In my best guess, the closest example of what we can (hopefully) expect from the metal exterior would be T-Mobile Arena. (also designed by Populous)
https://populous.com/project/t-mobile-arena
In response to Druh's comment about the importance of the bridge's underbelly, and the overall design remaining simple and slender...etc, this concept of the Skuru bridge via Bjarke Ingels is pretty cool and perhaps can lend some aspects to the Green Line bridge;
Source
It could be a neat...
A few rendering snips from the panels presented during the May 22nd open house.
Loving the design gradient of the tower facade!
Full panels can be found here FYI:
http://bucci.com/wp-content/uploads/2018/05/1712-COMMUNITY-BOARDS_MAY-FINAL.pdf
Thanks all!
The draft design package can be viewed here;
http://bucci.com/wp-content/uploads/2018/02/180220-1802-Radius-2-_Community-Feb-21st-Version.pdf
I'm interested in how they might integrate the brick work along the ground level.