Christchurch Southern Motorway Stage 2 (CSM2)


Customer: Waka Kotahi NZ Transport Agency

Contract: Construct only

Location: Christchurch, New Zealand




Transport Solutions New Zealand & Pacific Islands

 Fast Facts

  • 8 km of new 4 lane motorway
  • 5 km of SH1 duplication
  • 5 km of local roads and adaptions
  • Seven new bridges over the new highway, one bridge carrying the motorway over a local road together with a subway extension

The Christchurch Southern Motorway Stage 2 (CSM2) project addresses growing congestion in Christchurch’s south and southwest suburbs by delivering a four-lane, median separated motorway from near Rolleston to Robinsons Road. CSM2 follows the first stage of the new motorway, CSM1, which was completed in December 2012. 

The upgraded road network now provides better access between the south of Christchurch and the city centre and Lyttelton Port by improving the alignment, capacity and safety of the Christchurch Southern Corridor. The new motorway halves travel time between Rolleston and Christchurch at peak-times (from around 30 minutes down to 15) and will reduce the number of fatal and serious crashes by up to 40%.  

McConnell Dowell delivered the project in a joint venture with Downer, the same team that delivered the multi award-winning Russley Road Upgrade in Christchurch. The joint venture saw McConnell Dowell’s resources delivering the majority of structures and Downer undertaking the pavement works. 

The challenge

The project team engaged directly with 142 residents and property owners as well as a broad range of stakeholders, including CTOC (Christchurch Transport Operations Centre), the NZ Transport Agency and Selwyn District Council. Undertaken within and adjacent to live-road corridors, the project required several high-volume traffic switches, on occasion requiring the daily managed movement of around 25,000 vehicles.

With over 80% of the project site exposed to live traffic, vigilant planning was essential to keep motorists moving and protect the safety of our team and the public.  

The solution

While it would have been easier and simpler for the JV to close incoming local roads as the various bridges were constructed, Waka Kotahi placed significant value on maintaining network connectivity and opted to purchase land beyond the designation to accommodate temporary access roads. Construction of these roads included the need for walking and cycling routes and installation of additional lighting and associated infrastructure. The JV used a range of channels to communicate regularly with stakeholders and road users including letter drops, face-to-face communication, community meetings, and leveraging the Waka Kotahi’s social media platforms.  

We created staging plans to manage traffic changes in collaboration with key stakeholders, with the aim of creating the best outcomes for the entire network.  

Key to success

A collaborative approach to construction planning enabled the JV to minimise disruption to the local community.  


Construction started in 2016, with a staged opening of new areas to traffic from June 2020 and all remaining works completed early 2021. 

For further information on the project including gallery images and drone footage, please visit: Christchurch Southern Motorway – Stage 2 | Waka Kotahi NZ Transport Agency (

Project Gallery