Photo by sabine01 on Flickr.

By 2040, Metrorail ridership is expected to top 1 million daily rides and the system’s core will be severely crowded. To cope, Metro has been looking at long-term possibilities for expanding transit, whether on the Metro system itself or in other modes, like streetcars or BRT.

A “second generation” of the system might bring new lines to the region and extensions of lines beyond their current terminals. None of the plans are concrete right now, but the first step toward system expansion involves studying of multiple possible concepts and determining which make sense.

These projects are still very much in the planning phase. At this point, for Metro planners, it’s mostly about modeling ridership and attempting to find ways to optimize operations and redundancy in the system.

If this second generation system is constructed, only some of the lines and extensions up for consideration today will become a reality. And, before the work is complete, they may look significantly different than they do at this early stage. However, while changes to the current proposals are to be expected, these suggestions are noteworthy, nonetheless, as one or more of these scenarios likely represents the future of Metro.

Separated Yellow Line: As we’ve discussed before, Metro is looking at ways to separate the Yellow and Green lines. Mainly, this will allow for capacity increases on the Green Line, since the Yellow will still have to share with the Blue Line.

One concept involves building a new line under 10th Street SW/NW parallel to the existing Green/Yellow subway. This line would likely end near Thomas Circle. An alternative would take the line further east, crossing the Blue/Orange subway at Capitol South and ending at Union Station.


Potential separated Yellow Line alignments. Click to enlarge (PDF).


Separated Blue Line:
This idea is not a new concept. Metro has been talking about it for several years. It would greatly expand core capacity, especially on the Orange Line. Additionally, it would open up new areas of the core, such as Georgetown and Logan Circle, to rail service.

With regard to a separated Blue Line, Metro has looked at 2 basic concepts. Both would involve a new separated Blue Line from Rosslyn to the Anacostia River.

One option would be a subway roughly following M Street. From Rosslyn, it would cross the Potomac River to Georgetown, and then proceed east, toward Thomas Circle, Mount Vernon Square, and Union Station. It would rejoin the current Blue/Orange rail line at River Terrace, where the existing Blue and Orange lines diverge.


First potential separated Blue Line alignment. Click to enlarge (PDF).


An alternative vision also takes the Blue Line from Rosslyn to Georgetown, as described above. Then the line would turn south toward the State Department. It would run through Federal Triangle and Archives before curving north toward Union Station. It would then head east to rejoin the Blue/Orange lines at River Terrace.


Second potential separated Blue Line alignment. Click to enlarge (PDF).


Separated Silver Line: This option would shave a few minutes off of trips from Downtown to Tysons Corner and Dulles, but it would not add much capacity to the system. Instead of a new Blue Line subway along M Street, that line would be given over to Silver Line trains. Blue and Orange Line trains would continue to share tracks in DC.

The Silver Line would also get its own tracks in much of Arlington. After Rosslyn, the line would run “express” along I-66, with East Falls Church as its first stop after Rosslyn. It would share tracks with the Orange Line along I-66 before diverging to head out along the Dulles Toll Road toward Tysons.


Separated Silver Line. Click to enlarge (PDF).


“Brown” Line: The study is considering some completely new lines, as well. One, dubbed the “Brown Line,” would start at Friendship Heights and run down Wisconsin Avenue to Georgetown. It would then turn southeast, passing the State Department, before heading east toward Federal Triangle and Archives. It would stop at Union Station and continue north toward the Washington Hospital Center, Petworth, and Silver Spring. North of Silver Spring, the line would follow US-29 to White Oak and the Cherry Hill Employment District.


“Brown Line.” Click to enlarge (PDF).


Beltway Line: Another possibility is a heavy rail line circumnavigating the region. It would mostly follow the Beltway, but would deviate from that alignment to serve areas like Wheaton and National Harbor.

It would not replace the Purple Line light rail currently in the design phase. In the northern suburbs, the Beltway Line would be north of the Purple Line alignment, intersecting the existing rail lines at New Carrollton, Greenbelt, Wheaton, and Grosvenor.


Beltway line. Click to enlarge (PDF).


National Harbor spur:
Metro is also considering building a spur off of the Green Line, connecting Congress Heights to the National Harbor development on the Potomac River. This line would primarily follow MLK Avenue. Since it would be sharing the Green Line, it would constrain headways on both branches south of Anacostia.


Possible National Harbor spur and extensions. Click to enlarge (PDF).


Extensions: The planning group is also looking at extensions to some of the existing lines. Elected officials in outer areas and people on our “fantasy map” discussions have often suggested them.

Without additional core capacity, though, these additions will only further burden the system. Although not all of these extensions will be built, Metro is looking at a variety of options for modeling purposes. They’re considering how many new trips are generated, as well as how these extensions affect crowding in the core.

Potential extensions include:

  • Red Line: Western extension from Shady Grove to Metropolitan Grove
  • Green Line: Northern extension from Greenbelt to BWI Airport
  • Orange Line: Eastern extension from New Carrollton to Bowie
  • Blue Line: Eastern extension from Largo to Bowie
  • Green Line: Southern extension from Branch Avenue to Waldorf
  • Yellow Line: Southern extension from Huntington to Lorton, via US 1
  • Blue Line: Southern extension from Franconia to Dale City
  • Orange Line: Western extension from Vienna to Gainesville
  • Silver Line: Western extension from Route 772 to Leesburg


None of these are about to be built or even necessarily things Metro believes are good ideas. The study is simply evaluating options with an open mind. They generated some projections around ridership, which we’ll look at in more detail, and are also studying light rail and BRT options alongside or instead of Metrorail.

Matt Johnson has lived in the Washington area since 2007. He has a Master’s in Planning from the University of Maryland and a BS in Public Policy from Georgia Tech. He lives in Capitol Hill. He’s a member of the American Institute of Certified Planners, and is an employee of the Montgomery County Department of Transportation. His views are his own and do not represent those of his employer.