I saw them putting in the foundations for these a long time ago, put orange cones over most of them at the time. They may be related to the new signal system.
Next stop the square, journal square station next!
The cable poles they use elsewhere are also galvanized steel, so it's clearly going to involve stringing lines of some kind. The ones they have in use now have a steel suspension cable that the utility cables hang from with straps/clamps etc.
Next stop the square, journal square station next!