A person has been airlifted to hospital in a critical condition after a car was hit by a train at a private rail crossing in Te Horo, just south of Otaki.
Emergency services were called to the scene on State Highway 1 at 1.45pm on Tuesday.
The Transport Agency says part of the highway closed by the collision has reopened.
Police say there was only one person in the car.
KiwiRail says the train was a freight service travelling north from Wellington to Auckland.
The train usually travels at 50km - 60km an hour through the area.