SH1, electric trains under the Waitemata seabed?

The latest thinking in a study on another major crossing of the Waitemata Harbour sees the suburban electric rail network and State Highway 1 extending beneath the seabed in tunnels to connect the North Shore with the Auckland CBD and beyond.

The Waitemata Crossing Study team have released a the consultants report recommending a preferred route, having narrowed a long-list of 159 options to a short-list of three late in 2007.

Waitemata Harbour Crossing Consultants Report (PDF 1.3MB)

The recommended option comprises four tunnels - two for trains and two for the motorway - east of Auckland Harbour Bridge. The Central Motorway Junction on the isthmus would link to the Northern Motorway, while the suburban rail network could in future be extended northward from the Auckland Central Business District to the North Shore.

The study was commissioned in 2007 so steps could be taken to safeguard a future transport corridor, if necessary, before the Wynyard Quarter was redeveloped.

It has concluded that the use of driven tunnels gives the region flexibility as to the route and timing of project components, and future-proofs links with major transport infrastructural projects such as the CBD loop rail tunnel.

The rail connection from the north would run in deep tunnels east-west under the Wynyard Quarter which would be served by an underground rail station. The motorway tunnels would largely bypass the precinct on its south-western corner.

The study did not canvas when a crossing might be built, or how it would be funded.