Project introduction

The Western Corridor (SH1) provides access to Christchurch International Airport for people and freight from throughout Canterbury and the South Island. The corridor runs between the Northern Motorway in Belfast and the Main South Road in Hornby.

  • Estimated project cost

    $300 - 350 million +
  • Project type

    Road improvements
  • Project status


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Sections of the Western Corridor

This project is being built in section to reduce the impact on traffic using this busy route. For more in information on the individual project just click on the sections below.

What’s happening with the Western Corridor


The Western Corridor (SH1) connects north and south Canterbury with the Christchurch International Airport and runs between Belfast in the north to the large industrial area at Hornby in the south. Increased commercial and industrial activity, particularly in Hornby and at the airport, is creating more traffic and congestion at peak times. Most of the traffic on the corridor is heading to the city, the airport, Belfast or Hornby, with less than 15% of the traffic travelling further north or south.


  • Congestion will be reduced and travel times shortened along SH1.
  • Travelling to the Airport from the city will be safer and travel times will be shorter and more reliable.
  • The number of vehicles using Main North Road through Belfast will be substantially reduced improving safety and quality of life for Belfast residents.
  • The decrease in traffic volumes will make walking and cycling safer and more attractive.
  • Public transport will have greater scope for improvements.
  • Noise and air pollution will also be reduced.
  •  Ensure businesses are able to get their goods to and from markets and the Airport


  • What is the Western Corridor?

    Most of the Western Corridor already exists; it runs from the Groynes on Johns Road and along Russley, Masham and Carmen Roads. A new section is planned that starts from the Northern Motorway, bypasses Belfast and joins John Road near The Groynes. The Western Corridor's (SH1) role is to connect the northern and southern Canterbury areas with Christchurch International Airport, and allow medium to long distance journeys between Belfast and Hornby to be safe and efficient. Most of the traffic on the corridor is heading to and from Hornby, the airport or the city, with less than 15% of the traffic travelling further north or south. The focus of the project is to four-lane SH1 from The Groynes to the centre of Hornby and to provide the Belfast bypass. Selected intersection improvements at main roads are also programmed along this route.

  • Why is the four-laning of the Western Corridor needed?

    Around 42,000 vehicles per day (among the highest for any road in Canterbury) use Main North Road through Belfast to enter and exit Christchurch. This number of vehicles, and in particular the trucks and heavy vehicles using the road, discourage walking and cycling and restrict public transport. As traffic volumes grow, congestion will become worse and safety and public health concerns will increase around the Main North Road/Belfast Area. Further along the corridor, increased commercial and industrial activity, particularly in Hornby and at the airport, is creating more traffic and congestion at peak times. There is insufficient capacity in the existing two-lane road to absorb further traffic growth. To ensure businesses based outside Christchurch are able to get their goods to and from the airport, the current road requires upgrading to improve safety, reduce congestion and provide travel time certainty.

  • What are the benefits of the Western Corridor improvements?

    For traffic travelling along SH1 congestion and travel times will be reduced. For city businesses and residents travelling to the airport from the city, the upgrade of the intersection at Memorial Avenue and Russley Road will improve safety and speed up travel.
    For the Belfast community, an estimated 17,000 fewer vehicles per day on Main North Road will improve the safety and quality of life for Belfast residents. The decrease in traffic volumes will make walking and cycling much safer and more attractive and provide greater scope for public transport improvements. Improvements to air quality and noise reduction are also expected.

  • What does the Western Corridor project involve?

    State highway 1 from Belfast to Hornby (Johns, Russley, Masham and Carmen Road and the Western Belfast Bypass) will be four laned, with a Russley/Memorial Interchange as the gateway to the airport. This will improve travel time, reliability and safety along and across the state highway.

    The rural section of Johns and Russley Road from the Groynes to Ryans Road will be retained at 80 km/hr, with two lanes in each direction separated by a median barrier. This will be a free-flowing expressway with fewer, high quality intersections at main arterial roads only. Other intersections will be left-in, left-out or closed. This will require local traffic to use the local road network to access arterial roads to get on to the state highway.

    The urban section from Ryans Road through to Hornby will be a four lane, median divided urban arterial road with traffic signals at key intersections. Cyclists will have a mixture of on-road and off-road facilities along the corridor.

    The Russley/Memorial Interchange will have Russley Road (SH1) passing over Memorial Ave, this will separate the state highway traffic from traffic moving between the City and the Airport. People accessing the airport will have significantly less traffic to deal with - reducing delays and improving safety.

    Memorial Ave is the main route for pedestrians and cyclists to the airport, and they will have dedicated space through the intersection providing a significant improvement for accessibility and safety. This will also be the main route for public transport into the airport.

    An additional airport access point will be provided south of Avonhead Road. It will be a grade separated intersection (one road going over the other on a bridge)

  • What are the key features of this project?
    • Widening the highway to two lanes each way, separated by a raised median strip
    • Fewer but high quality intersections at main arterial roads only
    • Better treatment of stormwater run-off
    • Relocating overhead services such as power and telephone lines underground
    • An attractive landscaped road corridor
  • What are Roads of National Significance?

    The Christchurch Western Corridor and has been identified by the government as part of Christchurch’s Road of National Significance (RoNS) programme. This acknowledges the role this highway can play in supporting economic growth, reducing congestion and improving safety in our region.

    There are a number of Christchurch projects under this banner and they make up the Northern Corridor, Southern Corridor and Western Corridor.

  • The Greater Christchurch Urban Development Strategy

    The Greater Christchurch Urban Development Strategy (UDS) is a 35-year plan for managing growth in greater Christchurch, through integrating land use, transport, infrastructure and funding. The UDS partners are the Christchurch City Council, Environment Canterbury, Waimakariri District Council, Selwyn District Council and the NZ Transport Agency. This project is seen as being integral to not only achieving the UDS vision of a sustainable transport system that supports prosperous communities, but also supporting the Recovery Strategy and more recently the draft Land Use Recovery Plan.

  • Why is SH1 not diverted to the west of (behind) the airport?

    A Western Airport Bypass has been investigated in the past and recently too as part of a joint NZ Transport Agency, Christchurch International Airport (CIAL), Christchurch City Council (CCC) assessment. This is not a viable state highway option because it is likely to be used by less than 15% of current State Highway 1 users – those who are bypassing Christchurch.

    The majority of drivers on Russley Road (SH1) are heading to or from Hornby or turning on or off somewhere before this to go to the airport or the city, and therefore improvements to the existing State Highway corridor provide the greatest benefit. Not only will the existing 30,000 plus drivers who currently use this State Highway benefit greatly from the SH1 improvements, but all drivers in the future will be saved for the predicted delays and congestion.

    There are benefits to upgrading this route as a local road route and to this end the NZ Transport Agency are improving the Pound Road, Barters Road and Main South Road intersection, but this will not significantly relieve congestion on Russley Road (SH1).

  • Will there be provisions for pedestrians and cyclists?

    There will be a 2.5m wide shoulder on each side to the carriageway to accommodate cyclists (a significant improvement on what is there now). There will be cycle lanes and pedestrian crossings provided on Memorial Avenue at the signalised on and off-ramp intersections. 

    The existing cycle and pedestrian crossings will be maintained at the Harewood Road and Sawyers Arms Road roundabouts. With the increasing traffic on Russley Road other crossing points are becoming unsafe and cyclists will be safer to use the local network to connect with the dedicated crossing points at Memorial Ave, Harewood Road and Sawyers Arms Road.

    A pedestrian and cycle underpass will be built under the Harewood Roundabout. The underpass will provide safe access across Russley Road (SH1) and access to both the airport precinct and the MacLean's Island recreational area.

    The off-road pathway between Harewood Road and McLeans Island will be retained. In the Hornby urban area, there will also be off-road joint pedestrian/cycle paths from Kintyre Drive to Waterloo Road. 

    The numbers of cyclists that utilise the corridor as a cycling route are relatively few. Other more enjoyable local road options exist and can be used for recreational and commuter cyclists that connect with the safe SH1 crossing points – at Memorial Ave, Harewood Road and Sawyers Arms Road.

  • How will the Western Corridor four laning affect public transport?

    There will be no changes to public transport along the Airport route via Memorial Avenue, but the changes proposed at the Wairakei Road intersection may require the re-routing of any services that cross Russley Road to the Airport at Wairakei Road.

    At Bentley Street, the right turn from the State Highway has been retained to facilitate the number 84 and C bus route.

    NZ Transport Agency are working with Environment Canterbury to ensure effective bus services are maintained in the short and long term.

  • How are the Western Corridor projects split up?

    There are five distinct sections to the upgrading of the Western Corridor. From the north travelling south these are:

    • The Western Belfast Bypass
    • The Groynes and Sawyers Arms Road.
    • Sawyers Arms Road to Harewood Road
    • Harewood Road to Avonhead Park including the Southern Airport Access.
    • Avonhead Road to Yaldhurst Road
    • Masham and Carmen Roads between Yaldhurst Road and Waterloo Road.