KEY POINTS:
Auckland's waterfront is coming under intense scrutiny from transport chiefs faced with picking the most suitable landing point for a new crossing of Waitemata Harbour.
Two of three options short-listed in a $1.3 million study have homed in on Wynyard Wharf and the Tank Farm as part of the most direct route for a crossing from North Shore City to supplement the existing harbour bridge, which will reach its 50th anniversary in 2009.
That was Transit NZ's preferred route for a tunnel before it agreed to delay seeking a corridor designation while working with the Auckland Regional Transport Authority and councils on both sides of the harbour to consider other options.
But the study team has also raised the possibility of building a new bridge as a cheaper alternative to a tunnel on that alignment, as well as adding a longer underground route which would take general traffic to Grafton Gully and public transport passengers through a branch link to Britomart.
The team has yet to update an estimate by Transit in 2003 that a tunnel on the Tank Farm alignment could cost about $3 billion.
The study team is under pressure to complete its research for a final route decision by the end of March, before Auckland City opens planning hearings for the proposed $2 billion-plus redevelopment of the Tank Farm.
A proposal to double the width of Daldy St and turn it into an 800m-long park through the spine of Tank Farm would leave Transit room underground to extend a harbour crossing to possible connections to the Northwestern Motorway or back to the port.
Motorists wanting to stay on State Highway 1 would use the existing bridge, leaving the new crossing for those heading west or wanting to join the Western Ring Route once a connection through Waterview is built, providing another way of reaching the airport.
More straightforward for the planners would be to build a new harbour crossing just for public transport and to leave the existing bridge for general traffic with the addition of cyclists and pedestrians.
Whether the new crossing is a tunnel or a bridge, it would continue underground from the Tank Farm to Britomart, putting pressure on turning that into an open-ended railway station.
The new option of a longer tunnel, of up to 6.8km between Esmonde Rd and Grafton Gully, would reach landfall just to the west of the port's Bledisloe container terminal before continuing underground.
That follows a call by the Auckland Regional Council and its chairman, Mike Lee, for priority consideration to be given to an eastern route to improve the resilience of the transport network by diverting traffic away from the tight confines of Spaghetti Junction.
Among more than 160 route possibilities assessed by the study team was a tunnel continuing all the way to Glen Innes or Panmure to connect with the $1.33 billion Auckland Manukau Eastern Transport Initiative (Ameti) of new roading and public transport improvements proposed over the next 20 years.
Although that has been rejected, a workshop attended by the study partners agreed that the Grafton option could be configured "to allow a possible future connection to Ameti, with a possible link in the vicinity of Stanley St".
Auckland City transport committee chairman Ken Baguley said last night that although it would be "political suicide" to revive plans for an above-ground eastern highway through Hobson Bay, funds might eventually have to be found for a longer tunnel to get past such traffic choke-points as the Newmarket Viaduct, soon to be replaced by a slightly larger structure.
