State Highway One north of Hunterville has reopened after a fatal crash closed it on Tuesday.
A female passenger died when the vehicle she was in collided with another vehicle.
Both drivers are in a serious condition, with one flown to Palmerston North Hospital and the other taken to Waikato Hospital.
This latest death brings the unofficial road toll to 18.
The holiday period is from 4pm on 23 December to 6am on 4 January.