Toronto's newest subway line, one that's been in the works for over a decade, is entering its final stages.

A news release from the TTC issued today notes that another major milestone has been reached in the construction process for the Spadina Extension: test trains are now running in the tunnels!

"The third rail on the TTC's Line 1 Yonge-University extension into York Region was powered up for the first time yesterday, allowing for testing of the Automatic Train Control (ATC) signal system and trial runs for trains," reads the release.

We've already seen how far along some of the stations are on the new line. Downsview Park, for instance, is virtually complete. Further north, York University is shaping up to be the nicest station in the entire system.

The TTC has pegged this December as the opening date for the new line. With infrastructure projects of this scale, there's lots that needs to fall into place during the final stages to meet opening dates, but on a visual level, it looks well within reach.