New plans call to double the number of railroad tracks over the Potomac River between DC and Arlington, and to build a new pedestrian/bicycle bridge between Southwest Washington and Crystal City.
Plans would add two new structures parallel to the existing Long Bridge railroad bridge, which today carries two railroad tracks over the river. One new twin bridge would add two new railroad tracks, doubling the two for a total of four. The second new structure would add a separate dedicated bridge for people biking or walking only.
This map shows the existing railroad bridge, its proposed twin just upstream, and the proposed bike/pedestrian bridge just upstream from that.
More rail capacity
The District Department of Transportation (DDOT) presented the plans at a meeting November 29, following a years-long study of railroad crossing needs.
Long Bridge carries freight rail, Amtrak, and VRE over the Potomac into DC. Its two-track layout is at maximum capacity, and is one of the most serious bottlenecks on the east coast. Amtrak and VRE would like to run more trains, and MARC might like to extend its commuter trains into Virginia, but before any of that can happen, there need to be more tracks over the river.
Thus DDOT's study, which ultimately recommended keeping the existing Long Bridge and adding a new second rail bridge parallel to it to double the number of tracks.
Trail users get a bridge too
DDOT's plans also call for a dedicated bike and pedestrian bridge just upstream from the new rail bridge. The bike bridge would be built to benefit to the National Park Service in order to mitigate impacts to NPS parkland caused by the new rail.
On the DC side, the bike bridge would end at Ohio Drive on the East Potomac Park island. To cross Washington Channel and reach mainland DC, users would have to go a couple of blocks on surface streets and then pick up the sidewalk on the Case Bridge.
On the Virginia side, the bike bridge would have two landings: One down to the Mount Vernon Trail, and a second to Arlington's Long Bridge Park, where users can pass through on their way to Crystal City.
WashCycle has more details on the bike bridge.
More planning and money are needed
These plans are DDOT's initial “prefered alternative,” meaning their favored option out of the many they studied. But the study isn't over. DDOT will next look more closely at the potential environmental impacts, hoping to be done in 2020.
After that, it's up to the accountants. The new railroad twin bridge alone is estimated to cost $1.3 to $1.6 billion. The bike bridge would be extra, and although DDOT hasn't released cost estimates for it yet, as a lighter separate structure it would be only a fraction of the rail bridge's cost.
Construction would take five years. Taking into consideration time needed for detailed engineering, that puts the new bridge's opening at probably no sooner than 2026. Even that assumes no delay in securing funding, which is far from guaranteed.