Greater Greater Washington’s always had some great fantasy transit discussions – whether talking about the New Blue line, more fantastic visions, or even the multimodal vision for Baltimore and DC.  Over the last few days, the fantasy discussions have started again.  Though these are not always the most realistic discussions, they’re a great starting point for larger discussions about the role of transit in the transportation system in the city, and more importantly they discuss what kind of city we want to have.

This past week’s discussions have focused on the idea of a new Yellow line – originally posted here, along with my response.   The entire premise of separating the Yellow line from the Green line (at least as I understood it) was to increase the maximum capacity of both lines – the same premise behind the idea of separating the Orange and Blue lines.  That way, both colored lines would have full capacity for their entire length.  Doing such a project would also have ancillary benefits, such as adding redundancy to the system with multiple tracks on fairly similar routes, as well as opening up new areas to Metro service (such as adding Metro service to H Street NE with the New Blue line).  Each of these ideas is worthwhile, though slow to implement.  Given the facts that Metro is already straining to handle the crowds along the Orange line though the RBC, focusing on this kind of long term planning is important.  Building new subway lines will take a long time, and with Metro expected to reach capacity sometime between 2025 and 2030, starting the planning process now is vitally important (i.e. Metro was recommended as the preferred alternative for the Dulles Corridor in a 1997 report – the full line is now set to open in 2016 – nearly 20 years after the fact).

With that in mind, proposals that involve a great deal of capital construction must have a long term plan behind them to justify the investment.  The idea of separating the Blue and Orange lines is a good start.  Having a longer term plan to separate the Green and Yellow lines is also a good idea – even better would be to combine those efforts sowe have a nice 50 year map to follow for Metro’s development over time.

The lack of this kind of focus and long term vision troubles me with GGW’s latest series of posts about adding new trackwork in downtown DC.  The premise is a simple question: is there a simpler and cheaper way to add core capacity to Metro without building the entire New Blue line?

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 second iteration of the idea also generated a great deal of discussion:

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.

Both of these ideas are intruiging from an academic perspective, but completely lose sight of why you’re adding core capacity in the first place.

Remembering that the whole point of the New Blue line is to separate it from the Orange line tracks it shares through DC, the reason it gets brought up first is due to the popularity of the Orange line in Northern Virginia.  This GGW idea is an attempt to solve that same problem by essentially starting on a new Yellow line.  You’re essentially building half a subway, except that you’re building the New Yellow line first when the Blue line is the obvious choice.

If you’re going to put shovels into the ground, you might as well make sure that the plans have long term significance.  Metro’s genius is that it was concieved as an entire 100 mile system.  Even so, it functioned well before the full system was complete.

WMATA should take the same step here.  If you want to add new capacity to downtown DC by building half of a new subway, just start building the new Blue line – and do it in phases.  The first phase (say, from Rosslyn to the Connecticut Ave station) would accomplish the same thing – freeing up core capacity on the Orange (and Silver) line, as well as delivering Blue line riders to the core of downtown.   However, unlike the 9th street proposal, the Blue line would be readily expandable at a later date, much like how the Mid City portion of the Green line was completed in phases (with U Street opening in 1991, while Columbia Heights didn’t open until 1999).   Ideally, you’d like to do it in one fell swoop, but the entire premise of this idea is that the funds to do such a project aren’t there.  So let’s at least plan it with expansion in mind.

With that said, the idea of a new Yellow line isn’t a bad one at all, even if the timing isn’t quite right.  However, using 9th street doesn’t make a lot of sense when you already have lines along 7th and 12 streets downtown, and along 14th street in Columbia Heights.  The alignment proposed in the original post makes a lot more sense when viewed with a long-term lens.  A 9th street alignment would indeed be redundant, but almost too redundant – it wouldn’t open up any more area to Metro service, such as the transit poor Washington Hospital Center.  A North Capitol/Georgia Ave route would provide redundancy for both the eastern Red line, the whole of the Green line, and open up a major commercial street to Metro.  This line could also be phased in over time, initially operating as just a partial segment.

As Burnham said, “make no little plans.”  If you’re looking for incremental physical improvements, I’d opt to ensure that they’re part of a larger plan.  The final result will be far better for it.