Contents: History | Mt Roskill Extension | Completed Images | Images from Public Open Day | Construction Images

History of South Western Motorway

The South Western Motorway (SH20) has been under construction to connect to motorways in the north and south since the 1970s. From 1997 to now the motorway has been extended in both directions. The main purpose of the South Western Motorway is to provide connections to the Auckland Airport. Eventually when connected to existing motorways the motorway will be an alternative to the Southern motorway - completing the currently under construction Western Ring Motorway Network.

The first section of the South Western Motorway started construction in late 1977, the section was only a short approach to the old Mangere bridge bypassing the busy Onehunga area. The northbound Mangere Bridge after a very long construction process was completed in March 1983. It connected the already used Onehunga bypass to the newly completed crossing to create a total section between Neilson Street and Coronation Road of 1.8km.

Recent activity:
- In 1997 the Coronation Road to Puhinui Interchange, and link to Kirkbride Road section was completed.
- The Mt Roskill Extension in May 2009 opened; extending from Hillsborough Road to Maioro Street in the north-west.
- In mid-2010 both the Mangere Bridge duplication & surrounding widening and the Manukau extension opened. Widening the existing motorway and bridge and connecting the 1997 section to the Southern Motorway respectively.
- One project on the South Western Motorway is still to be completed; the Waterview Connection between the Mt Roskill Extension and the North Western Motorway.

This project is one of the projects of the Western Ring Route. The Western Ring Route will offer a much needed alternative to the congested Northern and Southern Motorways. There are seven projects on this network with five now completed, the Waterview Connection and North Western Widening projects are yet to be completed.

The Mount Roskill Extension

Complete; 4 years | $201m | All lanes opened on the 18th of May 2009.

The Mount Roskill Extension was the first section of the South Western Motorway to be extended, and extended the South Western Motorway 4km at the North West section of the existing motorway.

The Mount Roskill extension alleviates major traffic issues for the Mt Roskill & Sandringham areas where many arterials come together. It takes pressure off residential streets making them safer and provides an easier tri-city connection from Waitakere to Manukau through Auckland City.

The project included: two new interchanges at Hillsborough and Dominion Road, two overbridges for Hayr and May Road, two pedestrian and cycle bridges, future proofing for two bus lanes, and space for the Southdown Rail line, a new cycleway, the widening of Maioro Street to four lanes and a short extension of Sandringham Road. The Mount Roskill volcanic cone and basalt rock is preserved with light excavation techniques and motorway levels at different grades around the site.

The Mt Roskill extension is ready to connect to the preliminary Waterview Connection further north-west completing the Western Ring Motorway network.

Mt Roskill Extension Map

Mt Roskill Extension Graphic

Completed images

On Friday the 15th of May 2009 the official opening ceremony was held with Mayor John Banks, Minister of Transport Steven Joyce, Auckland regional manager of NZTA Wayne McDonald, NZTA CEO Geoff Dangerfield and CE of Fulton Hogan Bill Perry. The motorway opened in the southbound direction at 3pm with the westbound section to follow on Monday the 18th of May at 6am.

Between May Road and Ernie Pinches Pedestrian Bridge. Looking NW.	Ernie Pinches Pedestrian Bridge. Looking NW.
Sandringham Road extension.	Dominion Road off-ramp and interchange. Looking South.
Planting and acoustic walls.	Looking towards the Hayr Road overbridge. Looking South.
Hayr Road overbridge. Looking south.	Hillsborough Road interchange. Looking south.
Looking south from the Hillsborough interchange.	Ramp Signalling on the Hillsborough westbound on-ramp.
Urban design techniques which symbolise the Waitemata and Manukau Harbours.	Keith Hay pedestrian and cycling bridge.

Images from the public open day

On Saturday the 9th of May 2009 a public walking and cycling open day was held to give the public a chance to walk and cycle the new motorway before it opened on Friday the 15th of May 2009.

Looking south east from the Dominion Road interchange.	Looking South toward May Road overbridge.
Looking north-west along the Maioro Street extension.	Stormwater treatment ponds.
Large scale sound walls.

Images from construction

Hayr Road overbridge, under construction.

From Dominion Road looking south.

Looking west from the Dominion Road interchange.	Looking west by the Maioro Street extension and terminus of the extension.
Looking south from the Hillsborough Interchange.	Looking south toward May Road overbridge and Mt Roskill.