DDOT has completed the Oxon Run Trail Concept Plan and it does a great job of rebuilding and enhancing the existing trail.
The existing trail runs from from South Capitol Street SE to 13th St SE in the Washington Highland area. The new trail would extend southeast to the DC-MD line and connect with the trails in Oxon Hill Farm NP and northeast to Southern Ave (and the Metro station there) where, with help from PG County, it will connect to the Suitland Parkway trail.
There will be a full trail on both sides of Oxon Run, much of it widened to 10' and improved. There are several bike/ped bridges that cross the stream and those would also be widened and improved. Many of the sidewalks will be upgraded and new ones will be built. In some places the trail will be rerouted to make it straighter. Bike lanes will be added to Southern Ave and Mississippi Ave to serve as the northern piece. New bike ped bridges will be built in DC across Oxon Run south of the South Capitol Street bridge and in Maryland crossing the unnamed tributary to Oxon Run adjacent to the existing Oxon Cove Connector Trail pedestrian bridge; crossing the unnamed tributary along Audrey lane; and across Barnaby Run - all on NPS land. A new trail from Joliet St SW to Blue Plains Dr. SW is included too. Most of these bridges can be seen on the rendering below, which is of the southern section.
The project will have a significant stormwater element to it. Water now goes from street to stream,and the plan is to add bioretention elements as an interim step.
The southern extension is along NPS land and so has an added level of complexity. The rest of the trail is on land DC controls, but agreements with the NPS, MNCPPC, and the Town of Forest Heights may be required for potential easements or maintenance agreements once construction is complete. The northern extension is mostly on-road, away from Oxon Run. Due to the steep slopes in that plot of NPS-owned land, concerns about military uses on the land in the past (and possible buried contaminants) and some trees that NPS thinks highly of, DDOT doesn't think the park land there is as suitable for a trail.
DDOT has been working with the Oxon Run Citizen Association (ORCA) as a citizen stakeholder group and is now waiting on comments
If funding is found, they'll design it all at once, but the construction will be done in two phases. Building it will cost about $10.7M for 5 miles of trails, connections and other amenities. If lights are added, which the community really supports, that adds another $5M, in part because the lights can't be solar due to the tree canopy. The money would likely come from the Department of Parks and Recreation and it hasn't been identified yet.
That trail is in serious need of help, and if it becomes a connection between the Wilson Bridge, S. Cap trail and Suitland parkway, it could be a linchpin in bike/ped connectivity along the SE/SW border with Maryland. This is an overlooked, but critical project and I hope they find funding for it.