Regional Rail (RUR) & North-South Rail Link (NSRL)

[Teban54]

Perhaps a Crazy Transit Pitch, based on @F-Line to Dudley's post with planned station layouts:

Is there a way to flip the local and express tracks north of Route 128, such that outer tracks are express and inner tracks are local, as opposed to the more typical setup south of Route 128? Since Forest Hills and Hyde Park do have room for one island platform, but not two side platforms (at least without seemingly expensive modifications and/or eminent domain), this would theoretically allow the two center local tracks to share the platform and enable bidirectional local service. There seems to be ample length and width north of Route 128 for flyovers.

Forest Hills (4-track layout), Hyde Park (4-track layout)
====< local track
[<- Island platform ->]
====< express track / > local track
====> express track
====> local track

(FH is structurally unexpandable, and HP has to trade 3-track w/side platforms for 4-track w/squished island because of lack of space. With additional platforms physically impossible, it requires crossing over the express tracks to reach. Creates lots of conflicts that sharply limit which schedules can use these platforms. Any intermediate stops between FH and HP have to retain the same layout--even if there's room to do better--because more switches means an even bigger mess with crossing over. This right here is the Achilles heel of the whole works.)

 

[Riverside]

There seems to be ample length and width north of Route 128 for flyovers.

I think you will run into trouble with the (very inconveniently located) wetlands north of Route 128.

this would theoretically allow the two center local tracks to share the platform and enable bidirectional local service

If the Old Colony stations are any indication, the T prefers its center platforms to be "double width" (e.g. 24' instead of 12'). In practice, perhaps that could be condensed, but given that we are assuming significant demand at Hyde Park, a narrower platform seems less likely to fly.

I don't think the issue really is about the lateral space in the ROW, per se. Assuming 12 feet per platform and per track, the current ROW has enough (or nearly enough) raw width for 4 tracks and two platforms (or one platform of double width) at the station itself. The issue is a) keeping the express tracks as straight as possible for maximum overtake speeds, and b) fitting into the narrower ROWs north and south of the station.

Some overly simplified diagrams:

As-is

Empty "slot" in the ROW on the southbound side

Simple Quad Track, "Plow Through"

Southbound platform eliminated, existing slot filled in with a track. (Northbound platform would be closed.)

Amtrak Alternative Quad Track

As suggested in Amtrak's NEC plans, keep the southbound platform in place and run the fourth track around the outside. May require eminent domain and/or cutting under Business St, leaves all other tracks untouched. Green indicates expansion beyond existing ROW envelope

Offsetting Quad Track

IMO, this is a generalized description of basically all other theoretical alts (including a center platform alt). The existing southbound platform is kept in place and treated like an immovable "wall" of the ROW. The northbound platform is narrowed to make room for a fourth track on that side.

This alt requires expansion of the ROW to the north and south (again indicated in green) to handle the actual "offsetting"; unlike the Amtrak alternative, though, this requires a much more significant expansion of the envelope and requires a much longer amount of track to be moved; the Amtrak alt requires an "offset" to let the new track "bump out" to the outside of the platform, but because the high-speed trains won't be using it, the bump out can have sharper curves without worrying about the speed penalty. Sharper curves = shorter distance needed to "offset" = smaller expansion of envelope.

Offsetting the express tracks is much higher impact because they need a much longer amount of "runway" in order to offset by one "slot" (lots of quote marks in this post, idk why); though this diagram shows the offsetting curves (the blue diagonal lines) as being relatively short, in reality they would be much longer in order to accommodate the smooth curves of high speed rails.

This ^^ problem exists for a center platform as well. Diverging the tracks wide enough to fit a platform requires widening the ROW north and south of the station. And that may indeed be possible! But it's still a major increase in complexity for the project. Also, most offset alts will require much more existing track to be relocated than either the Amtrak or Plow Through alts.

~~~

As I look at it further, though, there is a Crazy Transit Pitch that could maybe kinda sorta work.

AM Peak: some northbound peak Providence trains stop at Hyde Park northbound platform
PM Peak: some northbound reverse-peak Providence trains through-run from Back Bay to Newmarket/beyond, providing LMA <> Fairmount service

A pair of small shuttle buses ping back and forth between Hyde Park and Fairmount for riders who wish to avoid the 8 minute walk

This approach comes at the expense of South Station <> Fairmount slots, which creates its own set of challenges.

~~~

Also, if we're talking about northbound-only service to Hyde Park, it's worth noting that even a doubleback commute would still be quite fast:

1. Back Bay/Ruggles -> Readville = 7-10 min
2. Wait at Ruggles for a northbound train = 2-15 min
3. Readville -> Hyde Park = 2 min

With no coordinated schedules, the doubleback would take at most 28 min (comparable to Orange + 32 today); with schedule coordination to support 5-min transfers, that drops to 17 min or less.

And, finally, worth noting that the 32 currently takes about 5 or 6 minutes to go between Readville and Hyde Park. So, a Purple -> 32 doubleback would itself also be something like 17 minutes (assuming 3 min to transfer).

It sucks because, on paper, a Hyde Park <> Back Bay EMU service should take, like, 10 minutes, which is amazingly fast, and is so tempting.

But, also: Hyde Park is 6.9 miles from Back Bay Station (7.7 miles from South Station), and... well, almost no one else in the region -- except Readville -- sees that kind of speed. Even with electrification, Fairmount will be 19 min from South Station, Newtonville will be 15 min from Back Bay, etc.

Anyway, it's like I said: if the Hyde Park community wants to shoulder the burden necessary for the Amtrak alt, then yay, they'll get a superfast express train coming every 15 min or better all day, taking about 10 min to reach Back Bay. And if they don't, they'll have a high frequency bus running to a high frequency superfast express train coming every 15 min or better all day, taking about 17 min to reach Back Bay. As "worst case scenarios" go, that doesn't seem terrible to me.

 

[TheRatmeister]

Perhaps a Crazy Transit Pitch, based on @F-Line to Dudley's post with planned station layouts:

Is there a way to flip the local and express tracks north of Route 128, such that outer tracks are express and inner tracks are local, as opposed to the more typical setup south of Route 128? Since Forest Hills and Hyde Park do have room for one island platform, but not two side platforms (at least without seemingly expensive modifications and/or eminent domain), this would theoretically allow the two center local tracks to share the platform and enable bidirectional local service. There seems to be ample length and width north of Route 128 for flyovers.

What about the 2 western tracks being local and the 2 eastern tracks being express? You would still have a flat junction with the Franklin line, but since that would only affect local service it's not nearly as big of a capacity constraint. That would solve the gradient issue at Readville since that area has way more room for an incline, and would also "solve" the platform issue at Forest Hills by reusing the existing not-quite-wide-enough island platform. There's plenty of room on the Franklin Line for double (Or even quad-track) here, so that's not an issue. To avoid a curved platform the station should probably be shifted northwards by about ~300-400ft, but it would be fully level with parallel local/express platforms. (Although without a flying junction there would be no same-direction cross-platform interchange.)

The one big operational hurdle is that to make this work where quad-track turns into triple-track, the Franklin Line would need to run on the left for this section, with a crossover between Readville and Endicott to go back to standard right-hand running.

Spoiler: How the merge works

With an Inbound Local | Outbound Local | Outbound Express | Inbound Express layout, the outbound services would share the middle track for triple-tracked sections.

I can't find any rule that says this is 100% verboten, but I don't think it's done anywhere else on the NEC. Perhaps @F-Line to Dudley has some insight on whether or not this is possible from a regulations perspective.

 

[F-Line to Dudley]

The only way I think that transfer would be of an acceptable quality is if it's a cross platform interchange with a timed, which would entail entirely rebuilding the station, at which point why not just build the flyover? If the platforms are kept in roughly their current locations, I'd estimate a minimum ~5 mins transfer time with a timed transfer, which brings with it concerns about delays. If one of the two trains is delayed either passengers need to wait a long time for their transfer or both trains need to be delayed.

Are we looking at the same current locations of the platforms? Because I see a very short footbridge connecting the Fairmount platform to the NEC platforms. It's only 130' from the Fairmount platform to the inbound NEC platform, which shouldn't take anywhere close to 5 mins.

View attachment 49155

The Fairmount platform is not going to stay in the current spot. It needs a double-track island to mix terminating trains with thru trains, and it needs to be moved off the Franklin-Fairmount connector because that's a freight clearance route preventing full-high platforms. The whole works is going to move about 375 ft. north across from the Milton St. parking lot entrance with an island slotting in the gap between the current mainline track and the freight turnout track. The turnout track would become the second mainline track, and another turnout track would be built on the east side so the high-and-wide freights miss the platform when they've backing in/out of the freight yard. You'd have to build new ramps to Milton St. from the Franklin and NEC platforms to enable cross-platform transfers. The walking distance would be a bit longer, but still reasonable.

 

[TheRatmeister]

Regarding the question of running Franklin-via-NEC, while you're right that NEC's capacity will hopefully not be an issue (though that's only possible without a Franklin flat junction), there's another reason why it may hurt: Every Franklin-Ruggles train means the loss of both a Canton Junction-Ruggles train and a Franklin-Fairmount train.

Given the obvious prominence of both lines, maximizing service on both is desired -- Fairmount clearly needs rapid transit frequencies, and I'd even say doing so for Canton Junction may not be a bad idea either, especially given SCR and boosting regional connectivity to Providence. While I suspect Franklin/Foxboro riders vastly prefer NEC over the Fairmount corridor, that can be mitigated with a transfer at Readville if NEC runs frequent trains and reinstates Readville platform (which, according to this F-Line post, is planned).

This F-Line post (part of what @bakgwailo cited above) also says "an endgame future of likely 85-100% of Franklin schedules going via Fairmount". While that's primarily due to the Franklin flat junction, this interlining may also be another reason, especially if the flat junction is also hard to remove as per discussions above.

I've been meaning to come back to this, and more specifically the question: Is running Franklin Line trains up the Fairmount Line the right solution to Fairmount needing more frequency? I'm not sure it is. Using the same trains, and more specifically the same rolling stock could have some unwanted implications:

• Any new Fairmount infills must be built to the standards of full length CR trains, rather than shorter trains that would be perfectly fine for the line and result in lower station costs
• CR trains would presumably have all transverse seating, which might not be ideal for the Fairmount Line where big rush hour crowds would use up that standing room really quick.
• The short stop spacing on the Fairmount Line is less appropriate for the "high top speed but lower acceleration" specifications that make sense on the rest of the CR. Opting for more subway style trains with a lower top speed but more aggressive acceleration could be desirable here.
• CR trains, which only see high passenger loads at a few stations such as Providence, South Station, or North Station, would likely have fewer doors, resulting in more significant boarding times at busy Fairmount Line stations. Additional doors would need to come at the expense of seating and could therefore be problematic for long routes.
• Linking Franklin service to Fairmount service would, at least partially, tie the reliability of the grade separated Fairmount Line to that of the Franklin Line with its many level crossings
• Linking the Franklin and Fairmount Lines would disincentivize future infills on the Fairmount Line

And of course the obvious problem, this routing would add 5-10 minutes and/or a transfer to almost all journeys on the Franklin Line, since most suburbanites don't really travel to Mattapan or Dorchester that often. This linking of the two lines would mean kneecapping both lines in exchange for either the cost of a road bridge+incline, or potentially just the cost of 4.5 miles of track. I cannot see these short-term cost savings remotely balancing out the longer term woes.

 

[F-Line to Dudley]

• Any new Fairmount infills must be built to the standards of full length CR trains, rather than shorter trains that would be perfectly fine for the line and result in lower station costs

How many new infills exactly are we envisioning? Certainly not more than 1 or 2 if we want to make "128-to-terminal in 30 minutes" any sort of secondary organizing principle for Urban Rail. It's not the length of platform that's blowing out station costs. It's primarily the soft costs of consultant-driven design and permitting. The cost difference between a 450-foot platform and an 800-foot platform is not large. Chewing through paper-for-paper's-sake and having long, drawn-out design-build processes is what's doing it. The Fairmount rebuilds and infills of a dozen years ago were pretty reasonably cost-controlled. That's what we should be aiming for.

CR trains would presumably have all transverse seating, which might not be ideal for the Fairmount Line where big rush hour crowds would use up that standing room really quick.

• The short stop spacing on the Fairmount Line is less appropriate for the "high top speed but lower acceleration" specifications that make sense on the rest of the CR. Opting for more subway style trains with a lower top speed but more aggressive acceleration could be desirable here.

I keep saying this/banging head against wall with every TransitMatters report that comes out stanning for 100 MPH service with breakneck acceleration: You can't order that rolling stock in this country right now. TM's modeling was based on the intercity variant of the Stadler FLIRT. The Stadler FLIRT was not bid in any form--intercity-class or commuter-class--for the T's pure EMU RFP or their BEMU RFP. Intercity-class propulsion matched with commuter or subway livery would be a fresh customization, where we'd be paying above the standard going rate for intercity-class rolling stock because of the need to customize it for very different seating configuration vs. the performance class, and do it safely (as is, not flinging standees around with intercity propulsion when there are no standees allowed on most intercity-class trains). It's going to cost a lot more than they're aiming to pay...a lot more in the absolute for the propulsion class, plus the going rate for doing a livery customization. The FLIRT has also never been made available at 48-inch level boarding interface...only 8-inch low boarding and Euro-class mid-levels (up to 29 inches). Stadler simply hasn't bid on any East Coast EMU orders despite those being far and away the largest installed base in the Western Hemisphere...it's thought because they don't want the usual-suspect agencies (MTA, NJT, SEPTA) overcomplicating their product and financial risk profile with chronic overcustomization. They've only offered the 8-inch platform configuration in this country (mostly for DMU's and hydrogen MU's). It would take a fresh first-time customization to offer it for 48-inch platforms, meaning the T is going to have to pay more on top of paying more for the intercity class and converting it for commuter duty.

It's make-believe modeling until somebody actually offers it for bid. And Stadler has stubbornly refused to do that, being corporately mistrustful of American clients. We want to implement Regional Rail sooner than later. That means we can't be throwing temper tantrums that the platonic ideal rolling stock that's never been shoehorned before into platonic ideal application...isn't being willingly shoehorned by the freeeeeeeee market into platonic ideal application. We're forced to order the rolling stock that is offered to us in the RFP's. When all of the offered product is commuter-class propulsion and figures to be in the free market for any follow-up bid requests...that's what we have to plan on. We got plenty of single-level bids...half-and-half single-vs.-bi-level in the bids. We got 2 x 2 and 3 x 2 traverse seating bids (no longitudinal, though there might be compromises to be had there in the configuration options), so there's some variety to choose from. We got different vestibule options (we won't be able to order quarter-point doors because we have curved platforms on the system, but a well-designed vestibule can accelerate passenger flow). We've got attractive options to work with there. But platonic ideals ain't happening unless you want to keep kicking out the timeline for implementing Regional Rail to some always-further future era where the free market starts cooperating with notoriously-difficult American transit agencies.

• CR trains, which only see high passenger loads at a few stations such as Providence, South Station, or North Station, would likely have fewer doors, resulting in more significant boarding times at busy Fairmount Line stations. Additional doors would need to come at the expense of seating and could therefore be problematic for long routes.

As said, curved platforms like Landsdowne, Weymouth Landing, or East Weymouth are no-go for some of the additional-door configuration options like quarter-points (i.e. no MTA M8/M9 clones), and some center-door makes wouldn't be able to open all doors at curved platforms. We can order with additional doors (i.e. vestibule + center doors) and use them in most places, but there'd be some degree of undesireable boarding/alighting procedural complexity with lines that have curved stations as exemptions. Especially ones in the :15-or-better Urban Rail zone like Landsdowne. No platonic ideals here. We didn't ban curved full-highs like the MTA/ConnDOT did.

• Linking Franklin service to Fairmount service would, at least partially, tie the reliability of the grade separated Fairmount Line to that of the Franklin Line with its many level crossings

Franklin doesn't have a lot of grade crossings. 1 to Walpole Jct. where Forge Park and Foxboro are service doubled-up, 1 on the Framingham Secondary for Foxboro service, 2 between Walpole and Franklin Jct. for solo Forge Park service, and 6 between Franklin and Forge Park. None are traffic-problematic (the Milford Branch's corkscrewing curves kill speeds before the crossings ever have a chance to). There are many other lines that are going to need crossing treatments before this one. Rockburyport, Reading, and Fitchburg in the :15 zone are all way more problematic. Franklin's a relative breeze.

• Linking the Franklin and Fairmount Lines would disincentivize future infills on the Fairmount Line

Yeah, but how many potential Fairmount infills are actually high-leverage gets? The multiple bus connections to other points on the compass are what makes all the existing stop roster sizzle under :15 frequencies. When we did the infill pros-and-cons exercise on the forums last month, we couldn't come up with any that had more than 1 bus that didn't duplicate one of the buses hitting the other stops. They were more heavily reliant on walkup than multimodal connections, and that dimmed the topline numbers a bit. Yeah, if you're going on rigid distance between stops you can probably come up with a couple slightly under-served walksheds. No...none of them were particularly high-leverage, and if you are concerned (as above) about station costs you're probably going to be hesitant to bite on them until Urban Rail service is very well established for a couple ridership-generating Blue Book cycles. They wouldn't be something you'd be building up-front.

 

[F-Line to Dudley]

Part II. . .

And of course the obvious problem, this routing would add 5-10 minutes and/or a transfer to almost all journeys on the Franklin Line, since most suburbanites don't really travel to Mattapan or Dorchester that often. This linking of the two lines would mean kneecapping both lines in exchange for either the cost of a road bridge+incline, or potentially just the cost of 4.5 miles of track. I cannot see these short-term cost savings remotely balancing out the longer term woes.

This is a legitimate question. Foxboro is fine making all local stops, but Forge Park starts getting a little bit long and Woonsocket and/or Milford start looking a lot more problematic. I think that's ripe for more exploration, especially whether judicious skip-stopping can help out the FP schedules. If Worcester is going to have to do that on the 2-track intra-128 portion and be projected by the Rail Vision to do that successfully despite a much heavier layer-cake of differing-length schedules, then there's no reason a Fairmount with ideal crossover placement and backfill short-turns can't do the same. It's all about how you portion it out, which can be ripe for going down an analytical rabbit hole.

Also...it needs to be repeated: "run Franklin over Fairmount" doesn't mean the NEC goes completely unused for the Franklin Line. The Rail Vision (and TransitMatters, who saw enough potential problems mixing traffic on the NEC to outright decline to endorse a routing choice...in spite of their generally extreme-permissive traffic modeling habits) merely state that reliable clock-facing full-day schedules are not going to be realistic running on the NEC. There will be headway hiccups to have to treat, whereas running via Fairmount would ensure all-day clock facing schedules with no trickery required. That doesn't mean a substantial number of slots can't run via the NEC. It just means all of them can't without undesireable bunching and gapping. With full traffic modeling, you would be able to figure out a scheme where Forge Park is generously served by the NEC. It just may not accomodate any NEC use for Foxboro without reducing Forge Park slots, may not allow for much of any increases over today for Forge Park, and may require short-turning tricks if trying to buttress Urban Rail/128 service on either NEC/Fairmount flank when picking-and-choosing slots. But it's not an all-or-nothing thing, so there's no reason for despair that the NEC is going to be this underutilized resource. You can use it plenty full...you just might have to pick your spots because of those scheduling headway hiccups.

 

[JeffDowntown]

I've been meaning to come back to this, and more specifically the question: Is running Franklin Line trains up the Fairmount Line the right solution to Fairmount needing more frequency? I'm not sure it is. Using the same trains, and more specifically the same rolling stock could have some unwanted implications:

• Any new Fairmount infills must be built to the standards of full length CR trains, rather than shorter trains that would be perfectly fine for the line and result in lower station costs
• CR trains would presumably have all transverse seating, which might not be ideal for the Fairmount Line where big rush hour crowds would use up that standing room really quick.
• The short stop spacing on the Fairmount Line is less appropriate for the "high top speed but lower acceleration" specifications that make sense on the rest of the CR. Opting for more subway style trains with a lower top speed but more aggressive acceleration could be desirable here.
• CR trains, which only see high passenger loads at a few stations such as Providence, South Station, or North Station, would likely have fewer doors, resulting in more significant boarding times at busy Fairmount Line stations. Additional doors would need to come at the expense of seating and could therefore be problematic for long routes.
• Linking Franklin service to Fairmount service would, at least partially, tie the reliability of the grade separated Fairmount Line to that of the Franklin Line with its many level crossings
• Linking the Franklin and Fairmount Lines would disincentivize future infills on the Fairmount Line

And of course the obvious problem, this routing would add 5-10 minutes and/or a transfer to almost all journeys on the Franklin Line, since most suburbanites don't really travel to Mattapan or Dorchester that often. This linking of the two lines would mean kneecapping both lines in exchange for either the cost of a road bridge+incline, or potentially just the cost of 4.5 miles of track. I cannot see these short-term cost savings remotely balancing out the longer term woes.

Perhaps there is a way to approach use of the Fairmont Line corridor that could work without most of the above negative implications.

What if we place a requirement on any suburban line being routed over the Fairmont corridor (Franklin or other options) that it use rolling stock appropriate to the Fairmont corridor (and that the suburban line be electrified). EMUs, shorter train sets, etc. Then the frequency we add is more consistent with the service needs of the Fairmont corridor. (It will also require more frequent service on the suburban line due to the smaller trains.)

 

[TheRatmeister]

Perhaps there is a way to approach use of the Fairmont Line corridor that could work without most of the above negative implications.

What if we place a requirement on any suburban line being routed over the Fairmont corridor (Franklin or other options) that it use rolling stock appropriate to the Fairmont corridor (and that the suburban line be electrified). EMUs, shorter train sets, etc. Then the frequency we add is more consistent with the service needs of the Fairmont corridor. (It will also require more frequent service on the suburban line due to the smaller trains.)

Or we could just run the Fairmount Line as a quasi-rapid transit line, just doing its own thing, with its own trains, and its own service, not dependent or reliant on other lines. Fairmount is not like the other CR lines, and we shouldn't be treating it as one or as an extension of one.

The Rail Vision (and TransitMatters, who saw enough potential problems mixing traffic on the NEC to outright decline to endorse a routing choice...in spite of their generally extreme-permissive traffic modeling habits) merely state that reliable clock-facing full-day schedules are not going to be realistic running on the NEC.

We don't need to accept these conclusions as facts, just because someone or some agency wrote a report doesn't mean they're automatically correct. There are plenty of double-tracked lines around the world with equal or better service as proposed that manage to do clock-face scheduling just fine despite running 12+ TPH through their core sections, the RER-B and Elizabeth Line are both examples, as I mentioned earlier. There are not enough Amtrak trains in the schedule that make 12TPH a significant problem with quad-tracking between Forest Hills and Readville, as the main bottleneck here is making sure the previous CR train can stop at and leave Ruggles before the Amtrak train behind catches up and this would not take more than 5 minutes, and with either the Readville flyover or local left-hand running options this can be done alongside the reconstruction of Readville station to remove the flat junction. I do not believe that these options have been studied with the depth they deserve, and that they would significantly change the outcome if they were.

Yeah, but how many potential Fairmount infills are actually high-leverage gets? The multiple bus connections to other points on the compass are what makes all the existing stop roster sizzle under :15 frequencies. When we did the infill pros-and-cons exercise on the forums last month, we couldn't come up with any that had more than 1 bus that didn't duplicate one of the buses hitting the other stops. They were more heavily reliant on walkup than multimodal connections, and that dimmed the topline numbers a bit. Yeah, if you're going on rigid distance between stops you can probably come up with a couple slightly under-served walksheds. No...none of them were particularly high-leverage, and if you are concerned (as above) about station costs you're probably going to be hesitant to bite on them until Urban Rail service is very well established for a couple ridership-generating Blue Book cycles. They wouldn't be something you'd be building up-front.

You're right, they might not be built up front. But as long as Franklin Line trains are running over the line they're probably not getting built at all. In terms of how many infills, Ceylon Park is probably the one I'd rate as most likely, with the 16 getting more frequent service under the BNRD and some nearby industrial sites are good places for future densification. Widdett Circle is prime for air rights development in the future and could also serve as a good interchange with an Urban ring service. River St is right next to a strip mall, another future redevelopment candidate, but that's likely further off than either of the previous two. That's at least 3 in the not-too-distant future without really accounting for the potential that new infill stations would lead to densification by themselves, land use and transport are incredibly interdependent after all.

 

[F-Line to Dudley]

We don't need to accept these conclusions as facts, just because someone or some agency wrote a report doesn't mean they're automatically correct. There are plenty of double-tracked lines around the world with equal or better service as proposed that manage to do clock-face scheduling just fine despite running 12+ TPH through their core sections, the RER-B and Elizabeth Line are both examples, as I mentioned earlier. There are not enough Amtrak trains in the schedule that make 12TPH a significant problem with quad-tracking between Forest Hills and Readville, as the main bottleneck here is making sure the previous CR train can stop at and leave Ruggles before the Amtrak train behind catches up and this would not take more than 5 minutes, and with either the Readville flyover or local left-hand running options this can be done alongside the reconstruction of Readville station to remove the flat junction. I do not believe that these options have been studied with the depth they deserve, and that they would significantly change the outcome if they were.

Yeah, but those somebodies DID do full-bore traffic modeling on the idealized RER vision for our CURRENT system, and ran into snags that says this is not likely to work. Skin-deep globe-trotting comparisons are not a full counterpoint to toothy traffic modeling on our system. It takes counterpoint traffic modeling to say there's no problem, and you don't have that anywhere here with these comparisons. This is a persistent problem I have with the globe-trotting transpo blogosphere; local conditions are too often skimmed-over and mercilessly shamed when there's an undesireable modeling result, but platonic ideals are always divine and unimpeachable. That's not how the real world works. We're in the real world, and RER is supposed to be a real-world thing we get implemented here within the next decade. If the experts (including TM, who chronically push the limits of credulity with their Extreme Train Sim modeling) are saying there's a snag here, we better be prepared in the real world to confront that there's going to be a snag here and adapt accordingly. I don't want to grow old and die on the chance that some perfect future will allow for platonic ideals; I want to ride this fucker usefully while I'm still able-bodied and well within the workforce.


EDIT: As well. . .

TM had no problem proposing quarter-billion dollar viaducts at Waltham and Framingham to brute-force treat grade crossing constrictions in lieu of even trying to model some in-situ treatments...so they have no qualms with "going big" when they think "going big" serves the end goal. Don't you think they would have proposed a "go big" flying junction damn-the-costs if they thought that would do the trick to keep traffic harmony on the NEC??? They didn't. They didn't because it's quite likely that even their very aggressive in-house traffic modeling didn't see a completely airtight solve out there for the frequency hiccups projected across an all-day Franklin-via-NEC schedule. To disprove them on that requires exacting counter-modeling on the Boston end of the NEC, not a "well, the RER-B and Elizabeth Line does it, so. . ." quip.

 

[TheRatmeister]

Yeah, but those somebodies DID do full-bore traffic modeling on the idealized RER vision for our CURRENT system, and ran into snags that says this is not likely to work.

You keep mentioning this but I've been unable so far to find it in the TM and RV reports. I've been able to find basically no mention of capacity constraints along the NEC in the TM reports, apart from one mention in the first report advocating the Needham Line replacement. The Rail Vision does mention running peak trains along the Fairmount Line, but I don't see any actual technical analysis beyond the mention that the interlining is necessary not because of NEC capacity constraints but because of South Station capacity constraints. (Which again, doesn't really check out based on the napkin math and TM is actually in agreement here.)

Spoiler: South Station Capacity

Assuming 3 tracks are dedicated entirely to Amtrak service, and the remaining 10 serve CR trains, with a relatively pessimistic turnaround time of 10 minutes + 5 minutes buffer we have 40TPH to spread around. Let's say 10 for Fairmount, 6 for Old Colony, 4 for Providence, 4 for SCR, 6 for Worcester, and 4 for Franklin/Foxboro. Even with this very optimistic schedule with a lot of service on the Fairmount Line, we still have 6TPH to spare while giving Amtrak 3 platforms, another conservative assumption.

 

[Teban54]

I've been meaning to come back to this, and more specifically the question: Is running Franklin Line trains up the Fairmount Line the right solution to Fairmount needing more frequency? I'm not sure it is. Using the same trains, and more specifically the same rolling stock could have some unwanted implications:

I'll explain this in a few different angles from what @F-Line to Dudley did (not all of which I agree, as alluded in the specifics below):

1. Most of your points are not saying "Franklin Line should not run via Fairmount", but rather, "Fairmount Line should not have been Regional Rail in an ideal world". While I absolutely agree with that statement alone, the line is essentially mode-locked; and regardless, that question is irrelevant to Franklin Line.
2. Two lines are affected by Franklin-via-NEC trains, and Fairmount is only one of them. The other is NEC further south: Providence, Stoughton and SCR. If slots on NEC are available, it's very plausible that adding more trains to those destinations (or even Amtrak) is more valuable than to Franklin/Foxboro, especially as their operational impacts are much lower.
3. Franklin trains running via Fairmount don't necessarily need to stop at all Fairmount stops. In fact, there may even be a legitimate argument for branding those trains as "Fairmount Express"!
4. (This is the most tangential and hypothetical, but I'll raise it for the sake of making the proposal somewhere) I personally think there's merit in extending the "high-frequency zone" from Fairmount to Norwood, and doing so means trains will need to run via Fairmount regardless.

#1: Is the problem Franklin... or Fairmount itself?

All of your points that do not involve infills -- namely, points 2 (seating), 3 (fleet engineering), 4 (doors and passenger flow) and arguably 5 (reliability), essentially say "Commuter Rail infrastructure is unsuitable for Fairmount Line". This is the implicit assumption behind @JeffDowntown's comment as well.

I think everyone agrees that, in an ideal world with unlimited budget and lack of ROW complications, Fairmount Line really should be rapid transit, not mainline rail. This doesn't just apply to fleet choice, which you acutely summarized, but also integration with the rest of the rapid transit system -- fares, transfers, and even branding.

Where this ideal breaks down is that, in reality, Fairmount Line is mode-locked into mainline rail (for reasons that have been described on this forum many times). Can it still get a dedicated fleet, even without the rest of the rapid transit features? I feel a dedicated fleet is unlikely, for several reasons:

• The T has not shown any willingness to even consider it, nor special treatment of Fairmount Line from other lines. I'll also point out that most calls to improve Fairmount Line come from not within the T itself, but politicians and local community, who are unlikely to know the differences in fleet, much less advocate for them.
• Complications for regional rail operations, in terms of maintenance (standardization of fleet is common practice), flexibility of dispatching and fleet swaps, etc. Also, NSRL would make the problem way worse, extending the flexibility problem from contingencies to regular ops: Where would the "quasi-rapid transit" trains go north of Boston?

But most importantly, I think running standard Regional Rail vehicles is good enough, even if not perfect. Yes, the (B)EMUs that Rail Vision will likely get are not ideal for Fairmount Line's character, but that doesn't mean they're worthless or should be opposed. Many other factors contribute towards a line's character and success -- stop spacing, frequency and capacity, ease of access to stations -- and on most of these, Fairmount Line can get as close to rapid transit as possible (given the mainline rail constraint), regardless of fleet. For capacity, you can even argue that less standing room is compensated by trains that can be twice as long as RL and OL. Just because these vehicles are not 100% suited for the line, doesn't mean they're insufficient in meeting the demands -- and I see no evidence to suggest that. (This discussion is reminiscent of our previous exchange about low-floor vs. high-floor LRVs, where my opinion was that a (mostly) grade-separated route isn't incapable of functioning as a rapid transit spine just because it uses low-floor LRVs.)

Bottom line: The root cause of this discussion is not Franklin-via-Fairmount trains, but Fairmount Line itself. Yes, Franklin-via-Fairmount trains do highlight and perhaps exacerbate some of these imperfections (with a caveat - see #3), but they're not the source. The discussion of whether Fairmount Line needs specialized equipment has nothing to do with Franklin, and its impacts on where to route Franklin trains is frankly minimal, as I'll elaborate in #3 below.

 

[Teban54]

Spoiler: Disagreement that "CR trains only see high passenger loads at a few stations"

• CR trains, which only see high passenger loads at a few stations such as Providence, South Station, or North Station

I have to strongly disagree with this. If we use Providence as the benchmark, the April 2013 Blue Book data shows that, in terms of weekly inbound boardings:

• The #2 and #3 stations systemwide, Salem and Beverly, each has around 90% of ridership as Providence (#1 in the system).
• 10 stations have riderships that are at least 50% of Providence's: Salem, Beverly, Lowell, Mansfield, Attleboro, Anderson, Worcester, South Attleboro, Framingham, and Norwood Central.
• Providence station only contributes 22% of ridership on the Providence line -- all its intermediate stops are significant. (If you include Stoughton branch, that drops to 18%.)

This suggests that boarding activity is very much significant at stations other than Providence. While South Station and North Station will obviously always take the crown in ridership, that's due to the radial nature of the network, which also applies to the vast majority of rapid transit lines worldwide and all in Boston. The statement feels akin to "Red Line only sees high passenger loads at a few stations such as Park St, Downtown Crossing, or Harvard, and therefore there's no need for quick passenger flow".

While all Commuter Rail stations in 2013 have much lower ridership (Providence only having 2325) than most rapid transit stations (gated stations have median 6590 per Blue Book), the former also receives vastly less frequent service at much higher fares, and can likely improve substantially with induced demand from Regional Rail. Understandably, suburban stations have different travel patterns than urban stations, but I don't think that explains the ridership gap entirely. Therefore, while individual Fairmount stations do have the potential to join the list of most-used stations in the entire Regional Rail system, I doubt they'll be a magnitude above the other stations to warrant significantly different demands for passenger flow and number of doors.

Spoiler: Reliability

• Linking Franklin service to Fairmount service would, at least partially, tie the reliability of the grade separated Fairmount Line to that of the Franklin Line with its many level crossings

So, in a vacuum, I think that's a valid concern. But in all likelihood, Fairmount Line is very unlikely to be a pristine, deinterlined route running by itself. Even pre-NSRL, it's already subject to South Station's terminal operations. Post-NSRL, it's subject to delays from whichever northern terminal(s) it's paired with, and delays from every single train in the entire Regional Rail system that uses NSRL. True, adding Franklin trains to it do worsen the reliability, but I feel that may be a smaller factor than the above (and thus manageable), especially given F-Line's comments about Franklin Line's relative lack of grade crossings.

I'll also note that regardless of the frequencies we're discussing, these trains are still much less frequent -- and much more reliable -- than street-running LRT. Yet, we frequently see proposals for Green Line branches to Mattapan and Arborway, sometimes even injecting them into the GLR system that's supposed to be as reliable as the Fairmount Line we're envisioning here.

Or we could just run the Fairmount Line as a quasi-rapid transit line, just doing its own thing, with its own trains, and its own service, not dependent or reliant on other lines. Fairmount is not like the other CR lines, and we shouldn't be treating it as one or as an extension of one.

I think my opinions above already explain why this seem impossible. There may be a shot if you deny it NSRL access, but that's extremely unlikely to be worth it.

#2: Where to send NEC slots: Franklin, or Providence/Stoughton/SCR?

While I understand that @TheRatmeister's comment primarily focuses on impacts on Fairmount Line, the question of "Franklin-via-NEC vs. Franklin-via-Fairmount" is incomplete without considering this half of the picture.

Here are some weekly ridership numbers from 2014 Blue Book:

• Franklin Line, Endicott and south: 7770
• Providence Line alone, Route 128 and south: 10454
• Providence/Stoughton Line: 12634

Providence/Stoughton Line undeniably has higher ridership, even though Franklin Line is the 3rd most popular line in the system. This does seem to provide a basis for preference of additional slots to Providence/Stoughton/SCR over Franklin/Foxboro, especially when considering the former line by line:

Spoiler: Line-by-line considerations of Providence/Stoughton/SCR

• Providence: Having more frequent service between Boston and Providence -- 2nd or 3rd biggest city in New England by most metrics -- offers a huge boost to regional connectivity, well beyond just commutes. Plus, it's the most heavily used line in the system. While I currently think of the "15-min everywhere" Rail Vision Alt 6 as overly bullish and unrealistic, if there is ever one "suburban" line that deserves 15-min frequencies to the terminal, it's Providence.
• SCR Phase 2: The very nature of SCR having two branches means greater demand for TPHs if both terminals are to have reasonable frequencies. For example, if half-hourly service to Fall River and New Bedford each is desired, that already necessitates 4 tph (15-min service) to Stoughton.

But I don't even think that's the main issue: after all, the success of Franklin Line means we definitely shouldn't deprive it of more service, from an equity standpoint. But there's another equity aspect: Franklin/Foxboro trains have via-Fairmount as an additional option, but Providence/Stoughton/SCR/Amtrak trains don't. This fact alone would lean in favor of using additional NEC slots for Providence: Doing so enables additional trains to both Providence and Franklin, whereas using the slot for Franklin offers no benefits for Providence. Sure, that extra Franklin train is slower and may not go where Franklin riders want to go, but it's one more train regardless; that can't be said for Providence -- this "kneecaps" Providence Line much, much more than Franklin-via-Fairmount would "kneecap" "both" lines.

The exception to this is if NEC's capacity is high enough to accommodate trains to all these destinations. But as F-Line mentioned above, if both the T and TransitMatters think that's unrealistic, I'm willing to believe that's unrealistic. And using the abovementioned principles, I feel the priority for allocating the slots should be in this order: Providence > SCR > Franklin > Foxboro. (If we can run all or some Franklin/Forge Park trains on NEC, great! But we will face this decision whenever it's not possible, i.e. when there is a capacity constraint.)

#3: Infills and "Fairmount Express"

The underlying assumptions behind your points 1 (infill length) and 6 (building any infills at all) seem to be that: (a) infills are desirable on Fairmount Line; (b) these infills are much more feasible as shorter platforms than as full-length 800' platforms; and (c) shorter platforms are fine for Fairmount Line trains but not for Franklin Line trains, which necessarily implies Fairmount gets special equipment with shorter trains. Let's accept (c) here, even though my point #1 is a rebuttal.

Regardless of (a) and (b), my main point here would be: Franklin trains don't necessarily need to stop at the "problematic" infill stations.

• If a station only has 400' platforms, Franklin trains likely need just skip it, but that seems perfectly fine. (You can also technically have trains stop with only certain doors open, which Amtrak already does.)
• Even for full-length stations, if Franklin Line's running time is a concern, I'm perfectly happy with having them only stop at major stations on Fairmount in order to save time. (This may indeed be necessary if Franklin is still running diesel trains while Fairmount runs EMUs.)

This does cause Fairmount Line stations to receive uneven service, but that may be a feature, not a bug. The skipped stations (infill or otherwise) will likely have lower ridership and are less crucial than the rest of the line. We can also treat the Franklin trains as "express" services for the major Fairmount stations, if you time them right, which I can see drawing their own demands. I'm also not particularly worried about this arrangement reducing service on Fairmount Line overall: adding another "local" train terminating at Fairmount is much easier than adding a train on NEC.

 

[Teban54]

I did examine assumptions (a) and (b). While I broadly agree with your choice of infills, I have major doubts over (b) as there doesn't seem to be cases where half-length platforms are feasible but full-length ones are not.

Spoiler: Fairmount infills

River St: I do think the infill is valuable, and the density map seems to justify it: its surrounding density is arguably even higher than BHA station. On the other hand, the ROW seems easily wide enough for two platforms in the 1400' between River St and Greenfield Rd.

Ceylon Park: In ideal circumstances, this is likely the most crucial infill of the 3. My rationale for supporting it are:

• Transfers to the 16/T16 bus, if an exit is on Columbia Rd. The 16's existing transfer at Four Corners/Geneva is less than ideal.
• Walk-up density: While the immediate surroundings of Ceylon Park is a bit lacking, to the west is a strip of high-density housing along Quincy St, some of which have a rather long walk to Four Corners/Geneva with no bus connections. To the east of it are neighborhoods around Kane Sq and especially Coppens Sq, with good density and a 10-min walk from Ceylon Park. Their walks to Four Corners/Geneva and Uphams Corner are much longer, and while they do have the option of taking the 15 to Uphams Corner, being within the walkshed of a station is obviously more convenient.

Given Four Corners/Geneva is 1.08 miles from Upham's Corner, the infill will still be about 2500' away from either, which roughly matches rapid transit spacing. The question then becomes ROW width. A limit to the north may be here near 12 Ceylon St, with houses on both sides. This block between Quincy St and Columbia Rd has abutting buildings on both sides; the 75' distance between them is more than enough, but the tracks may need to be shifted west. Otherwise, there doesn't seem to be much constraints all the way south to the curve, 1550 ft from the houses.

This seems pretty doable to me for parallel platforms, if you're willing to shift the tracks: you can even do so without modifying the Columbia Rd overpass. If you don't shift the tracks, offset 800' platforms seem possible. In either cases, I don't see shorter platforms offering significant advantages - it doesn't turn the station from infeasible to feasible..
(Not drawn to scale)

Widett Circle: I know you've mentioned it a few times, and I've always been confused where exactly you're referring to (given how big the actual Widett Circle is). Given the 3 options below, where would you like your platforms to be centered at (or inbetween)?

My opinions:

• Anywhere north of (1) is a no-go, as the NSRL portal starts just north of S Boston Bypass. I even have concerns for platforms centered exactly at or south of 1, parallel to the bypass road, due to interference with the portal, Old Colony crossovers, Amtrak Southampton Yard, and (storage?) tracks to the west.
• (3) is too close to Newmarket, and to a lesser extent that also applies to (2). It's 1700' between Newmarket and (2), and such stop spacing is only seen in downtown Boston's rapid transit stations.
• Regardless of location, the infill only seems worthy for me with some variants of Urban Ring, particularly one that goes to Andrew. If the goal is to have an exit near Southampton St (3) or I-93 (2) for transfers, we may consider shifting Newmarket instead of adding another station. Further north, like (1), may even lose out on Urban Ring connectivity. While Widett Circle does have TOD potential, that alone doesn't seem worthy of an infill until there are concrete plans, especially given the T's near-term eminent domain plans for it.
• Regardless of location and purpose, nothing here makes an 800' platform impossible, especially not in a way that makes 400' more feasible.

#4: High-frequency service to Norwood?

Unlike the 3 earlier points, this is more of a Crazy Transit Pitch than an analysis. I acknowledge that this is mostly a one-man's proposal (though it received some support from @Riverside previously), and as such, is much more open to debate. Regardless, it's not crucial and not closely related to the entire discussion.

The proposal is: Extend some Fairmount trains to Norwood Central (and possibly beyond), creating frequencies of 15 mins or possibly even better. This is intended to be a low-hanging fruit in a world with "quasi rapid transit" on Fairmount Line.

Spoiler: Motivations

What motivated this thought:

• Norwood Central ranks #11 in commuter rail ridership in April 2013; if you combine Norwood Depot and Norwood Central, which are just 3000' apart, they would have ranked as #4 (or #5 if you also combine Canton Junction and Canton Center), with 1817 combined boardings per weekday. Several intermediate stops also have good ridership, with Dedham Corp Center and Islington about 800 each.
• In terms of density, Norwood seems pretty good for outside-128. Not Lynn or Salam-level dense, but it seems similar to Braintree, Arlington Heights, West Roxbury, Needham and even most of Medford, all of which have either existing rapid transit or consensus for improvement. Most other suburbs outside 128 seem less dense. (Endicott has similar density.)
• I have previously expressed a hope of extending rapid transit service to 128 or possibly even a bit beyond, in order to expand the "urban" or rapid transit regions. Norwood is of a similar distance from downtown as Braintree. While building new transit extensions to 128 is expensive, using existing mainline rail infrastructure is a good first step. The previous point may suggest that Norwood is one of the better beyond-128 candidates.
• Norwood is also served by the 34E bus, with 400 weekday boardings pre-Covid. That number isn't too high, but 34E is also not very frequent and it's a long ride from Forest Hills, so there may be room to grow the demand for transit.
• Norwood Depot already seems to have some TOD, and Norwood Central has plenty of space for more.

But most importantly: Given that Fairmount Line is already terminating at Readville, this extension really is short enough to be considered a low-hanging fruit, even if not receiving as much service as Fairmount Line proper.

Interestingly though, the topology of Franklin Line means we may already get 15-min service to Norwood for free. That's automatically achieved if you have half-hourly frequencies to both terminals, Franklin and Foxboro (in a similar setup as SCR). Such frequencies seem enough for me, as I doubt the "Norwood extension" needs as much service as Fairmount Line proper (which sees, say, 10-min or better).

To tie this back to the discussion, having such frequencies to Norwood -- whether to intentionally provide them better service, or as a byproduct of :30 freqs to both Franklin Line terminals -- sounds much harder via NEC than via Fairmount, especially given uncertainties with the Readville flyover. (Another merit of this discussion is that, at least in the specific case of Norwood, we may want to stop thinking of them as "suburbanites" who only take the train to the city. Instead, most stations here have opportunity for more TOD, and the stop spacing even seem somewhat rapid-transit-like all the way to Norwood Central.)

If we can indeed achieve what F-Line said about running, say, all :30 Forge Park trains via NEC and all :30 Foxboro trains via Fairmount, that seems like the best outcome as long as the Readville junction allows it. But whenever conflicts arise that do not allow so many trains on NEC, my priorities would be: (1) adding more trains on Providence/SCR; (2) adding more trains on Franklin and Norwood to ensure good frequencies; and only then, (3) preserving Franklin-NEC OSRs. Whatever issues and imperfections Fairmount Line's own stations and equipment have do not seem related to these tradeoffs, and should be dealt with independently. This is perhaps a TL;DR of my whole comment.

 

[Teban54]

We don't need to accept these conclusions as facts, just because someone or some agency wrote a report doesn't mean they're automatically correct. There are plenty of double-tracked lines around the world with equal or better service as proposed that manage to do clock-face scheduling just fine despite running 12+ TPH through their core sections, the RER-B and Elizabeth Line are both examples, as I mentioned earlier. There are not enough Amtrak trains in the schedule that make 12TPH a significant problem with quad-tracking between Forest Hills and Readville, as the main bottleneck here is making sure the previous CR train can stop at and leave Ruggles before the Amtrak train behind catches up and this would not take more than 5 minutes, and with either the Readville flyover or local left-hand running options this can be done alongside the reconstruction of Readville station to remove the flat junction. I do not believe that these options have been studied with the depth they deserve, and that they would significantly change the outcome if they were.

Funny enough, your mention of 12 tph and Elizabeth Line etc. reminded me of another point.

Let's assume 4-track NSRL, and divide the 4 tracks into 2 pairs:

• "West Tunnel": Lines going west through Back Bay, including NEC and Worcester.
• "East Tunnel": Lines going south through South Bay Portal, including Fairmount and Old Colony.

(Given that any flyovers seem to be on the north side, there's no way to switch between the tunnels for southern lines.)

An interesting question becomes: What's the capacity that West Tunnel needs? Without any Franklin/Foxboro trains, assume:

• 2 tph to Worcester (express east of Framingham)
• 2 tph to Framingham local
• 1 tph Amtrak East-West Rail (same assumption as Riverside here)
• 2 tph Providence
• 2 tph Fall River
• 2 tph New Bedford
• 2 tph Amtrak NE Regional & Acela (source: Connect NEC C37)

That's 13 tph. If you add all Franklin Line trains (say 2 tph Forge Park, 2 tph Foxboro), that's 17 tph. You can mayyybe save 2 tph by cutting from SCR. It doesn't include :15 Providence, possible B&A "urban" trains (such as to Riverside), or anywhere close to the "15-min everywhere" Rail Vision Alt 6 or TransitMatters' similarly aggressive ones. (Like, if you want to get to that level, you need to almost double that figure to 31.) Even though you mentioned earlier that 17 tph is achievable in some of the busiest regional rail systems in the world, I have to think it's still cutting it close, especially when such capabilities have not been demonstrated in Boston nor most North American cities (AFAIK).

Franklin Line has the unique ability in that it's the only line that can switch between West Tunnel and East Tunnel to balance capacity. In most cases, even with rapid transit frequencies on Fairmount, East Tunnel will likely see fewer trains than West Tunnel. If 17 tph is too much in the West Tunnel (I'm not saying with confidence that it is), running some Franklin/Foxboro trains via Fairmount will instead send them into East Tunnel, balancing the load between the two trunks.

(This is obviously inapplicable with 2-track NSRL, but I think this calculation shows how insufficient that is.)

 

[Riverside]

But most importantly, I think running standard Regional Rail vehicles is good enough, even if not perfect. Yes, the (B)EMUs that Rail Vision will likely get are not ideal for Fairmount Line's character, but that doesn't mean they're worthless or should be opposed. Many other factors contribute towards a line's character and success -- stop spacing, frequency and capacity, ease of access to stations -- and on most of these, Fairmount Line can get as close to rapid transit as possible (given the mainline rail constraint), regardless of fleet. For capacity, you can even argue that less standing room is compensated by trains that can be twice as long as RL and OL. Just because these vehicles are not 100% suited for the line, doesn't mean they're insufficient in meeting the demands -- and I see no evidence to suggest that.

+1. The perfect easily becomes the enemy of the good here. As I understand it, Fairmount ridership has responded very positively (i.e. has grown significantly) to the increase to hourly, and now 45-min, frequencies. It seems extremely likely that that increase will be linear (if not better), meaning that even 20-min headways (which should be achievable with current infrastructure and likely with current rolling stock) will attract that much more ridership.

The current data suggest that this corridor very much is "run the trains and they will come". So, let's keep increasing the frequencies as far as we can on diesel; then let's increase the frequencies as far as we can on EMUs; then let's revisit the question of creating a specialized fleet for Fairmount with center-doors and single levels. By that point, my bet would be that demonstrated demand and current conditions will make it much easier to justify those expenses.

Again, this comes back to a fear I have about the Regional Rail PR strategy: the most important and immediately transformative steps are to rationalize the fares and run trains more often. Just. Run. The. Trains. The time improvements from M8-style center doors etc, and from electrification, are significant... but won't make a transformative difference until we move into the sub-30 min headway territory (if then).

Just. Run. The. Trains.

• Providence: Having more frequent service between Boston and Providence -- 2nd or 3rd biggest city in New England by most metrics -- offers a huge boost to regional connectivity, well beyond just commutes. Plus, it's the most heavily used line in the system. While I currently think of the "15-min everywhere" Rail Vision Alt 6 as overly bullish and unrealistic, if there is ever one "suburban" line that deserves 15-min frequencies to the terminal, it's Providence.

+1 here. The other candidate for this list is Lowell (even pre-electrification), in part due to its short distance to Boston. But, even for Lowell 15 minutes is potentially pushing it. Providence is definitely the strongest candidate.

• SCR Phase 2: The very nature of SCR having two branches means greater demand for TPHs if both terminals are to have reasonable frequencies. For example, if half-hourly service to Fall River and New Bedford each is desired, that already necessitates 4 tph (15-min service) to Stoughton.

I believe half-hourlies to both Fall River and New Bedford would actually create 15-min service all the way to Taunton... which does feel a little aggressive to me, for a city 30 miles away from Boston that hasn't had commuter rail service in 60 years. But hey, if FR and NB have demand for half-hourlies, let's rock and roll.

Franklin/Foxboro trains have via-Fairmount as an additional option, but Providence/Stoughton/SCR/Amtrak trains don't

I agree with your overall point, but, pedantically, there is a NEC->Fairmount connection, currently used by one late night service to Stoughton. But I think your overall point stands.

We don't need to accept these conclusions as facts, just because someone or some agency wrote a report doesn't mean they're automatically correct. There are plenty of double-tracked lines around the world with equal or better service as proposed that manage to do clock-face scheduling just fine despite running 12+ TPH through their core sections, the RER-B and Elizabeth Line are both examples, as I mentioned earlier. There are not enough Amtrak trains in the schedule that make 12TPH a significant problem with quad-tracking between Forest Hills and Readville, as the main bottleneck here is making sure the previous CR train can stop at and leave Ruggles before the Amtrak train behind catches up and this would not take more than 5 minutes, and with either the Readville flyover or local left-hand running options this can be done alongside the reconstruction of Readville station to remove the flat junction. I do not believe that these options have been studied with the depth they deserve, and that they would significantly change the outcome if they were.

Even though you mentioned earlier that 17 tph is achievable in some of the busiest regional rail systems in the world, I have to think it's still cutting it close, especially when such capabilities have not been demonstrated in Boston nor most North American cities (AFAIK).

The Elizabeth Line (and I believe the RER -- certainly RER A, not sure about RER B) have special signaling systems (including with automatic operation on the Elizabeth Line) that allow for high frequencies on dual tracks. (RER A's, IIRC, actually enables a train to enter a station while the train ahead is leaving the station -- how cool is that??)

I'm not optimistic about Boston's ability to garner funding to get something similar deployed on the NEC. London and Paris are among the world's largest metropolitan centers, and are the cores of their respective national economies. Boston is great, but it's not that.

Even for full-length stations, if Franklin Line's running time is a concern, I'm perfectly happy with having them only stop at major stations on Fairmount in order to save time.

Regardless of (a) and (b), my main point here would be: Franklin trains don't necessarily need to stop at the "problematic" infill stations. ...

• Even for full-length stations, if Franklin Line's running time is a concern, I'm perfectly happy with having them only stop at major stations on Fairmount in order to save time. (This may indeed be necessary if Franklin is still running diesel trains while Fairmount runs EMUs.)

One interesting wrinkle here is that, according to the 2018 data (which I think is the most recent we have), the only "major" stop on Fairmount is Fairmount itself:

Or we can categorize Four Corners/Geneva, Uphams Corner, and Newmarket as "minor" stops. But in either case, we're talking about significantly longer distances between express stations, which will cause express trains to have more disruption on the schedule. I definitely think there is a feasible solution somewhere here! I just think the ridership profile poses an interesting question.

(Of course, the Fairmount Line has changed a lot since 2018, so this profile has potentially changed radically.)

 

[Riverside]

#4: High-frequency service to Norwood?

Unlike the 3 earlier points, this is more of a Crazy Transit Pitch than an analysis. I acknowledge that this is mostly a one-man's proposal (though it received some support from @Riverside previously), and as such, is much more open to debate. Regardless, it's not crucial and not closely related to the entire discussion.

The proposal is: Extend some Fairmount trains to Norwood Central (and possibly beyond), creating frequencies of 15 mins or possibly even better. This is intended to be a low-hanging fruit in a world with "quasi rapid transit" on Fairmount Line.

Definitely a *two-man proposal! I haven't emphasized this idea as much myself because I think there are some unique operational and branding questions, to which I still haven't quite found satisfactory answers... but the concept/goal itself is definitely one I support, for all the reasons you cite.

I think there is a similar though weaker argument for similar service levels to Framingham, in terms of density, ridership, and station locations. Like Norwood, assuming a Marlboro branch, Framingham might potentially enjoy 15-min headways anyway.

Interestingly though, the topology of Franklin Line means we may already get 15-min service to Norwood for free. That's automatically achieved if you have half-hourly frequencies to both terminals, Franklin and Foxboro (in a similar setup as SCR). Such frequencies seem enough for me, as I doubt the "Norwood extension" needs as much service as Fairmount Line proper (which sees, say, 10-min or better).

(Emphasis mine.)

I see four tiers for a corridor like this:

• Services with 5-13 minute gaps between trains: show up and go ("SUAG")
  • mimics the rapid transit experience
• Services with 10-20 minute gaps: show up and wait ("SUAW")
  • these can be both viable and valuable, particularly if there is a pleasant cafe to enjoy a cup of tea while you wait 15 minutes for the next train
  • (and IIRC, at least one of the Norwoods already has a cute station building that could serve this purpose)
• Services with 20-40 minute gaps: plan departure, travel whenever ("PDTW")
  • trains are frequent enough that you can be unconstrained in your travel plans...
  • but infrequent enough that you will choose specifically when to leave for the station (station cafes are nice, but no need to hang out for 35 minutes)
• Services with more than 40-minutes between trains: plan travel around schedule ("PTAS")
  • your travel plans are governed (and limited) by the train schedule

These numbers aren't exact, especially in the lower frequency tiers, but are still illustrative.

Historically, the Commuter Rail was PTAS at most times of day, with most services bumping up to PDTW during peak, and a handful rising to SUAW for brief periods during peak. (Historically, the rapid transit system was SUAG; many of the T's current woes result in SUAW service instead -- with some services dropping to PDTW, especially on weekends, but with no public schedule to Plan Departure around.)

The Rail Vision is to move the entire system to PDTW all day. And most of us agree that the goal for Fairmount should be SUAG.

What you and I see in Norwood is the tier between PDTW and SUAG -- the SUAW "show up and wait" model. Now, even if Fairmount reaches SUAG, it'll probably be a low-freq SUAG -- something like 10 or 12-minute headways. If some of those trains continue to Norwood, that creates a SUAW service there, which I think seems pretty well-matched to its character.

Spoiler: using "SUAG" and "SUAW" to distinguish service character

The other thing to note about these tiers is that they allow us to differentiate among 4 tph services. To go back to the Taunton example: yes, half-hourlies to FR and NB could result in a train every fifteen minutes (SUAW)... if the trains are evenly spaced. If, instead, the northbound departures are at :00, :07, :30, :37, then that moves you into the PDTW tier.

And there's a similar (and probably more common) effect at 2 tph: evenly spaced, this is a pleasant PDTW service. Offset (e.g. :00, :10), this turns into a PTAS service.

This general "wobbliness" was one of the reasons I hesitated to trumpet an "Indigo Line to Norwood" concept: a named service like that should be consistently SUAG (or consistently SUAW), but I don't think it should change midway through. So.... "Indigo Line to Readville, Indigoish-Purplish Line to Norwood, Purple Line to Walpole and beyond"?

This is why I opted for a "Purple Line" vs "Central Regional Rail" model in my latest crayon map. Purple Line is SUAG, Central RR is SUAW. (Although, ironically, I sidestepped the Norwood question in that particular map, and kept it in my PDTW/PTAS tier. But, anyway, the concept is the same.)

 

[TheRatmeister]

The Elizabeth Line (and I believe the RER -- certainly RER A, not sure about RER B) have special signaling systems (including with automatic operation on the Elizabeth Line) that allow for high frequencies on dual tracks. (RER A's, IIRC, actually enables a train to enter a station while the train ahead is leaving the station -- how cool is that??)

I'm not optimistic about Boston's ability to garner funding to get something similar deployed on the NEC. London and Paris are among the world's largest metropolitan centers, and are the cores of their respective national economies. Boston is great, but it's not that.

The 12 TPH figure from the Elizabeth Line is not from the core tunnel, it's from the section to the west where trains run alongside mainline services. This section uses signalling anywhere from 30 to 70 years old, and is nothing particularly fancy. 12 TPH is a perfectly achievable throughput for Boston to strive for on the NEC. It would not even be the place on the NEC with the most TPH, that would be (AFAIK) the North River Tunnels with 24TPH.

 

[Teban54]

The 12 TPH figure from the Elizabeth Line is not from the core tunnel, it's from the section to the west where trains run alongside mainline services. This section uses signalling anywhere from 30 to 70 years old, and is nothing particularly fancy. 12 TPH is a perfectly achievable throughput for Boston to strive for on the NEC. It would not even be the place on the NEC with the most TPH, that would be (AFAIK) the North River Tunnels with 24TPH.

I think most of the concerns with 12 tph are with Franklin Line's flat junction, though. Those inbound Franklin trains will have a well-outsized impact on capacity in both directions. (I've already written about why I feel a flying junction may be unrealistic or at least have significant engineering challenges.)

 

[TheRatmeister]

I think most of the concerns with 12 tph are with Franklin Line's flat junction, though. Those inbound Franklin trains will have a well-outsized impact on capacity in both directions. (I've already written about why I feel a flying junction may be unrealistic or at least have significant engineering challenges.)

I did also provide a potential solution without a flying junction, if we're willing to accept an unconventional track layout.