Second Avenue Subway Discussion

[CenSin]

I was thinking Manhattan more than anything with my format.  You would have the (again, half of the current ) merging with the at 59th Street along with the merging with both at 36th (except late nights when the would be running 95th-Astoria).

 

As for Sea Beach, that would be a trade-off of this in order to better streamline Manhattan with the same number of trains per hour currently in play on Broadway. 

The thing is, post-phase 2, you have to roughly double the trains per hour, so the goal isn’t to use the same number of trains per hour on Broadway, but to increase it as well since Astoria will presumably require the same level of service. Broadway local has room for a service increase, but does not connect to 2 Avenue directly. Therefore, the minimal number of changes required to reach the new equilibrium (where supply meets demand) is to shift the over to 125 Street—doubling the trains per hour over today’s levels without overburdening DeKalb Avenue and the Broadway express tracks—and to boost service.

 

This goes to show that the trade-off is unnecessary. Extra designations that cover all manners of service configurations are superfluous and decrease the quality of service for perceived convenience.

[T to Dyre Avenue]

I was thinking Manhattan more than anything with my format. You would have the V (again, half of the current ) merging with the at 59th Street along with the merging with both at 36th (except late nights when the would be running 95th-Astoria).

 

As for Sea Beach, that would be a trade-off of this in order to better streamline Manhattan with the same number of trains per hour currently in play on Broadway.

Of course you were. You always do whenever you weigh in on these types of threads. The problem is, your proposals nearly always inconvenience riders in Brooklyn or Queens (amazingly, the Bronx has been left out of all that inconveniencing - so far). And for what? So there can be more "one seat rides" to Manhattan from every single branch in Brooklyn or Queens? Why is that necessary?

 

Answer: It isn't! You're proposing three locals on both 4th Avenue AND Broadway - the , V and . It is completely unnecessary to have three different Broadway/4th Avenue Local trains running on limited frequencies once they split off from each other. You keep making these types of proposals, which might work just fine if we're dealing with 30-minute peak headways on Metro-North, LIRR or NJ Transit. Or on automated people movers like the AirTrain. But the NYC subway is neither an automated people-mover, nor is it a commuter rail system running 30-minute peak headways. Stop treating it like it is! Subway trains are supposed to run far more frequently than that during rush hours. They can't if you have way too many routes merging and un-merging at various points along the trunk lines.

 

We don't need both a 4th Ave/Broadway Local from Sea Beach (your V) AND a 4th Ave/Broadway Local from West End (your W). With both going via the Montague Tunnel AND headed for Astoria. All we need is one of those services to allow the to go to 2nd Ave and eliminate its express-local switching at 34th St.

 

For those of you who missed it, I suggested running the as the sole Astoria service, but running 15 tph during rush hours (perhaps 10 tph during middays). I suggested turning alternating W's at Whitehall St on weekdays, while running the rest to Stillwell Ave via the Sea Beach Line while retaining the as the secondary service, so Sea Beach riders can still have an express in Brooklyn. On weekends and late nights, the would be the sole Sea Beach service. This was in response to CenSin's Proposal 1, which didn't mention what train would operate over the Sea Beach Line when the is not running (he has the weekday trains turning either at Whitehall St or 9th Avenue on the , which may imply that the Sea Beach Line would have no overnight or weekend service).

 

The reasons I prefer to run the new as a 4th Avenue Local via the Sea Beach Line instead of turning it at 9th Avenue, are because it would then be able to provide service at the 45th and 53rd St stations, both of which have higher ridership than some of the local stations above 36th St. And 9th Ave is not a very busy stop in need of a second service.

Edited July 28, 2017 by T to Dyre Avenue

[Around the Horn]

For those of you who missed it, I suggested running the as the sole Astoria service, but running 15 tph during rush hours. I suggested turning alternating W's at Whitehall St on weekdays, while running the rest to Stillwell Ave via the Sea Beach Line while retaining the as the secondary service, so Sea Beach riders can still have an express in Brooklyn. On weekends and late nights, the would be the sole Sea Beach service. This was in response to CenSin's Proposal 1, which didn't mention what train would operate over the Sea Beach Line when the is not running (he has the weekday trains turning either at Whitehall St or 9th Avenue on the line).

 

That would work. Those morning trips from Coney Island yard already do that job, to a point. (which I think they should expand as an easy way to add more capacity to 4th Avenue in the mornings) 

[darkstar8983]

Considering that since phase I of the second avenue subway has opened we haven't even gotten to the 14 tph projected that the line was going to require to operate the service, I don't even see the need to branch the route off from Astoria in this reroute. Most likely the from 125 St will need about 15 tph with 10-11 tph coming from the regular service and the rest from the [ via Sea Beach] during rush hours. Seeing as how the capacity is only truly needed during rush hours, what could be done is to just add the appropriate number of trains for every that is removed from Astoria but still provide the service in Astoria with revised headways. The could provide 10-12 minute frequencies in Astoria with the running every 6-7 minutes. Considering that the "crush-point" during the rush hour is only really from 7:45AM to 9:45AM from Astoria we could have those early AM rush hour put-in trains from 86 St just do one round trip.

 

Focusing more on the present-time, the second avenue phase I can get an immediate increase now if the MTA adds a train in between a 20-minute headway that is present at the start of service from 86 St to make it 10-minute frequencies and changes the train that is due at Astoria-Ditmars at 7:55AM to a to 96 St during the AM rush. If I am not mistaken, that N that is due at Ditmars Blvd at 7:55AM gets changed to a W train anyway (for the 8:03AM departure) and before the W train restoration, used to terminate at 57 St-7 Av anyways.

[darkstar8983]

Forgot to say that when phase 3 comes around, there won't probably even be the need for all those and trains because the train will need about 50% of the capacity space if not more because it will need to provide the only service along 2 Av south of 72 St. I envision a 70:30 split of service to service because of the capacity requirement despite the earlier projections envisioning a 50:50 split

[Wallyhorse]

Forgot to say that when phase 3 comes around, there won't probably even be the need for all those and trains because the train will need about 50% of the capacity space if not more because it will need to provide the only service along 2 Av south of 72 St. I envision a 70:30 split of service to service because of the capacity requirement despite the earlier projections envisioning a 50:50 split

Phase 3 is likely not to happen for at least 20 years if not more.  There likely will be multiple changes to the subways before then. 

[CenSin]

Phase 3 is likely not to happen for at least 20 years if not more.  There likely will be multiple changes to the subways before then. 

Wallyhorse, bringing in the reality.

[T to Dyre Avenue]

Considering that since phase I of the second avenue subway has opened we haven't even gotten to the 14 tph projected that the line was going to require to operate the service, I don't even see the need to branch the route off from Astoria in this reroute. Most likely the from 125 St will need about 15 tph with 10-11 tph coming from the regular service and the rest from the N [Q via Sea Beach] during rush hours. Seeing as how the capacity is only truly needed during rush hours, what could be done is to just add the appropriate number of W trains for every N that is removed from Astoria but still provide the service in Astoria with revised headways. The N could provide 10-12 minute frequencies in Astoria with the W running every 6-7 minutes. Considering that the "crush-point" during the rush hour is only really from 7:45AM to 9:45AM from Astoria we could have those early AM rush hour put-in trains from 86 St just do one round trip.

Focusing more on the present-time, the second avenue phase I can get an immediate increase now if the MTA adds a train in between a 20-minute headway that is present at the start of service from 86 St to make it 10-minute frequencies and changes the N train that is due at Astoria-Ditmars at 7:55AM to a Q to 96 St during the AM rush. If I am not mistaken, that N that is due at Ditmars Blvd at 7:55AM gets changed to a W train anyway (for the 8:03AM departure) and before the W train restoration, used to terminate at 57 St-7 Av anyways.

But then you would still have some trains (the remaining N's still serving Astoria) switching from local to express at Herald Square. And that may very well put a limit on the number of trains that can be run to 2nd Ave, as well as the number of additional trains needed for Astoria in your proposal. And you would be running more trains through DeKalb Junction, which already has enough difficulty handling the current amount of traffic running through there. But by beefing up the and making it the 24/7 and sole Astoria line, you can avoid all that. You wouldn't have to run significantly more trains through DeKalb Junction and you'd no longer have to have trains switching between the local and express tracks, though you would have to have some trains switch between local and express to run via the Sea Beach Line. But there are far less trains traveling through 59th and 4th, than there are at Herald Square or DeKalb.

 

Forgot to say that when phase 3 comes around, there won't probably even be the need for all those and trains because the train will need about 50% of the capacity space if not more because it will need to provide the only service along 2 Av south of 72 St. I envision a 70:30 split of service to service because of the capacity requirement despite the earlier projections envisioning a 50:50 split

That's true. But running the and on a 30:70 split would result in only 9 tph for the . That wouldn't be enough to meet its service needs on the Broadway express tracks or the Brighton local.

 

And there needs to be a second 2 Ave service south of 72nd St. There should not be more 2 Ave service Uptown than there is in Midtown or Lower Manhattan.

Edited August 1, 2017 by T to Dyre Avenue

[BreeddekalbL]

And there needs to be a second 2 Ave service south of 72nd St. There should not be more 2 Ave service Uptown than there is in Midtown or Lower Manhattan.

 

that's where a potential queens bypass service comes in 

[CenSin]

that's where a potential queens bypass service comes in

 

What are the odds that they will screw up the junction at 55 Street like they did with 72 Street?

[darkstar8983]

Not to be rude but the only reason I made that proposal with the keeping the and trains to/from Astoria is because of how much $$$ it would cost to run exclusively train service from Astoria to Whitehall St/Stillwell Av via the local tracks just so the merge is eliminated, especially in terms of maintenance requirements and number of subway trains necessary to run such a service. And the Dekalb av junction wouldn't really be strained any more than it already is because I'm not physically adding any trains to the Manhattan Bridge route. Only in the peak direction will additional trains are being run to save $$$ and provide appropriate serivice while saving $$$ to detangle other interlockings that have capacity constraints (like the Rogers Av Junction), but that is a separate issue altogether for another forum.

 

Honestly I think with CBTC they should be able to provide the 2 Av service that is needed for phase 2 with the and rush hour peak direction (N)s that do not go to Astoria, and keep the in Astoria where they belong.

 

Side point: I don't think that the politicians in western queens would ever accept this service change unless Astoria gets a benefit in the end. When the and swapped terminals, the MTA ended up placing the older subway cars on the route but then as soon as the R68s came in, they needed to be added to the route to show that Astoria wasn't getting a bum deal from the route swap. Don't think that Astoria would give up their direct express Coney Island service that easily is all that I'm saying ????

[BreeddekalbL]

What are the odds that they will screw up the junction at 55 Street like they did with 72 Street?

what do you mean i was told that there are provisions for a west to south service already at 63rd street

[Around the Horn]

What are the odds that they will screw up the junction at 55 Street like they did with 72 Street?

AFAIK 55th Street was always going to be two tracks unlike 72nd Street.

 

Forgot to say that when phase 3 comes around, there won't probably even be the need for all those and trains because the train will need about 50% of the capacity space if not more because it will need to provide the only service along 2 Av south of 72 St. I envision a 70:30 split of service to service because of the capacity requirement despite the earlier projections envisioning a 50:50 split

A 70/30 split? That's ridiculous...

 

If lower 2nd Avenue becomes so popular (which I'll agree is definitely possible), you use the 63rd Street connection, build the bypass from Queens Blvd, and introduce a new service from Jamaica-179 St to the lower SAS. I'll use for this service.

 

You can then do the following:

: 15 tph

: 15 tph

: 15 tph

 

Every station on SAS gets 30 tph (unless the were to split and one goes to Downtown and the other gets extended to Brooklyn)

 

[BreeddekalbL]

AFAIK 55th Street was always going to be two tracks unlike 72nd Street.

 

A 70/30 split? That's ridiculous...

 

If lower 2nd Avenue becomes so popular (which I'll agree is definitely possible), you use the 63rd Street connection, build the bypass from Queens Blvd, and introduce a new service from Jamaica-179 St to the lower SAS. I'll use for this service.

 

You can then do the following:

: 15 tph

: 15 tph

: 15 tph

 

Every station on SAS gets 30 tph (unless the were to split and one goes to Downtown and the other gets extended to Brooklyn)

 

So i guess this will rule out my idea for a 4th service like a U train supplimenting the with potential Brooklyn Service?

[Around the Horn]

So i guess this will rule out my idea for a 4th service like a U train supplimenting the with potential Brooklyn Service?

Not necessarily, however theoretically the could also do what your U would do in Brooklyn and serve Queens.

 

Reduce frequency slightly and you could fit a fourth service:

: 10 TPH

: 10 TPH

: 10 TPH

U:   10TPH

 

, and U: 30 TPH

, U and : 30 TPH

[BreeddekalbL]

Not necessarily, however theoretically the could also do what your U would do in Brooklyn and serve Queens.

 

Reduce frequency slightly and you could fit a fourth service:

: 10 TPH

: 10 TPH

: 10 TPH

U:   10TPH

 

, and U: 30 TPH

, U and : 30 TPH

 

so i could fit a 4th service in cause my idea south of 63rd street is that the V would run to a certain point as a queens bypass service to JFK 

[RailRunRob]

So i guess this will rule out my idea for a 4th service like a U train supplimenting the with potential Brooklyn Service?

 

Not necessarily, however theoretically the could also do what your U would do in Brooklyn and serve Queens.

 

Reduce frequency slightly and you could fit a fourth service:

: 10 TPH

: 10 TPH

: 10 TPH

U:   10TPH

 

, and U: 30 TPH

, U and : 30 TPH

This is always a block for me when it comes to route planning. So the longer the route the more trains required to maintain a certain headway. It's just like maintaining pressure or flows in dynamics so if you extended to per say to 9th Ave, Bayridge, BayParkway or CI and you had a 7 min headway you'd have to schedule another train at some point measured by distance vs travel time correct or am I overthinking? And at some point that would have an effect on the number of trains running on Second Ave. It's there type of rule used when planning service and headways?

Edited August 1, 2017 by RailRunRob

[T to Dyre Avenue]

Considering that since phase I of the second avenue subway has opened we haven't even gotten to the 14 tph projected that the Q line was going to require to operate the service, I don't even see the need to branch the N route off from Astoria in this reroute. Most likely the Q from 125 St will need about 15 tph with 10-11 tph coming from the regular service and the rest from the N [Q via Sea Beach] during rush hours. Seeing as how the capacity is only truly needed during rush hours, what could be done is to just add the appropriate number of W trains for every N that is removed from Astoria but still provide the service in Astoria with revised headways. The could provide 10-12 minute frequencies in Astoria with the running every 6-7 minutes. Considering that the "crush-point" during the rush hour is only really from 7:45AM to 9:45AM from Astoria we could have those early AM rush hour put-in trains from 86 St just do one round trip.

  

How is running significantly fewer express trains and significantly more local trains from Astoria any better than simply rerouting the to 2nd Av and expanding the to 15 tph in rush hours and making the 24/7 Astoria service? And please don't say "because Astoria line riders should have a choice between express and local service" because your proposal really does not give Astoria riders much of a choice. Who's going to wait for an express that runs only once every 10-12 minutes?

 

Not to be rude but the only reason I made that proposal with the keeping the and trains to/from Astoria is because of how much $$$ it would cost to run exclusively W train service from Astoria to Whitehall St/Stillwell Av via the local tracks just so the merge is eliminated, especially in terms of maintenance requirements and number of subway trains necessary to run such a service. And the Dekalb av junction wouldn't really be strained any more than it already is because I'm not physically adding any trains to the Manhattan Bridge route. Only in the peak direction will additional W trains are being run to save $$$ and provide appropriate serivice while saving $$$ to detangle other interlockings that have capacity constraints (like the Rogers Av Junction), but that is a separate issue altogether for another forum.

Honestly I think with CBTC they should be able to provide the 2 Av service that is needed for phase 2 with the Q and rush hour peak direction (N)s that do not go to Astoria, and keep the in Astoria where they belong.

Side point: I don't think that the politicians in western queens would ever accept this service change unless Astoria gets a benefit in the end. When the N and R swapped terminals, the MTA ended up placing the older subway cars on the N route but then as soon as the R68s came in, they needed to be added to the N route to show that Astoria wasn't getting a bum deal from the route swap. Don't think that Astoria would give up their direct express Coney Island service that easily is all that I'm saying

Sorry, but I'm not buying "it costs too much money" as a reason not to operate the as the sole Astoria service. If money were the sole reason for planning service routes and making changes, then the MTA never would have brought back the last November. And back in 2010, they might have axed a few other services too, like the late night between 148th St and Times Square or the Rockaway Park . Thankfully they didn't cut those services. But a case for saving could have easily been made for cutting either or both of those services during the 2010 service cuts. While you have to provide subway services that aren't wasteful, you also have to provide services that don't consistently get delayed in the same places. And they have to run on convenient frequencies and be able to change with an influx of riders. The more that trains switch and merge, the less frequently they can run. With the subway getting more crowded than ever and the City trying to squeeze more people into areas with easy access to the subway, it's only going to get more crowded. If, by eliminating a merge or two, you can fit a few more trains in and you aren't in belt-tightening mode, then why wouldn't you run more trains? Why also would you tinker with the existing service pattern just to keep the in Astoria "where it belongs"? Why does it "belong" there? And do you think Astoria politicians would be willing to accept the staying in Astoria, but with 10-12 minute headways?

[RR503]

This is always a block for me when it comes to route planning. So the longer the route the more trains required to maintain a certain headway. It's just like maintaining pressure or flows in dynamics so if you extended to per say to 9th Ave, Bayridge, BayParkway or CI and you had a 7 min headway you'd have to schedule another train at some point measured by distance vs travel time correct or am I overthinking? And at some point that would have an effect on the number of trains running on Second Ave. It's there type of rule used when planning service and headways?

 

Think of it this way. If a round trip takes x minutes, and you want y headway between trains, you'll need x/y trains in service (+spares). That's oversimplified, but basically how things are done. The total number of trains in service on a route has no bearing on a line segment's capacity -- the space between them is what counts. The only concern with # of sets is yard space. 

[RailRunRob]

Think of it this way. If a round trip takes x minutes, and you want y headway between trains, you'll need x/y trains in service (+spares). That's oversimplified, but basically how things are done. The total number of trains in service on a route has no bearing on a line segment's capacity -- the space between them is what counts. The only concern with # of sets is yard space. 

Gotcha..I guess that's kinda what I was thinking with gaps. So I'll use the for example. If they ever extended the the four miles to Ave U per say that would or wouldn't require an extra train set or two at peak hours (Rush) for extra the 15 mins tacked onto the trip and with a 7 min headway? In my mind, that would create a gap or can you balance it out amoung all the trains you have running? I guess that's what triggered my question in the 1st place and in the larger scheme of things how that would effect TPH. As I said I may be just over complicating things haha  . That's the equation in the head but I'm always willing to learn something new. I get your point with the Yard as well.

Edited August 1, 2017 by RailRunRob

[Mtatransit]

How is running significantly fewer express trains and significantly more local trains from Astoria any better than simply rerouting the to 2nd Av and expanding the to 15 tph in rush hours and making the 24/7 Astoria service? And please don't say "because Astoria line riders should have a choice between express and local service" because your proposal really does not give Astoria riders much of a choice. Who's going to wait for an express that runs only once every 10-12 minutes?

Sorry, but I'm not buying "it costs too much money" as a reason not to operate the as the sole Astoria service. If money were the sole reason for planning service routes and making changes, then the MTA never would have brought back the last November. And back in 2010, they might have axed a few other services too, like the late night between 148th St and Times Square or the Rockaway Park . Thankfully they didn't cut those services. But a case for saving could have easily been made for cutting either or both of those services during the 2010 service cuts. While you have to provide subway services that aren't wasteful, you also have to provide services that don't consistently get delayed in the same places. And they have to run on convenient frequencies and be able to change with an influx of riders. The more that trains switch and merge, the less frequently they can run. With the subway getting more crowded than ever and the City trying to squeeze more people into areas with easy access to the subway, it's only going to get more crowded. If, by eliminating a merge or two, you can fit a few more trains in and you aren't in belt-tightening mode, then why wouldn't you run more trains? Why also would you tinker with the existing service pattern just to keep the in Astoria "where it belongs"? Why does it "belong" there? And do you think Astoria politicians would be willing to accept the staying in Astoria, but with 10-12 minute headways?

Main Problem with the amount of to Astoria is where are you going to terminate them? Whitehall is full, and the next suitable place is 9 Av in Brooklyn. So we should send some to 9 Av?

Gotcha..I guess that's kinda what I was thinking with gaps. So I'll use the for example. If they ever extended the the four miles to Ave U per say that would or wouldn't require an extra train set or two at peak hours (Rush) for extra the 15 mins tacked onto the trip and with a 7 min headway? In my mind, that would create a gap or can you balance it out amoung all the trains you have running? I guess that's what triggered my question in the 1st place and in the larger scheme of things how that would effect TPH. As I said I may be just over complicating things haha  . That's the equation in the head but I'm always willing to learn something new. I get your point with the Yard as well.

It would most likely require a extra set to maintain 7 minutes headway because the total round trip time is longer. Total Vehicle is measured by Total Round trip time/driver break divided by the desired headway= amount of vehicles

[RailRunRob]

It would most likely require a extra set to maintain 7 minutes headway because the total round trip time is longer. Total Vehicle is measured by Total Round trip time/driver break divided by the desired headway= amount of vehicles

Figured so! 

[CenSin]

Not to be rude but the only reason I made that proposal with the keeping the and trains to/from Astoria is because of how much $$$ it would cost to run exclusively train service from Astoria to Whitehall St/Stillwell Av via the local tracks just so the merge is eliminated, especially in terms of maintenance requirements and number of subway trains necessary to run such a service. And the Dekalb av junction wouldn't really be strained any more than it already is because I'm not physically adding any trains to the Manhattan Bridge route. Only in the peak direction will additional trains are being run to save $$$ and provide appropriate serivice while saving $$$ to detangle other interlockings that have capacity constraints (like the Rogers Av Junction), but that is a separate issue altogether for another forum.

If you’re not adding any more and trains, then 2 Avenue does not get the projected 19 TPH. The combined TPH of the and today is 15 TPH max if Wikipedia is to be believed, although I think the actual number is a bit higher. (If the numbers aren’t accurate, it doesn’t take away from my point anyway.)

 

If I read your proposition correctly, you basically want to shift more trains from Astoria to 2 Avenue by adding a few more trains. Thus, you save money by underserving 2 Avenue and making the a Jekyll & Hyde sort of route.

 

Honestly I think with CBTC they should be able to provide the 2 Av service that is needed for phase 2 with the and rush hour peak direction (N)s that do not go to Astoria, and keep the in Astoria where they belong.

CBTC isn’t on the horizon and will likely not be done on-time to avoid sending both the and to 125 Street. There will be a period in between the completion of phase 2 and the completion of CBTC to DeKalb Avenue where you need a non-CBTC solution.

 

Side point: I don't think that the politicians in western queens would ever accept this service change unless Astoria gets a benefit in the end. When the and swapped terminals, the MTA ended up placing the older subway cars on the route but then as soon as the R68s came in, they needed to be added to the route to show that Astoria wasn't getting a bum deal from the route swap. Don't think that Astoria would give up their direct express Coney Island service that easily is all that I'm saying

They’re going to have to contend with the Upper East Side politicians then. It’s not like the MTA will be wrangling with Astoria alone to make an overall better system.

[Wallyhorse]

They’re going to have to contend with the Upper East Side politicians then. It’s not like the MTA will be wrangling with Astoria alone to make an overall better system.

And this is why I came up with the plan I did to split the into (via Sea Beach and express via 4th Avenue, Manhattan Bridge and Broadway to 125) and (via Sea Beach and local via 4th Avenue, Montague Tunnel and Broadway to Astoria).  

 

The becoming the main service to Astoria, done with most service in my revised plan to 9th Avenue or Bay Parkway via 4th Avenue local with SOME trains terminating/beginning at Whitehall at all times (except late nights when the would replace the in Brooklyn and run the old route to Astoria) to me is a compromise that keeps those in Astoria and the Upper East Side happy since in this scenario, the only merges would be (except late nights) the at 59th and at 36th with the and the current mergers at DeKalb and the Manhattan Bridge.  

 

Yes, Sea Beach riders might not like having half their trains running local in Brooklyn, however, those along Sea Beach looking for lower Manhattan would no longer need to switch trains along 4th Avenue either.  That's the one trade-off but it likely makes for better service overall with two and a half (of the current) lines running local and one and a half (of the current) lines running express in Manhattan with no merges in Manhattan.  

[RR503]

I would be for something like that if the frequencies worked out. If you're splitting N service which runs ~8tph during peak, you're going to get two services running every 15 minutes each, something that will harm commuters by reducing predictability. People like to be able to plan ahead, and you're not letting them do that. What I suggest instead is basically what everyone else has been saying: extend the W down Sea Beach. No new services, simpler merges, and more service on all the corridors you mention.