Queenstown police are warning motorists they will be on the roads in high numbers this summer.
Christmas and New Year are busy times for police, as many visitors arrive in the resort.
Drivers are a key focus for police this festive season.
Sergeant Derek Ealson, of Alexandra, said he had been in Queenstown since the beginning of December.
Police had been checking drivers for alcohol and cars for up-to-date warrants and registrations, he said.
Yesterday he and constables Leon Burdett and Ryan Fitzgerald stopped drivers for compulsory alcohol tests between 2pm and 3pm on Gorge Rd, one of Queenstown's main entranceways.
No drivers had tested positive for excess alcohol, which was "positive" for this time of year, Sgt Ealson said.
Const Burdett said the purpose of the checks was to make drivers aware of police presence on the roads in the district this summer.
He hoped this would help with driver safety.
"Hopefully, it makes the driver aware that we are about," he said.
Registrations on 12 of the vehicles checked between 2pm and 3pm yesterday were out of date, Const Burdett said.
