Street-level or elevated tracks? Province reviewing options for Calgary's Green Line

As work on the Green Line gets ready to roll again, the biggest question about the LRT project continues to be about its route through Calgary's downtown.

A provincial review of alternative alignments through the core is underway after the Alberta government deemed the plan to tunnel too costly.

"When you go underground, it's $1 billion a kilometre. If you stay at surface, it's $100 million a kilometre," Premier Danielle Smith said Thursday.

"So that's part of the reason why the cost is escalated. And so, we're going to work together to see if we can find a solution."

Though many details of the new version of the Green Line project are unknown, the province has made it clear a tunnel is no longer on the table.

Options to go through downtown "will be either at-grade or elevated and will connect into the Red and Blue lines, the new Event Centre and to southeast Calgary communities," reads a joint statement from Calgary's mayor and Alberta's transportation minister.

Street-level and elevated track options were considered by Calgary nearly a decade ago.

Ultimately, the city opted in 2016 to go for the tunnel option -- by far the costliest of the three considered -- due to public feedback and considerations of traffic disruption, property values, noise and even shadows caused by an elevated track.

An elevated line, which was considered to run up 2nd Street S.W., would also have to contend with some of the city's Plus-15 network.

Different alignment options come with different complications, transportation experts say.

"Our north-south streets are too short. They don't fit the trains that we have and one of the things that'll be very challenging on that is how do you reconcile that as part of what a new Green Line could look like downtown?" said David Cooper, a transportation planning consultant.

"Elevated, that's something that has been looked at. The city is full of Plus-15s, so how do we look at integrating the Green Line into the public right-of-way?" he said.

Former Calgary mayor and current Alberta NDP leader Naheed Nenshi called the province's handling of the Green Line "a catastrophe" and questioned how much money could really be saved with an alignment that doesn't include tunnelling.

"They will be surprised when they realize that an elevated alignment doesn't cost much less than a tunnel," Nenshi said.

"Because we know this. We already did that research."

On Thursday, the City of Calgary and Alberta government announced it would continue with the planning, design and construction work of the line from Shepard to 4th Street S.E. in Victoria Park.

The review of alternative options through downtown is being developed by AECOM and is expected in December.