Dunedin police breath-test motorists under the Pine Hill overbridge in George St yesterday.
Dunedin road policing manager Senior Sergeant Phil McDouall said five police officers breath-tested about 90 motorists from 1.30pm yesterday and none tested positive for alcohol.
''That's positive.''
Most motorists knew about the new drink-driving laws which came into force yesterday, he said.
Anyone caught with more than 250mcg of alcohol per litre of breath would be given an instant $200 fine and 50 demerit points, although those over the old limit of 400mcg would still face criminal sanctions.
A motorist would lose their driver's licence for three months if they received 100 demerit points within two years, he said.
The alcohol limit for drivers under the age of 20 remained at zero.
Police would be testing motorists ''day and night'' during December, Snr Sgt McDouall said.
