The official holiday period has ended with a preliminary total of 21 deaths and a number seriously injured from crashes on our roads.

'Our thoughts go out to those people who are dealing with the very worst of circumstances," says Police Assistant Commissioner, Road Policing, Bruce O'Brien.

"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."

Those behaviours are fatigue, impairment with alcohol or drugs, not wearing seatbelts, exceeding the speed limit, being distracted by cellphones or devices and sometimes drifting onto the wrong side of the road or rolling.

'Police have had many staff throughout New Zealand over the summer, doing impairment testing, he says.

The scene of a vehicle crash in Athenree Gorge. Photo: Supplied.

"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.

"Police can't be on every single road at every single moment so we really need people to take that responsibility when they get in their car because the absolutely devastating consequences that this has for families and friends that are left behind is just terrible."

'People are often travelling on unfamiliar roads at this time of the year and a moment's inattention could have catastrophic consequences, Assistant Commissioner O'Brien said.

Police's plea to people getting on the roads for the remainder of the holiday period is simple - we want you, and your family and friends to get home alive.

"Please, stay calm - treat the people in the cars around you like they're your own family.