Editorial: Road tunnel costly lesson

Opinion

Notices are being issued this weekend inviting road-building contractors to bid for a tunnel project that should relieve Auckland's worst motorway bottleneck, the Victoria Park viaduct. The news will be welcomed by every potential victim of this daily hazard.

The viaduct dates from the 1960s when it was supposed that Auckland's inner city would continue to draw at least as much commuter traffic as the suburbs that were beginning to sprawl north and south. Thus the southbound lanes from the Harbour Bridge were evenly split, two carrying traffic across the viaduct, two flowing into Fanshawe St.

The viaduct lanes became hopelessly inadequate decades ago. Every morning in peak hours and long after, lines of congested traffic crawl from the bridge to Victoria Park. Alongside them, the lanes to the city flow freely, or would do so were it not for southbound drivers determined to jump their queue.

The culprits come off the bridge in the city-bound lanes and slow down, looking for gaps in the southbound lanes, causing needless snarls in the city-bound lanes and furious ducking and diving as following traffic tries to get around them. Collisions are constantly on the cards.

It is a daily lesson in the dangers of shortsighted transport planning and evidence, which regional planners appear still to need, that downtown Auckland is not the destination of even half the commuters from this, or probably any, direction.

A solution is in sight at last, thanks to the recession. A $1 billion boost in national highway spending for the next three years has allowed the Transport Agency to schedule construction of a tunnel under Victoria Park for northbound traffic, allowing all four lanes of the viaduct to relieve the southbound congestion.

A cut-and-cover tunnel construction under reclaimed land is a fearfully expensive alternative to simply widening the viaduct as originally planned. But for some organised opposition to a wider structure across the park, the bottleneck could have been relieved years ago. When the national road-building agency finally agreed to the compromise of a one-way tunnel it still could not justify the expense of burying a few hundred metres of Auckland motorway against all other demands on its funds.

At the latest estimate the tunnel will cost $400 million to $430 million. By comparison, the complete reconstruction of the Newmarket Viaduct, also about to start, is to cost $195 million. The tunnel project includes an extra lane each way to the Harbour Bridge and a completion of the southbound bus lane, but the bulk of the cost is in the three-lane passage under the park. Let us hope this time the planners have assessed future traffic demand accurately.

The difficulty of widening a tunnel is one of the reasons Transport Minister Steven Joyce is looking at alternatives to an underground link for the western ring road at Waterview. The residents there will have taken heart at Thursday's announcement for Victoria Park. A Waterview tunnel might be 10 times as long but the bill for a bored tunnel is a fraction of cut-and-cover costs. And its purpose, to keep a settled residential community intact, seems more worthy than the visual qualities of an inner-city sports ground.

The expense at Victoria Park may be less of a concern when the economy needs the boost but by 2013, the project's completion date, the country could be still counting the cost with interest.

By then, at least, the bottleneck and its dangers should be a distant memory for motorists. Let's hope the lessons linger longer in the minds of those whose transport planning needs to take note of where people want to go.