Northland police are urging families to talk about road safety at home after a father and his 13-year-old son became the region's latest road fatalities.
The double fatality at the intersection of Port Marsden Highway and Marsden Bay Dr at One Tree Point about 12.10pm yesterday has taken Northland's road death toll to eight so far this year.
The region's road death toll was four at the end of January last year.
At least nine police cars and other emergency services vehicles were at the scene of yesterday's crash and the Port Marsden Highway was re-opened at 4.50pm after the Serious Crash Unit completed a scene examination.
An unmarked police car rushing to the scene collided with a SUV heading in the opposite direction in Oakleigh, about 500m north of the Mangapai intersection.
Two male police officers and the female driver of the SUV were unhurt but were taken to the Whangarei Hospital as a precautionary measure.
The police car was a write-off and an internal police investigation will be launched.
Both officers are expected to be back at work next week.
Northbound traffic was being diverted through Mangapai Rd and southbound vehicles were using Maungakaramea Rd, although neither road was suitable for heavy vehicles.
Steady rain from Thursday night continued until mid-afternoon yesterday and the two-car crash caused traffic queues as far back as Mata for northbound vehicles and up to the Lookout Hill for motorists heading south.
SH1 was re-opened about 1.45pm.
On the double fatality, Senior Sergeant Ian Row of Northland road policing said initial investigations showed a 31-year-old man was driving towards Refining NZ when he lost control on a straight stretch of road in heavy rain.
His 13-year-old son was sitting in the front passenger's seat.
"The car spun out of control and hit the tanker backwards. The tanker driver had slowed down to almost zero because he was only a short distance away from turning right for a local delivery," Mr Row said.
He said the car, which police believe was a Honda Civic, spun off to the side of the road from the impact.
Both occupants were locals and died at the scene.
The tanker driver was unhurt.
A Northland Rescue Helicopter flew to the scene but was not required.
Mr Row said the weather was atrocious and appealed to motorists to drive well below the posted speed limit.
"The posted speed limit is not the appropriate speed to drive in this weather. Police would like to see people talking to their family members about road safety because those we are trying to get the message across to aren't hearing it."
He said drivers should allow plenty of time for their journey so that no matter what happened, they did not get frustrated or angry but arrived at their destinations safely.
Mr Row said police were at pains to emphasise the need for drivers to slow down, wear their seat belts, have patience on the road and to drive to the conditions.
Eight deaths on Northland roads barely two months into the new year was very concerning, he said.
Last week, a 24-year-old man, from Kensington, was seriously injured after the car he was driving crashed on Maunu Rd, a few hundred metres from Whangarei Hospital.
He later died in hospital.