Turcot Interchange

The Turcot interchange, Quebec’s largest and third busiest, was built in 1967 and the structures were nearing the end of their useful life. 

Renovating an Important Structure within Montreal’s Transportation Network

More than 300,000 vehicles use the Turcot interchange every day, 10% of which are heavy vehicles. The owner, the department of Transport, Sustainable mobility and Electrification (ministère des Transports, de la Mobilité durable et de l’Électrification des transports - MTMDET), had to schedule a full rebuild in order to reduce the very high maintenance costs. 

The MTMDET has been preparing for this major project for several years, investing in the planning and execution of several pre-project studies and processes, as well as in the construction of preparatory structures using traditional methods. In February 2015, the MTMDET awarded KPH Turcot the final design and construction mandate for the main Turcot Project infrastructure (2015-2020). The KPH Turcot consortium is a partnership of Construction Kiewit Co and Parsons Canada Ltd, with Holcim Inc. and WSP as participants.

Large Scale and Complex Project 

The objective of this design-build project is to build a complex of interchanges and highways connected to the existing road network, capable of providing users with a high level of road safety, service and comfort while maximizing the infrastructure’s lifespan.
The project includes:

  • Rebuilding four major interchanges and sections of three highways;
  • Moving a section of highway and railway to allow for future development of the Turcot Yard;
  • Adding dedicated lanes for modal transport (bus and taxi);
  • Significantly reducing the number of structures;
  • Improving the geometry of the road layout;
  • Re-establishing conventional east-west traffic flow on the A-20;
  • Building new links to the local road network;
  • Adding bike paths.
concrete pavement
135,000 m²
Highway lanes
145 km
7 km

Innovative Engineering

This project, one of the largest in the province, has its share of challenges, including:

  • Proper coordination of the necessary closures in order to minimize the impact on users of this very busy interchange. Alternatives such as bypasses and increased public transit must be provided to mitigate the inevitable effects

  • Reduce environmental impacts of the work by applying noise and dust control measures.

Unexpected challenges also arose during construction. The discovery of remains of a tannery resulted in an unplanned work stoppage. We helped the archaeologists sent by the client to collect various artefacts before work resumed.

To enable the consortium to stay ahead of schedule and optimize construction costs, WSP also innovated by:

  • Using precast concrete for:

    • Pre-slabs for overpass decking. The slabs normally cast in place are cast in the factory, which allows for temperature regulation, thus improving quality. The proportion of precast slabs allows for faster construction, resulting in cost savings;

    • Retaining walls certified for overpass abutments, which are usually cast on site.

  • Using recycled stones from existing structures for the foundation of the proposed roadways. This option lowers costs and allows reaching project GHG emissions by reducing travel;

  • Designing reinforced concrete pavement shoulders, used as slabs for the concrete safety barriers at the top of the retaining walls. Anchoring the barriers to the shoulder and the wider shoulder help absorb the forces on the barrier during an impact.

Turcot Interchange

Comprehensive Engineering Services

  • Environmental permitting, including for other stakeholders;

  • Design (drawings, specifications and technical reports):

    • Overall design (final pre-project);

    • Preliminary design;

    • Final design;

    • Plans issued for an EPC contract;

  • Visual simulations for public hearings and for the website of Quebec’s MTMDET to help with validation of engineering concepts and the demolition/construction stages;

  • Plans for the protection and demolition of existing structures, in connection with geotechnical and structural components and vibration monitoring;

  • Construction support and site supervision.

In order to meet and even shorten the schedule, while giving due consideration to safety and budget, we integrated a number of design elements, including:

  • The design of a structure with a strong 72 degrees deflection, thereby eliminating the need for tunnel construction, thus saving time and money;

  • The use of lightweight polystyrene backfill over the existing collectors instead of concrete slabs on piles, which makes installation easier and saves on the cost of time and materials;

  • Pumping stations with dynamic integrated management, a first in Montreal, which allows them to operate based on data from weather stations. Optimal pump operation provides benefits in terms of maintenance and durability.

Turcot Interchange

Value Engineering Delivers Savings

While respecting the timeline, we were able to meet the MTMDET’s expectations by incorporating the following into the overall concept:

  • Safety for users and workers, both during and after work;

  • Addition of a public transit reserved lane, as well as provisions for active transportation;

  • Encourage sustainable practices, for instance by reducing GHG emissions;

  • Integration of the project into existing city life, through architectural integration and plantings.

To date, WSP has delivered plans on schedule, enabling KPH to finalize construction of the interchange nine months to one year ahead of the MTMDET’s deadlines.