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RR503

Subway Capacity Thread

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1 hour ago, LaGuardia Link N Tra said:

@Union Tpke I updated my map of NYC Subway Bottlenecks, but it's still a work in Progress. 

You might also want to add the northbound (J)(Z) switch at Chambers Street which also slows things down.

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23 hours ago, LaGuardia Link N Tra said:

I updated my map of subway bottlenecks, and this should be the complete result. @RR503 @Union Tpke and everyone else, let me know which bottlenecks I missed or need to change so that the information is accurate:

https://drive.google.com/open?id=1zW5OcTK4Zkc1_vlH-8LQ73k6UdrhA8hV&usp=sharing

A few comments: 

- Astoria and Dekalb should be major bottlenecks

- You should include dwell time constraints at Jackson Heights, Grand Central (both levels), 72/Bway, and mention dwells when talking about USQ. 

- Dunno where you'd put the marker, but highlighting restrictive (ie GT heavy) signal design along Eastern Parkway and its effects especially on 4/5 service may be worthwhile. 

- BG terminal ops should go on there. That's an easy 3 minute delay whenever they're short turning a train. 

- I'd be sure to describe what's bad about E180. It's the crossing move that 5s make

- Why do the 2 curves at Crescent get different rankings?

- I'd add the merge at 75 Ave

- I'd add Whitehall terminal ops

- I'd add Utica terminal ops

And a general question: what is your definition of bottleneck? An area that slows service? That reduces capacity? That does both? 

This is a good effort. We need more info like this publicly and concisely accessible. I'll think of more comments, I'm sure. 

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9 hours ago, RR503 said:

A few comments: 

- Astoria and Dekalb should be major bottlenecks

Alright. I can see why you’d rank them that way

- You should include dwell time constraints at Jackson Heights, Grand Central (both levels), 72/Bway, and mention dwells when talking about USQ. 

Okay. I forgot about Dwell Times. 

- Dunno where you'd put the marker, but highlighting restrictive (ie GT heavy) signal design along Eastern Parkway and its effects especially on 4/5 service may be worthwhile. 

I’d probably put the marker in the middle of the Eastern Parkway line, which I guess could be around the Grand Army Plaza Area. 

- BG terminal ops should go on there. That's an easy 3 minute delay whenever they're short turning a train.

 Wait, I didn’t add Bowling Green on my map or did I give it a different color?

- I'd be sure to describe what's bad about E180. It's the crossing move that 5s make

I’ll keep that in mind which means that this bottleneck is more impactful than I originally thought. 

- Why do the 2 curves at Crescent get different rankings?

One is wider than the other. But I guess I could combine the 2 markers into one and have them listed as one bottleneck. 

- I'd add the merge at 75 Ave

..........crap. I forgot about that one. 

- I'd add Whitehall terminal ops

- I'd add Utica terminal ops

👍

And a general question: what is your definition of bottleneck? An area that slows service? That reduces capacity? That does both?

This is a good effort. We need more info like this publicly and concisely accessible. I'll think of more comments, I'm sure. 

Other replies are in bold.

My definition of a bottleneck is an area in the system that slows things down for everyone and has a negative impact on our subways Capacity such as reducing the number of trains that we can run on a subway line. So bottlenecks in my eyes would include:

• Grade Level Merges.

• Flying Junctions (Which becomes even worse bottlenecks with Poorly Scheduled trains)

• Poor Terminal Operational Practice’s

• Poor Signaling (excessive GT’s at Areas where they don’t need to be) 

• Sharp Curves.

• Dwell Times. (Even worse if the Station has a poor Design) 

Can these bottlenecks be fixed? Not all of them, that’s for sure. But for the ones that can be fixed, what would it take to fix them? It’ll require are a few upgrades and Reroutes if necessary. 

Anyways, thank you for the feedback, I appreciate it. 

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Bottleneck Junctions or Merges at Stations between Exp and Loc tracks.

at 59 St on CPW lines.

Eastern Pkwy line near Franklin Av.

Sometimes at 149 St-GC.

Myrtle Av-Bway.

Canal St-8 Av line.

Queens Plaza-QBL.

Near DeKalb Av.

Between 34 St and 42 St on Broadway Line.

 

 

 

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I have a question specifically related to the (M) train...

As we all know the Williamsburg Bridge limits capacity on the southern end but how much extra capacity is available on 6th Av/Queens Blvd to run additional rush hour short turns to say 2nd Avenue?

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8 minutes ago, Around the Horn said:

I have a question specifically related to the (M) train...

As we all know the Williamsburg Bridge limits capacity on the southern end but how much extra capacity is available on 6th Av/Queens Blvd to run additional rush hour short turns to say 2nd Avenue?

I hear the number 28 thrown around a lot for 6th, though I wouldn’t be surprised if recent resignallings make it pushable to 30.

As you know, QB local is a mess thanks to Forest Hills and to a lesser extent the QP merge, but I’m pretty sure the signals there are still capable of ~30. 

So that’s a marginal increase of what, 3-4tph? 

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6 hours ago, RR503 said:

I hear the number 28 thrown around a lot for 6th, though I wouldn’t be surprised if recent resignallings make it pushable to 30.

As you know, QB local is a mess thanks to Forest Hills and to a lesser extent the QP merge, but I’m pretty sure the signals there are still capable of ~30. 

So that’s a marginal increase of what, 3-4tph? 

How would the recent resignalings allow for 30? With Canarsie, there would have been 14 (F)s and 14 (M)s.

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