More on Redundancy, engineered resilience, and subway systems: Metrorail failures will increase without adding capacity in the core

In response to the calls for more transparency from WMATA about why they want to reduce the service hours the system operates in order to have more time for maintenance (see "Re: Docket B16-03, Proposed changes to Metrorail operating hours," October 2016), WMATA did an interview with Greater Greater Washington ("Metro is being more transparent (and persuasive) about late-night closures... and weekend track work"). In response to the article and people's comments, which generally, are skeptical because they wonder why WMATA needs so much more time than peer systems, I wrote some comments myself (edited).

First, interestingly, the Bay Area Rapid Transit system is going through the same problems with significant financial needs for maintenance. They already have local sales taxes for transit, something not the case for WMATA. On next week's ballot in SF is Measure RR, which calls for spending $3.5 Billion on infrastructure improvement--for fixing only, not expansion ("Measure RR: BART asks voters to fund a major rebuild, KALW-FM/NPR).

Separately the MUNI system, which only serves San Francisco (BART does provide some intra-city service, but more functions like a commuter railroad) has two propositions on the ballot for system improvement there ("2016 Transit Propositions," SF Transit Riders Union).

It's instructive and relevant to our situation (as are the problems at MBTA).

2. People discussed the four tracks in NYC's subway system, some argued that it is for capacity not redundancy. But regardless, redundancy is provided by additional tracks. They also use the extra tracks for dealing with problems, which WMATA can't do because they don't have the option. No one in the NYC Subway system would argue that the additional tracks don't provide redundancy as well as more capacity.

Also inter-connections between NYC subway lines provide alternatives and capacity and redundancy as well. WMATA can't really benefit from such connections because in most cases the lines aren't proximate--it wouldn't help to shift riders to another line in the WMATA system for the most part because they would be delivered to stations many miles away from where they intended to go.

3. I've argued many times that additional tracks, even one, would provide redundancy and the ability to "staunch" service problems instead of spread them like a virus.

The same goes with interlining. Interlining between the blue, orange, silver, green and yellow spreads out problems across lines, it doesn't contain them.

I do think the points people made about separating lines (now I would do it with yellow and silver for sure, blue by continuing from Rosslyn and up Wisconsin Ave., and some branches such as for the green line) are important because long term it will provide more service, more uptime, and more reliability given the reality that no system can be maintained to the level of 100% SGR, especially because as trains age, they break down more.

All these issues were discussed in "More on Redundancy, engineered resilience, and subway systems: Metrorail failures will increase without adding capacity in the core," in March 2016.

4. As pointed out by others, London't Crossrail program doesn't really improve the Underground, theoretically, because it is a railroad program, but in reality it does, big time. It provides another mode, more connections, more capacity, just as repositioning these intra-metropolitan railroad services as complementary to the Underground by branding them as "London Overground" made the transit system more robust ("One big idea: Getting MARC and Metrorail to integrate fares, stations, and marketing systems, using London Overground as an example," May 2015).

MARC and VRE have more opportunity to play this role than they do currently. E.g., the Brunswick Line could provide bidirectional service and more service during the day were it used to shift travel between DC, Montgomery and Frederick Counties in both directions. VRE could provide more train service in the I-95 corridor.

5. I also argue that the Purple Line, not as big a deal as Crossrail sure, but it will have similar positive effects on Metrorail too, in terms of adding capacity indirectly, by providing options to transfer between subway and rail lines in the suburbs rather than forcing people to go to the center city first ("Maybe the Purple Line light rail project in Suburban Maryland is a lot bigger deal than is recognized (It's our Crossrail)," October 2016).

Expanding the Purple Line beyond the current project into Virginia will only strengthen these effects.

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Further refinements to creating separated subway lines for Metrorail

In "More on Redundancy, engineered resilience, and subway systems: Metrorail failures will increase without adding capacity in the core" I discussed a number of ideas for separating the lines.  I have a couple more refinements and additions.  Below is the same section from the original piece, but with edits and expansions.

Extension vs. intensification.  We need to distinguish between extending the system outward, or intensifying the system by adding capacity in the core, because these types of extensions have different impact.  It's the type of expansion that matters, not expansion generally.

Adding capacity in the core improves reliability while extending service outward, especially without increasing core capacity, degrades service.  Eliminating expansion in general limits the opportunity to improve system reliability.

Note that in some instances, system extension serves important purposes (e.g., such as to Fair Oaks in Fairfax County, extending the Orange Line, or to Fort Belvoir, which could be reached by extending the Yellow Line) but it shouldn't occur without simultaneously addressing how extension impacts the core system.

Conclusion: One of the best ways to improve reliability and safety in the Metrorail system is to create the Separated Silver Line within DC.   Sadly, this is where my lack of ability with graphic design software shows.  Many years ago David Alpert of Greater Greater Washington was kind enough to create a graphic of an idealized Metrorail system based on my thinking at that time.


But my thinking has continued to evolve and this is what I would propose now:

Separated Silver Line and Separated Orange Line

1.  Instead of what used to be called the separated Blue Line, I would now term it a separated Silver Line.  It could also be thought of as a "Downtown Relief Line."

Instead of joining the Orange Line at East Falls Church Station, instead treating it as a transfer station, the Silver Line could continue south to Route 50/Arlington Boulevard then east to Rosslyn, crossing to Georgetown, continuing eastward to Union Station (this adds capacity to serve Amtrak's plans for expansion), and then further east to H Street NE.  (The Arlington Boulevard alignment was suggested by commenter Ryan in a thread at GGW.)

2.  This would add stations in Northern Virginia and DC.  At the very least it would add one crossing and at least 9 new stations in DC, with 3-4 more stations if an additional Silver Line leg was constructed up Bladensburg Avenue.  It would serve key activity centers not currently served in Virginia (Arlington Boulevard/Seven Corners) and DC (Georgetown especially), providing additional capacity Downtown and at Union Station.

3.  The map above shows a separated silver line and a separated orange line with a transfer station at "River Terrace"/in the vicinity of RFK Stadium, I would route the Separated Silver Line onto the Blue Line alignment from RFK Stadium to New Carrollton (this is a change) and keep the current Orange Line routing.  This would allow transfers between the two lines.

4.  A separate intra-city leg of the Silver Line could be added along Bladensburg Road from H Street to New York Avenue and Fort Lincoln.

5.  The current bridge alignment of the Orange Line from Stadium-Armory over the parking lots to the Minnesota Avenue station would be eliminated, replaced by a tunnelized alignment along Benning Road from H Street and Bladensburg.  This would enable superior redevelopment of the RFK Stadium site.

Separated Blue Line/Brown Line

1.  The map above shows a truncated Blue Line ending in Rosslyn, and a "Brown Line" starting in Georgetown, extending south to National Harbor in Prince George's County and then west to Alexandria.

2.  I would merge the two lines so that the Blue Line continues from Rosslyn across to Georgetown and then up Wisconsin Avenue, connecting to the western leg of the Red Line, and turning east at some point in Upper Northwest, providing an east-west high capacity transit connection in the upper city.

3.  The Brown Line concept merges some of my ideas with Internet blogger MV Jantzen.  While the map above shows a southern alignment along North Capitol Street to Union Station and south into Prince George's County and then west to Alexandria, now I would probably have it go out New Hampshire Avenue into Montgomery and Prince George's Counties.  Before I thought that could be a more western leg of a separated Green Line.  It would have a transfer connection at Fort Totten.

The DC justification of extension out New Hampshire Avenue is to interdict commuter traffic to and from DC.  Montgomery and Prince George's Counties would see additional intensification benefits as well as an additional Metrorail connection to the Purple Line at University Boulevard.

4.  This would add a number of stations within DC serving areas currently not served by high capacity transit, plus an east-west connection in Upper Northwest, which has only one major east-west connection currently (Military Road-Missouri Avenue-Riggs Road).

Separated Green Line

Some of the visualization is difficult because I don't have a map of all these ideas.  The map that David Alpert did shows a brown line.  Now I suggest that the blue and brown line be combined, and the blue line should continue across the Potomac River to Georgetown and up Wisconsin, turning east and some point and providing an east-west connection across Upper Northwest Washington, connecting the east and west legs of the Red Line, plus the option of continuation out New Hampshire Avenue.

1. The Green Line could be separated and merely limited to its current footprint, without sharing stations with the yellow line.

2.  Alternatively, on the southern end it could be extended from its terminus at Branch Avenue to National Harbor and then across to Alexandria.  This change would serve National Harbor, one of the area's leading new activity centers in Prince George's County, and would provide more transit stations in Prince George's County and an east-west connection to Alexandria, Virginia.

3.  However, extending the Purple Line from New Carrollton to Alexandria with a connection to National Harbor could do the same thing and that probably makes more sense financially.

MetroForward 2040 Network concept map, WMATA.  I am not a fan of this proposal for a 
new 2040 Metrorail Network because it doesn't add service east of Union Station.

Separated Yellow Line

A separated Yellow Line within DC was first proposed in a blog entry by Dave Murphy and it could be extended to Montgomery County.

At first I wasn't supportive because of the low density nature of Georgia Avenue within DC, but long term the zoning could be changed and the area intensified, justifying the cost of creating a Metrorail line there.

1.  DC north.  Within DC, from the 7th Street-Shaw station the line could go north on Georgia Avenue from Howard University and extend outward into Montgomery County, either along Colesville Road or Georgia Avenue.

2.  Connecticut Avenue leg.  Based on a comment by Tom Quinn in the original post about the need for higher capacity transit service in the Connecticut Avenue corridor, in part as a way to interdict the heavy commuting traffic from Maryland, perhaps on the north a separated yellow line could have two branches.

In addition to the leg proposed above, extended in Montgomery County out either Georgia Avenue or Colesville Road, another leg could go up Connecticut Avenue, providing high capacity transit service in between the Wisconsin/Rockville Pike and Georgia Avenue corridors.

Benefits.  By separating the Silver and Orange Lines, each line would have the maximum capacity for 30 trains/hour, which is more than can be accommodated sharing the lines currently.  At least one additional crossing between Rosslyn and DC would be added.

Many more stations would be added in DC, as well as redundancy and more capacity in the core, increasing system reliability.  New areas would be served in all three jurisdictions, increasingly the ability to capture automobile trips and shift them to transit.

Note that adding legs, such as up Bladensburg Road on a separated Silver Line or both up Georgia Avenue and Connecticut Avenue on a separated Yellow Line would reduce capacity from the theoretical maximum because of time required to switch from the branch to the main line.  But there would still be more service and more reliability compared to how interlining works now.

A new alignment for a Blue Line across the Potomac and out Wisconsin Avenue would add service to areas underserved by high capacity lines now, a crucial east-west connection in Upper Northwest, and would add redundancy to the Red Line.  Extending the out New Hampshire Avenue into Maryland would add service there as well as enable the interdiction of commuter traffic into DC.

A separated Yellow Line extended on the south would add service to important parts of Virginia.  On the north, new alignments into two legs would provide service out Connecticut Avenue and Georgia Avenue in DC and on either Georgia Avenue or Colesville Road in Maryland as well as Connecticut Avenue.  (In fact, a Connecticut Avenue leg would probably mean that extending the east leg in Montgomery ought to be out Colesville Road.)

Extending the Purple Line on the south west from New Carrollton to Alexandria would provide other redundancy and access benefits, and provide a higher capacity transit connection to National Harbor which will soon be home to an MGM Casino and hotel complex.

Paying for it.  As I have discussed before, by increasing the allowable height at which buildings can be constructed in Downtown, DC's property tax base would increase significantly and become large enough to fund this kind of bold expansion and intensification of the transit system within DC.

Ideally, a "transit withholding payroll tax" could also be assessed, but for this to be worthwhile, the the federal government has to be willing to pay it (unlikely in the current economic environment), therefore this revenue source may not be worth pursuing.  In the US, certain jurisdictions in Oregon and in Greater New York have such a tax.  In France, this type of tax, called the versement transport, provides a preponderance of funding for transit service in most cities.

Funding for additions within Maryland and Virginia would be provided by those jurisdictions. But planning, design, engineering, construction, and financing should be coordinated, rather than discoordinated, as occurs at present.

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Purple Line impact on Metrorail system reliability.  The Purple Line will be a light rail line serving Montgomery and Prince George's Counties in Suburban Maryland.  Its western terminus will be at Bethesda Station on the western leg of the Red Line, and it will connect to the Red Line western leg at Silver Spring, to the Green Line at College Park, and to the Orange Line at New Carrollton, which is the eastern terminus for the line.

The original concept of the Purple Line.

The system won't interline with Metrorail so it won't impact system reliability in the way that the addition of the Silver Line has degraded service on the Orange and Blue Lines.

You could argue that by adding riders to the current system, it could add stress because of the failure to add capacity in the core.

However, by providing a missing east-west connection between the subway lines outside of Downtown DC, likely the Purple Line will "add capacity" by providing four new transfer points between subway lines, facilitating transfer between lines without requiring riders to go all the way to Downtown DC to do so, as is required today.