Optimal Local/Express TPH Arrangement

[Threxx 1,833]

I have a question/suggestion box type of thing for everyone:

 

Lets say you have a trunk line with 4 individual routes on it.

 

If one route was express, and the other 3 were local, what is the maximum TPH they could have combined to not overpower the one express? How frequent would the express have to be?

[TwoTimer 761]

What are you trying to convey by saying "overpower" (maybe a bad choice of word)?

Edited June 17, 2012 by TwoTimer

[DanTheTransitMan 355]

What are you trying to convey by saying "overpower" (maybe a bad choice of word)?

 

 

I think disrupt would be the better word here.

[TwoTimer 761]

I think disrupt would be the better word here.

 

I still don't think so. What disruption would there be if the services were completely separate from end to end (no merging). Now I think his idea was how many express tph would there have to be to make people want to take it over the local.

[Fan Railer 1,502]

I think a 1/3s - 2/3s arrangement would be around what is optimal for a trunk route of this setup. For every 3 trains coming through an express station, 1 would be express and the other two would be locals. That would be around 12 tph for express vs 20 or so tph for the local. From what I've read, 24-26 tph is the maximum on one track.

[overclocked 803]

Hope this helps

[Threxx 1,833]

No, it has nothing to do with signaling, let me explain better.

 

Lets say we have 8th Avenue, with the , , , & .

 

The is 6 TPH, the is 12, and lets have the be 12 as well for this purpose.

 

How high of a TPH would the have to have so it could be a successful express service?

[NX Express 292]

For the local to have 30tph, it would have to be a very busy line (as busy as Lex), so the couldn't have less than 30tph in that case.

[Threxx 1,833]

For the local to have 30tph, it would have to be a very busy line (as busy as Lex), so the couldn't have less than 30tph in that case.

 

 

But lets throw curveballs into this:

 

Cranberry has the & , which would be 36 TPH, way too much.

 

Should you terminate trains in Manhattan, then?

[NX Express 292]

The would probably run to 2 Av. Maybe the would be an via 8 Av then?

[Guest Lance]

@TwoTimer: I think the question Threxxbus is asking is what's the ideal local to express trains ratio and how many local TPHs would it take to throw off that ratio.

 

Answering that question, I think it depends on which trunk line we're talking about here as what works for one line probably wouldn't work for another. You also have to take ridership demands into account as well since some lines need more trains because of high ridership. I'll provide examples of what I'm talking about a bit later as I'm pressed for time right now.

[TheSubwayStation 908]

The would probably run to 2 Av. Maybe the would be an via 8 Av then?

 

Then you'd run into capacity problems with the sharing tracks with the .

[TwoTimer 761]

I really think ridership among the stations in question determines that.

[KeystoneRegional 246]

Well for a reasonable Express service, there is many factors within it. First of all, you need an Express Stop at a Major Street [ex-14th St., 59th St.] or a major Town/Transfer Point [ex-Jackson Heights-Roosevelt/74th St. and Forest Hills - 71st Ave.]. Second of all, the TPH must be reasonable enough so the Express will beat a local by at least a minute [ex-the must not reach 34th St. - Penn Station first after 14th. St. when a departed at the same time as the at 14th St.]. Again, Express, the (E)/(F) on QBL between QP and FH, (4)/(5) on Lex. between GCT and 125 and (A)/(D) on CPW are more successful because the Express is a true Express run, rather without much slowdowns and the stations are spaced apart reasonably. Numbers are numbers but I'd say 1 Express for every 2 Locals are more ideal on a route with average ridership.

[Threxx 1,833]

Well for a reasonable Express service, there is many factors within it. First of all, you need an Express Stop at a Major Street [ex-14th St., 59th St.] or a major Town/Transfer Point [ex-Jackson Heights-Roosevelt/74th St. and Forest Hills - 71st Ave.]. Second of all, the TPH must be reasonable enough so the Express will beat a local by at least a minute [ex-the must not reach 34th St. - Penn Station first after 14th. St. when a departed at the same time as the at 14th St.]. Again, Express, the (E)/(F) on QBL between QP and FH, (4)/(5) on Lex. between GCT and 125 and (A)/(D) on CPW are more successful because the Express is a true Express run, rather without much slowdowns and the stations are spaced apart reasonably. Numbers are numbers but I'd say 1 Express for every 2 Locals are more ideal on a route with average ridership.

 

 

However, here's a situation:

 

Imagine the SAS had two express lines, the & the , and two locals, the (I) & , on the Upper East Side. In a neighborhood like this, though the subway will get decent usage, it won't get as used as much. The is 24 TPH, the is 10, so that's 34, and the is 12, with the (I) being (8). That's 34-20. Is that too much of a disparity?

Edited June 20, 2012 by ThrexxBus

[VWM 404]

Subway tubes can't handle more than 30 tph if i'm right...

 

but people will still use the local if they have to it doesnt matter if the express runs more often.

[KeystoneRegional 246]

However, here's a situation:

 

Imagine the SAS had two express lines, the & the , and two locals, the (I) & , on the Upper East Side. In a neighborhood like this, though the subway will get decent usage, it won't get as used as much. The is 24 TPH, the is 10, so that's 34, and the is 12, with the (I) being (8). That's 34-20. Is that too much of a disparity?

 

 

Yes, in current state, it's too much of a disparity, If the line is sort of like a JFK Airtrain or Vancouver Skytrain system, the express might work, however with current infrastructure the and Express Service would face delays and really it wouldn't be reasonable to let trains arrived less than 2 minutes apart from each other, at the end, the Local would be the best option since the local will pass by the Express if 1 Express simply gets behind schedule.