5 ms·

> In other systems, undergoing recent upgrades (for example) you can run a train every 3 minutes as opposed to 6. That's only 20 trains per hour. London's Vict

> In other systems, undergoing recent upgrades (for example) you can run a train every 3 minutes as opposed to 6. That's only 20 trains per hour. London's Victoria Line now runs at up to 36 trains per hour, a train every 100 seconds. (Something I think about while waiting 20 minutes for a BaRT on a weekend.)

acjohnson55 8y ago
I assume OP was just giving an example, because the busiest lines in NYC subway (4/5/6) run about 20 trains an hour at peak times now, and that's with ancient signaling.
- AlphaSite 8y ago
  NY trains tend to have more tracks than London’s underground which is just north/southbound, instead of north, south, north express, south express (iirc).
  - Apeliotes 8y ago
    The London Underground has more miles of track which go in all directions, not just north and south. In fact cross rail which is the latest large expansion goes East to West. New York however has more stations and along with that 36 lines compared with London's 11
- bobthepanda 8y ago
  New York's busiest track pair is scheduled for 30TPH (E/F in Queens). These scheduled service levels tend not to pan out because of dwell times causing trains to get stuck in stations. CBTC helps mitigate this by allowing trains to run much closer, so the dwell time in stations is less of a limiting factor, and the busier frequency also allows platform overcrowding to be less severe.
  - acjohnson55 8y ago
    That's interesting! I ride the E train every day that I commute into the city (half of the weak), and I'm pretty sure that even at peak times, in Manhattan, it's more than 4-minute spacing. I once lived by the F train, and it's hard to believe that it ran enough trains to make up for that. So 30TPH seems wistful, indeed! The 4/5 actually seems to achieve 3-minute spacing consistently, though.
    - bobthepanda 8y ago
      It's a lot more noticeable in Queens; trains roughly do show up every two minutes. The major issue is that all the merging and interlining of services introduces many conflict points; most subway systems try to limit the branching of services on any given track pair, and very few have reverse-branching, the combination of branches into trunks in the outer parts of the system (like the E/F, the 2/5, the A/B/C/D, the B/Q, the D/N, etc.)
      - acjohnson55 8y ago
        Yeah, post Christie Street Connection, the branching is pretty wild. Nice for having some good options that minimize transfers, but I have to imagine it's hell for scheduling. The C shares track with the B in Upper Manhattan, the E in Midtown and most of Lower Manhattan, and the A from Lower Manhattan through Downtown Brooklyn until finally getting its own track. Going by common tracks, the A, B, C, D, E, F, G, J, M, N, R, Q, W and Z have to be considered correlated. So that's basically the whole IND+BMT, except for the L!
  - volkl48 8y ago
    Here's a pretty interesting map showing TPH (and number of train cars) in 1954 for the AM rush. I believe some lines are running fewer trains today than they were then. http://transitmap.net/image/55177865550 http://transitmap.net/image/55177865550
    - bobthepanda 8y ago
      The scheduled service on that map is 30TPH, although the theoretical max is 40TPH; the signalling system has never been used to that extent, mostly because the extra 30s between trains is used as contingency padding in case a train is late. The Lexington Line actually ran 30TPH at one point between the 4/5, but this has decreased because overcrowding has gotten so severe that it is now holding up trains as people struggle to enter and exit overcrowded cars. Prior to the opening of the Second Avenue Subway, the Lexington Avenue Line carried more than the transit systems of San Francisco, Chicago, and Boston combined. http://web.mta.info/capital/sas_docs/feis.htm http://web.mta.info/capital/sas_docs/feis.htm
jcranmer 8y ago
NYC's system has a lot of lines that basically run two lines on shared track, split them off, and then join other lines in complex reverse branching scenarios. This absolutely kills the ability to run high TPH (the Washington, D.C. metro also suffers this problem). The Victoria line has no revenue branches nor line sharing--it is much easier to get high TPH on those kinds of lines. Moscow Metro, in a similar situation, can pull 40TPH.
spiralx 8y ago
> London's Victoria Line now runs at up to 36 trains per hour, a train every 100 seconds. And have thinking about pushing it even further for quite a while now. https://www.londonreconnections.com/2017/ninety-second-railway-making-victoria-frequent-metro-world/ https://www.londonreconnections.com/2017/ninety-second-railw...

acjohnson55 8y ago

I assume OP was just giving an example, because the busiest lines in NYC subway (4/5/6) run about 20 trains an hour at peak times now, and that's with ancient signaling.

AlphaSite 8y ago
NY trains tend to have more tracks than London’s underground which is just north/southbound, instead of north, south, north express, south express (iirc).
- Apeliotes 8y ago
  The London Underground has more miles of track which go in all directions, not just north and south. In fact cross rail which is the latest large expansion goes East to West. New York however has more stations and along with that 36 lines compared with London's 11
bobthepanda 8y ago
New York's busiest track pair is scheduled for 30TPH (E/F in Queens). These scheduled service levels tend not to pan out because of dwell times causing trains to get stuck in stations. CBTC helps mitigate this by allowing trains to run much closer, so the dwell time in stations is less of a limiting factor, and the busier frequency also allows platform overcrowding to be less severe.
- acjohnson55 8y ago
  That's interesting! I ride the E train every day that I commute into the city (half of the weak), and I'm pretty sure that even at peak times, in Manhattan, it's more than 4-minute spacing. I once lived by the F train, and it's hard to believe that it ran enough trains to make up for that. So 30TPH seems wistful, indeed! The 4/5 actually seems to achieve 3-minute spacing consistently, though.
  - bobthepanda 8y ago
    It's a lot more noticeable in Queens; trains roughly do show up every two minutes. The major issue is that all the merging and interlining of services introduces many conflict points; most subway systems try to limit the branching of services on any given track pair, and very few have reverse-branching, the combination of branches into trunks in the outer parts of the system (like the E/F, the 2/5, the A/B/C/D, the B/Q, the D/N, etc.)
    - acjohnson55 8y ago
      Yeah, post Christie Street Connection, the branching is pretty wild. Nice for having some good options that minimize transfers, but I have to imagine it's hell for scheduling. The C shares track with the B in Upper Manhattan, the E in Midtown and most of Lower Manhattan, and the A from Lower Manhattan through Downtown Brooklyn until finally getting its own track. Going by common tracks, the A, B, C, D, E, F, G, J, M, N, R, Q, W and Z have to be considered correlated. So that's basically the whole IND+BMT, except for the L!
- volkl48 8y ago
  Here's a pretty interesting map showing TPH (and number of train cars) in 1954 for the AM rush. I believe some lines are running fewer trains today than they were then. http://transitmap.net/image/55177865550 http://transitmap.net/image/55177865550
  - bobthepanda 8y ago
    The scheduled service on that map is 30TPH, although the theoretical max is 40TPH; the signalling system has never been used to that extent, mostly because the extra 30s between trains is used as contingency padding in case a train is late. The Lexington Line actually ran 30TPH at one point between the 4/5, but this has decreased because overcrowding has gotten so severe that it is now holding up trains as people struggle to enter and exit overcrowded cars. Prior to the opening of the Second Avenue Subway, the Lexington Avenue Line carried more than the transit systems of San Francisco, Chicago, and Boston combined. http://web.mta.info/capital/sas_docs/feis.htm http://web.mta.info/capital/sas_docs/feis.htm

jcranmer 8y ago

NYC's system has a lot of lines that basically run two lines on shared track, split them off, and then join other lines in complex reverse branching scenarios. This absolutely kills the ability to run high TPH (the Washington, D.C. metro also suffers this problem). The Victoria line has no revenue branches nor line sharing--it is much easier to get high TPH on those kinds of lines. Moscow Metro, in a similar situation, can pull 40TPH.

spiralx 8y ago

> London's Victoria Line now runs at up to 36 trains per hour, a train every 100 seconds. And have thinking about pushing it even further for quite a while now. https://www.londonreconnections.com/2017/ninety-second-railway-making-victoria-frequent-metro-world/ https://www.londonreconnections.com/2017/ninety-second-railw...