Acoustic experts on behalf of the appellants and Cromwell Motorsport Park Trust Ltd (CMPT) failed to agree on a noise level rating to guide the Environment Court case in Queenstown this week.
Environmental noise consultant Malcolm Hunt, on behalf of CMPT, and Dr Jeremy Trevathan, on behalf of the 16 Cromwell appellants, had attempted to devise a five-star rating to classify each class of motor racing vehicle, from quietest to loudest.
Vintage cars would be at one or two stars, Minis at three stars, the motorcycle club at four stars and V8-engined cars at five stars.
However, the court heard yesterday that Mr Hunt and Dr Jeremy Trevathan could not agree on assigning the decibel levels, which could vary between 10 to 20dBA per class.
Commissioner Charles Manning asked if it was possible to know in advance what engine sizes would be in racing cars to classify them.
CMPT co-director Allan Dippie, of Wanaka, said large saloon cars in classic car races were divided above and below 2500cc, with cylinder subclasses.
Mr Manning said it was possible a range of racing cars would emit V8-level engine noise.
Mr Dippie said 10% of the field in a large saloon car race would come up to 85 to 90dBA.
"Some classes are quiet, others have a mixture and that is the nature of motor racing."
Central Otago Council counsel Graeme Todd said he recommended contacting Motorsport New Zealand or other car clubs to obtain their engine noise records.
Judge Laurie Newhook, of Auckland, said he was prepared to reconvene the case when his panel was next in Queenstown in early September if Mr Todd's line of inquiry was helpful.
However, the judge and counsels decided it would be a better use of the court's resources if they heard from experts and residents while they were available instead of waiting for possible noise records.
Mr Hunt submitted a map with contours that predicted the worst-case cumulative effect of 21 New Zealand V8-type motorsport vehicles on the proposed track, but V8 racing was not the typical motorsport proposed for the track.
He submitted that, although measurements of the existing Cromwell speedway had not been taken, he believed the noise level received at the closest residential site was likely to be the same as those predicted for the motorsport activity.
Governing body Motorsport New Zealand has enforceable noise management policies and CMPT did not apply to host top-end high-performance motorsports on the proposed track, Mr Hunt submitted.
Mr Todd and appellant counsel Gillian Clarke asked if weather conditions would affect noise levels received in Cromwell's centre, which was depicted within the 55-60dBA contour.
Mr Hunt said a light southwesterly wind could increase the noise by up to 4dBA within the town, 4km away, which would be within normal compliances.
Miss Clarke said the McKay Family Trust property would be within the 80-85dBA band and residents would be the most severely affected of the appellants.
In response to Miss Clarke's questions, Mr Hunt said the noise "would be noticeable and may affect communication.
I'd expect you would have to raise your voice at times . . .
Amenity values would be eroded."
Miss Clarke said Mr Hunt indicated the family could close their doors and windows, cutting the noise level down to 65dBA.
But she said there would still be competing noise and asked if it was reasonable to close the house during summer, when motorsports were likely to be held.
