The distance that the TTC’s new streetcars are travelling before experiencing a technical failure appears to be trending downwards, raising some concerns about the reliability of the vehicles.

According to statistics contained in a monthly report from TTC, CEO Andy Byford, the vehicles travelled an average of 5,530 kilometres before requiring repairs in April. That is down from an average of 7,372 kilometres travelled before needing repairs in March and 16,431 kilometres in February.

The number is also well short of the 35,000 kilometre threshold for defect-free travel that the TTC’s contract with Bombardier says must be reached, beginning with the delivery of the 60th streetcar.

Right now, there are 35 of the new streetcars in service.

“A lot of these are new designs. They are designs that haven’t been done anywhere else in the world so there are growing pains,” TTC Spokesperson Stuart Green said of the issues on Wednesday. “It is unfortunate that our customers do get caught in that sometimes but we will get there.”

Green said that the most common issues that the TTC has encountered on the new vehicles include defects with the doors, as well as the air conditioning system and the passenger information system.

He said that the new streetcars are under warranty so Bombardier has fixed all of the issues that have been discovered to date without passing the bill onto the TTC.

Green also said that there are some positive signs on the horizon, including one new streetcar which went into service a month ago and hasn’t yet had any issues.

“I will say that when we got the Toronto rocket subway cars they had door issues as well, they had some other issues and we worked with Bombardier to repair them and now it is considered one of the best subways in the world,” he said.

The TTC is spending $1.2 billion to replace its entire streetcar fleet; however the order has been plagued by numerous delays and vehicle quality issues.

In his report, Byford says the schedule for the delivery of the streetcars remains at risk due to “known manufacturing issues” but he said that Bombardier does “remain on track to deliver a cumulative 70 vehicles by year end.”

For its part, Bombardier has said that it remains on track to deliver all vehicles by 2019.