripheral vision is reducing.
By 30mg the ability to judge the vehicle's position on the road and focus on and track the movement of other vehicles is affected, as is alertness, the ability to judge time and distance, the ability to steer and brake and reaction times.
Clearly, the impairments are growing by the time 50mg is reached. By 80mg, the driver is obviously drunk.
It might well be these estimates from an Environmental Science and Research study are conservative.
The recent instance where a senior police officer drank 13 beers as part of a study and was still under the limit shows just how high the present limit can be in practice.
The officer himself said, although still within the limit, he was in no fit state to drive.
Internationally, the vast majority of developed countries have gone to a limit of 50mg or lower, the United Kingdom and the United States being exceptions.
Sweden, Norway and Poland are among those with a 20mg limit and some countries are at zero.
All Australia moved to 50mg for adult drivers, with positive results.
The average male would be over the lower limit after four to six 330ml beers consumed over two hours.
That is instead of six to nine for 80ml.
The figures for an average female would be three to five, instead of four to six.
Thus, responsible social drinking would still be possible.
It is true repeat offenders are part of the problem, involved - despite their small numbers - in a quarter of drunk-driving casualty crashes.
That, however, leaves the other three-quarters. Similarly, drivers under 20 remain a significant portion of the problem - but only a part of it.
The Government is well out of step with its own advice and the public. It needs to get into gear and treat the matter urgently.
Lost time means lost lives.
