State Highway 2 at Clive south of Napier is closed on Sunday morning after a person was hit by a car.
The police say the injured person's been taken to hospital and is in a serious condition.
The man was struck by a northbound car about 5am where the highway intersects with Farndon Road.
They say the driver of the car, who was unhurt, contacted emergency services and administered CPR.
Police say it's unclear why the man was on the road and the incident is being investigated by the Serious Crash Unit.
Motorists are advised to avoid Clive until the road reopens.