The New Zealand Police has reported a preliminary total of 21 deaths from road crashes during the holiday period.

The police force also said that the death toll, along with an undisclosed number of serious injuries, was “absolutely tragic”.

“It is completely unacceptable for 21 people to lose their lives in avoidable crashes over this year's holiday period, but unfortunately we're still seeing the same behaviours contributing to fatal crashes right throughout New Zealand and it’s really disappointing,” said Bruce O'Brien, assistant commissioner, road policing.

Some of the risky behaviours on the road that were linked to the accidents were fatigue, impairment with alcohol or drugs, not wearing seatbelts, exceeding the speed limit, distraction by cell phones or devices, and drifting onto the wrong side of the road or rolling.

O’Brien said that the NZ Police have deployed personnel across the country over the summer to do impairment testing.

In the Wellington area alone, 29 drivers were processed for excess breath alcohol at checkpoints and during routine traffic stops between 4pm on Dec. 31 and 11am on Jan. 1.

“It comes back to responsibility for drivers themselves, their passengers and other road users because we've all got that responsibility when we're in the vehicle,” O’Brien said. “Please, stay calm – treat the people in the cars around you like they're your own family.”