Budget 2026: Almost $1.8b to extend Waikato Expressway from Cambridge to Piarere as part of Roads of National Significance

Transport Minister Chris Bishop described SH1 between Cambridge and Piarere as a “critical freight and economic link” that connects the Golden Triangle connecting Auckland, Waikato and Tauranga with the central and lower North Island.

“This project has been talked about for years. Now we’re getting on with it,” Bishop said.

“The Waikato Expressway has already delivered huge benefits for the region, improving safety, reducing congestion, increasing reliability and supporting economic growth across the upper North Island.”

Bishop said the project is expected to reduce deaths and serious injuries by around 70%, and include a grade-separated interchange near Karāpiro Rd that will improve safety.

The project was identified as one of the Government’s now 17 Roads of National Significance in a 2024 policy statement on land transport.

However, the project had been outlined by NZ Transport Agency Waka Kotahi (NZTA) in plans and public consultation efforts since as early as 2016.

Labour transport spokesman Tangi Utikere said the project is “not a new road” and was something that his party announced when it was in Government.

“When it was costed in 2023 it was $1 billion cheaper. How it’s jumped up a billion in less than three years is alarming,” Utikere said.

“National promised 17 Roads of National Significance in 2023, and this is only one in their last Budget, who knows if it will actually be built.”

Utikere also claimed the Cambridge to Piarere project had a negative cost-benefit analysis.

Bishop said the project has a benefit-cost ratio of 2.7 to 3.1. Budget 2026 has allocated precisely $1.773 billion to it.

Bishop described Utikere as “wrong on multiple levels” regarding the project’s cost-benefit, saying the detailed business case for Cambridge to Piarere was approved by the NZTA Board under the last Labour Government in 2021.

“It’s a bit odd he is opposing the project now,” Bishop said.

“The NZTA Board approved an updated case for investment and for the project to proceed at its meeting earlier this year, and the Government has backed that direction with funding in Budget 2026.”

Bishop’s office provided the Herald with a page from the updated 2025 Benefit-Cost Ratio report which does state it sits at 3.1.

Green Party transport spokeswoman Julie Anne Genter also said this project had “been in the wings for a decade”.

“The story here is that they’re having to fund it from general Crown accounts, which is general taxation, not road user charges and fuel taxes.”

Genter said the National Land Transport Fund, primarily funded by motorists and road users, was not enough to fund the Government’s designated Roads of National Significance, and this was an example of that.

“That’s been a trend for a while now that they have been tipping Crown funding in to pay for highway projects, but I suspect the reason Cambridge to Piarere going [this Budget] is because it has a better economic assessment, or benefit to cost ratio, than others and it can get through the Crown funding.”

Genter said benefit-to-cost ratios only matter in comparison to other road projects and she suspected the Cambridge to Piarere highway project had the best cost ratio of the remaining Roads of National Significance. But this didn’t mean the project had a better benefit-to-cost ratio than rail investment.

“The Golden Triangle between Auckland, Waikato and Tauranga is home to more than half of New Zealand’s population and around 60% of the country’s gross domestic product,” Bishop said.

“This corridor is critical to New Zealand’s economic growth.”

Consents for the project were granted in September 2025, and early works approved by the NZTA board in December are now underway.

Cambridge to Piarere is the next major Road of National Significance to receive funding after the start of construction on the Ōtaki to north of Levin and Hawke’s Bay Expressway projects.

The procurement on the Warkworth to Te Hana stage of the Northland Expressway is also underway.

Bishop said a “preferred bidder” on this project was expected to be confirmed soon and detailed design and early construction works are expected to start this year.

The Government’s Roads of National Significance that have had investment cases completed include:

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