On Tuesday, a young driver died after he crashed into a truck carrying stock feed at Bankside, near Rakaia, in Canterbury.
The man, thought to be in his 20s and local, might have been blinded by dust on the rural road, police say.
A teenager is in a serious but stable condition after a three-car crash near Paihia on Tuesday.
The North Shore woman, aged in her late teens, was airlifted to Whangarei Hospital in a critical condition after the car in which she was travelling was hit by a ute and spun into a station wagon as it tried to make a turn into the Bay of Islands Holiday Camp about 10am.
She was cut from her car by firefighters.
She suffered a head injury and severe facial cuts.
Two other passengers were taken to hospital - one in a serious condition with a suspected broken pelvis and the other with moderate injuries. Both are now stable.
On Monday, 65-year-old Tauranga man Raymond Allen Valere Morreel died while motorbiking with family members on State Highway 28 in Te Poi.
The group were rounding a left-hand bend when Mr Morreel's motorcycle left the road and hit a farm fence, police said.
On Boxing Day Ngatokorua Tangimataiti, 80, and her 57-year-old daughter Are Tito died in a head-on crash south of Tokoroa.
They were travelling on State Highway 1 after leaving a whanau gathering.
Two people died in crashes on Christmas Day.
A French tourist died in a three-car crash in Northland and John Edward Davie, 57, of Ranui, died in a bicycle accident.
National road policing manager Superintendent Steve Greally said there had been too many crashes since the holiday period began.
"People's driving behaviour has not been safe."
Some families had already suffered tragedy this Christmas, he said.
