The chance of being breath tested is falling in New Zealand, with 350,000 fewer roadside breath tests in 2018 than the previous year, and the 20 per cent drop is causing alarm.
AA Motoring Affairs General Manager Mike Noon said the "general deterrent effect, or the awareness that it's not OK to drink and drive or you will be caught, has gone down because there's just less tests".
"On the face of it, the numbers of fatalities of drink drivers is increasing, so this would make us very concerned," he said.
ACT leader David Seymour said it was a matter of public safety.
"If people are out there driving drunk, then they should be stopped and they should be caught."
Figures released by the Official Information Act showed 1.4 million people were tested in 2018, compared to 1.75m in 2017.
It was reported that in 2016 1.9 million people were tested and in 2013, 3 million people were tested.
Police say they are targeting higher-risk areas, so fewer tests in conjunction with smarter methods.
National's police spokesperson Chris Bishop said "the police can say they're being smarter about it, they're being more targeted, but the reality is there's been a big reduction in the number of people being breath tested".
Associate Transport Minister Julie Anne Genter would not be interviewed by 1 NEWS but provided a statement.
“The drop in the number of roadside breath tests, and the impact this may have on road safety outcomes, is of real concern for me," the statement said. "I have asked officials to report to me in April on the proposed road policing activities for this period, including the rationale for the approach to drink-driving enforcement.”
Mr Seymour reminded Ms Genter and Police Minister Stuart Nash "they now have a serious duty to keep us safe".
Mr Bishop said that "talk is cheap in Opposition, delivery in Government is a lot harder".