Assuming the T went with the four track NSRL, would a Central Station make sense if it only served two tracks for the Indigo Line/Regional Rail/RER style EMU's? I'm guessing that might limit capacity by dividing the tunnel between EMU's and thru-running Amtrak/whatever dual mode commuter rail abomination ends up shoved down there, but adding a Central Station would be a huge addition to making inner core EMU proposals even closer to being full rapid transit.
That would be a nice thing if it didn't gunk up traffic, because the Urban Rail/"Indigoes" trains are the audience making quick-on/quick-off local trips who'd most utilize Blue. I think for some of the suburban 9-5'ers carrying suitcases the time chewed by getting down sprawly concourses and steep escalators gets them more strategically plotting how to make their transfers before the CBD (hello, Urban Ring!) or just outright preferring the multi-seat transfer at the shallower concourse so they don't have sweat stains on them when they walk into the office. It'll be a slightly less attractive prospect to that audience, so there is some question about how much the transfer is truly going to matter at the money it would cost which in turn is going to heavily influence what the cutoff $$$ is for attempting Central Station. The vertical transportation challenges will induce some *minor* distinctions in rider behavior down in the Link.
Problem with making it Indigoes-weighted is that everything else is still passing through single-file, and with CS being a more constrained station at the absolute depth-of-Hades bottom of the grade the need to time overtakes at crossovers way down there is going to complicate dispatching and make it an even more excruciatingly slow climb back up the grade to SS/NS. It's a much simpler and less conflict-prone operation if everyone just stays on their track and not switch at all until they're at SS or NS and some trains *miserly* may need to jump to a different platform slot to get their trajectory out of the tunnel. So I'm not sure split ops at CS would do more good than harm.
Given that a 2 track NSRL would be easier to fund right away, if you had to play flirt, marry, kill with the three service types (Amtrak intercity/high speed rail, dual mode thru running commuter rail, and "rapid transit" Regional Rail/RER style EMU's) which would you kill?
Amtrak is not going to be using the tunnel with much regularity because of their need for downtime between runs to change crews, restock food service, and (in case of all non-Acelas) loop the train around because they run pull-only and not push-pull in reverse like commuter trains do. That means all Acelas, all Inland Route services, all LD's (if there's more than just the Lake Shore Ltd.), and
most Northeast Regionals are going to be surface-bound for the access to Southampton Yard. You may see the Downeaster run thru the tunnel so it can access Southampton (if they have dual-mode locos by this point), and you may see just a handful of Portland NE Regionals super-extended through the tunnel like the Virginia Regionals (though fewer because Portland<NoVa). You're not talking many tunnel trains at all, and DEFINITELY not the oft-repeated daydream that all Regionals are going to run to Woburn; they have zero interest in dividing their bases like that.
The other throttles will probably be rapid transit expansions. We know Needham has to go Orange/Green because the SW Corridor can't handle the traffic. Orange Line to Reading may seriously have to go on the table because the inner Western Route's single-tracking and grade crossings + the busy Reading Jct. split with the Eastern Route are big capacity crimps. We already know if you do Urban Rail to Reading that Haverhill has to get the heave-ho back to the Lowell Line. Pair-matching amidst those kind of constraints is going to be very difficult, and doubly so when the Eastern Route is ready to accept a motherlode of new slots through that shared Western junction in Somerville.
Ultimately it comes down to a choice. Make very substantial upgrades to CR: reworking the entirety of the Medford-Malden stretch for double-tracking, zap half or more of the Melrose-Reading crossings, quad-track Reading Jct. somehow even though the I-93 decks are going to wreak havoc. Or...extend Orange to Reading with total grade separation and extending Track 3 to Oak Grove on the retired CR track, then retire Reading Jct. so the Eastern Route has all available capacity to load up for bear.
Alon Levy's crunched some numbers on this dilemma, and says hands-down Orange would be cheaper. Mainly for the grade separations. Doing partial but "meaningful" grade separation on RR requires such extended inclines that it bloats the project areas for each individual targeted crossing. Orange, being rapid transit, can handle such steeper grades and much lower-profile crossing eliminations that the project areas for each are very compacted vs. RR and that ends up saving more $$$ than the increased number of
total eliminations. Whether the powers that be will see it this way is up for debate, but we know the corridor has rapid transit-level demand. And if it's going to be real-world cheaper and clean up NSRL by solving a lot of fugly pair-matching underperformance...why the hell not?
I would marry the "rapid transit" line by building Central Station and mainly using the NSRL for connecting the underserved inner core/95 commuter rail zones, but would flirt with the idea of letting some thru running commuter rail into the tunnel. I'd kill Amtrak using the NSRL entirely, and leave additional intercity Amtrak and outer commuter rail slots for the second tube.
You know, if they don't do the stupid "build the same thing twice for twice the price" thing and pool the resources on the CA/T alignment, you
do have a Congress alignment that has been ID'd as a corridor you can tunnel on. The Alts. they're backing are weapons-grade stupid, but that doesn't mean you can't find something worthwhile for Congress.
A few years ago we debated on here the concept of the "Red X"...taking the Red Line Cabot Yard leads, feeding them through the ex-trolley Broadway upper level, then descending into NSRL for a 2-track RR/2-track HRT side-by-side. Ashmont and Braintree would switch off between the old Andrew-Cambridge alignment and the new Broadway-North Station/etc. alignment at double the frequencies so everyone was mainline-grade, and use the Columbia Jct. grade separation to make it conflict-free. The North Station platforms would be built on the second floor above the Orange level, it would travel out a doubled-up Community College portal, and then you could choose your adventure on which of the northside rail ROW's you wanted to take it...possibly tucking in a Community College stop before diverging. GLX-Medford at the time seemed like the most ideal HRT takeover because of the grade separation, ample demand, and fact that it would free up Green for Urban Ring and other branches.
No formal proposal...just a Crazy Transit Pitches debate point. I was sort of enamored with it at the time (before RER was on anyone's brain), but since then I've tilted hard to all 4 tracks being necessary for Purple.
However!...build the not-stupid Alt. with 4 tracks on the CA/T alignment, and Congress still beckons. So how about another "Red X" variant that goes:
- JFK & outbound [Braintree, Ashmont, Alewife, Community College/TBD]
- [split to Cabot leads]
- Broadway Upper [RL Under]
- South Station Under [RL Upper, SL/GL, CR, AMTK]
- Post Office Square
- State (northerly access) [OL, BL]
- Haymarket [GL, OL]
- North Station [GL, OL, CR, AMTK]
- Community College [OL]
- [choose your adventure]
Probably too expensive to be worth it, but something to play around with in the imagination.
Amtrak stopping at Back Bay, South Station, North Station, and then Anderson feels excessive (Does any other city on the NEC have that many closely spaced stops?), plus losing a 1 seat ride through the link is nothing compared to gaining clockfacing and same platform (more or less) transfers throughout the greater Boston area. That ease of transfer and new express routings would greatly appeal to the outer commuters who would see this compromise as gaining faster trips and easier transfers throughout the city.
In addition to the between-run needs detailed above, this is exactly why they have no interest in stopping at Anderson. Amtrak doesn't even hit both ends of the D.C. Capital Beltway, so there's no logic that they would put Route 128 on a higher pedestal. There will be Portland Regionals because that's already a bucket-list item for NNEPRA...albeit on the Inland Route, not NEC. But Portland has a finite audience down the coast so that's not going to be a major player amongst the schedules.
Transit advocates and planners will undoubtedly see this compromise as losing full thru running potential and capacity upgrades, and I know the NSRL is (rightfully) pitched in transit circles as really being about upgrading capacity; but politicians and the media only get excited for connectivity to their area and building "shiny" things like expansions/ new lines. Throw them a brand new "subway" network which not only connects north and south station, but adds a brand new Central Station and infill throughout the inner burbs, and they'll be blown away. Then, once they're comfortable with the NSRL "subway" lines, you introduce pilot programs for more thru running CR and a couple Amtrak slots too, which can be logically pitched into a 2nd tunnel for expanding this wildly popular service (and much needed capacity increases). The pilots and 2nd tunnel could be explained away as skipping Central Station because it's only for the rapid transit line, and you could have your second tube built to skip Central and follow whatever shitty grade is required by the dual-mode commuter rail/intercity stuff like Regionals going to Maine.
This is, in a nutshell, why the messaging on NSRL has been hopelessly bad. TransitMatters is doing yeoman's work cleaning up the talking points, but even they've got to put down their SSX pitchforks because stray stimuli aren't helping keep a laser-like focus. "It's the frequencies, stupid!" is the one talking point that resonates with citizens. And, yes, there is a capacity argument there...but you don't have to even say the word to ram home the point. "Frequencies, frequencies, frequencies!" Ask anyone why they hate their Red Line commute this month and that word is the one difference between a regular commute and the blinding rage we're seeing now. Our pols are literally being clubbed over the head that frequencies are the root of all functional transit. The other elements of NSRL pivot effortless off that or are achieved
through it. But put somebody paid to speak about this in front of a hot mic and they'll seemingly eat their own shoe rather than say the word. Out-of-touch doesn't begin to describe it.
From a ops and transit planning perspective it feels insane to build the NSRL with Central, potentially hamstring future capacity by using separated two track set-ups instead of four tracked optimization of all services, and most importantly to "ignore" the growing capacity nightmare with outer CR and all Amtrak stub ended at the current terminals. From a marketing perspective however, it seems like a no brainer to pitch the NSRL as an entirely new system of rapid transit lines that will not only transform the inner core/95 burbs, but save billions compared to the per mile cost of new transit by utilizing existing tracks/stations except for a tiny tunnel downtown and can be cheaply expanded upon by gradually electrifying more lines and stations.
It's not that Central is a *bad* idea, it's that the geometric constraints are what they are and the price tag is what it is. Even with less-than-full usage because of the shorter platforms it can still be used to a lot of benefit. But it's going to cost a fortune, and I have to wonder how useful the transfers really are going to be from max depth because it's well below Blue while Aquarium is already the deepest station in the system. If it takes 5+ minutes to get to the surface, that's going to throw cold water on its utilization and preferences for direct to Blue vs. two-step to Blue with less footwork. Which then pivots you right back to the cost conundrum because...yeah, it's Blue and you want Blue, but it's something a bit less than 'killer feature' Blue.
