KEY POINTS:
Uncertainty over Government funds for replacing Auckland's most earthquake-threatened motorway link has grown, ironically because of fast progress on other big roading projects.
Although Transit NZ still hopes to complete a southbound bridge for a replacement Newmarket Viaduct in time for the Rugby World Cup in 2011, it admits difficulties pinning down funds for an early construction start.
Northern manager Peter Spies has confirmed that his organisation is still deep in discussions with Government funder Land Transport NZ over the "affordability" of its overall portfolio of projects, despite clearing the legal hurdles for the Newmarket replacement a year ago.
That early clearance gave Transit hope then of bringing the Newmarket project forward, for enabling work to start at the end of last year, even though it was not due for completion until 2013.
But the estimated cost has risen about $30 million since then to $187 million, and Mr Spies said that good progress on other projects from a favourable summer construction season was putting extra pressure on funds.
These include motorway extensions through Mt Roskill and central Manukau and preparations for a duplicate harbour bridge between Onehunga and Mangere, a trio of projects costing more than $600 million.
"One of the advantages for us of a reasonably good summer is that our projects are progressing quicker than we expected, but it also means we are spending money faster than might have been forecast," Mr Spies said.
"It is putting pressure on the ability to bring [other] projects forward - it's fair to say it's getting harder rather than easier."
Although acknowledging that Newmarket Viaduct had "the lowest level of seismic resistance" of any structure on Auckland's motorway network, he said recent design work for the replacement project had ruled out concerns it might be even weaker than an engineering estimate.
Mr Spies acknowledged in February that there was debate among engineers as to whether the existing viaduct could survive an earthquake likely to occur no more than once every 500 years on average, according to the original estimate, or whether it might succumb to a one-in-250-years event.
But he now says that greater knowledge gained about the viaduct, by engineers considering how to demolish it, confirmed the 500-year estimate.
Even so, that is regarded as unacceptably risky by international standards in view of the viaduct's role as Auckland's main link to the south, and its replacement is being designed to withstand a one-in-2500-years earthquake.
Newmarket Business Association general manager Cameron Brewer says frustration over delays in replacing the 42-year-old viaduct, which carries about 200,000 vehicles each day, is growing among his members.
He said they feared tens of thousands of rugby fans travelling to Auckland for the World Cup will be confronted by "ugly hoardings and orange cones instead of Rangitoto and the sparkling waters of the Hauraki Gulf."
"It's a spectacular and heavily protected view shaft, yet when Auckland hosts the third-largest sporting event in the world, visitors won't be able to see beyond the construction hoardings," Mr Brewer said. "It's going to be nothing more than a huge construction zone when Auckland's big international moment arrives."
Mr Spies said a five-year funding commitment made by the Government in 2006 for a package of projects specified only that substantial construction of the viaduct replacement should have begun by 2011. Even so, he hoped that an enlarged four-lane southbound structure would be ready by then, although it was likely three lanes of northbound traffic would still have to use half of the existing viaduct.
He said Transit had a good record of keeping traffic flowing around major construction zones and should be able to manage the project so World Cup visitors would not have views blocked by large hoardings.
