The planned $10 billion expansion of Washington Union Station is a waste of money, but this does not mean that money appropriated for public transportation in the National Capital Region is a waste. The region has real transportation needs that should be addressed through urban rail expansion – just not through a rebuild of the intercity rail station. Those needs include local and regional travel, to be addressed through investment in both the Metro and the commuter rail networks. It is fortunate that when I probed on Twitter, there was broad if imperfect agreement among area advocates about what to do.
A $10 billion budget should be spent predominantly on new Metro Rail lines, carefully chosen to satisfy multiple goals at once: physical expansion of the reach of the system, additional core capacity, and deinterlining to improve reliability and increase the capacity of existing lines. For the purposes of the question I posed to area advocates, I set the expansion budget at $7.5 billion, good for 30 km at average global prices, leaving the rest for commuter rail improvements.
What to do about commuter rail
Washington does not have a large legacy commuter rail network, unlike New York, Chicago, Boston, or Philadelphia. It is not as old as those cities, and its conception as the southern end of an East Coast region stretching up to Boston is postwar, by which point investment in passenger rail was largely relegated to the past. Nonetheless, it does have some lines, three to the north as the MARC system and two to the south as the VRE system. They should be upgraded to better commuter rail standards.
Union Station already has the infrastructure for through-running. The junction between the through-tunnel and the terminal tracks is flat, and almost all intercity trains terminate and most will indefinitely no matter how much investment there is in high-speed rail to points south. This requires delicate scheduling, which is good up to about 18 trains per hour in each direction, either six through- and 12 terminating or the other way around. Running half-hourly all-day service on each of the lines, with some additional urban overlay in Virginia and extra service on the Penn Line to Baltimore, should not be too difficult.
Thus, the main spending items on the agenda are not new tracks, but electrification and high platforms. MARC runs diesel trains even under catenary on the Northeast Corridor, which problem requires no additional electrification to fix, but its other two lines are unelectrified, and VRE has no electrification infrastructure. Those lines total 327 route-km of required wiring, with extensive single-tracking reducing per-km cost; this should be around $600 million. But note that they all carry significant freight traffic, and additional accommodations may be necessary.
As far as platforms go, there are nearly 50 stations requiring high platforms (I think 49 but I may have miscounted). At Boston costs it should be $1 billion or a bit more, but that’s for long trains, and MARC trains are not so long, and a system based on shorter trains at higher frequency would be somewhat cheaper. Infill stations are probably unnecessary – there are Metro Rail lines along the inner sections of most of the lines providing the urban rail layer.
Metro Rail expansion
The most pressing problem WMATA’s trains have is poor reliability. Two changes in the late 2000s and 2010s made the system worse: the 2009 elimination of automatic (though not driverless) operations worsened ride quality and reducing capacity, and the 2014 opening of the Silver Line introduced too much interlining reducing both reliability and capacity. WMATA is aware of the first problem and is working to restore ATO; the Silver Line’s problems should be fixed through judicious use of deinterlining. Deinterlining by itself only requires a short extension of the Yellow Line to separate the lines, but it can be bundled with further expansion.
Consensus among area advocates is that there should be separate tunnels for the Yellow and Blue Lines and a new trunk line under Columbia Pike, which three lines total 21 km. Additional lines can consist of another trunk line going northeast from Union Station between the Brunswick and Camden Lines or an extension of the Columbia Pike line from Bailey’s Crossroads, the present outer limit of high density, to Annandale, which would require extension transit-oriented development along the line.
A full-size version can be found here; note that the lines at Union Station are moved around to get rid of the Red Line’s awkward U-shape. The northeast extension option is colored red but should be a Blue Line extension, but the Red Line taking over H Street and going to Largo.