Shore queries lack of third harbour crossing in 30-year plan

North Shore City is disappointed a third Waitemata Harbour crossing, with railway tracks, is missing from a 30-year regional transport strategy for Auckland.

It wants the Auckland Regional Transport Committee to remedy the omission from the draft document, on which public hearings will be held next month.

The city council says it is concerned at the lack of any commitment to a third harbour crossing - in addition to the main and Upper Harbour bridges - or to the extension of rail to North Shore within the strategy's 30-year overview. It has asked for the strategy to identify the planning and funding needed "as rail will underpin the necessary redevelopment and intensification of North Shore City".

The regional committee is also under pressure from the Auckland Airport company for rail to be extended to the airport before a target date range of 2031 to 2040 proposed by the strategy.

Feeding the North Shore's concern is the national Transport Agency's confirmation last month of engineering advice that the main harbour bridge's two-lane northbound clip-on may have only 10 to 20 years left without restrictions on heavy traffic and possible temperature controls on its metal joints.

The agency, which with KiwiRail is seeking route designations for road and rail tunnels expected to cost up to $4.1 billion, still hopes those management measures will give it 40 more years from both clip-ons.

But the North Shore submission has taken the agency's advice as an indication that the clip-ons, added in 1969, "will need to be replaced in the next 10 to 20 years".

It warns of serious disruption to access to North Shore City if the clip-ons have to be replaced in the absence of a new alternative harbour crossing. "As [the bridge] approaches the end of its feasible life, the risk of bridge failure increases."

Its submission also warns that a proposed "upgrading" of State Highway 1 between Puhoi and Wellsford for up to $2.3 billion, into one of seven roads of national significance, is likely to increase heavy traffic and further reduce the life of the bridge.

"Overall, there is an urgent and serious need to investigate and plan for a third harbour crossing."

The Transport Agency confirmed its engineering advice on the same day a month ago that it admitted to an 89 per cent cost blowout, to $86 million, for strengthening the clip-ons.

That led to a suggestion by Transport Minister Steven Joyce that construction of a new crossing, whether tunnels or another bridge, should start in 10 or 11 years for completion by about 2025.

But the draft regional transport strategy, which was prepared before the latest harbour bridge developments, has not included such a crossing in proposed transport spending of $46 billion for the next 30 years - for which it admits deep funding uncertainty.