504 King is the TTC's busiest streetcar route—but won't get new vehicles until 2018

When a TTC streetcar derailed on King Street on Tuesday, there was a potential silver lining to the transit chaos it created.

• 504 streetcar resumed service 9 hours after derailment at King and Bathurst

It wasn't just any streetcar that derailed. It was one of the TTC's shiny new Flexity models.

Yes, one of those delayed and controversial Bombardier streetcars. 

Have the new, low-floor models finally arrived on 504 King, the TTC's busiest streetcar route?

Unfortunately not, and they are more than a year away.

According to the TTC, the new streetcar was on King Street because it was needed to push an old and broken-down streetcar that had stalled on King Street. The new streetcar derailed after running over some debris.

New streetcars on shorter routes

The TTC has 23 of the new streetcars. The majority are running on the 510 Spadina and 509 Harbourfront routes.

There were an estimated 64,600 trips per day on the 504 King route last year, according to the TTC. Yet the new, higher-capacity streetcars aren't expected to be running there until 2018, according to TTC spokesperson Brad Ross.

Ross says the vehicles are being deployed this way so the TTC can get the biggest "bang for its buck."

With an estimated 43,800 trips in 2015, the 510 Spadina route isn't as busy as the 504 King, but it's a shorter route at about five kilmetres.

504 King is roughly 20 kilometres long.

"You're going to get much more out of the service with the new car on a shorter route like Spadina," Ross told CBC News.

With an estimated 43,500 trips in 2015, the 501 Queen route is slightly less busy than Spadina but much longer. The route is about 25 kilometres long.

Ross says deploying the few new streetcars the TTC has on long routes like King or Queen would be mean riders would see them much less frequently. "Once every five or six cars," Ross said in an interview.

The TTC has deployed one of the new streetcars on the new 514 Cherry route, which runs along a downtown portion of King Street, and more of the new vehicles are expected to land there.

"In the core it's really helping with capacity," Ross said.

Late delivery

Deploying the new streetcars would be a lot easier if the TTC had more of them, Ross says.

The TTC has ordered 204 of the vehicles from Bombardier. Seventy should have been delivered by now.

Ross says a new production schedule from Bombardier indicates that the TTC will receive between 30 and 35 vehicles by the end of this year and it's expecting to receive the entire fleet by the end of 2019.

The TTC has filed a $50 million claim against Bombardier for the late delivery. The claim, which is permitted in the contract, is currently being negotiated by both sides.

Ross says the delay is causing headaches for the TTC.

There aren't enough streetcars to sustain every route and some are being supplemented with buses.

Keeping the older streetcars on the roads also requires significant maintenance, Ross says, especially during the winter.

"It's another year, they're another year older. We are doing some rebuilds, but we are concerned that we're going to be short on streetcars."