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Subway Scheduling


MrTransitMan

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Hello,

 

I'm new to this I understand that scheduling works off of data from metrocards and possible rider checks. Are actual track maps used as well to assist with the scheduling. I actually met with a service planner for the subways and he stated that they try to schedule trains 90 seconds a part. I asked what determines a line to be local in one spot and express in another, and he said based off of metrocard data. For example, the C goes to Euclid rather then the E because it would run local and make the E very unreliable (which I didn't understand).

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Hello,

 

I'm new to this I understand that scheduling works off of data from metrocards and possible rider checks. Are actual track maps used as well to assist with the scheduling. I actually met with a service planner for the subways and he stated that they try to schedule trains 90 seconds a part. I asked what determines a line to be local in one spot and express in another, and he said based off of metrocard data. For example, the C goes to Euclid rather then the E because it would run local and make the E very unreliable (which I didn't understand).

 

 

The longer a route is, the more of a chance something on the line will happen. And yes, due to signaling issues, there cannot be more than 30 trains per hour. If the line doesn't have to/rarely switches/merges wih another line this can be exceeded.

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The express/local configuration also has to do with how the stations are laid out. In all but a few cases the express stations have two island platforms enabling passengers to transfer between the local and the express right across the platform. Like I said there are exceptions to this, but by and large the express stops are set in stone... well, in concrete.

 

And yeah, it makes more sense to send the (C) to euclid than the (E), the (C) starts in manhattan and goes to Brooklyn, the (E) starts in Queens and goes to manhattan. You don't want the line too long because yes, the longer the line, the longer the possible delays. If someone holds the doors delaying the train 30 seconds at every stop, after 10 stops that's 5 minutes, after 20, it would be 10. An extreme example (though only barely) but illustrative of the problem.

 

During the rush hours, for most routes it's pretty much all-in: Run the line at capacity. Bear in mind that capacity is limited by choke points. The (E) and the (M) for instance have to share trackage between Queens Plaza and 5th/53rd, then the (M) has to share trackage with the (F) between Rock Center and B'way Lafayette, and THEN it's sharing a three track line with the (J) / (Z) between Essex and Myrtle. So, that gets complicated... and that's why the (M) doesn't run as frequently as a lot of other trains. Bear in mind that an (M) carrying an evening rush into Queens was going against the rush out of Metropolitan, so it is sharing one of the 3 tracks with the (J). So yeah - rush hours, the scheduling is largely determined by what the system can actually handle.

 

Off hours, well, thats where the metrocard data comes in. That's when capacity isn't the limiting factor and you can decide on 5, 10, 15 minute spacing based on usage.

 

Hope that makes some semblance of sense.

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Sometimes it's politics. Some trains are express because people don't want to wait a few minutes. Some trains are local because people living along the local stations want to go where it's going.

 

A fine example that illustrates both is the (F) in Queens: folks up there hated it when the (F) trains ran express between Forest Hills and Jamaica because it skipped their stops, but the same folks wouldn't let the (F) run local between Manhattan and Forest Hills during evenings because it'd slow down their ride (while all those suckers along the local stations would have to wait twice as long for service from the (E) train).

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The express/local configuration also has to do with how the stations are laid out. In all but a few cases the express stations have two island platforms enabling passengers to transfer between the local and the express right across the platform. Like I said there are exceptions to this, but by and large the express stops are set in stone... well, in concrete.

 

And yeah, it makes more sense to send the (C) to euclid than the (E), the (C) starts in manhattan and goes to Brooklyn, the (E) starts in Queens and goes to manhattan. You don't want the line too long because yes, the longer the line, the longer the possible delays. If someone holds the doors delaying the train 30 seconds at every stop, after 10 stops that's 5 minutes, after 20, it would be 10. An extreme example (though only barely) but illustrative of the problem.

 

During the rush hours, for most routes it's pretty much all-in: Run the line at capacity. Bear in mind that capacity is limited by choke points. The (E) and the (M) for instance have to share trackage between Queens Plaza and 5th/53rd, then the (M) has to share trackage with the (F) between Rock Center and B'way Lafayette, and THEN it's sharing a three track line with the (J) / (Z) between Essex and Myrtle. So, that gets complicated... and that's why the (M) doesn't run as frequently as a lot of other trains. Bear in mind that an (M) carrying an evening rush into Queens was going against the rush out of Metropolitan, so it is sharing one of the 3 tracks with the (J). So yeah - rush hours, the scheduling is largely determined by what the system can actually handle.

 

Off hours, well, thats where the metrocard data comes in. That's when capacity isn't the limiting factor and you can decide on 5, 10, 15 minute spacing based on usage.

 

Hope that makes some semblance of sense.

 

 

Same happens with the entire (N) line, the (Q) in Astoria and Broadway, the (R) on Broadway and 4th Avenue, and (D) on 4th Avenue. Now it runs parrarell somewhat around on Sea Beach with West End and Culver. Hence why ridership is lower on Sea Beach and those lines lead to Midtown Manhattan anyway...

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Hello,

 

I'm new to this I understand that scheduling works off of data from metrocards and possible rider checks. Are actual track maps used as well to assist with the scheduling. I actually met with a service planner for the subways and he stated that they try to schedule trains 90 seconds a part. I asked what determines a line to be local in one spot and express in another, and he said based off of metrocard data. For example, the C goes to Euclid rather then the E because it would run local and make the E very unreliable (which I didn't understand).

 

 

The E is very frequent, due to the heavy loading it encounters in Queens. The A is also quite frequent coming out of Brooklyn in the morning. The C, in contrast, is much less frequent, because the local stations in Brooklyn aren't terribly busy and most of the local stations in Manhattan are shared with the B or E.

 

Running the E into Brooklyn as the local would give the local stations about twice as much service as their loads call for. Worse yet, the A and E probably wouldn't even fit through the Cranberry tube under the East River, since most lines are capped at 30 trains per hour or less due to signal system constraints. In order to run the E as the Brooklyn local, service on either the A or the E would have to be reduced!

 

That's why the C is the local in Brooklyn, not the E.

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Thanks for the responses and happy thanksgiving. How are these loads determined? I'm not from NYC all I have is a track book I'm sure most of you are aware of and the information I learned from actually meeting the service planner. Is it just knowledge you build from just riding the trains on the regular? Also how do you make the subway line symbols that I see in posts? Thanks again.

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Thanks for the responses and happy thanksgiving. How are these loads determined? I'm not from NYC all I have is a track book I'm sure most of you are aware of and the information I learned from actually meeting the service planner. Is it just knowledge you build from just riding the trains on the regular? Also how do you make the subway line symbols that I see in posts? Thanks again.

Just put the letters into brackets, for instance ( A ) (remove spaces); would give (A)
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Not necessarily by letter, but Trunk more so refers to the line it primarily uses in Manhattan, so 8th Ave line/the routes that operate it are colored blue, 6th Ave line colored Orange, Broadway, yellow etc. All the lines have a primary local and express train and normally 1 or 2 additional /supplement routes that operate all times except nights and/or weekends and share a large majority of its route with other ones, so for the 6th Ave line (B)(D)(F)(M)..the (D)(F) operate 24/7...the (B) supplements the (D) in the Bronx & Manhattan and the (Q) in Brooklyn. The (M) supplements the (F) in Queens/Manhattan and the (J) in Brooklyn. It's cut back to just a Middle Village Shuttle on weekends because ridership on that Branch doesn't warrant one seat service into Manhattan during these times and those are the only stations along its line thats only served by that single train (although I'm sure one would argue that it could supplement the (J) as that line has become packed on weekends recently. The B doesn't operate at all on weekends because it's entire route is served by other trains and the ridership on weekends doesn't call for the extra capacity. Its the same idea with other routes (4)(6) primary (5) supplement. (1)(2) primary (3) supplement. (N)(Q)primary (R) supplement. Most supplement routes share mostly their entire trackage with other routes or serve a handful of stations towards the end of their line that mostly have lower ridership (and becomes a shuttle service that just connects the riders to the primary route which most likely will be running local at that time or is simply absorbed by an extension or revised stopping pattern of the primary route, I.E. (4) extends to New Lots at night replacing the (3) or the (N) runs via Montague after 11PM replacing the (R) which becomes a shuttle between 36th St and 95th street) Most of this is based off of ridership patterns. During the day and rush hours you want to run as many trains to Manhattan as possible and try to provide as much express service and travel options as you can to handle to loads of people traveling. On weekends and most definitely late nights as this demand goes down, you don't need as much service, so operations become simpler and volume of trains lower.

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Oh okay thanks, Being lines are usually grouped together, is there a trunk and feeder like dominance?

This is somehow like a tricky IQ test, but if you're asking what I think you're asking:

  • 8 Avenue: (A)

  • 7 Avenue: (1)

  • 6 Avenue: (D) / (F)

  • Broadway: (N)

  • Lexington Avenue: (4)

  • 2 Avenue: (T) (hypothetical)

  • Flushing: (7)

  • Canarsie: (L)

  • Nassau Street: (J)

  • Crosstown: (G)

  • Grand Concourse: (D)

  • Jerome Avenue: (4)

  • White Plains Road: (2)

  • Pelham: (6)

  • Hillside Avenue: (F)

  • Myrtle Avenue: (M)

  • Jamaica: (J)

  • Fulton Street: (A)

  • Brighton: (Q)

  • Sea Beach: (N)

  • Bay Ridge: (R)

 

See if you can figure out what the items have in common. The keyword here is "dominance" as in what route "owns" the line if there is such a concept. <_<

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A clue is the line that the entire trunk took the 1947 color from, and also, originally the full time express:

(A)(D)(N)(2)(J)(4).

The exception being the (4), since the 1967 color was magenta, and that was used on the (7). In the 1967 colors, green was generally used for BMT/IND locals. Also, the (N) had been stripped totally down to a full time local, while the (Q) became the full time express. BEfore the service cuts, the (N) had become a part time express again, but now with the (Q) back, that now pretty much took the "iwenership" of the line.

In the old BMT pattern of 1920-76, the (N) was the 24/7 express to 57th. The (Q) express was weekdays only, and the rest of the time, QB/QT locals ran; then in '67 the whole "Q" family was reduced to an [afterthought] five-interval one way rush hour special, as 6th Ave. service was forced onto the system. In '76, they began stripping the (N) down little by little, when it was merged with the EE local to Queens, and then had to pick up some local runs to Whitehall or Canal in the rush hours. In the '86-04 bridge work, it seemingly permanently was banished to the tunnel and local, and by the time that was finished, the (Q) became the primary express, so the (N) was always first to go local again off hours and in more recent service changes.

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But the subway is too much of a vast of people to get an accurate number, how does that even work?

 

 

It doesn't have to be perfectly precise. When I've seen traffic checkers out, there are usual several of them on the platform - probably one for every two or three cars.

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