New Blue Line Connections

July 12th, 2013

Adding new Blue Line connections seeks to restore train frequencies  to every six minutes during the peak period between Pentagon and Rosslyn stations, resulting in less waiting time and crowding for Blue Line riders in Northern Virginia. Once the Silver Line opens, the Blue Line service will operate every 12-14 minutes as opposed to the previous six minutes. The feasibility analysis is currently underway and has identified two potential alternatives to create new connections:

  • Alternative 1: Add rail track that would create a new connection between the Blue and Orange/Silver Lines, or
  • Alternative 2: A second Rosslyn Station for a new Blue Line with an underground passageway to the existing Rosslyn station, which would connect to the Orange/Silver Lines with a pedestrian tunnel.

Graphic for Rosslyn Interline ConnectionGraphic for Second Rosslyn Station

Purpose and Need

In 2012, to prepare for the Silver Line and better match ridership growth on the Orange Line west of Rosslyn, service changes were implemented that added more capacity to high-growth areas along the Orange Line. Due to the limit of 26 trains per hour per direction from Rosslyn into Washington, Blue Line service was reduced from every six minutes to every twelve to fourteen minutes. Even with expanded Yellow Line service between Virginia and Washington, Metro recognizes that this service change has been disruptive to thousands of riders, especially those who are among the 32,000 peak period daily trips recorded between the west side of Washington and south Arlington and Alexandria. When the Silver Line opens, Blue Line frequency will decline slightly.

This initiative will restore peak period Blue Line service between Pentagon and Rosslyn stations and provide more frequent trains to Metro’s Blue Line customers in Northern Virginia by adding physical capacity for more trains to move to and from and potentially through Rosslyn station. By creating this capacity, Metro will also be provided with needed flexibility at one of the system’s most congested sections.


  • Both alternatives would add five more trains per hour during the peak period between Pentagon and Rosslyn stations, which would provide capacity for at least 4,000 more passengers per direction. This would reduce crowding and wait times by an average of three minutes per trip for around 16,000 trips. These more frequent trains would also benefit new intra-Virginia trips that may occur after the Silver Line opens.

Alternative 1: Add rail track that would create a new connection between the Blue and Orange/Silver Lines

  • Enables a one-seat ride between Dulles Airport, Tysons Corner, Ballston, the Pentagon, National Airport, and Alexandria without having to travel through the core;
  • Adds five more trains in the both directions on the Silver/Orange Lines west of Rosslyn, adding capacity on one of the busiest sections of the system; and
  • Adds operational redundancy and flexibility so that riders will have more options to avoid congested areas of the system.

Meanwhile, Alternative 2, a second Rosslyn Station with an underground passageway to the existing Rosslyn station, would set the stage for a second connection across the Potomac – the first step in creating a new east west line into and through downtown Washington.


  • Both alternatives have complex constructability and must safeguard existing high density development.
  • Construction may impact federal property and monuments, such as Arlington Cemetery and the US Marine Corps Memorial, which will require a lengthy environmental review and a high level of mitigation.
  • Stopping short of adding the cross-Potomac connection, neither alternative increases capacity across the Potomac River. The restriction remains 26 trains per hour.
  • The total time-frame of ten years for planning, design, procurement and construction calls for an early start. Metro is currently conducting a feasibility study.

Status of Ongoing/Previous Studies

  • Capacity Study (2002): developed plans and profiles of both alternatives.
  • Northern Virginia Core Capacity Study (ongoing, 2013): examines feasibility of the alternatives in greater detail and exploring other short-term and interim-term solutions.

FY2014-2019 Investments

These investments are already included and funded in Metro’s current six-year CIP.

  • Planning and feasibility studies
  • Pocket track/crossover feasibility testing

Total – $1M

Order of Magnitude Cost Estimate

$1 billion (2012$)

  • Alternative 1: Add rail track to create a new connection will require mined tunnels and large trenches to expose existing tunnels plus new rail cars
  • Alternative 2: A second Rosslyn Station will require tunneling of tracks, an underground station, large trenches to expose existing tunnels, plus new rail cars


Timesline - Blue Line

For more information:

Download both the full Momentum plan and the Executive Summary.

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  1. Matt Dickens
    July 12th, 2013 at 10:26 | #1

    Alternative 2 has to happen so that in the future we can run a separate Blue Line through the core.

  2. JDC
    July 12th, 2013 at 11:32 | #2

    I concur. It makes no sense to do Alt 1, when Alt 2 is what would be needed several years down the line.

  3. Jim
    July 12th, 2013 at 12:26 | #3

    I’m on record as favoring Alt. 1 (I once wrote Mayor Euille urging him to support it). But if the purpose and need is to increase frequencies between Franconia/Van Dorn and the Pentagon, there’s an obvious quick and cheap alternative: install a pocket track on the at grade tracks between Pentagon and Rosslyn. That would enable half a dozen extra “short Blue” trains to run between Franconia and Pentagon. It should be doable within a couple of years and would therefore match up with the increased pseudo-BRT traffic along the new I-95 HOT lanes into the Franconia bus station.

  4. JDC
    July 12th, 2013 at 12:38 | #4

    Jim has a very good idea there, but I think the idea is to get the folks all the way to Rosslyn, which that modification would not allow since it would just dump people at Pentago, who would still need a Blue to Rosslyn (unless a bus of some sort was running back at forth).

  5. Michael
    July 12th, 2013 at 15:20 | #5

    I support Alternative 2 being the preferred path forward. Eventually, to deal with an increase in use across the system, the Blue Line needs to be seperated from the existing Blue/Orange lines through Washington. A new underground Blue Line across the river and in to DC under M or N or P streets would bring more train access to the north part of downtown.

    JDC brings up an interesting temporary solution to implement in the near-term, the pocket track addition on the at-grade section of track south of Arlington Cemetery Metro. It’s about time Metro is going on record saying we need new tracks in the central part of the system.

  6. Justin
    July 12th, 2013 at 16:33 | #6

    @Jim Interesting idea about a “short Blue,” Jim. How would that differ from continuing those trains to L’Enfant and beyond as a Yellow line train from Franconia to Greenbelt?

    That might achieve the same effect, but with other benefits – gives more riders the choice to ride straight into downtown, and increases service on the Green/Yellow core?

  7. July 13th, 2013 at 09:49 | #7

    Alternative 1 also is a step toward an expanded cross-Potomac capacity, and at much lower cost than a new Blue Line tunnel. It enables the separation of green and yellow lines in DC and use of the yellow line bridge at 100% capacity instead of the current 50%. Conceptually, blue line trains would all go through Foggy Bottom again, and silver line trains would use the yellow line bridge. This adds just as much capacity as a new blue line under the Potomac and through DC, since the blue line which shares track with the yellow line in Alexandria can’t run at more than 50% capacity where it has its own track.

  8. JDC
    July 15th, 2013 at 11:21 | #8

    I like Ben’s interim idea – basically a Silver line that runs south from Rosslyn, paralleling the Blue line through Arlington Cemetery, and then going north at Pentagon into the heart of DC at L’Enfant via the underutilized Yellow Bridge. That would a) increase service at Arlington Cemetery and b) increase use of that bridge and c) make a nice short trip to Dulles from L’Enfant. Downside: L’Enfant is already near capacity in terms of trains from Yellow and Green. Adding Silver would make it worse and, I think, require one or two less Green or Yellow trains, which would upset a lot of people.

  9. Andrew
    July 16th, 2013 at 10:25 | #9

    Really, it comes down to maximizing the capacity of the entire system. Any segment of track shared by two or more lines is near or at capacity, whereas any other segment (besides on the Red line) has capacity to spare. It would be great to build a new blue line tunnel through downtown, and planning now should take that into account. However, it doesn’t make any sense to send only blue line trains through it, since the tunnel would never be more than half full.

    Rather than building a new two-track Rosslyn station connected to the existing one with a passageway, it seems that really the goal should be a new 4-track Rosslyn station, with both outbound tracks stacked above both inbound tracks. A new color could then be added from Franconia-Springfield (call it “teal” for the moment) where blue line and orange line trains use the old tunnel and silver line and teal line trains use the new tunnel. This is the only way to maximize the capacity of BOTH tunnels, and Rosslyn becomes the convenient transfer point between these four lines. Stadium-Armory would then need to serve as a similar cross-over station on the other side, with teal and orange headed to New Carrolton and blue and silver headed to Largo.

    Both the Pentagon and Rosslyn stations have a distinctive split-level design. I can imagine how it could be possible to put two more tracks and platforms through the existing station rather than needing to build a new one. It even seems possible to add a single “pocket platform” below the upper platform at both Pentagon and Rosslyn to allow for blue line “shuttles” that don’t interfere with the orange, silver or yellow lines.

    The challenge, of course, is keeping the station operational while doing that.

    Alternative 1 could be pursued separately and certainly seems useful. But then the question becomes: what do you do with those trains once they get to Pentagon? If they continue south, they in effect reduce capacity on the yellow line bridge. If a second wye is built bypassing the Pentagon station and routing the Silver line to L’Enfant, this in effect reduces capacity on the green line. If a THIRD wye is built routing silver line trains to Navy Yard, this finally solves the capacity problem. But if Pentagon and L’Enfant are both bypassed, the proposed station near the Jefferson memorial would need to be built as a transfer station, and wouldn’t really be convenient for commuters.

    The other way to make Alternative 1 work would be to add lower-level pocket platforms to BOTH Rosslyn AND Pentagon. Some silver line trains could terminate at Pentagon, and some blue line trains could terminate at Rosslyn.

  10. Rich
    November 18th, 2013 at 17:23 | #10

    I definitely think Alt 1 is the best choice. As jobs and population continue to explode in Fairfax (especially around Tysons and Ft. Beloir), it seems prudent to plan for a line that bypasses any river crossing.

    Silver could be redirected from Largo to Springfied. Or (vice-versa), Blue could be redirected to Dulles. Also, as a commentor had on another planitmetro post, WMATA could plan for a “Skyline” train (light blue color?) that could travel b/w Dulles and National with limited or no stops.

  11. Joe McKinney
    December 12th, 2013 at 14:03 | #11

    These two options are not alternatives:

    Option one makes extraordinary sense to enable one seat service between IAD and DCA. Could initiate the service by using the middle track at DCA as the end/start of the direct trains between airports–maybe every 15 or 30 minutes? something like that.

    Option two will be required to facilitate the M Street line (or whatever.

    This system has so little flexibility built into it for operations, Alternative one is an example of initiating some of that type of capability into the system.

  12. McKay
    March 14th, 2014 at 13:54 | #12

    Why don’t we really focus on getting more across the Potomac. I’ve always thought there should be another stop closer to the Lincoln Memorial, as it’s the part of the mall almost inaccessible by walking.

  13. March 21st, 2014 at 22:11 | #13

    I agree about the need for another rail crossing of the Potomac, and in the long run it will have to be heavy rail. Meanwhile, how about extending the Columbia Pike streetcar beyond Pentagon City, across the Arlington Memorial Bridge, and up past the Kennedy Center to the H Street line?

  14. Badwolf
    June 15th, 2014 at 21:04 | #14

    Alternative 2. Duh. Anyway, after crossing the Potomac, there would probably be 2-3 stops before a transfer to the Farraguts. Then a stop at Longfellow/Thomas or Scott Circles before a transfer to Mt. Vernon Sq. Another station would be at Eye Street and NJ Ave before a transfer at Union Station. Then down 2nd Street with a station there before turning east onto East Capitol Street with a station at Lincoln Park before heading east to the Orange Line with a new transfer at Oklahoma Ave (4 Track) and the Blue Line would continue on it’s current route to Largo. The Silver Line could have Airport Express trains from Dulles to Union Station, with a stop at Reston Town Center, then skip Tysons and act as an express of sorts from East Falls Church, then stop at a new Rosslyn station, cross the Potomac onto H Street, stop at Farragut Sq, then a new station between Metro Center and Gallery Place and have connections to both stations, and the Airport Express trains would have their own tracks to terminate at Union Station. The local trains would continue along H Street with a station at 6th Street NE and another along Benning Rd at the Atlas District and terminate at their own Oklahoma Ave station.

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