Killer combination: Northland teen killed in car airborne at speeds more than 150km/h

A coroner says speeding drivers are a major public health and safety issue. Photo / File

A young driver and speeds of more than a 150km/h played a role in the tragic and avoidable death of a Northland teenager, a coroner ruled.

Emily Rose Dahl, 17, of Hikurangi, died on November 2, 2018, when the vehicle she was a backseat passenger in became airborne as it crested a hill on Kokopu Rd at a speed more than 150km/ around 500m from the turnoff to Mangakahia Rd in Poroti, Whangārei.

The BMW, carrying three other passengers who were all wearing seatbelts, swerved off the left-hand side of the rural road where it crashed through roads signs and vegetation before hitting a culvert.

The car then tumbled and rolled before coming to rest in a nearby paddock.

Dahl sustained a severe traumatic head injury and died at the scene. The young driver, who also suffered a traumatic brain injury, was flown to Auckland City Hospital.

Two other passengers were taken to Whangārei Hospital with serious and moderate injuries.

The Police Serious Crash Unit found the driver, in breach of his restricted license at the time, had exceeded the speed limit before the crash and lost control.

The driver was charged in relation to Dahl's death but was unfit to plead or stand trial because of his brain injury.

Investigators also discovered the car had recently failed a warrant of fitness because of faults in the vehicle's steering, suspension and tyres.

Coroner Tania Tetitaha said these faults may have affected the handling and directional stability of the vehicle, contributing to the crash.

The driver's age and speed "largely contributed" to Dahl's death and highlighted further how speed was a "major public safety and health issue" nationwide, Tetitaha said.

Waka Kotahi NZ Transport Agency's Communities at Risk register showed Northland had the highest personal risk of death or serious injury related to drivers aged 16 to 24, from 14 other regions.

The register identified Kaipara as the district with the most risk linked to young drivers followed by the Far North tied with Buller in the West Coast.

The coroner said motorists were consistently driving too fast on rural roads not built for it.

"If we reduced average speed on New Zealand's roads by just 4km/h from 102 to 98km/h – it is estimated that 52 fatalities, 133 serious injuries, and 257 minor injuries would be saved."

She said a significant part of the country's rural road network was built under an 80km/h open road speed limit regime.

Tetitaha had asked the Whangārei District Council if speed restrictions under 100km/h and physical speed deterrents – such as markers and signs – were required on Kokopu Rd and was told about the council's work reviewing speed management on local roads – including Kokopu Rd - to assess appropriate speed limits, signs and speed control devices.