Finance Minister Nicola Willis says the Government is committed to coalition transport projects despite a new report showing they could cost double.

The new coalition government agreed to commit to progressing the National Party’s policy of building 13 new Roads of National Significance, as well as four major public transport upgrades.

National’s election transport document laid out how much it estimated each project to cost. However, the NZ Herald this week reported it had seen a Waka Kotahi document from late last year that showed updated cost estimates for transport projects.

According to the Herald, the transport agency estimated that 17 projects that National campaigned on could cost between $30.9 billion and $46.6 billion, which would be up to $24 billion more than what National forecasted for the same projects.

These included the Cambridge to Piarere road, East-West Link, Second Mt Victoria Tunnel and Basin Reserve Upgrade, as well as three public transport projects.

NZTA outlined in the document the costings were preliminary and based on the “latest known project scope”.

Minister Willis said the promises made at the election and in the coalition documents stood.

“We will have more to say about our future transport plans in the Government’s Policy Statement,” Willis said.

“I am not going to get ahead of the Minister of Transport’s announcement. We remain very committed to a significant number of transport projects which will be illustrated in the Government Policy Statement.”

National’s transport policy includes four main funding methods for its plans, including reprioritisations from the National Land Transport Fund and the New Zealand Upgrade Programme, partnering with more global and local investors, and new value capture tools.