Toronto's new fleet of streetcars has been plagued with problems from the get go, especially since they failed to arrive on time.

But while more and more of these vehicles are appearing on TTC routes through the city, the Toronto Star reports that they might not meet reliability targets.

TTC CEO Andy Byford's latest report shows that the mean distance between failures (delays of five minutes or more) dropped to 5,530 kilometres, from 16,000 in February.

When the 60th streetcar is delivered (it's supposed to be in November), the report says the reliability target is 35,000 kilometres between delays of five minutes or more.

A streetcar engineer told the Star it wouldn't be possible for the Bombardier streetcars to meet these reliability targets by November.

Most of the problems leading to the delays are relatively minor and mainly have to do with the streetcar doors, but if the vehicles continue to miss reliability targets beyond the 60th car, the TTC would have the right to refuse additional deliveries from Bombardier.