A Coroner has found that the death of a woman killed when a boulder hit a car she was in might have been prevented.
Heather Thompson, of New Plymouth, died from her injuries on State Highway 3 at Mahoenui in King Country on 28 March this year.
The 74-year-old was a passenger in the car driven by her sister Nancy Gernhoefer. As it was travelling down a hill and passing a rock bluff, a section of the rock above the road slipped and several large boulders cascaded onto the road.
One boulder landed on the roof of the left side of the car and the impact was sufficient to push the room and the "A" pillar of the vehicle into the front passenger seat, causing serious injuries to Mrs Thompson. Her sister escaped with minor injuries.
In a report to Coroner Peter Ryan, the New Zealand Transport Authority indicated that it was well aware of the hazard associated with the bluffs along State Highway 3 and that preventive maintenance had been undertaken on a reasonably regular basis since June 2000.
A request for funding in July 2010 to undertake a full investigation and removal of hanging boulders in the area was not approved.
However, the agency was to carry out further work for scaling and de-vegetation which was scheduled to start three days after Mrs Thompson died.
Mr Ryan said it is unknown if the death would have been prevented had the work been done earlier, but it is reasonable to infer that Mrs Thompson's chances of avoiding the incident would have been significantly improved.
He said he hoped the NZTA had learned lessons from the incident - particularly in relation to the identification and mitigation of the risks posed by rocky bluffs.
Mr Ryan hoped such learnings would be translated into ongoing action to reduce the risk of such an incident occurring again.
The Waikato-Bay of Plenty Regional Manager for NZTA, Harry Wilson, said regular maintenance work was thought to have been enough and it was for a number of years. He said there is not an endless bucket of money, so work across the highway network has to be prioritised.
Mr Wilson said New Zealand is a risky country and it has topography and geography that is hard to manage. More work has been done in the area where Mrs Thompson died including wire ropes and caging to contain any rock falls, he said and it is a lot safer now than it has ever been.