KEY POINTS:
Mixing worn snow tyres with summer tyres and texting while driving led to the deaths of two teenage sisters earlier this year, the Levin Coroner has found.
Lucy Elizabeth Simon, 18, and Isabelle Jan Simon, 15, were killed on January 23 after their car slid on the Manakau
bridge near Levin on State Highway 1, slamming into an oncoming truck.
Both girls died instantly.
Coroner Phillip Comber said in his findings the prime causes of the accident were that the car had aged worn snow tyres on the rear unsuitable for New Zealand conditions and that there was an in-cab distraction from text messaging. These led Lucy Simon to lose control of the vehicle on the wet road.
Cellphone records showed Ms Simon had sent a text message from her phone three minutes before emergency services were called.
Police found the flip-top phone open on the floor, near the driver's seat.
Ms Simon had been advised to change the rear snow tyres after she bought the car, but had not done so even though she had had a previous accident, losing control of the car because of them.
The tyres had enough tread to pass a warrant, but in Japan where they were made it is illegal to use them after they are 50 per cent worn - a level the tyres on Ms Simon's car were well below.
Mr Comber said it was the second inquest he had held in 12 months involving a vehicle fitted with snow tyres in the rear and summer tyres in the front.
Land Transport New Zealand (LTNZ) tested the tyres after the accident and warned drivers about the risks of their use.
Their tests found a mixture of snow tyres on the rear and summer tyres on the front could in wet conditions be seriously dangerous, with the potential for a driver to lose control if the vehicle was subjected to a sharp steering input.
Mr Comber said LTNZ's warning was encouraging, but further steps needed to be taken.
He made several recommendations:
- Used imports should not be allowed to be sold with snow tyres fitted to them.
- Snow tyres should be discarded when they are 50 per cent worn.
- Vehicles should be refused a warrant when they have a dangerous mix of tyres.
- Police should specifically examine and report on any types or combination of tyres which may have contributed to a collision.
Mr Comber said it was also the second inquest he had held in 12 months in which texting on a cell phone appeared to have played a part in the crash.
"While not going so far as making a formal recommendation about the use of hand-held cell phones by the driver of a motor vehicle, it is, I believe, a topic which needs serious discussion and investigation."
- NZPA