Photo: RNZ / Richard Tindiller
The chairperson of Greater Wellington Regional Council says it feels like they are being "excluded" from information continuously sought from KiwiRail relating to its ageing rail network.
In December, the council released a report stating there was a billion-dollar shortfall in funding for the capital's rail network.
The report also identified a significant backlog of maintenance renewal programmes that KiwiRail has to deliver in the region.
But at the regional council's Transport Committee last week, councillors still had questions about the exact details of renewals work needed on the lines.
They have asked their officers to seek a detailed breakdown of critical infrastructure on the rail lines for which funding has been sought to renew them and the impacts of the infrastructure on train services.
They also asked their staff to provide a breakdown of service reductions that would be caused by the failure of these pieces of rail infrastructure and the implications on Metlink passenger numbers and ticket revenue.
A report on this would be provided in August.
Regional chairperson Daran Ponter told RNZ KiwiRail has provided sufficient information for them to ascertain future service impacts, but they do not have a list of all the hundreds of assets that need renewing.
Ponter said they do not want that information for just "idol curiosity".
"Our commuters rely on that network on a daily basis, and we have a responsibility to them for their safe and efficient movement on the network and we can't guarantee that.
"We can't make any statements about that unless we have a clear understanding from KiwiRail about what the renewals programme looks like and the specific pieces of equipment lengths of line etc. that need to be renewed."
Ponter said he could not say how many times he has asked for that information, but that it felt like they had asked it a lot.
"It does feel like that information is sitting in a black box ... it does feel at times that we are being excluded from that information."
He said their view is that information should be available to both the regional council and the public.
"We have a vested interest in what is prioritised, when it comes up for renewal work, what the status of the actual pieces of equipment are at the moment in part that we might make some of our own assessments about the risks to our commuters of having equipment that is in need of equipment."
When RNZ approached KiwiRail for comment, it said in September it provided the regional council with a detailed draft rail work bank for the next 10 years, including track, signals, civils and other work.
The company's spokesperson said in February, KiwiRail provided the council information on potential temporary speed restrictions which could result if the work was not done.
"If the information we have provided to date doesn't meet the council's needs, we are happy to provide more or different information."