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The City Rail Link project is a NZ$5.5 billion twin-tunnel commuter rail system running 3.45 kilometres beneath central Auckland, connecting Waitematā Station in the CBD to Maungawhau (Mount Eden) via two new underground stations. Since tunnelling concluded in late 2022, the project has advanced through the high-risk systems integration and testing phase, with a full test train completing the first end-to-end run through the completed tunnels in February 2025. Construction and testing are now expected to wrap up by June 2026, with Auckland Transport and KiwiRail targeting a passenger launch in the second half of the year, with August cited as the earliest realistic opening.

Construction Review Online reached out to Auckland Council for the latest on the project. Auckland Transport, responding on the council’s behalf, provided updated figures and a detailed account of the testing now underway — the basis for the information set out below.

New Zealand Rediscovers Its Rail Appetite

The CRL’s imminent opening marks a turning point for rail infrastructure confidence across New Zealand. The project’s total cost settled at NZ$5.493 billion after a NZ$1.1 billion blowout in 2023, and Auckland Council faces an estimated NZ$235 million annually in operating and depreciation costs once services begin, prompting a 7.9% rates increase in the 2026/27 budget. Despite the cost pressures, the network effect is real: the CRL is expected to triple heavy rail capacity and carry up to 19,000 passengers per hour through the city centre during peak periods. The opening has also renewed optimism for other rail investments in the country. Most recently, KiwiRail has moved swiftly to shortlist Acciona, a Downer/HEB joint venture, and Martinus Rail for a design sprint on the Marsden Point Rail Link in Northland, drawing directly on the market confidence and contractor capability demonstrated through Auckland’s underground build.

Inside the CRL Testing Programme

When the City Rail Link opens, the expectation from Aucklanders will be simple: trains that are safe, frequent and reliable from day one. Achieving that outcome depends on months of complex, carefully staged testing that brings together infrastructure, technology, people and procedures across the entire rail system. CRL testing is split two ways — systems testing inside the stations, and network proving across the wider network.

Systems testing focuses on everything that happens inside the CRL environment, ensuring systems and processes talk to each other and everything works as it should. In total, there are 16,000 individual tests to be completed across the CRL. These range from everyday operations — ticket gates, CCTV, help points and air-conditioning — to the most complex scenarios, including large-scale emergency evacuations. The evacuation scenarios confirm that stations, tunnels and trains operate safely in unplanned circumstances, rigorously testing fire detection, ventilation and communications systems alongside evacuation routes, lifts, escalators and wayfinding. Crucially, they also test how passengers behave in unfamiliar, high-pressure emergency environments — insights that no desk-based plan or simulation can fully replicate.

Network Proving

Full network timetable testing, or dry runs, is the other critical part of getting ready to open later this year. The CRL does not operate in isolation; it reshapes Auckland’s entire rail network, better connecting people and places. Dry runs test large volumes of trains across the system to validate new timetables, confirm system integration and identify pinch points, allowing teams to resolve issues before opening. The work involves train drivers, train managers, controllers, customer service staff and digital systems working together as one. January 2026 marked a key milestone with the first network-wide CRL timetable test, providing early insight into train movements, congestion and system behaviour under load — lessons that directly informed the next round of testing during the April school holidays.

Large-Scale Emergency Testing Wraps Up

Large-scale emergency testing is wrapping up on Auckland’s City Rail Link, marking one of the most critical phases in preparing the country’s largest transport infrastructure project for passenger service. Auckland Transport, alongside City Rail Link Ltd, Link Alliance, Auckland One Rail, KiwiRail and emergency services, undertook the extensive testing schedule from late April to early June 2026. The programme used realistic simulations with smoke machines and volunteer “passengers” to recreate scenarios including fires, onboard incidents and tunnel evacuations across the new underground stations, tunnels and Waitematā Station.

With stations sitting as deep as 33 metres below ground, emergency planning is a key priority. Evacuation drills — some involving hundreds of participants — tested everything from fire alarms and ventilation systems to emergency doors, communications and coordination, allowing teams to validate procedures under real-world conditions and adjust where required.

The emergency exercises represent just one part of a much broader readiness programme. Work continues to integrate new systems with Auckland’s existing rail network across infrastructure, signalling and services. Attention is also turning to the customer experience, with more than 10,000 public-facing information items needing to be updated so passengers understand how to navigate the new network and the travel options open to them across Tāmaki Makaurau. At the same time, train crews and customer service staff are training to get familiar with their new environments and to be ready to assist customers through the change. Across every workstream, safety remains the overriding priority.

Project Overview

• Project Name: Auckland City Rail Link (CRL)
• Location: Central Auckland, New Zealand (Waitematā to Maungawhau via Te Waihorotiu and Karanga-a-Hape)
• Developer / Owner: City Rail Link Limited (construction); KiwiRail and Auckland Transport (post-handover)
• Total Cost / Value: NZ$5.493 billion (final revised budget, 2023)
• Scale / Capacity: 3.45 km twin-bore tunnels; four stations; capacity for up to 19,000 passengers per hour through the city centre at peak
• Construction Start: 2016 (preliminary works); major works from 2019
• Expected Completion: Construction and testing by end of June 2026; passenger opening second half of 2026
• Funding / Financing: 50% New Zealand Government; 50% Auckland Council (NZ$2.75 billion each)
• Current Status: Systems testing and commissioning underway; emergency trials and timetable validation completed
• Key Milestone: First full end-to-end test train journey completed through CRL tunnels in February 2025

Project Team

• City Rail Link Limited — Project Owner and Construction Oversight
• Link Alliance — Main Construction Consortium (tunnels, stations, rail systems)
• VINCI Construction Grands Projets — Lead Partner, Link Alliance
• Herrenknecht — TBM Manufacturer (Dame Whina Cooper)
• Auckland Transport — Public Transport Operator (post-handover) and Co-Owner (stations)
• KiwiRail — Rail Network Operator (post-handover) and Co-Owner (rail infrastructure and tunnels)
• Auckland One Rail — Rolling Stock Operator
• New Zealand Government — Co-Funder (NZ$2.75 billion)
• Auckland Council — Co-Funder (NZ$2.75 billion)
• Waka Kotahi / New Zealand Transport Agency — Rail Safety Regulator

Reported 17th September 2022: The tunnel boring phase of the City Rail Link (CRL) project in Auckland, New Zealand has been concluded. The tunnel boring machine (TBM) Dame Whina Cooper broke through at Te Waihorotiu (Aotea) Station.

This phase required drilling twin, 1.6 km-long tunnels up to 42 m beneath the largest metropolis in the nation. Over 64,200m3 of concrete were used to build the City Rail Link tunnels. The TBM traveled more than 3.2 km to bore the twin tunnels from Maungawhau/Mount Eden Station to Te Waihorotiu Station. Thus this has led to placing 2,118 segment rings and removing 260,000t of spoil.

The Dame Whina Cooper TBM measures 130 metres in length and 7.15 metres in diameter. It weighs 910 tons. As tunnel boring is now complete, this TBM will be disassembled and raised above the ground. It will be delivered to the port so that it can be shipped back to its maker, Herrenknecht.

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City Rail Link to boost mobility in Auckland

A collection of firms known as Link Alliance is in charge of providing CRL with the main tunnels, stations, and rail systems. “The swifter conclusion of the second tunnel reflected operational improvements and efficiency benefits,” said Francois Dudouit, project director for Link Alliance.

The current project is an updated version of earlier rail access improvements to Auckland’s downtown. They were first proposed in the 1920s. A revived interest in the plan resulted from the rise in rail ridership in Auckland at the beginning of the twenty-first century. Additionally, it was partly caused by the completion of the Britomart Transport Centre in 2003. The CRL was identified as the most significant transportation investment for Auckland in the 2012 Auckland Spatial Plan. Thus, the project has great popular support.