Connecting Canterbury through safer, more reliable transport infrastructure

Overview 

Christchurch Southern Motorway Stage 2 (CSM2) completed the southern motorway connection from near Rolleston to Robinsons Road. The project addressed growing congestion across Christchurch’s south and southwest and to strengthen access between Selwyn, central Christchurch and Lyttelton Port. 

The contract was awarded to the McConnell Dowell–Downer Joint Venture in 2016 and delivered 8 km of new four-lane motorway, 5 km of duplicated State Highway 1, 5 km of local-road works and adaptations, seven bridges over the new highway, a bridge carrying the motorway over a local road and a subway extension. Construction began in 2016, staged openings started in June 2020, and the remaining works were completed in early 2021. 

Lasting impact 

The completed motorway improved the alignment, capacity and safety of the Christchurch Southern Corridor. Peak travel between Rolleston and Christchurch was reduced from around 30 minutes to 15 minutes. 

The project delivered a continuous four-lane, median-separated motorway connection from near Rolleston to Robinsons Road, while upgrading State Highway 1 and adapting local roads to work with the new corridor. Staged commissioning allowed new sections to be brought into use from June 2020 before final works were completed in early 2021. 

CSM2 completed an important piece of the region’s strategic transport network. By increasing capacity and improving the corridor’s safety and alignment, the project supports Christchurch’s role as a South Island gateway for people, freight, tourism and trade. 

The project also demonstrates the value of combining specialist delivery strengths through a joint venture. Downer’s pavement expertise, integrated with structural capability and collaborative traffic planning, enabled a complex motorway programme to be delivered beside live traffic while maintaining local connectivity.