The road toll now stands at six after a person died in a crash between a car and a truck in the Selwyn District near Christchurch this afternoon.
Dust from a rural shingle road appears to have contributed to a young driver being killed in a collision with a second truck police fear he never saw.
A man, who police are yet to formally identify but believe is a local in his 20s, was driving on Mitchells Rd at Bankside, near Rakaia when the horror crash happened shortly after midday today.
The shingle road in the extremely dry farming area was fanning up large clouds of dust from vehicles today.
Senior sergeant Peter Stills said it appears the driver, and sole occupant of the car, has not seen the second of two oncoming trucks, which had been in the area transporting stock feed.
The car hit the second truck and the force of the collision has smashed it off the road and into a sheep farm fence.
The driver was dead at the scene.
The truck driver is believed to have been uninjured.
Mr Stills did not believe speed had played a part.
But he said the fatal accident highlighted the dangers of driving on unsealed roads, and drivers should slow down or stop if dust is hindering their vision.
Police are still at the scene piecing together exactly what led up to the accident.
It's believed the driver will be formally identified later today after next of kin are informed.
Last night a police spokeswoman said there had been a total of 550 reported crashes in New Zealand between 4pm on December 24 and 7pm last night.
She said the 550 crashes included all crashes reported throughout New Zealand and ranged from minor nose to tails where no one was injured or much damage was caused, to the serious and fatal crashes.