The police's response was a trial of a lower tolerance of speeding - down from 10km/h over legal limits to 4km/h - over one holiday weekend. This recognised that the roads are at their most dangerous in such periods because of the traffic density.
When the trial proved successful, the lower tolerance was extended permanently to all holiday weekends. This ploy was backed up by a strong police visibility on the road over these periods. As well, there has been a big increase in the number of speeding tickets issued thanks to the introduction of digital speed cameras.
The much-enhanced threat of a fine for exceeding the limits has caused most drivers to take their feet off accelerator pedals. The upshot has been fewer accidents and a substantial saving of lives. It also appears that the lower average speeds and calmer approach during holiday weekends has carried over into everyday motoring, even though the police lack the resources to provide a visible and totally effective deterrent for much of the time.
It is notable, and another feather in the police's cap, that the improvement in the road toll has been achieved without heavy-handed activity or getting drivers' backs up. Even with the jump in the number of speeding tickets, there have been far fewer of the customary allegations of revenue-gathering or unfair police tactics.
This owes much to the largely discreet manner in which the police have achieved their goal. Their resources have been deployed more effectively to areas of risk.
In practice, that means police cars and cameras have been stationed in accident blackspots, where speed is an issue, rather than on safe stretches of highway.
It should also mean the issuing of warnings, not tickets, to motorists who are exceeding the speed limit by a small amount but creating no danger to other road-users.
The task for the police now is to ensure drivers do not revert to old habits. They must also make further inroads into the toll, given that New Zealand's accident rate is still higher than that of comparable countries.
The police's success in reducing permanently the instances of drink-driving must be extended to speeding. Clever education campaigns will help, but there is no easy way to achieve this.
A strong police visibility on the road and speed cameras will continue to be necessary until motorists display an unambiguous readiness to stay within the speed limits.
It is, however, much to the police's advantage that their latest tactics have proved so successful.
Road-users never appreciate those who place them at risk. They will be happy to co-operate with a strategy that has proved successful in more efficiently catching those who breach speed limits while also promoting a calmer atmosphere.