Why do we need the Southern Motorway?

The primary access to Lyttelton Port of Christchurch (Lyttelton Port) from the south of Christchurch has been Main South Road, Blenheim Road, Curletts Road and the Southern Motorway and on to the Brougham Street Expressway. This southern link often reached capacity during peak travel times leading to frustrating delays for motorists. These delays impacted on people and freight trying to reach the Lyttelton Port, reducing the efficiency of transport and increasing the costs. Heavy traffic travelling along Main South Road and Blenheim Road made these roads more unpleasant for cyclists, pedestrians, local businesses and residents.

The new Christchurch Southern Motorway Stage 1 (CSM1) diverts traffic away from Main South Road and Blenheim Road providing safe, efficient travel for traffic heading to Lyttelton Port.

How long has this project been planned?

The intention for "a new road outlet in order to supplement the Main South Road" was originally anticipated by the Minister of Works and gazetted on 27 November 1952 – 60 years ago.

Ten years later, in November 1962, the Christchurch Regional Planning Authority’ adopted the Master Transportation Plan which included "the Southern Motorway on a line passing south of Wigram Airfield and thence curving west across Springs Road on a line which joined the Main South Road just west of Templeton".

The original stage one Southern Motorway, running from Barrington Street to Curletts Road, was opened in May 1981. The Curletts Road extension, from Blenheim Road to Halswell Road, was completed a few years earlier (1979).

What does the CSM1 project involve?

This project connects the Brougham Street Expressway (SH73) in the east with Main South Road (SH1) in the west and is approximately 10.5 kilometres in length. There are three distinct sections to this project:

  • Duplication of the existing 2-lane motorway between Collins Street and Curletts Road (3km).
  • Construction of a new 4-lane median-separated motorway between Curletts Road and Halswell Junction Road (5km).
  • Upgrade Halswell Junction Road between Springs Road and Main South Road (SH1) (2.5km) – a temporary link until Stage 2 of the Southern Motorway is built.

The project included seven new bridges, two pedestrian and cycle subways, one extended subway and a parallel shared use path for cyclists and pedestrians.

What are the benefits of the CSM1?

The CSM1 provides a range of benefits from savings in travel times and reductions in vehicle operating costs, greater certainty in travel times through to productivity gains resulting from the reduction in time and costs involved with transport. Other benefits include:The CSM1 will reduce the travel time between Barrington Street and the Main South Road (SH1) by about 10 minutes.

  • Reduced traffic congestion.
  • Improved and more reliable travel times.
  • Improved access for freight traffic to Lyttelton Port and for motorists heading into or out of Christchurch’s Central City.
  • Safer streets by using improved motorway standards; putting in place a median barrier the full length of the motorway; and by moving heavy traffic off suburban roads, making local streets safer and more pleasant for walking, cycling and public transport.
  • Economic growth through the millions of dollars invested in the Christchurch economy during construction – directly and indirectly – and by reducing vehicle operating costs and improving productivity through reduced travel times.
  • The Benefit-Cost Ratio for the CSM1 is 2.4.

What did CSM1 cost?

The cost of constructing the CSM1 was $140 million, which includes all design and physical construction costs.

How much traffic uses CSM1?

The new motorway carries 41,000 vehicles daily between Collins Street and Curletts Road; and 21,000 vehicles between Curletts Road and State Highway 1.

Where will Stage 2 of the Southern Motorway connect to Stage 1?

Stage 2 of the Southern Motorway currently in the consenting phase, will connect to stage 1 just before the Springs Rd. roundabout. When stage 2 is completed Halswell Junction Rd will revert to a local (Christchurch City Council) road.

How many people were employed on the Southern Motorway Project?

More than 2100 workers, from different companies, have worked on the CSM1 site, with an average of 150 workers on the site at any one time.

The project achieved an outstanding on-site safety record with more than 1000 Lost Time Injury Free Days, i.e. there being no injuries on the site that required workers to take time off.

Who built CSM1?

A consortium, headed by Fulton Hogan in partnership with BECA (an engineering design consultancy), was awarded the contract to construct the Southern Motorway Stage 1 in January 2010.

Where can I get on or off the Southern Motorway?

Full movement on or off the motorway is available at the Springs Road roundabout, the Curletts Road interchange and the Barrington St Interchange.

Why is there no access to the CSM1 from Dunbars/Awatea roads and Aidanfield Drive?

Every on-ramp leads to slower speeds as traffic merges and increases the risk of accidents compromising the safety of road users. Additionally, the motorway is designed to improve access for people and freight entering Christchurch from the south and travelling to the CBD and Lyttelton Port. With this traffic moving onto the motorway, the local network has been freed up, reducing congestion and improving travelling times for residents as well as improving opportunities for public transport, cycling and walking.

What facilities are there for cyclists and pedestrians?

A parallel cycleway/pedestrian walkway runs beside the entire length of the motorway, with regular cross-connections (subways under the motorway).