The Toronto Transit Commission is expressing concern Bombardier (BBDb.TO) may not be able to meet its original timeline for delivering long-awaited streetcars. In a report issued Wednesday, the TTC said its staff assessment of Bombardier’s production readiness at facilities in Thunder Bay, Mexico and Europe sowed doubts as to whether the Quebec manufacturer can deliver the promised 204 streetcars by 2019.

“Staff believe that there is a risk that Bombardier may not be able to meet its revised delivery schedule as submitted on May 18, 2016 and there is a risk that Bombardier may not meet the revised delivery schedule for contract completion of 204 new streetcars by 2019,” according to the report.

The TTC also noted the average age of its current fleet far exceeds the normal operating life of 30 years, and that it will be forced to press more buses into service as a result of Bombardier’s issues.

“A life of 32-37 years without a major carbody rebuild is unheard of for a streetcar of this type operating in the conditions experienced in Toronto,” the report states. “The risk of failing to meet streetcar service demands requires supplementing with bus service on some lines until the [Low-Floor Light Rail Vehicles] delivery is complete.”

The TTC is scheduled to have 30 of the new vehicles in service by end of year, and 70 by December 1, 2017. The project has been marred by production delays, which union officials at Bombardier’s Thunder Bay, Ont., plant have partially blamed on poor-quality components made in Mexico.