$430m city tunnel fast-tracked

Graphic / NZ Herald

Auckland's congested central motorway system is about to receive up to $430 million of further heart surgery by way of a northbound tunnel beneath Victoria Park.

Transport Minister Steven Joyce yesterday announced that construction of the three-lane "cut and cover" tunnel - beneath the constricted 1960s-era concrete motorway viaduct which spans the park - would be brought forward 10 months to start next January.

He said the Transport Agency was preparing to issue a formal request this weekend for expressions of interest by road-building contractors.

His announcement came as construction signs appear around the site of a $195 million replacement for the Newmarket Viaduct which is due to be completed by the end of 2012.

The tunnel will be the region's most expensive roading project so far and follows January's opening of the $356 million Northern Gateway toll motorway and the completion in 2007 of a $207 million refit of Spaghetti Junction.

It will almost double the capacity of State Highway 1 past Victoria Park from late 2013 or early the following year by allowing both two-lane carriageways of the viaduct to be used for southbound traffic.

One lane will also be added in each direction to the motorway section between the park and the harbour bridge, giving it 10 traffic lanes and a southbound bus lane along St Marys Bay.

Mr Joyce said the breakthrough followed the Government's decision to boost the state highways funding "pipeline" by almost $1 billion over three years, giving the Transport Agency confidence to bring forward the tunnel as the first of seven newly designated roads of national significance.

It would greatly ease congestion for more than 100,000 vehicles trying to squeeze through the corridor each day.

"The current viaduct is a huge chokepoint for the network," the minister said. "Adding a tunnel for northbound traffic will double the capacity of this section of the motorway."

Mr Joyce said he had been advised that the project might not have been affordable under a reduction of highway funding flagged by the previous Labour-led Administration.

A new estimate of $400 million to $430 million is markedly higher than a previous forecast of $320 million, but Government officials say that is because it represents escalated dollars to 2013. They deny having a financial blowout on their hands.

The minister's office said that without the accelerated start, the project might have ended up costing $470 million.

Transport Agency northern director Wayne McDonald said accurate figures would not be known until the construction industry had a chance to bid for the work.

He noted that the successful tender for the $220 million Hobsonville motorway contract, on which construction began in October, came in $30 million lower than estimated.

Although all necessary resource consents have been granted for the Victoria Park project, Mr McDonald said a re-examination of its design had ensured its compatibility with a possible new $4 billion underwater road and rail crossing of the Waitemata Harbour.

The tunnel announcement was enthusiastically welcomed by North Shore Mayor Andrew Williams, who said the extra motorway capacity would make life easier for the many thousands of people who commuted from his city to Auckland and beyond each morning.

It would also improve the flexibility of the Northern Busway, which the Transport Agency has always said must remain off-limits to high-occupancy cars until the Victoria bottleneck is cleared, because of difficulties merging with queues of general traffic tailing well past the bridge.

Auckland Business Forum chairman Michael Barnett said that the announcement was "exactly the news Auckland needs and wants to hear. It will ensure job continuity for many, help address a big bottleneck in Auckland's daily transport woes, and give confidence to the construction industry and its suppliers going forward".

He said the announcement left just one major gap in Auckland's key roading network, the Waterview motorway connection being the final missing piece of the western ring route.