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Interesting comments, everybody. A couple thoughts:

I think a separate yellow line is not a bad idea, if ridership and TPH can warrant it. It would be great if it eventually continued north to Silver Spring, perhaps up Georgia avenue (there's already a planned streetcar on this route). But there's already reasonable redundancy in that region through Ft Totten. Even better might be if it cut across through Adams Morgan and then on toward Bethesda. That would give us better east/west transit options inside of the Purple Line route and outside of the separate blue line, and some redundancy over that very long stretch of western red line.

I like the idea of building three-way intersections around Rosslyn, Pentagon and L'Enfant, and I think it's long overdue (they work really well on the BART in SF, though they also have four parallel tracks through some sections). And it could make a great deal of sense to route Silver Line trains through National Cemetery to L'Enfant and Nationals Stadium.

On the other hand, the tracks at Rosslyn and Pentagon are configured with one rail above the other to allow trains to avoid crossing each other's tracks, and it will probably be tricky and costly to connect them the other direction. South of L'Enfant plaza, it would probably have to be a three-way level crossing intersection, not the greatest for throughput. And in each of these cases, trains would need to completely avoid the current transfer station. Silver Line trains would go Clarendon -> Court House -> Arlington Cemetery -> Jefferson Memorial (isn't it about time?) -> Waterfront. Probably not the best for ridership.

But if DC is going to get into the business of building new lines parallel to existing lines, what this region REALLY needs is express service. A split Yellow line should skip Navy Memorial, for instance.

But Al is right: the most cost effective option for express service and additional core capacity is to look more closely at MARC and VRE services. MARC already provides an "express service" to New Carrollton, Silver Spring, Rockville, College Park and Greenbelt; VRE provides it to L'Enfant Plaza, Alexandria and Franconia-Springfield. Let's focus our effort there.

If there was a train once every 15 minutes or less from Rockville or Greenbelt through to Franconia-Springfield, that would solve a large chunk of our capacity problem, and it would be felt throughout the entire system. The only lines not directly effected would be the western Orange and Silver lines and the southern Green line, but capacity adjustments elsewhere could relieve these lines somewhat.

Of course, the rail lines have a capacity problem as well, and it is largely due to through-freight trains. CSX just built a third track on the Virginia side, but a more southerly Potomac bridge would be better to route trains around the city. MARC has talked about adding a third track to the Brunswick and Camden lines, but that's likely to be difficult, and they still need a dedicated storage facility at Union Station.

But most of the freight trains that roll past Silver Spring are headed from West Virginia toward College Park or Baltimore and back. Why didn't Maryland build a couple of tracks parallel to (or instead of!) the ICC to allow these trains to avoid fouling the tracks around Union Station? This would have freed up all of rail lines in the city core for passenger service, shortened freight runs and may even have allowed MARC service from Baltimore to Frederick.

But alas. Keep dreaming...

by Andrew on Jun 30, 2009 11:21 am • link • report