Lifeline threat?

Allowing trucks back onto the outer clip-on lanes of the Auckland Harbour Bridge may cause them to fail, even after a $45 million upgrade programme to prevent exactly that. The upgrade, once completed, was supposed to allow the lanes to carry traffic, including trucks, for 30 years.

But the report is saying that if trucks are allowed back on once the work is complete, the lanes will fail in as little as ten years, so trucks may need to be banned permanently (they’re banned until the work is complete). This new assessment came about after NZTA officials looked at the possibility of adding cycle/pedestrian lanes to the bridge, and found not only that the weight couldn’t be added, but that trucks will likely need to be banned permanently.

This all matters because the Auckland Harbour Bridge, which carries State Highway One, is the main north-south link. If it fails, it would create chaos for the economies of the Auckland region on northward.

The bridge was opened in 1959 with four traffic lanes, two in each direction. Within a few years, the bridge had reached capacity and more lanes were needed as the North Shore boomed. In 1969, a Japanese company added clip-on lanes on either side of the bridge, adding a total of four more lanes (two in each direction). The company chosen led to the nickname “Nippon Clip-ons” for the added lanes.

According to the New Zealand Herald, Transport Minister Steven Joyce will soon announce the acceleration of several roading projects, possibly including the Waterview connection to the motorway system, completing the western motorway bypass of Auckland. That would provide a second north-south motorway route. More controversially, plans to construct another Harbour crossing, probably a tunnel, may get a hurry-up from the Government despite the current projected cost guesstimate of $14 billion.

It’s important to note that NZTA, which is in charge of roading, is an independent agency and not a tool of the Government of the day. So, while the report on the bridge may give the Government justification for pushing through roading projects, that doesn’t mean the agency manufactures that justification. While engineers may—and probably will—disagree with all or parts of NZTA’s conclusions about the bridge, no one would suggest a political motivation for them.

It was certain that whichever party won the November election, they’d be facing the same issues after decades of chronic under-investment in infrastructure. The Labour Government made a start on reinvestment, and it’s now up to the National Government to carry on and expand that work. The current report shows the urgency of much of it.

The photo accompanying this post is of the underside of the bridge at Northcote Point (which I took at the same time as the ones I used in this post). The box running along the right side of the bridge contains steel beams that need to be reinforced. At the moment, the spot where this photo was taken is closed as work continues on the reinforcement programme.