Police are calling on motorists to take extra care over the holiday period, following a weekend that saw two people killed, several seriously injured, and two others rescued from a car hanging in a tree.
On Saturday, a 19-year-old woman, who was thrown from her four-wheel-drive in the Bay of Plenty, died while a rescue helicopter was flying her to hospital.
BayTrust Rescue Helicopter pilot Art Kowalski said emergency services found the woman in a serious condition in a paddock, some distance from where her vehicle had rolled and come to rest.
He said it was unclear what had caused the crash, which happened around 6pm on a relatively straight stretch of Troutbeck Rd, near Galatea.
Paramedics had stabilised her before Mr Kowalski and his crew took off to fly her to hospital.
"We wanted to take her to Waikato Hospital because of the extent of her injuries, but we thought it was best to take her to Rotorua Hospital to save time and get her more stable," he said.
"It looked like she was going to make it to the hospital, but unfortunately she didn't."
The police serious crash unit is investigating the cause of the accident.
On Friday, a motorcyclist in his 40s died in a head-on crash with a car on Old North Rd at Waimauku in northwest Auckland about 7.10pm.
An ambulance spokesman said he was one of two motorcyclists travelling together.
Just before 5pm on Saturday, on Tapu-Coroglen Rd in the Coromandel, two young Thames people were lucky to survive when their vehicle left the road and crashed into a tree about 12m down a steep drop.
Auckland Westpac Rescue Helicopter advanced paramedic Chris Deacon said the vehicle had landed on its side in a precarious position in the tree, and had to be secured by firefighters.
"They were lucky there was a bit of bush there, as it could have been far worse."
Because it was too treacherous to go down the bank unaided, rescuers extended a ladder down the drop and smashed the vehicle's back window to get its trapped occupants out.
The 29-year-old man and 22-year-old woman were unharmed but shaken by the incident.
On the same day, two people were injured in separate crashes in Waikato, one critically when a truck and trailer unit rolled down a bank near Lake Karapiro.
The incidents come as police are bracing for the holiday period and its traditional crash risk.
"Summer is a particularly risky season on our roads," a police spokesman said.
"There's more traffic, people are driving long distances on unfamiliar roads, they might be tired or perhaps distracted by children in the car," the spokesman said.
'We're asking drivers to do all they can to reduce their risk of crashing.
"Stay under the speed limit, and slow right down if conditions are poor.
"Take regular breaks and always drive sober."
What the stats say
• Christmas Eve has the highest crash risk of the holiday period. Its peak between noon and 5pm is probably because of last-minute travel.
• The national risk for injury crashes is likely to be lower during the Christmas holiday period than year round, but crashes are likely to be more serious.
• Year round, 39 per cent of injury crashes occur on the open road. This rises to 54 per cent over the Christmas holiday period.
• 51 per cent of fatal and serious crashes occur on the open road, increasing to 66 per cent over the Christmas holiday period.