Auckland's new $1.4 billion twin-tunnel Waterview Connection will open early next year and planning is now underway for a series of celebratory public opening events.

Andy Knackstedt, NZ Transport Authority national media manager, said that was the time frame for when Aucklanders would be able to get into the tunnels connecting State Highway 20 to the North Western Motorway.

He could give no precise date but he firmly rejected speculation amongst industry officials that Auckland biggest new infrastructure project might open before the year's out.

"I've checked with the team and can confirm that the project will not be open by Christmas. While a specific opening date has not been determined, the project remains on-track to open in early 2017," Knackstedt.


Motorists will then be driving the 2.4km underground tunnels, each three lanes wide, as a result of the biggest underground job in Auckland to date.

So will people be able to cycle or walk through the tunnels before they officially open to traffic? That's not yet been revealed but seems highly likely.

A NZTA spokeswoman said many events would be announced for the opening.

"Planning is now underway for a series of opening events next year, which will include involving the public in some way, however the final make up of those is still being decided," she said.

Matt Lowrie of Transport blog said he had heard Waterview would open between January and March.

Watch: Look inside the new Waterview tunnels:

"They've said for quite some time that it will be open in 2017 so it will be roughly on time," he said.

Industry sources said the job was running ahead of schedule and the tunnels might open sooner than expected, probably early in the New Year.

While a specific opening date has not been determined, the project remains on-track to open in early 2017.

Others expected the project with its 13.1m diameter tunnels to be open around Easter in mid-April next year.


Graham Darlow, chief executive of Fletcher Construction which is part of the Well-Connected Alliance building Waterview, could give no indication of whether the project was ahead or behind the initial time frame.

Others in the alliance are McConnell Dowell, Parsons Brinckerhoff, Beca Infrastructure, Tonkin and Taylor and Obayashi Corp of Japan.

In 2014, Alice the tunnel-boring machine was making 16m of progress a day but then sped up to burrow 20m a day, according to Rory Bishop, construction manager of McConnell Dowell Constructors.