The largest transit infrastructure investments in Canadian history

• 40 station expansion to Metrolinx GO system   
• 5 mile, five station twin bore tunnel expansion to Yonge North subway line 
• 4.8 mile, four station two-way tunnel expansion to Scarborough subway line 

Since 2022, Mace-Comtech-SYSTRA (MCS) has supported Metrolinx as delivery partner for the GO Expansion, working as an integrated team at enterprise, program, and project levels to manage complex workstreams involving varied contract types and multiple delivery methods. 

At its core, the $61 billion, 10-year GO Expansion program is about transforming what has primarily been a system providing commuter services into an all-day, high-frequency transit network with trains running every 15 minutes.  

The improvements will transform the region’s entire mass transit network, making it a highly efficient system that, once fully operational, will have the capacity to serve more than 200 million passenger trips per year. Live, program-wide digital tracking enables the team to pre-empt schedule and cost overruns to keep the program timelines and budget on-track.  

The highly complex program is progressing as planned, including more than 375 miles of electrified track, 78 miles of new track, 40 new stations, signalling systems, supporting infrastructure, and maintenance facilities.  

Building on trust established in the GO program, Metrolinx and MCS subsequently launched a second delivery partnership to oversee projects extending the Scarborough and Yonge North subway lines, comprising $11 billion in capital investments. The Scarborough project marks Canada’s first use of the progressive design-build model with an adjacent design-build-finance contract to construct a new 4.8-mile, two-way tunnel. The project also includes four new stations, traction power, signalling, and ventilation systems.  

We formed an integrated team to manage the Subways program, which includes the progressive-design builder, operator, tunnel representatives, and municipalities to foster collaboration for effective delivery. Given the complexity and number of new approaches being utilised, capabilities development is a core part of the program to help Metrolinx effectively implement the progressive design-build model, while maintaining the schedule and target-cost negotiated-price provision. 

Furthering our partnership, in 2024, Metrolinx selected Mace as its operational excellence provider of record, ensuring that the improvements we deliver will benefit the region for generations to come.  

Throughout delivery of these programs, the partnership leverages industry-best practices, collaborative management, continuous improvement, and local supply-chain and workforce  capability, enabling industry-leading performance, delivery assurance, and outcomes benefiting the greater community.