A Tram on Stilts: Calgary's Green Line

Eric Davidson | Calgary, Canada | 2025/03/27

Since the 1980s, Calgary has envisioned a north-central to southeast transit spine to complement the Red and Blue Lines. City planning documents were clear: low-capacity options like buses or trams/streetcars were not going to cut it for even medium-term ridership needs. Calgary needed a true CTrain line for all-day city-wide mobility. The Green Line was supposed to be that next-generation line: a high-performance, high-speed, and high-ridership CTrain line to move hundreds-of-thousands of people through Calgary’s core and beyond.

We got a tram on stilts instead

Fast forward to 2025, and the Green Line is going ahead, but not in the form originally imagined. The city has committed to building a fully elevated guideway through the Beltline, Downtown, and Eau Claire. This is metro-scale infrastructure: stations with elevators and escalators, heating and cooling systems, complex vertical access, and all the costs and operational overhead that come with it. It’s the kind of construction you expect for a metro system or at least high-floor trains like Calgary’s existing network. Instead of putting a high-capacity train on that guideway, we’re planning to run low-floor trams. The city procured these sleek-looking, European-style vehicles before finalizing the alignment. And once the vehicles were locked in, everything else (station design, platform height, turning radii, etc.) was forced to accommodate them. We’re now left with a bizarre mismatch: massive infrastructure with low-capacity trams.

This is profoundly absurd

Trams are incongruent with the infrastructure we're building. The Green Line’s low-floor vehicles are significantly different from the Siemens high-floor trains we use on the Red and Blue Lines. Trams are lower capacity by design, and because they’re low-floor, they’re also longer and narrower to fit the same number of passengers. This makes them feel more like elongated buses than trains. There’s less space, fewer seats, and more standing-room congestion. The boarding experience doesn’t match what Calgarians have come to expect from rapid transit. Trams work perfectly in at-grade, street-integrated systems in cities like Amsterdam, Dublin, Zurich, Nice, or even Waterloo (Ontario!). But on a billion-dollar elevated guideway? It’s the wrong tool for the job. Not only is this overbuilt for a tram, but it also locks us into a low-capacity mode on a corridor that desperately needs higher performance. And that’s before we even get to the long-term costs.

The long term cost

Building elevated transit infrastructure is expensive to construct and operate. We’re committing to decades of higher costs for maintenance of viaducts, snow clearing, elevators, escalators, HVAC systems, and more. An at-grade tram line wouldn’t require any of this. It would have been simpler, cheaper, more flexible, and easier to build. In fact, it’s estimated that going with the elevated structure added at least $1 billion to the cost of the Green Line. That money could have built 13–15 kilometers of additional at-grade track, added ten or more stations, and served tens-of-thousands of more Calgarians. It could've extended the Green Line all the way to the South Health Campus, or potentially even north of Stoney Trail into Livingston. But instead, we're spending a billion dollars to elevate vehicles that were never meant to fly.

There's still a viable path forward 

At this point, the elevated structure is locked in, and so are the low-floor trams. But there is still a viable path forward. Calgary already identified two long-term tram projects in its official transit planning:

• A tram line along 9 Avenue SE through Inglewood and into International Avenue

• A tram line from Mount Royal University to Westbrook Station

These are perfect projects for the low-floor vehicles we’ve already bought. Even if those projects aren’t built for another 5 to 10 years, the trams could be stored and used when the time is right. The cost is already sunk. Meanwhile, the Green Line could be retrofitted to high-floor platforms and equipped with Siemens S200 vehicles, the same trains already in service on the Red and Blue Lines. This would align the Green Line’s infrastructure with a mode that matches its scale and ambition. It would unlock higher capacity, better service quality, and full system integration. Any additional vehicles not needed for these projects could also potentially be divested.

Let's step up to high-floor trains

Putting trams on this kind of infrastructure is not just a technical mistake, it’s also a strategic failure. There is something absurd with building the infrastructure for a full CTrain line and putting trams on it. The result is an expensive, overbuilt, underperforming hybrid that satisfies no one. It’s not too late to fix it. Let the trams serve the streets, as they were meant to. Let the train serve the spine, as it was always envisioned. Calgary still has the chance to get this right.