Auckland's City Rail Link — a $5.5 billion pair of underground train tunnels through the city centre — will open to the public on Sunday, 13 September, according to an Auckland Transport billboard spotted on Fanshawe Street early Thursday morning. The date had not been formally announced before the billboard appeared. RNZ

It is the biggest transport project ever built in New Zealand. Construction has been going for a decade. Auckland councillor Richard Hills had earlier said Aucklanders were frustrated that no opening date had been confirmed.

Before the full opening, the public will get limited chances to look around the new underground stations for free. These "First Look" events are on three Saturdays in August: 8 August at Maungawhau, 15 August at Karanga-a-Hape, and 22 August at Te Waihorotiu. Free tickets come out one week before each event.

Auckland Transport's website had been pointing to a 2026 opening, saying on a page dated 2 August that the CRL would open "later in 2026". The rail network has also been going through a major upgrade to get ready.

Some related work is still going. A new access bridge at Takaanini Station, with a start date of September 2025, is due to be finished in mid-2026. Design work is done for level crossing removals at O'Neill's Road and Corbans Estate, but no construction dates have been confirmed.

The project adds new underground stations and a new platform at Mt Eden, connected by escalators, stairs and lifts to the existing Western line.

Once it's running, trains will come much more often. At busy times, trains through the city centre will run every five minutes. Other parts of the network will average about every 10 minutes. On weekends and during quieter times, trains on the new lines will run every 15 minutes, up from the current 20-minute wait.

The broader context here is worth noting. A project this big and this expensive, arriving a decade after work started, will be watched closely for how the opening is handled and communicated. Using a billboard instead of a formal announcement is unusual for something of this size. But it fits what councillor Hills described: people getting impatient, and pressure building on the agencies to commit to a date.

The free preview events do two things at once. They let the agencies test how the stations work with real crowds before the full launch, and they give the public a chance to see what is coming. Staggering them across three Saturdays with limited tickets suggests a careful, step-by-step approach rather than one big opening day.

The real payoff for passengers is how often the trains run. Cutting the wait from 20 minutes to 15 in quieter periods, and running trains every five minutes through the city centre at peak times, makes the rail network far more useful for getting around. Whether enough people actually use it will be what Auckland Transport and central government watch closely, because both have money riding on the project's success.

The 13 September date now gives something firm to hold agencies to. If it holds, the CRL stops being a construction story and becomes a story about how well the trains run, and the political attention moves with it.