I did a search about it and this is what I found out:
The Rhode Island Avenue Pedestrian/Bicycle Bridge will link the Metropolitan Branch Trail and its connecting neighborhoods to the Rhode Island Avenue Metro Station and adjacent communities. It will create a safe passageway for community members who currently use the Rhode Island Avenue underpass, which is narrow and dark, or who cross the active railroad tracks increasing access to transit and recreation for thousands of residents.Also on the site are construction updates. This is the one from April:
The truss bridge is designed in the style of an old railroad bridge. Ramps on both sides will provide wheelchair and bicycle access while a stairway on the west side will provide a more direct route. The open design will allow for visibility as well as beautiful city views and 24-hour lighting will enhance safety. The bridge will connect into the open section of the Metro station, providing connectivity even when the station is closed. The design is the result of unprecedented cooperation among numerous stakeholders including DDOT, WMATA, CSX, utility companies and the community.
Crews are currently focused on drilling and preparation to install piers on the southeast side of the CSX railroad tracks adjacent to the Rhode Island Avenue Metro Station. A shield has been installed to protect any potential impact to WMATA right of way areas. Crews are also working on the main stairway on the Met Branch Trail side. None of this work is expected to impact the travelling public. Please use caution when travelling along the Metropolitan Branch Trail in this area. The project is projected to be completed on time by January 2015.
I'm still not sure how this is going to work. Seems to me that there are going to have to have fare gates somewhere for people to use. I don't see, right now, where those are going to go. But it will be interesting to see how things develop.