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”.
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.