Waterview tunnel concrete collapse rumour 'incorrect' - NZTA

If you're expecting the long-awaited new Waterview Connection to ease Auckland's rush-hour traffic, prepare to be disappointed.

NZTA Auckland highway manager Brett Gliddon told The AM Show on Friday the $1.4 billion tunnel will twice a day likely suffer the same gridlock as the rest of the city.

"We've never said it would fix peak congestion in the city," said Mr Gliddon. "There's still going to be a morning peak and an afternoon peak, and the tunnel will be a part of that."

Since initial forecasting was done about a decade ago, more than 100,000 people have moved into the city.

"Traffic volumes are probably higher at opening than what we originally thought," said Mr Gliddon.

Outside of peak hours is when the tunnel will truly shine, he says.

"Off-peak and any other time of the day, it's going to make a huge difference. All that traffic that currently runs through all those local suburbs is now going to be able to use this link."

It's estimated around 90,000 vehicles will use the six-lane connection daily. It'll allow traffic heading through Auckland to bypass 'Spaghetti Junction' in the CBD completely, via the west of the city.

"It's going to make a huge difference. It finally completes the motorway network," said Mr Gliddon.

The project has been hit with delays however. Mr Gliddon said rumours shoddy concrete caused a ventilation tower to collapse - as suggested by the Green Party earlier this week - are wrong.

"A lot of the rumours are incorrect, I can assure you of that. What happened is we're testing a lot of equipment to go into this tunnel… and some of it just wasn't operating as we wanted it to.

"We had some issues with some valves that opened the deluge system, and some of the issues with the jet fans. We're now over those, we've got those systems working. We're now in the phase of testing the tunnel as a whole, complete system.

"We weren't going to open the tunnel until it was safe. The valves were sticking. It wasn't all of them, it was only a few of them, but we're not going to open unless it's 100 percent right."

There is still no confirmed date for the tunnel's opening, even though some GPS mapping systems have reportedly been sending motorists its way.

"Hopefully in the next couple of months," said Mr Gliddon. "As soon as it's ready, we're going to open it."