Emergency personnel have credited the use of appropriate restraints for saving lives, including those of a baby and a toddler, in a three-car pile up in the Manawatu this afternoon.
Up to 15 people were believed to be involved in the crash.
One man, the driver of the vehicle carrying the two young children, was the only person injured in the crash that happened between Sanson and Bulls near the Ohakea Air Base, around 2:30pm.
Police, ambulance and fire were called to the crash on State Highway 1. Earlier reports indicated four cars were involved in the crash but it appears the last car on the scene actually belonged to a witness.
Feilding fire brigade chief fire officer Bradley Shanks said it took awhile for them to free the injured man, who was later airlifted to hospital with serious injuries.
However, he said, fortunately the children were well-restrained.
"They came out unscathed; they were really well-secured."
Shanks said things could have been a lot different if they hadn't been so well-secured given the seriousness of the crash.
While it was wasn't the most serious crash he'd attended, Shanks said there was a lot of damage, which gave the potential for more serious injuries.
"It was spread across quite a large area, probably a hundred metres."
Shanks urged motorists to "take your time on the road, abide by the speed limit and just be careful out there. There's a lot of traffic".
Police said traffic near the accident was still backed up this afternoon and would take some time to clear.
Diversions remained in place at Fagan and Speedy Roads as scene investigations were done and the scene was cleared.
A police spokeswoman also reiterated how good it was to see the appropriate restraints were used.
"In this case all occupants in the vehicles were appropriately restrained and we believe this saved lives of those involved."
Meanwhile, motorists were also being warned of traffic delays in Tauranga after a car hit a pedestrian shortly before 2pm.
Police attended the crash, near the Bayfair Shopping Centre roundabout, that has left one person with injuries that are believed to be life-threatening.
Police asked motorists to be patient as emergency services cleared one of the eastbound lanes.
About the same time as the Tauranga accident, a person crashed in the Waikato after having a heart attack.
Emergency services, including police, ambulance and fire were called to the crash on Arapuni Rd, near Te Awamutu, shortly after 2pm.
A fire service spokeswoman confirmed one person suffered a cardiac arrest. She was unable to give any further details.
Police understood a medical event contributed to the single vehicle crash in the Waipa District.
A spokeswoman said the last update indicated ambulance crew were still working on a patient. The person's status remained unclear.
The Serious Crash Unit was on its way to the accident.
UPDATE: Stop/Go traffic management now in place. Expect delays or use alternate route if possible ^TP— NZTA Akld & Nthlnd (@NZTAAkl) January 2, 2017
Meanwhile, a third crash north of Auckland this afternoon, shortly before 2pm, saw one vehicle roll down a bank.
A police spokeswoman confirmed the crash happened on SH1 some 700m past Mahurangi Rd West, Pohuehue.
She understood only one vehicle was involved and no one appeared to have any serious injuries.