There was little organisers could have done to prevent two motorcyclists' deaths during races in 2012 and 2014, a former motorsport head has told a coronial inquest.
Malcolm Foster and Kevin Waugh, who were both 59, died competing in the Cliffhanger Hill Climb on a closed road near Carterton - Mr Foster in 2012 and Mr Waugh in 2014.
Family members of the men, along with several motorcycling aficionados, attended today's inquest in the Wellington Coroner's Court, before Coroner Peter Ryan.
Constable Glen Marshall, who investigated both crashes, said Mr Foster died during his fourth run up the hill.
He said there were no speed restrictions in place during the event and Mr Foster had increased his speed on each run and was likely to be doing almost 180km/h when he crashed.
Constable Marshall also investigated Mr Waugh's death, which occurred on his fifth attempt at the hill climb.
He said Mr Waugh would have been going between 180km/h and 220km/h.
The corner where the crashes occurred had been improved significantly since the deaths, but it would be impossible to totally rule out all dangers of the course, he said.
Former Motorcycling New Zealand president Bernard Tuckerman said even experienced riders could make mistakes, pointing to the death of Wellington motorcycling legend Robert Holden on the Isle of Mann as an example.
He said the race had not been under Motorcycling New Zealand but, even if it had, the deaths could still have occurred.
Mr Tuckerman said both men had been slightly out of line, and there was little that organisers could realistically have done to prevent either accident.
Ian James, a steward at the 2014 race, said cones were put out on the corner where Mr Waugh died and riders had been briefed of the danger.
"I would have told them it was a tricky corner because they come up to that corner very fast - accelerating all the way and suddenly there's a corner they've actually got to slow up a little bit for.
"I've sort of found it was sometimes quite difficult sometimes to tell, 'hey, you've got to slow up'."
The coroner has reserved his decision.