Four people died and six were critically injured in the first 24 hours of Waitangi weekend.
A senior police officer described the carnage as "absolutely appalling".
Just three people died on the roads during the long weekend last year.
Road policing national manager superintendent Steve Greally said New Zealanders needed to take responsibility for their driving.
"We have been bloody clear of what the risks are and people keep ignoring it," Greally said.
"We point the finger at visiting drivers but 94 per cent of crashes are Kiwis killing Kiwis."
"It's not worth the grief for families involved. It's not just that person who had their future robbed, it's innocent people as well."
The heartbreak on the roads started on Friday when a man died after losing control of his motorcycle at 9pm in New Plymouth. He was taken to hospital in serious condition but died of his injuries.
An hour later two men were killed and a woman was critically injured when two cars and a truck collided near Hamilton. Both men died at the scene.
Early yesterday a 23-year-old man died after being flung from a vehicle that crashed in Manawatu. Police said the man lost control of his vehicle while rounding a right-hand bend on Tangimoana Rd near Ohakea about 2.40am.
Other serious crashes resulted in critical injuries.
At 1am yesterday three people were injured in a crash north of Auckland. Four ambulances rushed to Whangaripo Valley Rd near Wellsford. The injured were taken to Auckland Hospital.
Hours later there were two crashes, four hours apart, in exactly the same spot on the winding roads of Karangahake Gorge.
After the first head-on crash, at 10am, a 69-year-old Cambridge man was airlifted to Tauranga Hospital where he was last night in the intensive care unit in a stable condition.
At 1.45pm two cars collided head-on and three people were critically injured.
Helicopters flew two people to Waikato Hospital and one to Tauranga Hospital.
The tragic weekend is hot on the heels of one of the deadliest Christmas tolls.
Traffic bosses were already disappointed as the year kicked off with 23 people killed on the roads during the holiday period.
The Christmas/New Year toll was nine more than the previous year and included 13 drivers, five passengers, four motorcyclists and a pedestrian.
A child and three teenagers were among those killed.