Drunk drivers were blitzed with twice as many breath tests last year as the year before - but alcohol treatment agencies say they can't cope with the numbers of drinkers seeking treatment.

A new police national alcohol assessment shows that the number of breath tests doubled from 1.15 million in 2006-07 to 2.33 million in the year to last June. Tickets issued for drunk-driving also increased last year, from 33,189 to a record 35,928.

But Alcohol Drug Association chief executive Cate Kearney said treatment agencies were struggling to keep up with the number of people seeking help for drinking problems.

"The system is clogged. We really can't see people as quickly as we'd like to see them," she said.

Acting road policing manager Inspector Peter Mckay said drink-driving tickets were up 23 per cent over the past three years, reflecting a deliberate increase in enforcement.

"This includes enhanced and increased breath-testing operations, particularly in the Auckland area, the delivery of new high-tech booze buses last year and increased staffing numbers," he said.

Police Association president Greg O'Connor said no one could argue with the resources being poured into breath-testing because the results showed up in last year's road toll being the lowest for 49 years.

"The roads are safer and the death toll's going down."

Ms Kearney said the dramatic increase in breath-testing, combined with a hard-hitting Alcohol Advisory Council advertising campaign, were welcome signs that drink-driving was being taken seriously at last.

"Everyone is looking at the huge costs of alcohol to the community when you start to drill down into every part - health, education, crime, the road toll. You see alcohol everywhere. It's the elephant in the room."

Addiction services treated 22,700 people in the year to last May. But Ms Kearney said this was only 0.5 per cent of the population, compared with 17.7 per cent of adults who reported what the Ministry of Health called "hazardous" drinking patterns in the last national health survey in 2007.

The National Committee for Addiction Treatment recommended last year that addiction services should be boosted over the next three years to serve 1 per cent of the population.

Wellington alcohol and drug counsellor Roger Brooking said police figures showed that only 7 per cent of convicted drink-drivers were ordered to have assessments in 2006. Last year 69 per cent of convicted drink-drivers were fined, 23 per cent had to do community work, 4 per cent were sent to jail and 4 per cent got lighter sentences such as just losing their licences.

Mr Brooking said New Zealand's penalties were "very soft" compared with other countries. In Australia, drink-drivers with a third conviction and double the blood alcohol limit were disqualified for life.