Our Civil West team has completed the 4th Avenue Flyover Bridge Rehabilitation Project, nearly three months ahead of schedule! All lanes are now open, restoring full access to Calgary’s downtown core and significantly improving traffic flow for thousands of daily commuters.

This milestone was not simply a matter of speed. It was the result of meticulous planning, disciplined execution, and a deep commitment to collaboration. Something the EllisDon team is not new to. Our teams worked through winter conditions, executed five full weekend shutdowns, and navigated around two Calgary Stampedes, all while maintaining the highest standards of safety and quality. The result is a revitalized bridge to serve the city for decades to come.

Where Roads Meet Real Life

The 4th Avenue Flyover is a vital artery for Calgary’s commuters, and keeping traffic moving throughout construction was a top priority. To achieve this, our team navigated 30 distinct traffic control configurations—an added scope introduced after the project was awarded and one that fell outside EllisDon’s traditional expertise. Rather than outsource or sidestep the challenge, we leaned in. We coordinated targeted skills training for our on-site personnel and ensured tight alignment across teams, particularly during night shifts and weekend closures. This deliberate expansion of our capabilities reflects our commitment to adaptability, collaboration, and delivering results under pressure.

Diving into the Details

Rehabilitating the bridge’s centre pier—anchored deep in the Bow River—posed one of the project’s most complex engineering challenges. The river’s fast-moving currents and unpredictable conditions ruled out conventional repair methods. EllisDon leaned into the challenge with a bold, resourceful approach that redefined what was possible in this environment.

The team proposed a specialized underwater construction strategy: large, watertight steel enclosures, essentially inverted bathtubs, would be sealed around the pier. With the help of commercial SCUBA divers, these enclosures were installed directly in the riverbed. Once the water was pumped out, crews could step into a dry, controlled space and carry out concrete restoration with precision and safety.

This wasn’t just a technical workaround, it was a high-stakes orchestration of people, equipment, and timing. Divers operated in low-visibility, high-pressure conditions, while topside crews managed logistics, structural work, and real-time coordination. Communication had to be constant. Safety protocols had to be airtight. Every move was deliberate.

It was a rare and highly specialized scope that few firms are equipped to handle. EllisDon didn’t just handle it. We led it. The solution had precedent in other projects, but this execution pushed the boundaries, combining underwater construction with live restoration in a way that showcased our ability to think differently, act decisively, and deliver under pressure.

This moment became the defining technical achievement of the project and a clear reflection of EllisDon’s commitment to innovation, adaptability, and excellence in complex infrastructure delivery.

Quality Decisions and Lasting Solutions

Adaptability was a defining feature of this project. We set out to replace nearly one kilometre of bridge railing, but encountered a major challenge: the structural cables running through the bridge were not evenly spaced. This meant each section of railing had to be uniquely designed to fit around the cables without compromising safety or structure. Using precise field measurements and close collaboration with our fabrication partner, we developed over 200 custom pieces, each tailored to its specific location on the bridge.

“Quality isn’t just a checkbox for us. We solve problems as they arise and make decisions that stand the test of time,” said Jonah Tsumura, Project Manager, EllisDon. “Our approach at EllisDon is grounded in making decisions to remain effective for decades to come. We adapt, we solve, and we always go the extra mile to ensure our work lasts for decades.”

Wrangling Roadwork During the Stampede

The Calgary Stampede transforms the city into a high-energy hub, drawing hundreds of thousands of visitors and placing intense pressure on downtown infrastructure. At the heart of this movement is the 4th Ave Flyover, the primary artery into the Calgary’s downtown and a critical access point to many of the Stampede's main events. Managing construction on and around this bridge during Stampede season demanded agility, foresight, and seamless coordination with municipal partners. Preserving this vital connection to the city’s biggest event was a necessity. Access needed to be available to ensure the Stampede could unfold without disruption, and downtown could continue to function under extraordinary demand.

To accommodate the surge in traffic, we temporarily opened an additional lane during the July 2024 Stampede and restructured our work schedule to avoid major closures on peak days. Our teams adjusted signage, staging, and work hours to ensure construction activities did not interfere with the festivities. It was a high-pressure environment where every decision had to be executed flawlessly. It was also a moment that showcased EllisDon’s ability to adapt in real time, maintain operational excellence, and deliver results without compromising safety or quality.

A Milestone That Reflects More Than Speed

The early reopening of both lanes on the 4th Avenue Flyover stands as a testament to EllisDon’s dedication and expertise, marking a significant milestone for Calgary. By minimizing disruption and maximizing impact, we continue to earn the trust placed in us for projects of scale and complexity. When the demands are greatest, EllisDon delivers; with precision, reliability, and a relentless focus on quality.