New Blue Line Connections Revisited

July 3rd, 2014

A recent Metro study determined that a Rosslyn bypass is infeasible but a second Metrorail station in Rosslyn to restore frequent peak period Blue Line service is possible.

In a post last year describing the strategies in Metro 2025, we described some options for new Blue Line connections.  The first was a Rosslyn bypass that would allow some Blue Line trains to connect directly to the Orange Line at Court House.  The second was a second Rosslyn station that would connect to the current Rosslyn station via an underground walkway.  Both of these options, illustrated in the graphics below, would allow increased frequencies on the Blue Line during peak periods.

Graphic for Rosslyn Interline ConnectionGraphic for Second Rosslyn Station

Metro recently completed a study that evaluated these two options (pdf).  The bad news is that the Rosslyn bypass (interline connection) was deemed infeasible.  This is due to the location of building foundations and the turning radius required by the track.

However, the second Rosslyn station was deemed feasible, as illustrated in the map below.


Location for a proposed second Rosslyn Station, including three potential options for a pedestrian walkway.

This new Metrorail station would connect to the current Rosslyn station via one underground walkway.

Metro Office of Planning is submitting the second Rosslyn station for project development funding.


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  1. July 3rd, 2014 at 11:15 | #1

    What is the effect of this on the proposed loop solution for the core capacity problem? Orange and Silver Line trains inbound in the existing tunnel will not be able to use the Yellow Line bridge. If only Blue Line trains can use the new loop tunnel under the Potomac, the tunnel will be limited to 50% of its physical capacity.

  2. Justin
    July 3rd, 2014 at 11:55 | #2

    @Ben Ross Good question. The “loop” idea proposes adding a connection from a third line in Virginia, so that Orange/Silver trains could split off and use a new tunnel too. That way we could use 100% of the tunnel’s capacity.

  3. July 3rd, 2014 at 13:48 | #3

    There are other ways to make the loop work at max capacity without the connection from the 3rd line in Virginia. For example, trains could turn around before the end of the loop:

    This doesn’t max out trains across the bridge, but it increases trains across the Potomac from today, and it gives you full capacity at stations on the loop.

  4. July 3rd, 2014 at 16:16 | #4

    @Justin As I understand it, this makes the Orange Line express bypass almost essential if the loop is built. If you build the loop without the bypass, you get only half a track (in each direction) of extra capacity across the Potomac. (You also double the capacity of the south side of the Green Line.) With the bypass, you get a total of 1 1/2 tracks of extra capacity across the Potomac. Is this correct?

    I don’t think David Alpert’s plan is a solution to the capacity problem, because Rosslyn has substantially more exits than entries during the am rush. This means that trains are more crowded between Rosslyn and Courthouse than between Rosslyn and Foggy Bottom. And even if Rosslyn to Foggy Bottom is slightly more crowded, you need added capacity on both legs to fix the problem.

  5. July 3rd, 2014 at 17:18 | #5

    Would the plan for the feasible option then be to have every other Blue train go to the 2nd station – so there is still a transfer-free route to downtown DC on half the trains and a terminating stop in Rosslyn for the other half? Or is the plan to eliminate single-seat service from Alexandria to Foggy Bottom, etc. when this is built?

  6. July 3rd, 2014 at 17:50 | #6

    @Ben Ross: If Rosslyn to Court House is more crowded than “my” plan (it’s one of several options Matt Johnson identified) works great. Silver-Orange would use up 100% of track capacity between 772/Vienna and Largo/New Carrollton. You would be maxing out trains in that segment; they would ALL then continue to Foggy Bottom.

    Meanwhile, you’d get half capacity from Pentagon to Georgetown, then full capacity from Georgetown to Waterfront, and half capacity again back to Pentagon.

    Alternately, since the Rosslyn station is going to be separate, you could actually put a turnback there and get 100% capacity to Rosslyn and only half capacity between Rosslyn and Pentagon.

    So basically Yellow trains are Huntington-Rosslyn via the loop and Blue trains are Franconia-Waterfront via the loop.

    Or, build an extra platform at Pentagon one day and they can loop around and make a P shape. Then you’ve got every track maxed out except Pentagon-Rosslyn, and you still get to have that at half capacity, as good as it ever was on Metro. And that’s a lot less new trackage than on the Orange/Silver bypass plan (but you don’t get the express train).

    I’m not against the bypass, just thinking about ways to max out trackage without building so much new trackage.

  7. Caelestor
    July 4th, 2014 at 04:46 | #7

    Good to hear that the second Rosslyn station can be constructed. Expanding Metrorail will involve a series of steps, probably as follows:

    1. Creating a makeshift terminal for the BL should be an immediate priority, so that 10 tph between Rosslyn and Franconia be reinstated. With the interlining between the BL and OL removed, SL tph can be increased as ridership to Tysons grows.

    2. Afterwards, the BL can be extended to Farragut Square via Georgetown, and tph along the stretch can be increased to 16. Ensure that a quick transfer to the RL is built, so the L line probably needs to be.

    3. Build to Union Station to relieve the crowds on the RL.

    4. From there, reassess what needs to be built. By then, the OL is likely to be overcrowded, so build the SL Express with 10 tph feeding into the L/M St line. I’m not fond of the southern section of the planned loop line, but it should be considered if NoVa continues to grow.

  8. Phil
    July 6th, 2014 at 22:15 | #8

    Better than worrying about the loop (which shouldn’t get built) would be to untangle the whole system with a goal to reduce interlining. This would boost capacity as well as provide improved passenger distribution and redundancy.

    The world’s best systems – London, Paris, Tokyo and Moscow – work because their cores feature a dense network of connecting, but separate, lines that distribute riders well across the system. In the case of disruption, riders can be transferred to parallel or connecting lines easily. A loop that continues to merge these lines and require switches lowers the throughput of each line and the system as a whole, meaning longer waits between trains and increased crowding. A second Rosslyn station is a critical aspect of this goal.

  9. July 6th, 2014 at 23:02 | #9

    The best we can do is a 500′ ped tunnel? A proper, cross-platform interchange station could have been built underneath Central Place, if only we’d known a few years earlier. That would have saved commuters countless precious minutes over the decades!

  10. July 7th, 2014 at 01:10 | #10

    And @Phil: loops are quite elegant from a system design standpoint. The switching losses, especially with modern switches, are quite minimal. Those are outweighed by the capacity gain from not taking trains out of revenue service at a terminal, the ability to finely tailor branch capacity vs. a through-routed system, and its ability to achieve maximum coverage with a minimum of construction.

    BTW, the Yamanote is just such a loop that features prominently in Tokyo’s commuter rail system, and works very well. Melbourne also runs its commuter lines’ distribution via an underground loop.

  11. Phil
    July 7th, 2014 at 10:03 | #11

    @Payton Chung

    The difference is that the Yamanote Line runs independently of the rest of the network and is complemented by other JR lines at various points throughout its route.

    Melbourne is actually a good example of how a loop presents a capacity problem, in that the system’s ridership is growing quite fast but the number of trains entering the loop is capped and I believe approaching, if not already at, its maximum number of trains per hour. The state government of Victoria has been attempting to reconcile this by splitting off certain routes into a more metro-style, cross-center route, similar to the concept of untangling the system.

    A good case in point in this is London’s Circle line, which was de-looped a few years ago because the lack of a set terminus means that recovery time in case of disruption as well as issues in terms of managing incoming and outgoing trains from the H&C, Metropolitan and District lines degraded service. The deep tube lines are able to run 31 or so trains per hour expressly because they’re not beholden to dealing with other lines at all.

  12. Andrew
    July 8th, 2014 at 15:39 | #12

    Does anyone have a link to the study that was done?

  13. Allison
    July 8th, 2014 at 17:13 | #13

    Thanks for all the comments. A couple of clarifications and food for thought.
    (1) @Ben Ross – This would be the first step to enable the future downtown subway expansion.

    (2) A third Potomac crossing inherently creates a mismatch between the line capacity in Virginia (52 tphpd) and river crossing capacity (78 tphpd). A third line in VA helps to resolve this. However, more importantly, the 2040 demand west of Rosslyn clearly indicates a very high level of demand that requires heavy rail expansion in the corridor from Rosslyn to Tysons.

    (3) The loop is not actually a loop, but rather is a lasso or lollipop. For example, BL trains would start AND end at Franconia-Springfield, moving clockwise around the core. YL trains would start AND end in Huntington and move counter-clockwise around the core. This would maintain the terminal stations as they are today. This is different from the Yamanote Line or the original TfL Circle Line that simply operates in a loop with no clear terminal, which as many have indicated, presents operating challenges.

    (4)@ David Alpert Terminals in/near the core are challenging in terms of operations standpoint with very little available space to accommodate the ends of the line and turnbacks.

    (5) @SaveTheBlueLine The operating plan could work in a number of ways, as you suggest. However, continuing to operate some Blue Line peak trains on the existing track, while building new track and a new station to operate only a handful of trains would greatly underutilize the new station/track.

  14. Sue
    July 8th, 2014 at 20:39 | #14

    Some thing that nobody seems to be talking about, but which is abundantly obvious to everyone in the area, is the lack of metro train – which could be incorporated into the new/second Blue line – to go to Florida Ave/ Union Market /H Street NE/ Atlas/ Trinidad.

    Metro talks about (old) studies which say that there is insufficient density in these areas, but that is simply not the case. The amount of apartment and condo buildings being constructed currently in the H Street NE area is phenomenal and more are slated/already permitted to begin construction in 2014/2015. In addition, the existing bus lines (e.g. X2) – which are touted as premium transit – are utterly unreliable and inadequate in number and frequency.

    We also know that even if the streetcar ends up running from 2014 onwards, it is not something that commuters will use, since the streetcar will always be too slow and have too many stops, by design, to be of use to people on a timeline who have to get to work. Streetcar might be good for tourists, but not for commuters and streetcar may not ever end up going further than Union Station. Most people need a direct line into downtown NW DC to get to work.

    I find it amazing that NE DC is thoroughly neglected in WMATA’s plans – and nobody has addressed these issues. The plans are shortsighted and are based on out-of-date studies.

  15. Allison
    July 9th, 2014 at 17:10 | #15

    @Sue – thanks for your comments on the 2040 regional transit system plan (RTSP). As you clearly understand, there is a strong link between transportation and land use. The work we are doing to develop a long-range plan is based on the Metropolitan Washington Council of Government’s (COG) adopted Cooperative Forecast , which is updated annually. This is developed in concert with all the jurisdictions’ planning offices, including the District’s Office of Planning, and includes population, household and employment projections for each five-year increment through 2040.

    Our plan accepts this forecast as adopted by the region and from there, has developed a comprehensive transit network to meet the region’s future demand. Throughout the project, we have worked closely with representatives from each local jurisdiction including DDOT and DCOP. The plan is multi-modal and includes Metrorail, light rail, streetcar, commuter rail, commuter bus, and bus rapid transit, as well as an extensive base of local bus services from Metrobus and other operators. While it is tempting to envision Metrorail as the only option for transit region-wide and feel that an area or neighborhood is being overlooked if Metro is not provided, there is a wide range of modes between Metro and local bus. Additionally, there are capital and operating costs associated with the expansion that the Compact jurisdictions and the region’s residents must agree to fund. Based on growth projections through 2040 from the adopted cooperative forecast, the amount of development and growth projected in Northeast Washington resulted in an overall transit demand below what is needed to support Metrorail expansion on multiple corridors. However, the plan calls for a full array of high-capacity, high-frequency surface transit with transit priority that will complement Metrorail and provide more transit options that the region desperately needs.

  16. Sue
    July 9th, 2014 at 17:26 | #16

    Hi Allison. Thanks for taking the time to reply. I appreciate what you are saying but my point is that bus and streetcar are not feasible or reliable means of transport. The poor manner in which WMATA and DDOT run bus services, and the frightfully late delivery and disorganised planning of the entire streetcar project, ultimately leave the average NE DC commuter to conclude that Metro trains are indeed the only credible/ reliable means of transport in the so-called “multi-modal” network. The multi-modal transport concept remains merely a theory in DC – not presently a reality. I appreciate that you personally are not responsible for WMATA/ DDOT ineptitude – but it’s important that we all address a point that is “the elephant in the room”.

  17. Mike in Tysons
    July 9th, 2014 at 17:54 | #17

    Rather than building a new Blue Line station under N. Fort Myer Drive, has any consideration been given to placing the new station under the current Rosslyn station under N. Lynn Street? I realize that there could be geological issues (i.e., is the rock strong enough to support the current station above a new one perhaps 40-50 feet lower?), but if that is not a problem, such a station location would save travelers a long walk between the current and future station locations as proposed above, instead providing a much shorter vertical transfer between stations. And the new Blue Line station would need to be lower than the current station in any event in order to be low enough to get under the Orange Line tracks heading west to the Court House station.

  18. Andrew M.
    July 15th, 2014 at 08:38 | #18

    I agree that it is essential to build a new set of platforms at Rosslyn, and am pleased that WMATA is developing plans to carry this out. However, I suggest that many factors need to be considered:

    1. Throughput of trains

    It is essential that all lines be able to operate at capacity in the future system. This part you have covered by building the new pair of platforms. It is also essential, of course, to build underground flyovers so trains on different routes do not interfere.

    2. Ease of transferring for patrons

    Unfortunately, the plan shown above results in a 2 block walk to transfer between lines. This is longer than the shortest distance between the two Farragut stations. If all BL trains terminate at Rosslyn, a large number of patrons will need to make this transfer, so the platforms must be MUCH closer to each other. If they can’t be stacked vertically, they should at least try to minimize walking distance.

    Rosslyn and Pentagon stations have a unique design in which one track is at a different level from the other. It should be possible to take advantage of this layout to facilitate transfers with a minimal amount of changing levels.

    3. Keep the 2040 plan in mind

    How will the existing and new platforms interface with the 3rd river crossing, Arlington express tracks and interlining possibilities that are in the 2040 plan? I strongly suggest that the new platforms be built with all of the track connections necessary to facilitate this interlining in the future. (Or, decide now on a way to reduce interlining, and make the station compatible with that).

    For example, here is one vision for how Rosslyn could look in 2040:

    It changes the existing platforms to service only eastbound trains; envisions a new, parallel pair of platforms to service southbound trains; and another new, perpendicular pair of platforms to service westbound trains. This allows a wide range of interlining options, while maximizing track capacity and minimizing transfer time between lines. It also minimizes confusion for riders, because trains to each destination always arrive on the same track regardless of their origin.

    The new Rosslyn station proposed above fits nicely with this vision; it could serve both north- and southbound trains when the Georgetown tunnel is built, and could then become the southbound-only platforms when the Arlington express tracks are built. However, it is important that all the necessary track connections and crossovers for these platforms be built now to allow the new tracks to serve in these other roles in the future.

    Some more thoughts:

    1. Pentagon

    It is not just Rosslyn that is constraining capacity on the BL: Pentagon is too. It would make a lot of sense to build a second set of platforms at Pentagon at the same time. This would allow a maximum-capacity shuttle service to operate between the two in the short-term, and would in the long-term allow something like this:

    2. Virginia turnaround service

    If track connections were to be built from the OR/SV to the new BL platforms, it would become possible to operate a turnaround service serving Virginia destinations, even without the wye option that has new been ruled out. Think about how the BART operates the SFO station; the train pulls in from one direction, then reverses and continues along its route. In this way, half the BL trains could use the existing station and continue to Largo, and the other half could use the new station, reverse and continue to Loudon.

  19. Phil
    July 15th, 2014 at 13:57 | #19


    The loop/lasso still doesn’t do anything about untangling the system; interlining has been one of the biggest issues Metro has to deal with and a sure-fire way for delays to occur as well as limiting capacity.

  20. July 18th, 2014 at 21:01 | #20


    Wouldn’t it make sense then to build an Orange/Silver Connector to the Rosslyn-2 station as well and route some of their trains there too so that the new station can be fully utilized. That connector has to be built anyway for the planned Metro-2040 hope of having Blue share the tunnel with express Orange Silver. Otherwise, this plan eliminates single-seat service to the economic and employment hubs in West DC for Blue Line riders and seems like a further effort to screw the Blue Line.

  21. Allison
    July 23rd, 2014 at 16:42 | #21

    @Phil and @Save, your back-to-back comments are what makes transit planning so complex. WMATA’s interlining is a challenge that we will continue to face and one where we are looking for solutions both in technology and new lines. However, separating lines is not without its own issues. Interlining provides a one-seat ride to most customers by allowing multiple lines to serve the same station. However, as @Phil points out, it can sometimes impact reliability. Separating shared lines would increase the number of transfers that customers would take on a daily basis, which @save is seeking to avoid, but could improve reliability. Essentially interlining is a discussion of reliability vs transfers. As indicated by your posts and comments in the general public, there are two very different and opposing opinions of what is important to our riders.

    Clearly, the original system design opted for interlining. This also had the extra benefit of lower initial construction costs. Separating all of our existing lines would be extremely expensive in terms of construction and right-of-way acquisition, not to mention the increase in operating costs every day for the region. For example, the Blue Line would need its own right-of-way from Franconia-Springfield to Largo, including significant new tunnel. This would mean that it would no longer serve the Eye Street, NW corridor or key locations like DCA, Crystal City and Pentagon without a transfer. This contradicts @save’s desire to maintain a one-seat ride to many of these destinations. We cannot both separate all the lines and provide a one-seat ride for all customers.

    So – which do you prefer? Given the costs and the limited available funding, does that change your mind?

  22. July 23rd, 2014 at 22:22 | #22


    First off, I appreciate the thoughtful reply.

    I don’t think that my comment and Phil’s are (completely) at odds with each other. Interlining in many parts of the system are destined to persist. I don’t see the Yellow and Blue not sharing their Alexandria tracks for a long time, for example. But undoubtedly building a second tunnel from Rosslyn must be done to deal with the 3 lines that are now sharing the track (frankly, the process for it should have started a decade ago when the Silver Line was being planned).

    When building the tunnel, it is reasonable to then discuss where stations go in the city once that line is built, and whether to do loops or keep end-to-end tracks. Obviously with more stations (and less interlining), riders may have to transfer to get to a different line if their station is not at the destination point. But I think that would be viewed as an acceptable trade-off for expanding the rail-accessible portion of DC.

    My point is more a medium-term concern. If Metro goes forward with the Rosslyn-2 station, and diverts all Blue Line trains there, then Blue Riders will have 6 minute spacing for the Blue Line train, and then a 2.5 minute wait at the station to catch Orange/Silver plus a walk from one Roslyn station to the other – in other words, depending on how long it takes to walk from Rosslyn-1 to Rosslyn-2 pretty close to the 12 minutes of waiting they see today.

    But also, the research I’ve seen says that riders prefer adding 8-10 minutes to their commute to avoid a rail-to-rail transfer. So even though this portion of Momentum is being marketed as “restoring Blue Line service,” I expect that many of the Foggy Bottom to Metro Center commuters who are upset this week would see it as a further downgrade rather than improvement. In 2040 there would be benefits – but 15 years without a single seat ride to West DC is a very long time to wait (especially after having had service to there for decades that is slowly being taken away).

    [Also, on a related point, and appologies for the long post, this is an even bigger deal in the evenings and weekends when there are long headways on all the lines. Most people I know will never take Metro evenings/weekends if it involves a transfer. Between less traffic (so the alternative is faster) and the likelihood of 20+ minutes of waiting at the two stations, it just isn’t worth it]

  23. July 31st, 2014 at 23:31 | #23

    @Phil: The Yamanote does, in fact, interline quite extensively (albeit usually on dedicated tracks, as with the Shinkansen along its eastern flank). Interlining, as Allison points out, has benefits — like increasing train frequency in the region’s much more densely populated core.

    At a more philosophical level, the argument’s merits from an operational standpoint matter little. We have neither the funding commitment, nor honestly the urban density, to permit a tangled weave of single-line subways through the District.

  24. Tom Greenfield
    May 27th, 2015 at 14:32 | #24

    Hi Allison,

    Where can a citizen get a copy of the WMATA study that deemed the Rosslyn bypass (interline connection) infeasible?

  25. Allison Davis
    May 28th, 2015 at 11:07 | #25

    Tom, We did a fairly high level assessment of the bypass and a second Rosslyn station. It can be found here:, under Metrorail Plans and Projects.

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