The fast pace of new construction along the Green Line's southern leg, especially around the Navy Yard station, could put pressure on future transit capacity. Image by the author.

Metro has a well-documented need for a second tunnel to separate the Blue, Orange, and Silver lines at Rosslyn. However, the way the District is growing is creating another rail bottleneck  on the other side of town that will have to be addressed in the future.

When Metro studied capacity constraints within its core rail network a few years ago, many people were surprised to see Metro propose a subway loop around central DC, rather than simply separating the Blue Line. This full loop is needed in part because the Capitol Riverfront and Southwest neighborhoods are growing much more — and more quickly — than was anticipated, requiring relief for the Green Line.

Cranes dot the skyline above the Navy Yard, in a view from the 11th Street Bridge. Image by the author.

Boomtown, DC

The Capitol Riverfront is easily the fastest-growing part of DC right now, and by some accounts one of the fastest-growing neighborhoods in America. In 2014, almost as many housing permits were issued in just this one neighborhood as in the entire rest of the District combined: 47 percent of the housing permits were issued on just one percent of the District's land. Now that those buildings are welcoming residents, the local BID expects the area’s population to double to 14,000 within a year. Even larger residential complexes are planned, from South Capitol all the way to 12th St. SE.

The neighborhood is finally fulfilling its potential to feel lively, with dozens of restaurants, a supermarket, and a reopened school all bringing crowds even on the 3/4 of days when the Nats aren't playing at home. All of these new businesses put more jobs and amenities within reach of residents in nearby neighborhoods like Capitol Hill, Southwest, and Historic Anacostia. Substantial new tax revenues are flowing for the District, some of which paid for amenities like Yards Park.

A thriving neighborhood has quickly sprung up. Image by the author.

We're seeing the fruits of planning

DC planned far ahead for the growth now taking place in Capitol Riverfront. Postwar comprehensive plans identified the Washington Navy Yard as a facility with excess land and proposed various redevelopment schemes. Most notably, in 2003 the District adopted the Anacostia Waterfront Framework Plan, a detailed, long-term plan for growth along the Anacostia waterfront.

The AWFP identified specific locations for how and where growth would occur, urged that "a major waterfront park destination" be at the center of the Capitol Riverfront, and identified that new bridges at 11th Street and South Capitol Street could both transform the region's transportation network while also catalyzing development opportunities. However, even the AWFP only forecast 3,000 new housing units in Near Southeast.

Current plans aren't enough

Transportation plans formulated by the District Department of Transportation and Metropolitan Washington Council of Governments have other long-term ideas for additional improvements around Capitol Riverfront, like a redesigned M Street SE/SW

These plans largely take the Comprehensive Plan at face value, and assume that the Capitol Riverfront will develop in the more distant future. However Metro's ridership forecasts, which now factor in development proposals, foresee that the area's rapid growth might require additional investments. 

If all 11,978 new housing units proposed within the Capitol Riverfront get built, the area around Navy Yard station would have the largest household population of any Metro station. Plus, the Navy Yard station also already serves DC's largest employment center outside downtown (rivaling Rosslyn or the Pentagon), and is zoned for enough additional office space to become a job center on par with Farragut Square. Soon, there will also be two sports stadiums nearby, with 60,000 seats between them.

Station Households within walking distance Jobs within walking distance Trains per peak hour, 2015 Trains per peak hour, potential
Navy Yard (2014) 2,704 20,394 11 13
Navy Yard (proposed) 11,981 80,000 11 13
Columbia Heights 10,842 5,711 16 26
Dupont Circle 10,636 35,501 20 26
Silver Spring 6,775 21,477 20 26
Foggy Bottom 5,350 34,386 26 26
Farragut North + West 1,436 88,964 46 52
Rosslyn 4,346 19,906 26 26

Yet this area doesn't have equivalent rail service to other high-density activity centers — and Metro's current infrastructure means that it can't. Since the Green Line's southern branch shares downtown’s 7th Street tunnel with the Yellow Line, it is effectively only half a Metro line, with a capacity of 13 trains per hour. Without a second tunnel to split the Yellow and Green lines, Metro forecasts that the Green Line's southern branch could soon be the system's most overcrowded segment.

Farther up the line, platforms at L'Enfant Plaza and Gallery Place will also need to be upgraded as more Green Line riders transfer to other lines.

On its own, though, Metro is powerless to advance its member jurisdictions' long-range investment plans — and, as we know, there simply isn't enough money on the table to contemplate major new Metro expansions in the near future.

Yards Park's waterfall is a popular summertime destination for families. Image by the author.

Where's the next stop?

Right now, there are still plenty of vacant lots awaiting development, and the Green Line's southern leg is still among Metro's least crowded segments, but those conditions won't last forever. Near- and medium-term transportation plans can focus on ways to improve surface transportation around the Capitol Riverfront, like expanding bus service and making bike corridors more comfortable.

In the longer term, DC also needs to look past at the horizon to the time when the Capitol Riverfront is built out. Just as DC laid the groundwork for the Capitol Riverfront's growth back when its population was still shrinking, DC must plan and invest now for its next new neighborhoods. Capitol Riverfront was an easy place to steer growth to: it had many empty transit seats, but few neighbors who will complain about construction.

Now, many of these easy-to-grow places have been claimed. Luckily, lots of other places in DC can handle more growth, but they'll be harder places to grow: they're within or adjacent to existing neighborhoods, are further from Metro, or require transformational infrastructure investments.