Quote:
Originally Posted by ByeByeBaby
The last time I checked, the schedule had 27 or 28 trains during the highest hour westbound at City Hall in the AM. The maximum capacity that Washington DC Metro has is 26 trains per hour (the central red line as well as the shared blue/orange and green/yellow) segments. In San Francisco, BART puts 20 trains an hour through the Transbay Tunnel. Those are both totally separated heavy metro systems. SkyTrain has trains every 2-3 minutes on the combined Expo/Millennium line, which implies 24 trains an hour.
Basically, it's a miracle we put the volume of traffic through that we do on a system with road crossings. (Of course, it's actually the City doing a very good job, not an actual miracle.)
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I'm not sure that it is a miracle or the city doing some miraculous job as much as it is likely a function of the heavy systems you mentioned being drive-by-signal (ATO, etc) as opposed to the C-train, once past the switches being drive-by-sight.
Which, in turn, means that the trains are operated slower. Theoretically, you could have even more trains going down there if they go even slower, achieving headways approaching station dwell times. But that wouldn't be very useful.
So I guess it is impressive that given the street intersections they are doing quite well, but looking at headway alone in this case might miss the fact that it is also a product of comparatively slow operation. For the downtown commuter, less of an issue. For anyone going through, fairly annoying.
Quote:
Originally Posted by MalcolmTucker
Speed isn't the reason to bury the lines, capacity is.
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So the above being said, the main reason might be capacity, but speed is a pretty good incidental reason.