Mangere Bridge (bridge)

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For the suburb of the same name at the south end of the bridge, see Mangere Bridge, New Zealand

Mangere Bridge is a motorway bridge over the Manukau Harbour in south-western Auckland, New Zealand, crossing between the suburb also known as Mangere Bridge and the suburb of Onehunga. Completed in 1983, it carries a four-lane motorway with a cycle and pedestrian lane suspended underneath the west side of it.

In April 2008, work began on a duplication the bridge to cater for increased traffic (to serve up to 160,000 vehicles per day in 2021).^[1] The process was being delayed by disagreements over design and funding, as well as the scope of the bridge project and an associated interchange, which are still not fully decided on as of May 2008.

Contents 1 History 2 Bridge duplication 2.1 Project history 2.2 Wider area 2.3 Public transport link 2.4 ACC interchange issues 2.5 Construction 3 See also 4 References 5 External links

[edit] History

The Mangere Bridge replaced an earlier bridge (built in 1914), which was closed in the 1970s to all but foot traffic,^[2] and is slowly deteriorating, especially after it sustained damage when a ship accidentally rammed it some years ago. A second ship, the 300 ft container transport Spirit of Resolution, crashed into the old bridge on 8 October 2005 during 140 km/h winds, despite the ship's engines being on full, causing further damage.

It was envisioned that this bridge will be dismantled and replaced by a newly designed footbridge. However, complaints about this course have for now (2006) stopped these plans while 'heritage options' are being considered as part of the general transport plans in the area.^[2]

[edit] Bridge duplication

[edit] Project history

On 17 May 2006 Finance Minister Michael Cullen announced in the Budget that funds were being allocated to Land Transport New Zealand, to help the National Land Transport Programme accelerate certain projects. This includes bringing forward the widening of the existing crossing of the Manukau Harbour (1983 Mangere Bridge) by duplicating the original to the east. The 2006/07 National Land Transport Programme indicates that only $2.78 million funding is currently approved for investigation of the project. However, Transit New Zealand may apply for additional $1.5 million for further investigation of this project in the current financial year. The bridge is currently (July 2007) expected to cost NZ$ 330 million.^[3][4]

A crucial part of the Manukau Harbour Crossing Project, the duplication of the Mangere Bridge would result in the widening of the existing carriageway from four lanes to eight lanes between the Onehunga interchange and the Mahunga Drive/Rimu Road interchange. Bus lanes will be provided on the shoulders of the bridge. The bridge will be duplicated to the east, with a fewer number of piles than the current bridge. However, these piles will be located to match the existing ones, to minimise any negative visual impact. Noise walls are proposed as part of the project along significant lengths of the motorway.

[edit] Wider area

As a wider part of the Manukau Harbour Crossing Project, the motorway will be widened between Walmsley Road in the south and Queenstown Road in the north from four lanes to six lanes. This widening will predominantly take place to the east of the existing motorway. The Onehunga interchange (known as the Gloucester Park Interchange) will be significantly reworked, to provide a more logical link with the motorway, and to ease congestion along Onehunga Harbour Drive. A standard diamond interchange was initially chosen by Transit New Zealand, but after consultation with Auckland City Council this has been reworked into a quarter-diamond design, with the northbound onramp hooking underneath the proposed Neilson Road bridge.

As part of that investigation, Transit New Zealand may consider whether it is worthwhile to toll new capacity to assist in funding its construction. This could be in the form of tolling the new lanes along this route, which would ensure an untolled alternative is available, while the tolled new lanes would be far less congested. Transit New Zealand has however recently (mid 2007) indicated that it will not seek a decision on funding the bridge via road tolls before starting work on construction. Auckland International Airport had accused Transit of threatening to defer the project if it could not gain backing from the public and local Councils. As the bridge is to be finished for the 2011 Rugby World Cup, further delays would possibly result in the bridge not being completed in time.^[3]

[edit] Public transport link

In early 2007 Transit New Zealand has indicated that it would be "more than willing" to develop a bridge that could also accommodate a rail link, intended for a possible future Auckland City - Auckland International Airport rail line (the closed Onehunga Branch, which has recently (2007) been approved for re-opening, currently terminates at the northern end of the bridge). A combination solution is now being debated which would see a rail link use the same bridge foundations. The change came after repeated lobbying by the Auckland Regional Council, which was of the opinion that a previous provision - restricted to allowing space for an additional, but separate bridge - was not sufficient.^[5]

In September 2007, ARTA proposed to pledge NZ$ 2.5 million for future-proofing works which are to ensure that a rail link can be included in the future. The design envisaged would have the future railway line run on the piers for part of the distance underneath the motorway structure, thus saving some of the high costs associated with strengthening the bridge to be able to take a cantilevered bridge, estimated at around NZ$ 20 million in extra costs.^[6] The bridge is already intended to accommodate bus shoulder lanes.^[7]

[edit] ACC interchange issues

In July 2007, Auckland City Council commissioners have given approval to widening the approach motorway for the bridge through Onehunga Bay, but have opposed the new interchange design north of the bridge as favoured by Transit New Zealand, which intended to build it around 7 m high over Gloucester Park and the Hopua volcanic tuff ring. A favoured version would instead be built in a cut and cover tunnel.^[4]

The recommendation, which Transit New Zealand can ignore only at the risk of drawn-out legal fights at the Environment Court (which would be likely to delay the project until after the 2011 Rugby World Cup), was based on residents concerns, who fear that the new interchange would increase and cement separation of their suburb from the Manukau Harbour.^[4] Partly due to this, Transit New Zealand decided in August 2007 to continue with building the new bridge without including new interchange for the time being.^[8]

[edit] Construction

Construction of the new bridge was officially begun on 9 April 2008. The new bridge will provide four lanes and bus shoulder lanes (like the existing bridge), and will also be provided with new pedestrian and cyclist footbridges connected to a shared path along the Mangere Bridge waterfront reserve. Transit New Zealand also confirmed that provision will be made for a future rail link under both bridges to connect to Auckland Airport.^[1]

[edit] See also

• Auckland Harbour Bridge
• Upper Harbour Bridge

[edit] References

[edit] External links

• Mangere Bridge (bridge) is at coordinates 36°55′60″S 174°47′17″E / -36.933220, 174.788060 (Mangere Bridge (bridge))Coordinates: 36°55′60″S 174°47′17″E / -36.933220, 174.788060 (Mangere Bridge (bridge))