Department of Subways - Proposals/Ideas

[RR503]

On 3/15/2020 at 2:01 PM, bobtehpanda said:

Which neatly sorts out the B Division's northern half. Personally, I think that most of the current subway's systems resiliency problems stem from the northern half, and southern deinterlining is unnecessary.

Gonna disagree with you here. You're right that Queens and 59 St are trash, but Dekalb and 36 are no walk in the park either! Dekalb is especially troublesome beyond its discrete operational impacts given that it is upstream -- in both directions -- of operationally complex and capacitally restricted areas. For southbound trains, intervals arriving bunched and/or in the wrong order at Coney Island, Brighton Beach or 36 St causes congestion, while northbound variability will throw merges at 34, 59, etc. Those are nontrivial impacts! 

In my research on this issue, the general pattern that keeps resurfacing is that a chain is only as strong as its weakest link. You can make one part of the system work well, but if all of that capacity is going to run into some mess like Dekalb, you're not going to be able to realize nearly the benefit that you could have if you tried to fluidize the entire line. Now, of course, that one merge probably will become easier to operate because you're going to have fewer cascading impacts running into it, but it's still going to have a nontrivial negative impact on your capabilities. See, for example, Camden Town on LU's Northern. 

[RR503]

Now, for some fun. I finally made maps of my various deinterlining ideas. 

Today's service 

https://drive.google.com/open?id=1HHNa2XqlrDKPIKUzpTJcyQbSndtbs1cM

What I'd do without spending any capital $$$

https://drive.google.com/open?id=1yZcwJfjcO1tfYuttqW2lUuatAFvIaxuz

What I'd do with capital $$$

https://drive.google.com/open?id=15z4fvc1cfxxtY_ZhUbFex3jxgT0dt3lm

The general principles here are to minimize merges/maximize capacity while trying to preserve a maximum of important connectivity (so we deinterline CPW, but not Essex or Bergen), and on the no-$$$ map to try to jump for deinterlinings that can largely be achieved through low-effort swaps, ie , , . Nothing on here will be all that unfamiliar to those of you who've been reading my ramblings for a while, but I thought it'd be nice to see it all on one map. 

Edited March 17, 2020 by RR503

[Union Tpke]

19 minutes ago, RR503 said:

Gonna disagree with you here. You're right that Queens and 59 St are trash, but Dekalb and 36 are no walk in the park either! Dekalb is especially troublesome beyond its discrete operational impacts given that it is upstream -- in both directions -- of operationally complex and capacitally restricted areas. For southbound trains, intervals arriving bunched and/or in the wrong order at Coney Island, Brighton Beach or 36 St causes congestion, while northbound variability will throw merges at 34, 59, etc. Those are nontrivial impacts! 

In my research on this issue, the general pattern that keeps resurfacing is that a chain is only as strong as its weakest link. You can make one part of the system work well, but if all of that capacity is going to run into some mess like Dekalb, you're not going to be able to realize nearly the benefit that you could have if you tried to fluidize the entire line. Now, of course, that one merge probably will become easier to operate because you're going to have fewer cascading impacts running into it, but it's still going to have a nontrivial negative impact on your capabilities. See, for example, Camden Town on LU's Northern. 

I agree with you about DeKalb. Earlier on you had posted that you would prefer that operational fixes be made, and then if those failed, then do deinterlining. What finally pushed you to believe in deinterlining there? Do you think any upgrades would be needed at Atlantic Avenue. A transfer should be built between Broadway-Lafayette and Prince Street.

[RR503]

Just now, Union Tpke said:

I agree with you about DeKalb. Earlier on you had posted that you would prefer that operational fixes be made, and then if those failed, then do deinterlining. What finally pushed you to believe in deinterlining there? Do you think any upgrades would be needed at Atlantic Avenue. A transfer should be built between Broadway-Lafayette and Prince Street.

Knowing more. I've done a lot of work with that area and with those lines, and the more you get into it the more you realize just how impossibly difficult it is to run a reliable and frequent railroad with merges like Dekalb. This isn't to say we shouldn't go for things like eliminating the CCTV stop, better signing area STs and the like -- if for no other reason than I have about 0% confidence of Dekalb deinterlining going forwards anytime soon -- but there's just no way to run a system used by humans precisely enough that you can make a 30 second wide merge window.

[Union Tpke]

Great maps! I find it interesting that you elected to extend the  to 179th Street in that map to relieve pressure off of Continental. Why extend the  over the ?

[LGA Link N Train]

4 minutes ago, Union Tpke said:

Great maps! I find it interesting that you elected to extend the  to 179th Street in that map to relieve pressure off of Continental. Why extend the  over the ?

I’m wondering that as well, cause I saw these same maps on Twitter a few days ago
 

@RR503 wouldn’t an  extension add to the total runtime of its route? And at that point, wouldn’t it be better to swap the  and  to avoid such an issue? The  train in your “No-Cap.” Deinterlining map would still serve Ditmars. 

Edited March 17, 2020 by LaGuardia Link N Tra

[Union Tpke]

Just now, LaGuardia Link N Tra said:

I’m wondering that as well, cause I saw these same maps on Twitter a few days ago
 

@RR503 wouldn’t an  extension add to the total runtime of its route? And at that point, wouldn’t it be better to swap the  and  to avoid such an issue? The  train in you No-Cap. Deinterlining map would still serve Ditmars. 

Yard access.

[LGA Link N Train]

1 minute ago, Union Tpke said:

Yard access.

I guess, but the  and  share the same fleet. So I don’t see how Yard Access would be a problem. Besides, the crews can always switch the signage between the  and  at Ditmars Blvd. Not sure if they still do that given the recent fleet swap.  

[RR503]

6 minutes ago, Union Tpke said:

Great maps! I find it interesting that you elected to extend the  to 179th Street in that map to relieve pressure off of Continental. Why extend the  over the ?

I'd prefer to see the  given that the  is already a bit of a mess, but given the blowback experienced on a certain pilot because we were replacing 10 cars with 8, I figured that may be a price worth paying. It's not a decision I have any strong feelings about, though. 

1 minute ago, LaGuardia Link N Tra said:

I guess, but the  and  share the same fleet. So I don’t see how Yard Access would be a problem. Besides, the crews can always switch the signage between the  and  at Ditmars Blvd. Not sure if they still do that given the recent fleet swap.  

You could work it like that, but there's also a capacity problem. Both the  and  run 10tph peak into Manhattan from Brooklyn -- you can't merge those both into Astoria with current terminal infrastructure. You could run more 96 St s, but then it becomes harder to manage yards. There's a similar issue with Queens, the 's 10tph can't all turn at Whitehall, so you're either stuck with an ugly mainline discharge at Canal or an extension to Brooklyn, at which point we're basically back where we're started. The nice thing about the  is it's a low frequency overlay that's easily adjustable into capacity gaps. I think it's best we keep it that way, and if we're really worried about the 's length, extend the  instead.

[Jova42R]

Here’s a plan for the Rockaway Beach Branch reactivation:

 Rockaway Beach Branch / Queens Blvd Local / 63 St Tubes / 8 Av Express

UNDER THIS PLAN, s are rerouted to Ditmars and s are rerouted to 96th. The  are the only QB Locals.

Howard Beach

Liberty Av

Atlantic Av

Jamaica Av

Myrtle Av-Forest Park

Union Tpke

Yellowstone Blvd

63 Dr

 makes all  stops to 36 St

36 St

21 St-Queensbridge

Roosevelt Island

Lexington Av-63 St

via the  tunnel

NEW STATION: 5 AV

via a new tunnel to a new junction just north of 59th, then merging to 8 Av Exp

59 St

 makes all  stops to Canal St

Canal St

WTC

Thoughts?

 

Edited March 17, 2020 by Jova42R

[Union Tpke]

@RR503 Why do you elect to improve Burnside over Bedford Park Boulevard? Doing that along with grade-separating the yard leads could allow for express service.

Also, why do you leave the  at 20 TPH. I would add your proposed Westchester Square conversion.

Edited March 17, 2020 by Union Tpke

[RR503]

3 minutes ago, Union Tpke said:

@RR503 Why do you elect to improve Burnside over Bedford Park Boulevard? Doing that along with grade-separating the yard leads could allow for express service.

It would, and in a perfect world I'd do just that. But I was trying to keep the list of things there to things I could actually see happening, so Burnside switches it is! 

(Also, demand growth in the Bronx is concentrated in the southern portion of the borough. Don't know if we necessarily want to be running 30tph+ that far north)

[Union Tpke]

@RR503 Does your map have an  West End express?

[JeremiahC99]

47 minutes ago, RR503 said:

Now, for some fun. I finally made maps of my various deinterlining ideas. 

Today's service 

https://drive.google.com/open?id=1HHNa2XqlrDKPIKUzpTJcyQbSndtbs1cM

What I'd do without spending any capital $$$

https://drive.google.com/open?id=1yZcwJfjcO1tfYuttqW2lUuatAFvIaxuz

What I'd do with capital $$$

https://drive.google.com/open?id=15z4fvc1cfxxtY_ZhUbFex3jxgT0dt3lm

The general principles here are to minimize merges/maximize capacity while trying to preserve a maximum of important connectivity (so we deinterline CPW, but not Essex or Bergen), and on the no-$$$ map to try to jump for deinterlinings that can largely be achieved through low-effort swaps, ie , , . Nothing on here will be all that unfamiliar to those of you who've been reading my ramblings for a while, but I thought it'd be nice to see it all on one map. 

Nice maps

For the second map, what I would've done was to have the  move to 96th Street with the , with the  getting a service boost to 12 trains per hour (your map depicts broadway mostly remaining the same). The would remain mostly unaffected, though it would have one less merge to deal with. This would allow for more frequent service on the SAS, and more reliable local service. 

For map number 3, 59th Street is depicted as serving the , but the  is already on West End. Shouldn't it be  since the  is going to 95th Street? In addition, I would also keep the mixing of trains at 145th Street that you feature on Map 2. Since the  are the 8th Avenue express and the  are 8th Avenue local, it would make some sense to have one of each on both northern end, that way no one loses their express service, and the passengers in Washington Heights and the Bronx have access to both 8th Avenue and 6th Avenue again, all while deinterlining 59th Street. That's just my take. I also would've recommended a rebuild of 149th Street-Concourse junction since the current  service over there is still popular. That's just my take on it.

Also, what software did you use to make the maps? I would like to make something similar in terms of track capacity for other proposals, such as 4-track SAS, new Northern Blvd subway, etc.

[RR503]

1 hour ago, Union Tpke said:

@RR503 Does your map have an  West End express?

That's something I forgot to add/would definitely do. 

1 hour ago, JeremiahC99 said:

For the second map, what I would've done was to have the  move to 96th Street with the , with the  getting a service boost to 12 trains per hour (your map depicts broadway mostly remaining the same). The would remain mostly unaffected, though it would have one less merge to deal with. This would allow for more frequent service on the SAS, and more reliable local service. 

Issue is capacity along Broadway. You need the full 15tph for loads in Astoria, and you can't go above 21tph at City Hall Curve. The math there just doesn't work -- 6tph to/from Queens Blvd just won't cut it. If that constraint didn't exist, that's absolutely what I'd do. 

1 hour ago, JeremiahC99 said:

For map number 3, 59th Street is depicted as serving the , but the  is already on West End. Shouldn't it be  since the  is going to 95th Street? In addition, I would also keep the mixing of trains at 145th Street that you feature on Map 2. Since the  are the 8th Avenue express and the  are 8th Avenue local, it would make some sense to have one of each on both northern end, that way no one loses their express service, and the passengers in Washington Heights and the Bronx have access to both 8th Avenue and 6th Avenue again, all while deinterlining 59th Street. That's just my take. I also would've recommended a rebuild of 149th Street-Concourse junction since the current  service over there is still popular. That's just my take on it.

Good catch. Will fix. 

I deinterlined 149 because the current merges there are just...so...bad. I'm sure I've posted the chart before, but if not:

Despite the  bypassing 138 at rushes, runtimes are almost double what they are off peak. That's 100% merge congestion, and it's congestion that really isn't doing any good for Lex. You're right that it'd be an unpopular move, but honestly with runtimes that nuts, it may actually work out to a net positive in total trip time. 

The logic at 145 builds off of this: with 30tph of capacity going up Jerome and greater capacity along Lex, there's less of an incentive to have Concourse operating as an interlined relief route. That's why I undid 145, though it isn't a decision I'd be all that unhappy about reversing -- 145 is a crap merge, but thanks to its design it generally doesn't create cascading impacts. 

[Union Tpke]

@RR503 Why does your frequency chart have the  only running at 20 TPH with capital improvements?

[RR503]

10 minutes ago, Union Tpke said:

@RR503 Why does your frequency chart have the  only running at 20 TPH with capital improvements?

I had to copy and paste that section so many times before I got all the errors worked out, I must have forgotten to fix that. Thanks. 

[Union Tpke]

Just now, RR503 said:

I had to copy and paste that section so many times before I got all the errors worked out, I must have forgotten to fix that. Thanks. 

Are you going to change it to 30?

[Union Tpke]

Also, I would up the  and , provided you note the requisite capital projects needed to do so.

[RR503]

3 minutes ago, Union Tpke said:

Are you going to change it to 30?

Maybe not 30, given that Concourse and CPW aren't _that_ high ridership, and that returns to additional trains really start to go down >20. 24, say?

And yes, I'll add those.

Edited March 17, 2020 by RR503

[Union Tpke]

@RR503 If you want to deinterline in the peak direction, you can also add a third track to the Williamsburg Bridge.

[Around the Horn]

Related since we're talking about Broadway capacity: how feasible is fitting out City Hall lower level as a short turn terminus?

I would imagine if it is feasible it would be orders of magnitude better than short turning at Canal Street and fumigating.

Edited March 17, 2020 by Around the Horn

[RR503]

2 hours ago, Union Tpke said:

@RR503 If you want to deinterline in the peak direction, you can also add a third track to the Williamsburg Bridge.

You could, but again, I'm aiming for investments that could concievably get done by the MTA in this day and age. I also am still somewhat unconvinced that this specific project should be a priority -- it'd be $$$ for a nontrivial operations gain, but only a small capacity gain. 

49 minutes ago, Around the Horn said:

Related since we're talking about Broadway capacity: how feasible is fitting out City Hall lower level as a short turn terminus?

I would imagine if it is feasible it would be orders of magnitude better than short turning at Canal Street and fumigating.

If you reconfigured it a bit (ie abandoned 4 tk and used M and 3 only) you could probably extend the western island. Then you'd just need to signal it properly... It's something I'd like to see looked at, though only if it's found that CBTC cannot fix the curve issue. 

[bobtehpanda]

7 hours ago, LaGuardia Link N Tra said:

Between Flushing and Union Turnpike, I could see it happening, but wouldn’t the foundations of the Whitestone Bridge have to be rebuilt in order to handle the weight of subway service? Between Union Turnpike and Jamaica seems like a tough obstacle because of sprawled homes and the  and  in the way. I’m also assuming that a new yard would have to be built somewhere, maybe in College Point. 

Who said anything about the Whitestone Bridge? Personally I am not a huge fan of using it since it is surrounded by a whole lotta nothing on the Bronx side, and using it bypasses dense areas on the Queens side.

The East River is shallow. Tunnel from Flushing to the Bronx would go under Linden > 28th > College Point Blvd, re-emerging in the Bronx under Soundview Av and WPR.

Edited March 18, 2020 by bobtehpanda

[bobtehpanda]

6 hours ago, RR503 said:

Now, for some fun. I finally made maps of my various deinterlining ideas. 

Today's service 

https://drive.google.com/open?id=1HHNa2XqlrDKPIKUzpTJcyQbSndtbs1cM

What I'd do without spending any capital $$$

https://drive.google.com/open?id=1yZcwJfjcO1tfYuttqW2lUuatAFvIaxuz

What I'd do with capital $$$

https://drive.google.com/open?id=15z4fvc1cfxxtY_ZhUbFex3jxgT0dt3lm

The general principles here are to minimize merges/maximize capacity while trying to preserve a maximum of important connectivity (so we deinterline CPW, but not Essex or Bergen), and on the no-$$$ map to try to jump for deinterlinings that can largely be achieved through low-effort swaps, ie , , . Nothing on here will be all that unfamiliar to those of you who've been reading my ramblings for a while, but I thought it'd be nice to see it all on one map. 

Neat!

One suggestion, if you don't mind - I think to fully illustrate the impacts of what deinterlined service could give us, it would be useful to vary the line width by frequency. If I had no context and was your average straphanger your diagrams would look like a service cut.