The Christmas random driver breath testing campaign has started and Senior Sergeant Steve Larking warned every driver stopped by police will be breath tested.
''We will be mass testing as many drivers as possible at peak times at both road checkpoints and also carrying out random stops,'' Snr Sgt Larking said.
During December 2011 and January 2012, 45,909 drivers were stopped in the Southern region, with 291 charged with drink or drug driving offences.
Extra police will also be on patrol until after the New Year in an effort to try to stop anti-social behaviour.
Senior Sergeant Kelvin Lloyd of Dunedin said police were busy during the weekend dealing with mostly alcohol related offences.
''It's not unusual for this time of the year with Christmas parties and people out celebrating,'' he said. There were a high number of assaults in the inner city area on Saturday night and Sunday morning almost all involving alcohol, Snr Sgt Lloyd said.
People just needed to be aware of their personal security and the environment they are in and should take sensible precautions such as not walking alone, Snr Sgt Lloyd said.
''People out in the inner city on the weekend should expect to see plenty of fluro vests around,'' he said.