An expensive High Court fight over finishing the Transmission Gully motorway near Wellington has ended.
The Transport Agency announced on Tuesday it has reached a confidential settlement with Wellington Gateway Partnership and its subcontractors.
They have been wrangling for over a year over claims that work areas have not been properly cleared up.
The deal's impact is to restructure the existing public-private-partnership, PPP, that operates the road.
The agency told RNZ the ongoing payments to the Gateway Partnership would decrease by between $5-10m a year.
The parties had agreed to binding non-disclosure requirements which prevented disclosing specific details, the agency told RNZ.
"However, we can confirm the settlement does not bring increased costs for the taxpayer and the completion cost of Transmission Gully is expected to remain $1.25 billion."
Ventia would continue with maintenance and operations services, and complete some capital works to standards set by Waka Kotahi, funded out of allocations set aside for the gully road in the 2024-27 NLTP (national land transport programme).
"There may be scope for other contractors to be used as required," said the agency.
Quarterly payments to Wellington Gateway would continue to repay it for the capital it raised to build the road.
Its cost to taxpayers has been put at $1.2 billion, but that is widely considered a big underestimate.
The settlement was in the best interests of taxpayers, said the agency in a statement.
"This settlement gives NZTA responsibility for project completion and involves it taking a more significant role in ongoing operations and maintenance," said national manager of commercial delivery, Andrew Robertson.
"It also removes the uncertainty that ongoing, and potentially lengthy, legal proceedings would bring.
"Quite simply, it allows us to move forward with certainty."
The settlement also removes the construction joint venture from the mix over who is responsible for environmental controls and discharges at the road, which had previously caused confusion around who Greater Wellington might target over breaches around sediment runoff.
NZTA said it now would have a more direct relationship with the regional council, which monitors the discharge consents the transport agency holds at the motorway.
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