The new Ontario Line will include protective barriers at all stations to separate platforms from the tracks, something the Toronto Transit Commission has been considering adding to its subway system for years. "Platform edge doors" will be a part of all 15 stations on the 15.6-kilometre downtown subway line, slated to open in 2031, city staff said at a budget meeting Wednesday. The doors are transparent barriers that open to allow riders inside when trains roll in, but otherwise keep people, animals and debris off the tracks.