Posts about Separate Yellow Line
Yesterday, we discussed how Metro could grow its core capacity if it chooses to build a Rosslyn wye in the short run. Today we'll look at how a terminal for the Blue Line could fit into the picture.
Today, Rosslyn is the biggest bottleneck in the system, which will only get worse when the Silver Line opens. Three lines vie for space in one tunnel from Rosslyn eastward, which limits trains on the Blue, Orange, and Silver Lines.
Metro could relieve the pressure for now by either building a new terminal for the Blue Line at Rosslyn, or a "wye" to let some trains from Tysons go to Arlington Cemetery and farther south in Virginia. But in the long run, Metro needs more capacity over the Potomac River.
Post-2025 solutions with a Rosslyn terminal
The Rosslyn terminal would enable Blue Line trains to terminate at Rosslyn without interfering with the Orange or Silver Lines. This would allow more Orange and Silver trains from Tysons and the Rosslyn-Ballston corridor. But it also means that all Blue Line riders going to DC would need to transfer at Rosslyn or Pentagon.
That solution might work for a few years, but if Metro ridership continues to grow, the Rosslyn terminal would need to become the first phase of a new Potomac crossing.
A separated Blue Line: Metro could easily expand a Rosslyn Terminal into a new line to DC. A likely path would take the line under the river to Georgetown and then east into the downtown core.
In addition to the 26 trains per hour (TPH) running between Rosslyn and Downtown on the Orange/Silver subway, an a separated Blue Line to Georgetown and into downtown would allow 12-16 additional trains to cross the Potomac at Rosslyn.
This would increase the number of trains running between Virginia and DC per hour during the peak from 40 to 52.
However, because the Blue Line shares with the Yellow Line, the new subway across downtown Washington would only be able to operate at roughly half of its maximum capacity. That's probably fine in terms of ridership for a while (and off-peak for much longer), but in order to get the full potential out of the new line, it would need to be separated from the Yellow Line.
A separated Blue Line could also allow for more service on the Green Line through the Waterfront or Capitol Riverfront areas, which are quickly adding jobs. Metro could get some additional Green capacity by shifting some Huntington trains to the new Blue subway via Rosslyn (a sort of reverse Rush Plus).
Shifting some Huntington trains to run through Rosslyn would not increase the number of trains crossing the Potomac beyond what could cross under the first separated Blue Line scenario, but it would enable more service on the Green Line.
Two new subways?
What about both a separated Blue Line and a separated Yellow Line? Two new subways in the core would be very expensive. But if Metro wants to maximize the capacity on its system, it has to separate each line in the core.
One way to do this is to build a new terminal for the Blue Line at Pentagon. The Blue Line could have its own platforms, and trains from Franconia-Springfield (now all colored Yellow, or perhaps a new color) and Huntington would all cross the 14th Street bridge.
This would also have the advantage of reducing the amount of interlining in the system. With the lines no longer sharing with each other, delays wouldn't cascade across multiple lines if a train were to break down or some other mishap were to occur.
But the real issue is being able to have the flexibility to balance trains across the different lines. Right now, the Blue and Orange must be balanced based on ridership demand, as do the Green and Yellow. The problem is that Metro is bumping up against the absolute capacity of both subways.
With just a separated Blue, there would still be demand for a direct trip across the 14th Street Bridge. And once that demand outstrips Metro's ability to provide supply, Metro won't be able to do anything (because the Yellow shares with the Green). With just a separated Yellow, service between Pentagon and the western side of downtown is constrained by demand for the Orange/Silver.
At some point in the future, if Metro keeps growing, it may become necessary to build the other separated line. With both a separated Blue and a separated Yellow, the number of trains crossing the Potomac would increase to a maximum of 78.
Other improvements would probably be necessary to enable a full 26 trains per hour to run on the Green Line. It's not clear if the terminals at the end of each line could handle turning 26 trains each hour. Metro would probably need places for trains to turn around short of the terminals, like the pocket tracks at Silver Spring and Grosvenor on the Red Line. Alternatively, Metro could look into rebuilding the terminals, Branch Avenue and Greenbelt, with more capacity.
It's hard enough to say if we can get one new subway by 2040, given the funding picture today. But a second new subway might be in the cards farther down the line, and now is the time to start planning for it.
Last week, we talked about plans to give Metro the capacity it needs to get through 2025. What about beyond? The primary issue after 2025 will be cross-Potomac capacity.
Metro will likely choose to build, hopefully by 2025, either a new terminal for the Blue Line at Rosslyn that doesn't share tracks with the Orange or Silver Lines, or a "wye" so trains from Vienna and Tysons can turn toward the Pentagon.
However, neither solution increases the number of trains that can cross the Potomac River. Metro will need to start planning for the next phase very soon, since it takes so long to plan and build transit. Also, Metro's plan beyond 2025 could influence which of the options (terminal or wye) it chooses for 2025. Let's look at how Metro might expand its core capacity starting with each of the 2 primary Rosslyn alternatives.
Post-2025 solutions that go with a Rosslyn wye
Without construction in the core, a Rosslyn wye alone can't add any cross-Potomac capacity. Metro could build a second wye at Pentagon, for trains from Vienna and Tysons to cross the 14th Street bridge. However, the 7th Street tunnel, which carries the Green and Yellow Lines through downtown, can't take any more trains.
Wyes at Pentagon and L'Enfant: If Metro builds a total of 3 wyes, at Rosslyn, Pentagon, and L'Enfant Plaza, it could fit a few more trains across the river. Trains from Arlington Cemetery could cross the 14th Street Bridge, then continue east onto the Green Line toward Branch Avenue.
This scenario would let Metro fill unused capacity in the system without building any new trunk lines. However, much of this new capacity would go on the Green Line south of Waterfront station. Customers wanting to get to the downtown area would have to transfer.
It would, however, significantly add service to the growing Waterfront and Capitol Riverfront areas. DC has zoned much of these areas for downtown densities, but instead of the 5 lines that serve downtown or 3 in the Golden Triangle, this area has just one. This option would beef up service there, though many of the people riding there would want to come from downtown, and this doesn't boost that connection.
To absolutely max out capacity, Metro would need to run a line, like the lime-colored line on the map above, from Franconia to Branch Avenue. It's not completely necessary, but it would allow more full use of the capacity.
Unfortunately, this would increase the amount of interlining in the system, because trains would be running across multiple lines. The complex scheduling it would take to run this sort of service pattern might actually lower the total number of trains Metro can run through a tunnel.
This scenario would increase trans-Potomac capacity from 40 to 52 trains per hour, or just to 46 TPH without the Franconia-Branch Avenue Line.
Pentagon wye and separate Yellow Line: Metro has talked about building a separate tunnel for the Yellow Line. It's not clear where it would go yet. It could run north along 9th or 10th Street, or it could run east toward Capitol Hill before turning north.
This subway would separate the Yellow and Green Lines. That would allow Metro to run additional Green Line service between Greenbelt and Branch Avenue, including more service between downtown and the Waterfront/Riverfront areas.
It would also allow more service across the Potomac by decoupling the Green and Yellow Lines. However, since the Yellow Line shares tracks with the Blue south of Pentagon, this new subway would not be used to its full capacity.
Metro could get some additional capacity by routing some trains from Tysons via Arlington Cemetery over the 14th Street Bridge and into the new subway, if it built a wye at Pentagon. This would increase service across the Potomac to 52 TPH. Without the line running from Tysons through Arlington Cemetery, that would drop to 46 TPH.
Splitting Yellow Line service: Another option Metro studied for the Yellow Line is a new tunnel through the Capitol Riverfront, past the Capitol, and north to Union Station. This would increase service at Union Station, a major bottleneck, and give riders two ways to get downtown from the Waterfront/Riverfront area.
However, a lot of the riders in Alexandria and southern Arlington don't want their train to go so far east. They want to get to the 7th Street corridor. Therefore, Metro studied the idea of splitting the Yellow Line, with some trains taking their current path through L'Enfant Plaza and Archives while others would go to Union Station.
This operating plan makes a lot of sense with the Rosslyn wye, because those trains can fill the "gap" left on the 14th Street Bridge by Blue Line trains running north toward Rosslyn. With a new path for some Yellow trains, there would be room to add more Green Line service.
This approach would allow 52 trains per hour to cross the Potomac.
Tomorrow, we'll look at another set of long-term solutions, which Metro might pursue if it builds a new Blue Line terminal and then can send the Blue Line across the river toward Georgetown.
WMATA hopes to lengthen all its trains to 8 cars, add pedestrian connections at downtown stations, and maybe build new rail tunnels for the Blue and Yellow Lines in the region's core. That's part of a strategic plan which its media relations team showed only to the Washington Post this week, and which board members will see at a meeting today.
More broadly, the agency will focus on safety, service quality, better regional mobility, and its own financial stability in the strategic plan. Besides a set of still somewhat amorphous connections and service improvements, the plan calls for building a system where riders can more easily "plan, pay, and ride" in a smoother customer experience.
The big money, up to $20 billion, in the plan would be for tunnels to separate the Blue Line at Rosslyn and the Yellow Line at L'Enfant Plaza, the two major chokepoints, as part of a vision for Metro by 2040. Silver Line trains from Dulles Airport could also turn at Rosslyn to go toward Arlington Cemetery, then stop at Pentagon before crossing the Yellow Line bridge into DC.
By 2025, Metro wants to have the railcars and power stations to run all trains with the full 8 cars. It would like to build pedestrian tunnels to link Farragut North with West and Metro Center with Gallery Place, and a train tunnel so that some Dulles trains can go down to Franconia-Springfield, which would relieve some of the immediate Blue Line problems of Rush Plus, which will only get worse once the Silver Line opens.
WMATA Media Relations team makes transit supporters' task harder
This plan covers a lot of ground, and is at times very detailed yet at others quite vague. I wasn't able to get all of the details, because WMATA decided to give an exclusive look at the plan to the Washington Post.
This has been the agency's practice every since Barbara Richardson, Lyn Bowersox, and Dan Stessel took over at WMATA communications and media relations. This isn't a matter of blogs versus traditional media, though that's been an ongoing problem as well; WMATA also does not tell the Washington Examiner about its major initiatives.
This seems inappropriate, and really disrespects the journalists and bloggers who care about transit in the region. It's also pretty foolish, because it forces others to write about the plan in a more hurried way than they otherwise would.
WMATA planning head Shyam Kannan spent an hour talking to me after midnight last night, and this post was still not done by 4:30 am as a result. Still, there are plenty of questions I did not have time get answered.
What will happen with Union Station and commuter rail?
While the plan goes into a fair amount of detail about how there could be a second Pentagon station for the trains making the new track connection, the plan does not talk about whether the new lines would serve Union Station, the system's biggest point of overcrowding. It seems obvious for any separated Blue Line to go there.
One of the biggest opportunities to improve regional travel would be to let MARC trains reach L'Enfant Plaza, where riders can transfer to all four lines that don't serve Union Station, and onward to Virginia. Unfortunately, perhaps bowing to political realities, the plan just calls for WMATA to play a role of supporter and advocate.
Finally, the plan shows some diagrams with vague arrows depicting potential extensions to the ends of lines, regional transit in the suburbs, and streetcars crossing the river:
All of these ideas and more were part of a study WMATA has been working on for a few years, called the Regional Transit System Plan. That also included proposals to send the Yellow Line through the rapidly-growing Capitol Riverfront and up to Union Station.
According to Kannan, the RTSP study is still going on, and even many decisions about which routes WMATA wants to pursue in the future are not fully set.
Customer service, trip planning are even more central to the plan
Kannan emphasized that the rail expansions and connections are not the "real meat" of the plan, despite what was in the Post article; instead, it really focuses on "an improved customer service experience today" that will let riders plan, pay, and take transit more smoothly than today. The vision for 2025, which is not far away, is fundamentally about "the completion of a journey to a self-service system. He explained:
Imagine, for a moment, walking into a Metrorail station or a Metrobus platform and not needing to ask for assistance in either route planning, fare payment, and even walking to or from your bus or train. There would be improved lighting so you can read your book, mobile payment options so you can use your smartphone to pay your fare.With these added services, Kannan said, station agents will not need to sit in their booths all day to handle everyday needs. Instead, Metro could dedicate its staff to "customer-facing ambassadors" who could roam around and help people, and choose people for those jobs best suited to a customer service role, which as we all know is not always the case with today's station agents.
Another big element of this self-service world is better trip planning. Kannan talked about having a "unified regional trip planning technology" so a rider can use a desktop computer, smartphone, or other device, pick where he or she wants to go, and get transit suggestions that could use Metro, commuter rail like VRE or MARC, or regional buses like Ride On and DASH.
The plan describes that as "Provide transit riders with a regional trip planning system that is mobile-device friendly." Hopefully this language does not lead the agency to decide it should issue a procurement for a big IT project to build one single integrated trip planner that works on today's mobile devices, and that's all. WMATA is not in a position to be a good customer-facing software company, and a big contracted software project will build something that will likely be obsolete as soon as it launches.
Rather, the agency needs to offer open data and support open source projects to create the building blocks of trip planning. VDOT funded a grant, which I wrote for Arlington County, to make progress on some open source technology for trip planning. If WMATA can support the efforts of the people who are going to do this work, and other developers who contribute and create other tools of their own, it will do far more to "provide" this kind of "unified regional trip planning technology."
The plan is not very detailed about how to reach this or most other goals, from "Educate the customer about transit coverage and usage in regional emergencies" to "Work with partners to ensure seamless connections between Metro and other transit systems in the region." Those are fodder for future plans. Meanwhile, though, if top management buys in and directs the organization to follow this plan, it can get the 13,000-person organization moving all together in some important directions.
The WMATA board will discuss the document at a meeting today. As usual with WMATA's process, since staff don't release anything until the very last minute before a board meeting, that means board members won't have the opportunity to hear any considered feedback from riders, to the extent they are interested in riders' views, as some are, while others are not.
Matt Johnson and I have also been working on some posts about the core capacity Metrorail proposals, and will try to better illuminate what kinds of tradeoffs Metro faces as it tries to deal with its bottlenecks and overcrowded segments.
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.
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.
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.
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.
"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.
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.
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.
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.
Before long, the Metro system will be bursting at the seams, besides those spots where trains are already stuffed to the gills. What can we do?
To figure out some solutions, Metro's planning department has been analyzing many different alternatives for fixing the capacity bottlenecks. They've been posting the presentations to their Technical Advisory Group on PlanItMetro, allowing us to get a look at some of the possibilities even before they're fully analyzed.
To start with, Metro definitely needs to upgrade power systems to accommodate more 8-car trains, and build enough railcars to make up those trains. Other key capacity fixes that have been talked about for years include pedestrian walkways between Farragut North and West, and between Metro Center and Gallery Place.
Even with all of this and the "Yellow and Orange Line Service Increase" plan, trains will have 22% more demand than capacity by 2040, particularly on the Orange Line between Court House and Rosslyn, Yellow between Pentagon and L'Enfant Plaza, and Green between Congress Heights and L'Enfant, especially the segments around Waterfront and Navy Yard.
In the past, we've discussed some of the possibilities. One long-discussed option is to separate the Blue Line into a new tunnel of its own through Georgetown, the Mount Vernon Triangle, and H Street.
Another would be to build a separate tunnel for the Yellow Line next to the current Yellow and Green tunnel between L'Enfant and Mt. Vernon Square. This would allow more Yellow and Green trains since ethey would no longer have to share tracks.
However, it would cost a lot of money yet not provide access to any new areas or deal with the growing transit demand as Southwest and Near Southeast become dense residential and job centers. Nor would it do anything about the heavy demand at Union Station, which will only increase as MARC and VRE add capacity.
Another option would be to route the new tunnel through SW and SE, along I Street SW/SE, then turning north past the Capitol to Union Station. Some trains over the bridge could take this route, while others could take the current route. Already, Metro plans to make some of the trains from Franconia-Springfield go over the bridge, so the Franconia trains could be the ones to take the 7th Street route while the Huntington trains went to Union Station, for example:
One drawback of this option is that this new tunnel will not carry the maximum frequency of trains. That's because there's a limit to the number of trains through the King Street-Pentagon route, some of which would go to Rosslyn, some to L'Enfant, and the rest in the new tunnel.
The study estimates 6-minute headways during peak and 12-minute off-peak. By comparison, the Red Line has 2.5-minute headways peak and 6-minute off-peak.
In general, this is a drawback of the way the system was originally designed where different lines (except Red) share tracks. Many links don't get the maximum possible number of trains. To fix that, Metro could separate more lines with new tunnels. Or, they could add more switches so that different routes could use the available capacity:
This option adds four track connections. Three, between Waterfront and the 14th Street bridge, between the bridge and Arlington Cemetery, and between the cemetery and Court House, would enable a new service between Branch Avenue and Dulles Airport.
A fourth lets trains on the Dulles line turn toward Vienna to maximize trains on both of the northern Fairfax branches. New stations connected to West Falls Church and Pentagon for the new lines would also accommodate transfers.
This option gives Virginia a lot more service and the whole system more flexibility to route around problems. On the other hand, it's likely to lead to more people transferring at more stations, and creates more crowding at Rosslyn since many trains will now bypass it. (Or can Rosslyn get another station like Pentagon does in this option?)
The clear question with all of these is whether Metrorail expansion is even right to consider, or whether money is better spent on light rail and bus service. Dan from BeyondDC always argues that for the cost of one heavy rail line, you can get streetcars and light rail all over the place.
Metro planners also took a look at many of these options, some of which are in the presentation already online while others will come up in future phases of this plan. Stay tuned for more great nuggets of information as the study progresses.
Squalish diagrammed a potential service pattern where some Blue trains take the 14th Street bridge, while others go past the cemetery to Rosslyn. Likewise, some Silver trains go through the Rosslyn tunnel, while others go past the cemetery the other way to 14th Street.
Squalish's diagram shows most (2/3) of the Blue and Silver trains going past the cemetery, but fewer could as well. Most trains would follow the more direct route into DC, but a few would use the cemetery track to switch places. We'd have some service past Arlington Cemetery, allowing people to transfer, but not so much as to let the merges and unmerges slow the whole system down.
To make things simpler for riders, we should give a single color to all trains following a particular route through Arlington and DC. If one color follows two paths, it should only do so at the periphery. I recommended the same for the proposed "Blue Line Split".
Nevertheless, this could definitely confuse riders. There are now, eight services, six involving the Virginia side: Dulles-New Carrollton, Dulles-MV Square, Vienna-New Carrollton, Franconia-Largo, Franconia-MV Square, and Huntington-MV Square. Whereas calling Franconia-Greenbelt service "Yellow" only affects those going to the four stations south of King Street, none of which draw tourists, this would also affect the 14 stations on the Orange and planned Silver Lines, including everyone going to Tysons or Dulles Airport.
Most likely, Metro would need to begin giving trains secondary designations, such as numbers, as New York does, with one number for the Orange Line to Vienna service and a different number for the Orange Line to Wiehle Avenue or Route 772.
One of the possibilities from Metro's core capacity study involves a short 9th Street tunnel from L'Enfant Plaza to Mount Vernon Square. That could be a cheaper way to add Metro capacity across the Potomac, the system's current bottleneck. It wouldn't add service to much-needed areas like the McMillan/AFRH area of DC, (though allowing that possibility in the future), but would address the impending overload of trains from Virginia once the Silver Line opens.
If we could run more trains over the 14th Street bridge, where would they go in Virginia? I can see two possibilities: convert the Arlington Cemetery segment to a shuttle train, or add connections to route the Silver Line over that segment as well as the Blue Line.
The shuttle train option
The Blue Line could simply run over the 14th Street Bridge with the Yellow Line to the new section. Silver and Orange share some tracks, Blue and Yellow others, with no other merges. To replace Blue at Arlington Cemetery, create a shuttle train
To avoid having the shuttle merge and unmerge with Orange/Silver at Rosslyn and Blue/Yellow at Pentagon, Metro would need to add a new platform at each station. Probably this could work with just a single platform inside the station, with a switch as close as possible. Trains would come in, unload and reload, then reverse out to make room for another train. Such an arragement would limit the capacity on the line, of course. Ideally, the platform(s) would go right across the platform from one of the two existing tracks in each station, minimizing the walk necessary to tranfer.
Pros: This requires fewer merges than in the current arrangement. Also, all merges happen outside of the highest ridership core areas, minimizing delays.
Cons: Commuting from Alexandria to "Orangeton," or southern Fairfax to Tysons, becomes more difficult, requiring either two transfers or a trip through DC.
The new connections option
Squalish got this one. In Metro's earlier core capacity study, they suggested adding some track connections for service flexibility. Those included a connection from Court House to the Arlington Cemetery tracks, and another one from the other end of those tracks to the 14th Street Bridge. If we built both of those, then the Silver Line could use the track in the opposite direction from the Blue Line, to get from Court House to L'Enfant Plaza.
Pros: There are lots of services going to lots of places. Riders along Rosslyn-Ballston or King St-Pentagon can choose either bridge. And except going to and from Yellow Line stations south of King Street, riders can go between any two Virginia stations entirely within Virginia with at most a single transfer.
Cons: Lines are merging and unmerging a lot, which creates operational challenges. Silver and Blue each have to share tracks with three other lines for part of their routes. If all lines are running at capacity, then at Pentagon (for example), a Silver Line train needs to reach the wye just as a Blue Line train reaches it from the other direction, or else one of the trains will have to wait, delaying all later trains.
Metrorail will reach its capacity by 2030. The Orange Line is already just about maxed out in Arlington. We can build light rail, BRT, streetcars and other modes to relieve the pressure, but Metrorail will remain the fastest and most desirable mode. The separate Blue Line would relieve some of the pressure, allowing for more trains through Rosslyn. However, a new Potomac tunnel and subway across DC would cost billions. If we can't fund that, is there a cheaper way?
How about separating the Yellow Line instead? The Yellow Line plan Dave Murphy suggested last week, and some of your comments, suggest a possibility. If we separate the Yellow and Green lines in DC, then Metro could put many more trains over the 14th Street bridge. According to Metro planners, this option would involve building a shorter subway tunnel from the 14th Street bridge to the Convention Center along 9th Street.
While the tunnel at Rosslyn is already at its capacity, the 14th Street bridge isn't, because all its trains must merge with Green Line trains from Branch Avenue. Metro can squeeze a few more Yellow Trains in if they reduce Blue trains, but not that many. If the trains didn't have to compete with the Green Line, the 14th Street bridge could carry many more trains from Virginia.
The new Yellow Line could connect to Green, Blue, and Orange at L'Enfant Plaza, stopping on a new platform just west of the existing station. Metro already wants to link Metro Center and Gallery Place with a walkway; the new line could stop along there as well to connect to all other lines.
For the other two stations, walkways probably aren't necessary. We could give them different names (Convention Center West?) However, the stations are extremely close to the existing ones, unless we put them in different spots. One advantage of lining them up and even giving them matching names is night service. When the Yellow and Green Lines are running at low frequencies, it would make more sense for Yellow trains to merge with Green, as they do today, to give each station more service (and save money by closing some entrances).
While this plan mostly benefits Virginia, it does do some good for DC and Maryland as well. The Green Line south of L'Enfant won't be able to carry more trains, even as development picks up in the Capital Riverfront area and, hopefully, in River East and Prince George's County one day. A separate Green Line would let all stations benefit from more frequent service. Finally, ending the Yellow Line at Convention Center always leaves open the possibility of extending it through DC and into Maryland along some route one day.
One big question mark remains. Yellow Line trains also have to compete with Blue Line trains for space between Pentagon and King Street. If we add trains over 14th Street, they have to go somewhere on the other end. How would we handle service on the Virginia side? I've come up with two possibilities, which I'll show tomorrow. What can you come up with?
Naturally, the terrible crash on the Red Line has generated a great deal of press attention and discussion. Had this been a nasty pile-up on the Beltway, we would probably would have stopped talking about it by now, and it certainly never would have been international news. The fact that service disruptions continue on the Red Line is another reminder of this horrible accident. After all, these disruptions have a far greater impact on Metro than a bad traffic accident has on area highways.
If there is an accident on US-29 in Montgomery County, I can drive on Georgia or New Hampshire Avenues. But the stations that were shut down the past couple days isolated eastern Montgomery County from the rest of the Metro system. Originally, I tinkered with a map showing a separated Yellow Line for the sake of greater capacity and more geographic coverage for the Metro System. This week's accident has shown that adding redundancy to the system can be just as valuable as adding capacity.
Separating the Yellow and Green Lines would add capacity to existing track, much like separating the Blue and Orange Lines. In the case of the Yellow Line, it would allow for increased capacity on its Potomac River Bridge. If separated, the entire Green Line and the Yellow Line north of Pentagon would have the same capacity as the Red Line.
Here's a possible separate Yellow Line:
View Separate Yellow Line in a larger map.
This alignment is not 100% original either. Bringing Metro to North Capitol Street and Georgia Avenue is in no way a new idea. In these cases, however, people seem to want it for the geographic coverage, and not the additional capacity or system redundancy. Coverage is good, it brings transit to a new area. Capacity and redundancy, however, improve the entire system.
Perhaps I added a few too many stations, but they are just suggestions. While this would add service to the North Capitol Street and Georgia Avenue corridors, it would add redundancy to both the Green and Red Lines via Silver Spring, Georgia Av/Petworth, Union Station, and L'Enfant Plaza.
If this line existed already, the station closures on the Red Line might only have meant an additional transfer for Montgomery County commuters instead of the shuttle services to which Metro resorted after the crash.
Cross posted on Imagine, DC.
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