Taking even the most obvious of steps to improve road safety seems to be a fraught proposition for many politicians. The previous Government did nothing about drivers' use of cellphones. This one has been similarly hesitant about lowering the legal blood-alcohol limit from 80mg to 50mg of alcohol per 100ml of blood. Finally, this week it acted, saying it had been convinced by a two-year review of the impact of reducing the limit. Its move was as welcome as it was belated, finally bringing this country into territory long occupied by similar jurisdictions.

The delay was based on the flimsiest of pretexts. In 2010, former Transport Minister Steven Joyce pointed to a lack of New Zealand-specific research on the issue. This ignored the wealth of overseas studies, which explained why all the Australian states have had the lower limit for 30 years. It also failed to explain why New Zealanders would react any differently to alcohol than drivers overseas. Most likely, the Government, like its predecessor, was concerned mainly about a public backlash to any change.

That threat no longer exists. A multitude of health experts have succeeded in changing most people's attitude towards drink-driving. Heavy drinking before taking the wheel is now widely regarded as unacceptable. That removed any final obstacle to the Government lowering the limit. As a punishment, those drivers testing positive between 50mg and 80mg will receive a $200 fine and 50 demerit points.

The outcome of the local research also left little option. The Government said this showed that 3.4 lives would be saved a year and 64 injury-causing crashes avoided. That, in itself, is an odd finding. This month Assistant Commissioner Dave Cliff told a parliamentary select committee that overseas studies indicated between 10 and 25 deaths would be prevented by a lower limit. Announcing the Cabinet's agreement on the new mark, Transport Minister Gerry Brownlee made no attempt to explain the discrepancy. But it seems highly unlikely that it is the result of New Zealanders being better drivers than their overseas counterparts, or being less susceptible to alcohol's influence, or the country having superior roads.


What the local data did was make it easier for the Government to impose penalties that it must have known would be criticised in some quarters as too lenient. But these are largely sensible and would have been so whatever the results of the research. It is reasonable to expect that a substantial number of drivers will be apprehended above the new limit, and the courts would have been even more burdened if the breach had warranted a criminal conviction. As it is, the 50 demerit points, especially, are a considerable deterrent given that the accumulation of 100 points over two years leads to a three months' licence suspension.

The new limit will not, of course, solve the problem posed by heavy, recidivist drinkers. They are likely to disregard any legal constraint or public opprobrium. Even a zero limit would prove ineffective against many of them. Only the threat of being caught, most probably at regular and highly visible checkpoints, will cause such people to think twice. Creating a fear of apprehension must be the police's main focus.

The limit will, however, eradicate the slight impairment of judgment that was part and parcel of the generous 80mg level. This is the point at which most people's brains start to go fuzzy. But it does not mean people cannot enjoy a reasonable level of social drinking. This is far from a harsh crackdown. It is a step that finally finds the Government in tune with the level of drink-driving that most people here and abroad think acceptable.