The numer of people caught drink-driving could almost double once the new lower alcohol limit comes into force next year, official estimates show.
Transport officials calculate nearly 20,000 people will be caught by the lower drink-driving limit - earning the Government $5 million extra in fines. This is despite crash data showing those who will be caught by the law change are historically involved in less than 2 per cent of all accidents.
Transport Minister Gerry Brownlee announced earlier this month the Government would lower the drink-driving limit from 80mg per 100ml of blood to 50mg, and the breath limit from 400 micrograms per litre of breath to 250mcg/l.
Those caught between the lower limit and the existing one would not face criminal sanctions but instead be fined $200 and have 50 demerit points put on their licence.
Brownlee said at the time the change had the potential to save 3.4 lives a year and avoid 64 injury accidents.
But the report, and its accompanying data that the Government based its decision on, shows those in the 50-80mg/l range are by far the smallest group in terms of at-fault accidents.
While 53 crashes were attributed to this group, nine times as many - 440 - were by drivers with more than 80mg/l in their blood. Of those, the vast majority had alcohol levels of nearly three times the legal limit, the data shows.
A separate, larger study of 1042 at-fault crashes between 2008 and 2012 found just 19 (1.8 per cent) involved a driver in the 50-80mg/l range. Half of all drivers had less than 30mg/l in their blood, while 178 had alcohol levels of between double and triple the legal limit.
A report to Cabinet by the Ministry of Transport said only "modest" gains should be expected from lowering the drink-driving limit, and most of those gains will come from young men in urban areas.
Bigger gains could be made by targeting recidivist drunk drivers, who caused most of the accidents, through increased penalties and car seizures, the report said.
"While there is a case for lowering the BAC (blood alcohol concentration), the crash data in this paper shows that drivers who drive with a BAC level well in excess of the current adult BAC limit are responsible for a higher proportion of alcohol-related road deaths and serious injuries," the report said.
"Repeat drink-driving offenders also pose a problem on New Zealand roads. International research estimates a recidivist offender is 36 times more likely to be involved in an alcohol-related fatal crash."
Officials estimate 19,100 new offenders will be caught in the first year of the lower limit despite the Government saying the law will not hit those who drive after a couple of after-work drinks.
Reports to Cabinet also show the Government decided to remove the right to a blood test for drink-drivers who blow between 250mcg and 400mcg because of concerns drivers were using it to circumvent the law. Officials warned, however, that removing the right may be open to legal challenge.
Drivers refusing a breath test will still get a blood test - but if they fall between 50 and 80mg/l range their fine will be more than doubled to $500.
Auckland traffic lawyer Steve Cullen said targeting those in the 50-80 range was a "vote catcher" but was not likely to make a difference to the road toll.
"I would be very cynical about seeing any appreciable movement in the numbers of serious or fatal crashes. It's just going to catch Joe Public trying to get home."
Cullen said if the Government was serious it would target recidivist drink drivers and speedsters using speed limiters in cars and alcohol interlocks.
The MOT's report recommends the use of alcohol interlocks - devices that prevent drink-drivers from starting their vehicle - for repeat offenders, as well as a review of penalties for drink-driving.
The Government has said it would consider both recommendations next year.
- Sunday Star Times
Should the speed limit be raised to 110kmh on some roads?Related story: 110kmh limit moves closer