The TTC is getting a little bit spooky in advance of the opening of its new subway line. As the Toronto York Spadina Subway Extension nears its debut, the final stages of testing are taking place, part of which involves what's called "ghost service."

Despite the name, it's not a train full of poltergeists, but rather, a testing phase in which the trains operate as normal, just without passengers.

A post shared by Joanna Kervin (@joanna.kervin) on Feb 21, 2017 at 8:32am PST

The way this system will work is simple. For subway riders, Sheppard West will continue to be the end of the line, but after they've departed, the trains will continue to operate through the rest of the line up to Vaughan Metropolitan Centre as though they were still occupied.

TTC spokesperson Stuart Green says this allows the drivers, signal operators, and other staff to be trained in bringing the train through the six new stations, stopping at each, and returning back down the rest of the line.

A post shared by Joanna Kervin (@joanna.kervin) on Jun 3, 2017 at 11:06am PDT

This ghost service offers additional testing opportunities in other areas as well, including the opportunity to gauge timing and headways, which are crucial to have nailed down before the line opens to the public.

Examination of timing is particularly important. This allows the TTC to “time trips and then, if needed, adjust service to meet need. This will be helpful in collecting that information," Green says.

The ghost service is the final stage of trials in a long year of testing. CP24 reports that other phases have looked at safety issues, design corrections, and covering the trains in polystyrene to see if they bump into the walls.

A post shared by Joanna Kervin (@joanna.kervin) on Jun 4, 2017 at 4:46pm PDT

Ghost service isn't the only intriguing aspect of TTC testing on the TYSSE. Back in the spring, Joanna Kervin, director of the project, posted a photo showing the trains filled with concrete blocks, which was used to mimic the weight of passengers for high speed testing.

Ghost service will begin on November 26. These trials will continue until the new extension officially opens to the public on December 17.