Louis-Hippolyte La Fontaine Tunnel — Quebec, Canada

  • Ministère des Transports et de la Mobilité durable (MTMD)
Project Value






The ministère des Transports et de la Mobilité durable (MTMD) of Quebec is currently undertaking a major rehabilitation project for the Louis-Hippolyte-La Fontaine Tunnel. The goal of the rehabilitation is to ensure the infrastructure’s sustainability so that it can continue to play its key role in the mobility of people and goods along Highways 20 and 25. Inaugurated in 1967, the Louis-Hippolyte La Fontaine Tunnel is an important road link for users and freight transport in the region, Quebec, and Canada. As an integral part of Highway 25, it connects the east end of the Island of Montreal to Longueuil via Île Charron.

The Louis-Hippolyte La Fontaine Tunnel is the largest underwater tunnel in Canada, 1.5 kilometers long, and connected to a 457-meter-long bridge.

Our Role As Owner’s Engineer For The Louis-Hippolyte La Fontaine Tunnel

In a joint venture (JV) with TetraTech, we have been acting as the owner’s engineer on this mandate since March 2018, utilizing a design-build finance project delivery contract. The JV was in charge of preparing the technical specifications and establishing the performance criteria. The JV also assisted the client during the request for proposal and is presently providing technical support throughout the construction. Construction began in the summer of 2020.

Canada’s Top 100 Infrastructure Projects

The Louis-Hippolyte La Fontaine Tunnel is featured as a part of ReNew’s Top 100 list of Canada’s Infrastructure Projects (#33).

Check out the full list!

Construction In Progress

  • Wall and vault repair in tunnel traffic tube, southbound traffic tube
  • Wall repair at the portals and approaches, southbound traffic tube
  • Replacement of portal concrete support beams, southbound traffic tube
  • Wall repair in the tunnel corridor
  • Airlock chambers for evacuation purposes
  • Saccardo ventilation system installation
  • Repair of the Souligny Interchange structures
  • Construction of a covered structure at the portals
  • Rehabilitation of various components of the tunnel, including the concrete screed, joints, and drainage
  • Modernization of electrical, lighting, ventilation, monitoring, and communication systems

Completed Construction

  • Saccardo ventilation building at the portals
  • Electrical building construction near the ventilation towers
  • Placement of portal steel support beams
  • Road works on Highway 20, including new pavement, drainage, and signage
  • Multi-use path and noise barrier wall bordering Curatteau Street
  • Construction of three incentive parking lots for public transit
  • Implementation of mitigation measures in public transit, including a highway widening and the addition of bus-dedicated lanes at different locations of the provincial roadway network

Upcoming Construction

  • Rehabilitation of the northbound traffic tube
  • Addition of rockfill over the tunnel
  • Reconstruction of the concrete pavement of Highway 25 on either side of the tunnel between Île Charron and Sherbrooke Street in Montréal
  • Tunnel architectural features, i.e., covered structure at the portals, lighting, and landscaping
Explore Our Groundbreaking Tunnel Innovation

For over 70 years, we’ve planned, designed, engineered, built, and managed complex tunnels from transit to sewers and pipelines. Many of these projects involve challenging geologic environments, from seismically active Southern California to the Chesapeake Bay’s alluvial littoral. Our unparalleled experience includes over 250 tunnels and ocean outfalls around the globe. Learn more.

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