Just saw this on TTC website:
Cherry and Sumach streets - streetcar track testing
April 19 to 22, 2016
Work description and purpose
Testing to prepare for streetcar operations on Cherry and Sumach streets from the loop at the south end of Cherry Street to and through the King/Sumach intersection will begin at 9 a.m. on Wednesday, April 20. The testing will continue through to the morning of Friday, April 22, weather permitting.
Parking Reminder
As a reminder, parking is not allowed on streetcar tracks and is subject to tow at the owner’s expense. Effective 11 p.m. on Tuesday, April 19, 2016, please do not park on the streetcar track allowance on Cherry and on Sumach streets.
This testing is important and is essential to commissioning the new track for service. Any vehicle found on or near the track allowance that may interfere with the movement of the test streetcar will be subject to tow by Toronto Police at the owner’s expense.
A streetcar will be used to test all aspects of the new streetcar track from the loop to the intersection of King and Sumach, including track switches and the overhead relay to commission the track for the new 514 Cherry streetcar route, scheduled to start on June 19, 2016.
Thank you for your cooperation during these necessary preparations for the new streetcar service.
Work hours
Over the course of the three days, crews may also work overnight. Activities associated with the testing require TTC overhead trucks and a streetcar to be on site for the majority of the testing.
Thank you for your patience as we work to improve transit in Toronto.