Posts about Separate Yellow Line

Transit

Metro planners contemplate system's second generation

by Matt Johnson   •   June 21, 2011 3:57 pm

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.

Photo by sabine01 on Flickr.

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.

Transit

Metro ponders new tunnels and connections

by David Alpert   •   January 24, 2011 11:37 am

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?

Photo by ep_jhu on Flickr.

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.

Left: Possible separate Blue Line. Right: Possible separate Yellow Line.
Click on an image to enlarge.

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:

Click to enlarge.

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:

Click to enlarge.

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.

Transit

A cheaper route to Metro core capacity, part 3: More complex service patterns

by David Alpert   •   July 1, 2009 2:25 pm

If Metro separates the Yellow and Green Lines to add capacity across the Potomac, we could align service various ways. What about a hybrid of the two?

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".

Click to enlarge.

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.

Transit

A cheaper route to Metro core capacity, part 2: Virginia service patterns

by David Alpert   •   June 30, 2009 10:03 am

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

Click to enlarge.

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

Click to enlarge.

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.

Next: A hybrid option?

Transit

A cheaper route to Metro core capacity?

by David Alpert   •   June 29, 2009 12:26 pm

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?

Transit

Imagine a separate Yellow Line

by Dave Murphy   •   June 26, 2009 8:41 am

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:

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.