What's That Mysterious Yellow Line in Related's Hype Video for The 78 Land

With all of the Amazon news last week, we stumbled across an old video for Related Midwest's hype video for their new development called "78".  Here is the video:

While the video isn't new, one thing stood out to us and it was this frame:

The interesting thing to us was that yellow line going down the west side of river.  Does anyone have any knowledge of what that would be?  We know there are an abundance "tracks" there, but curious if there are grand plans for this space.

Anyone know about that?