Officers carried out 222,860 screening tests in Otago and Southland in the 12 months to June 30, up 55% on the year before.
The numbers have been bolstered by the re-establishment of three specialist driving impairment teams disbanded in 2016.
The first was restored in the Otago Coastal policing area, based in Dunedin, in 2020.
An Otago Lakes Central team in Queenstown followed in 2021, and a Southland team, based in Invercargill, began operating in April.
Otago Lakes Central area road policing manager Senior Sergeant Steve Watt said the Southern district was probably leading the country with its driving impairment operations, with a "massive" increase in the number of people being charged with drink-driving offences.
The teams could set up checkpoints or fatigue stops at which hundreds of drivers could be tested in a couple of hours, Sen Sgt Watt said.
Those drivers told their family, friends and workmates.
"It’s that ‘anywhere, anytime’ deterrence.
"The more people talk about it, the more that ripple effect goes through the community."
Under the terms of a funding agreement with the Ministry of Transport and Waka Kotahi NZ Transport Agency, the police are expected to carry out three million roadside tests a year.
They achieved only half that number in 2020-21 and 2021-22, continuing a trend since 2014.
However, a decision by police top brass in 2021 to refocus on breath-testing, and the end of Covid-19 alert level restrictions, resulted in police carrying out 2.66m tests in the 12 months to June 30.
Sen Sgt Watt said the Otago Lakes Central driving impairment team continued to operate on a trial basis since its formation in December 2021.
It had a target of 5000 breath-screening tests a month in an area stretching from Glenorchy and Makarora down to Roxburgh and Ranfurly.