The official road death toll for the Easter period remains unconfirmed, but police counted seven deaths on the roads from 4pm on Thursday until 6am on Tuesday.
The Ministry of Transport's toll remains at six. There are questions as to whether a crash between a motorbike and a tractor is being counted.
Road policing director Superintendent Steve Greally said officers dealt with everything from illegal street racing to fatal crashes over the long weekend.
He said it served as a reminder of "everything police do not want to see on New Zealand roads".
Greally said the quadruple-fatal crash on State Highway 8 near Lake Tekapo on Saturday was "absolutely horrific".
Two Malaysian students killed in a horror crash were studying at the University of Canterbury.
Police are still investigating the circumstances of the crash, Greally said.
He said police put out a lot of safe driving messages before the weekend.
Just short of confirming the seventh death, Greally said one of the crashes "potentially happened on private property, which wouldn't count in terms of the official statistics".
Police data showed the behaviours contributing to incidents on roads include people not wearing seatbelts, alcohol and drugs, fatigue, distraction, and speed.
"Speed affects around 60 per cent of all crashes involving death and serious injury."
He said police had been enforcing rules at "levels that are unprecedented".
Breath tests were up, as was speed enforcement on rural roads.
"We had 31 less deaths last year."
There were 1070 dedicated police officers primarily based on the open road deterring people from making "bad decisions", Greally said.
“Up and down the country, road policing staff have seen drivers overtaking on congested roads, speeding and taking unnecessary risks,” said Greally.
“Seven people have lost their lives and several others are seriously injured. That’s seven families that will never see their loved ones again, seven Easters ruined and seven avoidable deaths.”
Three people also died after crashes in Waikato, Bay of Plenty and Tasman.
For emergency services attending these incidents, it never gets easier.
“A crash where people are dead or seriously injured is a horrific scene, and I cannot but commend the staff that respond and serve with utmost professionalism,” said Greally.
The Automobile Association said impatient and frustrated drivers were leading to more people making bad decisions on our roads.
AA road safety spokesperson Dylan Thomsen told Morning Report drivers were losing their lives as a result of risky behaviour.
While it was too soon to comment on the specifics of the recent crashes "there's a lot of indicators showing that we seem to be seeing more frustration, more anger, more bad behaviour out on the roads", Thomsen said.
"That is a terrible thing, and it can lead to people making some really bad decisions and taking risks that can end up costing people their lives in the worst case."
He said AA was concerned about an increase in "really extremely reckless behaviour".
The overall road toll was down from the late 1990s - from about 530 a year to 340.
Research in 2017 looked at a number of fatal crashes and found half of them involved reckless, extreme behaviour, he said.
"We did some analysis earlier this year looking at the recent Christmas / New Year periods and in those periods we're up to more than 3/4 of the fatal crashes involving either a drunk driver, a drugged driver or somebody not wearing a seat belt."
He hoped the legislation would change this year to allow the use of drug testing devices like in Australia and Europe.
Thomsen said a larger police presence on the roads could lower the death toll.
Easter weekend deaths
Early on Sunday morning, one person died in a crash on State Highway 5, Whakarewarewa, south of Rotorua.
Another person died in a three-vehicle crash at Okaramio, northwest of Blenheim on Sunday afternoon. The person died at the scene, and two others were injured.
On Saturday morning, a motorcyclist died in hospital after crashing into a tractor in the Matamata-Piako district.
There were three tractor crashes on the same day.
And four people died after a crash between two vehicles and a motorcycle near Lake Pukaki. Three of them died at the scene on Saturday afternoon, and another who was seriously injured died in hospital two days later.
Two foreign students from the University of Canterbury were among those who died. One of the deceased was riding a motorcycle.
