At about 4:30 a.m., the TTC took one of its new streetcars on a brief trip along Bathurst Street from its Hillcrest facility to the subway station and back.
The TTC's Brad Ross tweeted pictures of the "maiden trip" Thursday morning.
Another test is tentatively scheduled to take place in the early hours of Friday morning, with the streetcar heading south to the Exhibition loop then back to the Hillcrest facility.
Andy Byford, the TTC's chief executive officer, said that the first test was viewed as a "massive step forward" with promising results.
"Last night, we were testing every form of system on the vehicle — the propulsion, the overhead wires, seeing how it performs going up and down hills and around curves — and so far, so good," he said.
Byford said there are many more tests to go before the streetcars will be ready for service.
"These are very early days … and we are going to be undertaking an exhaustive series of tests throughout the rest of this year to make sure that this car does what we want it to do," Byford said.
"We’re buying 204 vehicles, we want to get them right."