About this Project

Mt Roskill Extension and the Western Ring Route

Mt Roskill Extension is a key part of the Western Ring Route. Once completed, the Western Ring Route will provide an alternative to State Highway 1 (SH1) between Manukau City and Albany via State Highway 20, State Highway 16 and State Highway 18.

The Western Ring Route will provide quicker and safer travel between North Shore, Waitakere, Auckland and Manukau cities and will play an important role in reducing central Auckland congestion, by enabling traffic to completely bypass the Auckland Harbour Bridge.

For more information on the Western Ring Route, see www.transit.govt.nz/projects/wrrconsultation/

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Mt Roskill Extension - Key Facts

4-lane motorway from Queenstown Road through to Richardson Road, Mt Roskill
4 km long
2 interchanges at Hillsborough Road and Dominion Road
4 bridges at May Road, Dominion Road, Hayr Road and Hillsborough Road
2 pedestrian/cyclist bridges at Keith Hay Park and Ernie Pinches Street
New roundabout where the motorway intersects Sandringham Road
Maioro Street will be widened to four lanes
A dedicated cycleway alongside the motorway is being developed in conjunction with Auckland City Council
Rail provision
Estimated cost - $186m
Construction to be completed in mid 2009

Quick facts

6,704 metres of boundary fencing
33,300m3 of top soil
193,600m of drainage
15,974m² of retaining walls
13,127m² of guard rails and safety barriers
3,409 new trees
250,000 new plants
262,457m² of landscaping
140,000 m2 of pavement
800,000 m3 of earthworks
1.7km of noise walls

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Key Features

The Mt Roskill Extension project will extend the Southwestern Motorway (SH20) 4 kilometres into Mt Roskill, from Queenstown Road in Hillsborough.

There will be interchanges at Hillsborough Road and Dominion Road, with on- and off-ramps in both directions (eastbound and westbound) and motorway overbridges for local traffic.

The extension will end at a new roundabout which links to Sandringham Road Extension. Maioro Street will be widened to four lanes to accommodate motorists accessing the motorway extension.

Two pedestrian/cyclist bridges have been constructed at Keith Hay Park and Ernie Pinches Street. A dedicated cycleway is being developed in conjunction with Auckland City Council and will run parallel to the motorway.

The project features two dedicated bus shoulder lanes as well as provision for a rail line in the future, connecting to ARTA’s proposed rail link to Auckland International Airport (For more information on ARTA’s future bus and rail plans, visit www.arta.co.nz)

May Road Bridge

First motorway overbridge to open
Constructed December 2005 - December 2006
Opened 15 December 2006
Bridge makes driving easier for local traffic by separating the local road network from motorway traffic
Estimated traffic flow on May Rd: 14,500 vehicles per day
Cost - $6 million
Height: 5.6m
Length: 61m
Number of beams: 24 beams, 3 spans
Number of piers: 2 slender piers
Width of piers: 300mm thick
Height of piers: 16m
Approach ramps to the bridge use a reinforced earth system, tied back to concrete facing panels

Dominion Road Interchange

Dominion Road Bridge was second motorway overbridge to open
Constructed March – October 2007
Opened 24 October 2007
Full diamond interchange with two on-ramps and two off-ramps
4-lane overbridge for local traffic
Bridge will ease congestion on Dominion Road – one of Auckland’s busiest routes – by separating the local road network from motorway traffic
Estimated traffic flow on Dominion Rd: 13,000 vehicles per day
Cost - $1.3 million
Height: 5.25m
Length: 40m
Number of beams: 26
Number of piers: 1 central pier - 360mm thick and 31m high

Click here to see how the final interchange will look

View new photos of construction progress

Hayr Road Bridge

Piers and abutments have been constructed
Approach ramps in place
Bridge deck now in place with 7 spans
Once the approach ramps have settled, retaining walls will be added to each side
Expected opening June 2008

Click here to see how the bridge looks currently and here to see the final layout

View new photos of construction progress

Hillsborough Road Interchange

Hillsborough Road Bridge was third motorway overbridge to open
Constructed January – December 2007
Opened 28 December 2007
6-lane overbridge will carry traffic over Hillsborough Road while construction continues underneath, to align the future motorway and new eastbound and westbound ramps
Full diamond interchange under construction, with 2 on-ramps and 2 off-ramps to provide access to motorway in both directions
Estimated traffic flow on Hillsborough Rd: 40,000 vehicles per day
Estimated cost - $1.5 million
Expected completion – 2009
Height: 8m
Length: 40m
Number of beams: 26

Click here to see how the final interchange will look

View new photos of construction progress

Keith Hay Park pedestrian bridge

First pedestrian/cyclist bridge to open
Constructed January 2006 – February 2007
Opened 16 February 2007
Cost – $1.2 million
Bridge creates safe pedestrian and cyclist access by providing a dedicated link across the Southwestern Motorway (SH20) for local residents and students from three local schools: Mt Roskill Primary, Mt Roskill Intermediate, Mt Roskill Grammar
Estimated pedestrian flow on bridge: 2,000 people per day
Unique features: A cable stay bridge design allows cables to support 500 tonnes. Downlights have been incorporated into a stainless steel handrail for safety
Height: 25m above motorway level to the top of the supporting pylon
Length: 170m
Number of spans: 13 pre-cast concrete decking slabs
Length of largest span: 39m across the motorway
Number of piers: 11
Width of piers: 600mm square at the base, spreading into a ‘Y’ shape at the top to hold the deck
Length of pier: Varying heights up to a maximum of 5.5m
Height of handrail: 1.4m
Number of cables: 12
Thickness of cable: 36mm

Ernie Pinches pedestrian bridge

Second pedestrian/cyclist bridge to open
Constructed August 2006 – March 2007
Opened 30 March 2007
Cost – $1.2 million
Bridge increases safe pedestrian and cyclist access by providing a dedicated link across the Southwestern Motorway (SH20) from Richardson Road, for local residents and students from Wesley Primary and Intermediate schools
Estimated pedestrian flow on bridge: 500 people per day
A cable stay bridge design allows cables to support 500 tonnes. Downlights have been incorporated into the stainless steel handrail for safety
Height: 25m above motorway level to the top of the supporting pylon
Length: 170m
Number of spans: 13 pre-cast concrete decking slabs
Length of largest span: 39m across the motorway
Number of piers: 3 (1 central pylon, 2 piers)
Width of piers: 600mm square at the base, spreading into a ‘Y’ shape at the top to hold the deck
Height of piers: Varying heights up to a maximum of 5.5m
Height of handrail: 1.4m
Number of cables: 12
Thickness of cable: 36mm

Stoddard Road and Sandringham Road Extension intersection

The motorway will link to Richardson Road and Stoddard Road at a new roundabout.

These links will be created by extending Maioro Street to the new roundabout, from the intersection of Maioro Street and Richardson Road.

Sandringham Road will be extended from Stoddard Road to the new roundabout on SH20.

Stoddard Road will also be widened and the new intersection will have traffic lights in place.

Click here to see how the final interchange will look

Queenstown Road

Click here to see how the final interchange will look

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Public transport

A dedicated cycleway running alongside the motorway is being developed in conjunction with Auckland City Council. The cycleway will link to cycle routes in Hillsborough and Mt Roskill.
Two dedicated bus shoulder lanes
Enabling works have been completed to make provision for rail in the future and to link with ARTA’s proposed rail link to Auckland International Airport

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Benefits

The Mt Roskill Extension project will deliver the following benefits

Create a key link in the Western Ring Route, easing congestion on SH1
Improve traffic flow on local roads by separating motorway traffic and local traffic with overbridges
Give better public transport options with two dedicated bus lanes and provision for rail in the future
Provide a key link to Auckland International Airport from the Auckland CBD including ARTA’s proposed rail link to the airport

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Working with others

Throughout the construction of the project, Transit is collaborating with utility companies and agencies to work on services such as water, power and telecommunications. By working together at the same time, Transit aims to minimise disruption to local residents and help to future-proof and improve links to local roads.

The following agencies are carrying out work alongside Transit:

Auckland City Council
Transit is working closely with Auckland City Council to underground overhead power and phone lines. Transit is assisting in the construction of the new cycleway running alongside the motorway. Auckland City Council is also improving links to local roads where the motorway ends in Mt Roskill and Blockhouse Bay.

Vector
Transit is working with Auckland City Council and Vector to underground the power lines in Maioro Street.

Telecom
Overhead telephone lines will be moved underground along with the power lines in Maioro Street, as part of this project.

Watercare
Sewerage services have been diverted and redirected over new bridges along the project.

Metrowater
Water services will be moved as part of the widening of Maioro Street.

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Public awareness

Local residents and the wider public are kept up to date on construction progress via media releases, letter drops, newsletters and this website. Major closures affecting local roads are advertised well in advance. For more information, see the News and Media section of this website.

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Timeline

Contract signed July 2005
Construction start 30 August 2005
Construction completion expected mid 2009