Wet conditions, a slippery road with poor bend geometry and an inappropriate speed for the conditions all contributed to a crash which killed a Taupō 17-year-old, a coroner has found.
Coroner Gordon Matenga last week released his report on the 2016 crash where Liam Grant Cradock, a loved son and brother and promising young footballer, died while travelling home at the end of the school year.
Liam was driving to Taupō on the evening of November 25, 2016 after his final exams at his boarding school in Auckland when the crash occurred on State Highway 1, just north of Tirau.
The only witness was a driver heading the other way who said he came around a corner to find a car sliding and spinning towards him on his side of the road.
He had "nowhere to go" and collided with it. Liam suffered critical injuries and died while awaiting airlift to hospital.
Another fatal crash occurred less than two months later at the same spot in similar circumstances, with a southbound car crossing the centre line and colliding with a vehicle heading north.
Liam's family have criticised the police crash investigation and also said the police did not act with empathy or understanding, which compounded their grief.
They also said the police unfairly jumped to the conclusion that Liam caused the crash because he was young and inexperienced and had been driving too fast. They felt Liam had been discriminated against because he was 17.
Liam's parents Grant Cradock and Karen Millar were also upset and frustrated that that stretch of road had been scheduled to be remedied in 2016 but instead an alternative cheaper option by NZTA was to erect an electronic speed-activated warning sign to try to slow the traffic around the 75km/h corner.
It later lowered the advisory speed limit of the corner as well.
Liam's family also pointed to concern with the state of the road from Tirau to Taupō which has been the subject of recent public debate and news reports following a series of fatal crashes.
Liam's family commissioned independent crash investigator Dr Timothy Stevenson to do his own report, which included information from Opus, NZTA and pavement condition data, while the police report did not.
Dr Stevenson indicated from his analysis that Liam was travelling at between 79 and 84km/h at the time of the crash and his report concluded that the design of the road and low and uneven road surface grip were likely central causative factors.
He also identified other factors, including lack of electronic stability control in Liam's car, poor wet weather tyre grip, road surface contamination, engine braking, speed and driving experience.
Dr Stevenson said police should have conducted skid testing on the night of the crash.
Police admitted at the inquest hearing in March that their investigation did not follow best practice because it did not include road friction testing and other information.
The police report's conclusions were that the wet road and driver inexperience were contributing factors, along with possible distraction or inattention and driving too fast for the conditions.
Experienced police crash investigator Senior Constable David Tidmarsh reviewed the police crash investigation file and Dr Stevenson's report at the Coroner's request.
He concluded that while there were areas of the police scene investigative work that were not completed in accordance with police best practice standards, the report's conclusions were sound.
However, he said taking into account the road conditions and design, Liam should have still been able to negotiate the curve at a speed close to 90km/h. There was no firm evidence to show that Liam's speed was above what would be considered safe for the environment.
The coroner's finding said while both crash analysis reports highlighted the poor state of the road, the bad weather and speed, they differed on how the contributing factors should be emphasised.
The police report put more weight on speed, while Dr Stevenson put more towards issues with the environment and Liam's vehicle lacking electronic stability control.
The coroner concluded there were no faults with Liam's car that contributed to or caused the crash.
There was no evidence that distraction or inattention contributed. However the wet road, failing road surface with patches of bitumen/asphalt bleed, the bend geometry of the curve and inappropriate speed for the conditions were all found to have contributed to the crash.
Since Liam's crash, and the other fatal crash in January 2017, NZTA has made improvements to the bend and lowered the speed advisory for the curve from 75 to 65km/h.