NYCT - Bottlenecks Discussion Thread

[CenSin]

1 hour ago, N6 Limited said:

Some trains are held at 169th Street waiting for a slot at 179th.

What a shocker! Isn’t that particular terminal famous for turning back over 60 trains per hour? Those 4 tracks and extra pockets past the station have got to be good for something.

[NBTA]

Just now, CenSin said:

What a shocker! Isn’t that particular terminal famous for turning back over 60 trains per hour? Those 4 tracks and extra pockets past the station have got to be good for something.

We talking about Jamaica operators here man. lmao

[CenSin]

2 hours ago, NBTA said:

We talking about Jamaica operators here man. lmao

They’re only using it for 17 trains per hour max. What are they doing to screw it up?

[nightmare402]

8 Av canal st brooklyn bound

[Calvin]

The bottleneck was mentioned about Rogers Av:

Something, I noticed when the  reach the Franklin Av station, if one train arrives and open doors first, that train enters President St first. 

 

During AM rush, on the  train meeting the  such as Newkirk Plaza, connections most of the time were never made. 

[S78 via Hylan]

1 hour ago, Calvin said:

The bottleneck was mentioned about Rogers Av:

Something, I noticed when the  reach the Franklin Av station, if one train arrives and open doors first, that train enters President St first. 

 

Not in every case. There have been times where I was on a  that arrived or departed Franklin first and still had to let a  or  pass.

[Abba]

It might be which train gets to the JUNCTION first but I’m not sure .What I am sure is that its very annoying waiting there . I’m always worried the will get a BIE there.  If it’s  me on the  and a  or  goes BIE at least they can send the train to Utica.Thankfully it hasn’t happened to me yet 

Edited October 30, 2019 by Abba

[Abba]

Deleted

Edited October 30, 2019 by Abba

[NYCTNostalgia]

On 10/26/2019 at 8:52 PM, Calvin said:

The Dekalb junction: that's correct going north but going south is like making a choice if the  and  or and  meet at the same time. 

I second this. The  doesn't know how to be on time for ANYTHING, but  and 's &  and  always arrive perfectly on time to interfere with one another, causing one of the trains to be held on the Bridge thru DeKalb Junction for 4-8 minutes. Annoying as hell.

Another annoying bottleneck is Whitehall Street. When I take my  into the city and I check MyMTA, if the  is scheduled to arrive within 2 minutes of a departing Queens Bound , we will be held before Whitehall St on a crowded  for 3-6 minutes. It drives me insane.

Edited October 30, 2019 by NYCTNostalgia

[T to Dyre Avenue]

This same thing also happens at Herald Square and 36th Street, Queens, all the time. Seems like the northbound  almost always gets to 34th at the same time a northbound  or  gets there. Same with the northbound  and  at 36th Street. 

I’m always seeing northbound ’s and ’s run in bunches of two at Canal, so you get a  behind an  (or vice versa), then a long wait before the next two trains. Definitely related to dispatching shenanigans at DeKalb.

Edited October 31, 2019 by T to Dyre Avenue

[LGA Link N Train]

3 hours ago, T to Dyre Avenue said:

This same thing also happens at Herald Square and 36th Street, Queens, all the time. Seems like the northbound  almost always gets to 34th at the same time a northbound  or  gets there. Same with the northbound  and  at 36th Street. 

I’m always seeing northbound ’s and ’s run in bunches of two at Canal, so you get a  behind an  (or vice versa), then a long wait before the next two trains. Definitely related to dispatching shenanigans at DeKalb.

That seems like there's a trend here when it comes to trains going Northbound. 

DeKalb Junction > Canal Street Bunching > 34th Street and / meet up. > 1-3 Minute delay depending on who gets lineup.

DeKalb  Junction > Grand Street-West 4th Bunching > 59th Street Merge with the . (I'm not sure how long a or train has to wait when an or Train is given lineup.)

  53rd Street (one given lineup, other waits about 3 minutes) > Queens Plaza. I'm not sure if bunching occurs, but an waits for around 3-5 minutes if an is given lineup. (Same situation happens in the Vice Versa scenario) Enlighten me if this negatively affects the . > 36th Street Merge (alternating on both going at slow speeds; one given lineup; latter waiting about a minute) > Dwell Times at Roosevelt? I don't notice it myself. > Forest Hills. Conga Line on the ; Bunch up at around 6-8 PM. > 75th Avenue Diverge. Trains and Morning Trains run at around 15 MPH. (Not sure if this affects Express Trains) 

Upon Entering Church Avenue and the area between Jay Street (York Street going S/B) and Caroll Street, trains go at around 10-15 MPH from my experience, if not slower. Any reason for this at all?  (Aside from merging and diverging from the )

[CenSin]

Given the gripes mentioned here, it seems there is good cause for partial deinterlining. Is having a one-seat ride really worth these headaches? Broadway’s have got to be the most egregious of the examples mentioned; there are delay opportunities everywhere!

• Queensboro Plaza/Queens Plaza ( & )
• 42 Street–Times Square/34 Street–Herald Square ()
• South Ferry–Whitehall Street ()
• DeKalb Avenue ()
• Prospect Park ()
• 36 Street ()

Edited October 31, 2019 by CenSin

[LGA Link N Train]

14 minutes ago, CenSin said:

Given the gripes mentioned here, it seems there is good cause for partial deinterlining. Is having a one-seat ride really worth these headaches? Broadway’s have got to be the most egregious of the examples mentioned; there are delay opportunities everywhere!

• Queensboro Plaza/Queens Plaza ( & )
• 42 Street–Times Square/34 Street–Herald Square ()

If there's one thing we can all agree on here, it's sending the to 96th Street with boosted Service along Astoria, and eventually the being rerouted to Astoria as well. Ofc, we can't do much about the Queens Plaza Merge unless we rearrange 8th Avenue/CPW and 53rd/63rd Street services. 

• South Ferry–Whitehall Street ()

I don't really know much about this bottleneck, but the least I can say is that its either the poor scheduling/bad operations management that creates this bottlenecks or its the signals

• DeKalb Avenue ()

DeKalb is a pain in the neck to deal with. However, it was rebuilt as a flying junction and thus, its meant to run interlined services. I'd say (with a grain of salt) that the schedules for the and Lines need to be better balanced, and the signals need to be upgraded. If that STILL Doesn't work, only then should we make the call that "Hey, we need to de-interline DeKalb Junction" 

• Prospect Park ()

This is a rather interesting one now that I think of it. I don't normally pass by Prospect Park so I'm not sure if they hold trains going Northbound. But towards Sheepshead Bay and Brighton Beach, there's a bottleneck in that general area. 

• 36 Street ()

I'm aware of the work that happens along 4th Avenue. I'm also aware that the Train travels at a slow speed between 9th Avenue and 36th Street. But what exactly happens around 36th. I don't live nor work in Sunset Park, but I'm curious. 

My notions as to how these issues and how they can be addressed are highlighted in bold. 

 

[Jemorie]

For me, personally, Rogers Junction is the number one worst bottleneck in the entire subway system. Me, along with @Lex, @S78 via Hylan, and @JeremiahC99, have all pointed out our reasons. On top of that, the way the junction was built. Trains have to physically cross infront of one another in both directions before getting to their respective following station stops. Rush hour is when delays occur one by one. It should have been foreseen from the beginning. No excuses. It's totally unacceptable and a merge reason why capacity is limited on the  followed by the already poorly terminal setups at Flatbush Avenue on the  and Utica Avenue on the  as well, even the 142nd Street Junction on the , which has a similar design like the Myrtle Avenue Junction on the .

But I also can't deny the delay opportunities (like @CenSin just now pointed out) of all the other bottlenecks in the system, particularly north of 34th/B'way where  trains have to switch from express to local and vice-versa, delaying all other trains behind. The Broadway Line sucks for this very reason. Then comes along the entire  route, the most infamous line in the system. The more complex the system is, the more delay opportunities, the more capacity is limited, etc. Trains aren't physically guaranteed to run on-time despite what is said in black and white. As someone else said before, they are not so good at running on schedule, yet are so great at running behind schedule to the point they end up meeting up with other lines they know will be merged with together right then and there. Pity. Some folks will agree to send all Broadway Express trains to/from SAS and the 4th Avenue Line, and all 6th Avenue Express trains to/from the Brighton Line. The 4th Avenue Line feeds onto the Broadway Line anyway. But then some other folks will go ups and arms about the loss of their one-seat rides.

The  should be given priority all the time at Canal Street since it is the least frequent all day and evening long, at 10-minute headways. The  runs every 4-minutes rush hours, 6-minutes middays (excluding its crappy 12-minute weekend headways). The  headways, however, vary across the day depending on direction and peak load point. But I do think it is every 7-8 minutes off-peak (10-12 minutes Sundays) from what I've noticed on its timetable. So unless the  gets its headways increased sometime in the future, I would personally suggest that it be given absolutely priority at all the bottlenecks along its run. It's already piss-poor as it is anyway, and any delay by other lines at merge points would only extend the  's wait times at following stations further up the line to the point where trains become bunched up at 168th Street north/Euclid Avenue south. @RR503, what do you think btw? Would this make the  run better or will it just make the other lines it merges with worse despite them being relatively more frequent than the ? Even the  and  run up to 10 trains an hour each during the rush.

Edited October 31, 2019 by Jemorie

[CenSin]

51 minutes ago, Jemorie said:

Trains aren't physically guaranteed to run on-time despite what is said in black and white. As someone else said before, they are not so good at running on schedule, yet are so great at running behind schedule to the point they end up meeting up with other lines they know will be merged with together right then and there.

This not the root cause, although it is the key reason for merge delays. Trains just don’t line up nicely. It’s like playing Tetris where you have to work with the pieces you get.

54 minutes ago, Jemorie said:

The  should be given priority all the time at Canal Street since it is the least frequent all day and evening long, at 10-minute headways. The  runs every 4-minutes rush hours, 6-minutes middays (excluding its crappy 12-minute weekend headways). The  headways, however, vary across the day depending on direction and peak load point. But I do think it is every 7-8 minutes off-peak (10-12 minutes Sundays) from what I've noticed on its timetable. So unless the  gets its headways increased sometime in the future, I would personally suggest that it be given absolutely priority at all the bottlenecks along its run.

The best remedy might actually be first-come-first-serve. If trains need to be held for scheduling reasons, then the schedule has too much padding or the train needs to be held elsewhere where it won’t piss off passengers or hold up other trains. As long as trains are spaced evenly, I don’t think it matters that a train is too late or too early or not coming in the order that they are scheduled. There ought to be some place to put in an extra train when gaps get too wide.

[Calvin]

During this time, an expectation of the  from Church Av to Kings Hwy: trains will run slow speed (takes at least 10-15 minutes with leaves on the track). The  runs normal speed though. 

[Abba]

Prospect Park northbound on  and  usually isint so bad . 

[CenSin]

56 minutes ago, Calvin said:

During this time, an expectation of the  from Church Av to Kings Hwy: trains will run slow speed (takes at least 10-15 minutes with leaves on the track). The  runs normal speed though. 

Then the saves no time??

[Calvin]

7 minutes ago, CenSin said:

Then the saves no time??

Not much

[Trainmaster5]

On 10/30/2019 at 12:02 AM, Abba said:

It might be which train gets to the JUNCTION first but I’m not sure .What I am sure is that its very annoying waiting there . I’m always worried the will get a BIE there.  If it’s  me on the  and a  or  goes BIE at least they can send the train to Utica.Thankfully it hasn’t happened to me yet 

Depends on who is calling the shots at the Junction. ATS might have a or running late so that train goes first. If Utica tower has control and there's a late sitting there that train has priority, especially if Utica needs that stuck behind the   train. Basically it boils down to a timetable vs the situation on the road. In a perfect world no one gets delayed at the Junction because the timetable doesn't have trains crossing each other's path at the same time. There were times when I left Utica n/b on a crossing over to the express track at Utica behind a train that I followed from New Lots and both of us waited, side by side, at Nostrand, while a crossed over from President Street and I followed that all the way to Dyre Avenue. That train was supposed to be ahead of a train which left Utica two minutes before I did. That Flatbush becomes a late train with heavy ridership in the pm rush all the way n/b and my train is probably late too. BTW the to Nereid behind me is going to close in on both of us between Freeman and East 180th St and, if there's a delay on n/b service, that train is going to get crush loaded at the East and probably end up going in service to 241 St. What I just described was a fairly common occurrence and I learned to live with it and not get bent out of shape. One late train at a choke point can cause all of that.  The problem could have happened s/b and caused the delay. Carry on.

[P3F]

1 hour ago, CenSin said:

Then the saves no time??

I ride the  most weekdays, and for the vast majority of trips these past weeks, I haven't noticed any slowdowns (except when there's planned work). Generally it's been going as fast as it usually does.

[Calvin]

From what I mentioned about the  , it was just today. Going to Manhattan, it made a brief stop at Avenue H around 4:30 PM. Held 5 mins but arrived at Newkirk Plaza but in slow speed. It was drizzle rain outside and leaves were on the track as a thought that may slowed down the train. 

[RR503]

As y'all can imagine, I have a _lot_ to say on this subject, but alas I've been under a pile of work this week. Weekend, maybe. 

I just wanted to note that there are actually a bunch of intervals that are scheduled to pass through Rogers w/in 1 minute (some even 30 secs!) of each other, esp. during the PM rush. Schedule sure isn't perfect! 

Edited November 1, 2019 by RR503

[NewFlyer 230]

On 10/29/2019 at 5:58 PM, CenSin said:

What a shocker! Isn’t that particular terminal famous for turning back over 60 trains per hour? Those 4 tracks and extra pockets past the station have got to be good for something.

That’s what happens when you have  trains bunched up. It’s really not uncommon to see 3-4  trains arrive within the span of a few minutes. 

 

 

Another annoying bottleneck is the  merge at Columbus Circle. With no fail almost every morning going to work trains get backed up to 47th-50th probably even further than that but I always get on the  or  at 47th-50th. I just can’t believe it’s that bad honestly. There has been several times that I ended up being a few minutes late to work because of that merging situation. 

 

[RR503]

1 hour ago, RR503 said:

As y'all can imagine, I have a _lot_ to say on this subject, but alas I've been under a pile of work this week. Weekend, maybe. 

I just wanted to note that there are actually a bunch of intervals that are scheduled to pass through Rogers w/in 1 minute (some even 30 secs!) of each other, esp. during the PM rush. Schedule sure isn't perfect! 

To put a finer point on it, here are arrival headways (h/t to a friend for the code for the charts):

And here are departure headways (yes, these are different, many of the 0-.5 min arrival headways are 'resolved' by adding holds in the schedule to space things out):

Edited November 1, 2019 by RR503