Crazy Transit Pitches

In some of the European cities with major regional airports (Paris, Frankfurt), they have rethought the role of the airport. Rather than just connectors (which exist) they also treat the airport as a full fledged transportation hub in its own right. So these airports have not only connector service into the city, they also have TGV or ICE through or originating high-speed service that connects them regionally. The airport as transportation hub concept is so ingrained now that you can book combination air/train connecting tickets.

It's not possible to drag Amtrak service out to Logan with the way it is located. Your argument against the SL in essence contradicts itself when you start talking about making easy regional rail connections from the airport. Logan IS connected to South Station/Commuter Rail & Amtrak service via an easy (terminal-side pickup!) 1-seat FREE ride on the SL1.

We don't have a situation like Berlin where they're landlocked and can easily drag additional S-Bahn service down to a new (farther away) main airport (BER) simply by drawing a line across the ground.
 
^^ Looks like the map isn't public, asap_mozart. I get a 403 error, telling me I don't have permission.
 
Here's what I don't get about the cost of typical underwater tunnel construction. As I understand it, the general process is:

1) Dredge harbor
2) Float pre-assembled tunnel segments into place, sink them
3) Cover tunnel segments with silt
4) Pump out new tunnel
5) Connect to tunnel segments on either side

I see how #5 can balloon in cost, but dredging a channel has been going on for centuries and at this point is pretty routine, while pre-assembly of the tunnel segments seems like it would drastically cut down on labor and underwater construction difficulties.

So why are building underwater tunnels still such a big hassle?
 
Build the Urban Ring LRT with a terminal loop if we're concerned that SL1 sucks. When I said more of the same, THAT was a necessary and very non-optional part of more of the same beefing up the robustness of Logan Airport transit.

The point still stands:

-- Logan isn't in the CBD. It's on a landfilled peninsula jutting into the Harbor. You can't change basic geography and make it a de facto part of the CBD by distorting the transit system. The transit system isn't anchored there because it has never been part of the CBD. People go to Logan because they have to go to fly, pick up somebody, perform some other aviation-related job function, or something else which is indirectly tethered to the airport. That is a very small subset of the reasons to stop in Boston on regional rail.

-- The area in 1 sq. mile of South Station and 1 sq. mile of North Station encompass just about all the CBD, and every single major transit line intersects in that area. There are eight bazillion reasons people travel there. There is only a limited set of reasons why they travel to Logan.

-- EVERY line on the commuter rail network converges on the CBD. You cannot have a functioning regional rail system with the entirety of the southside running up the Eastern Route. Which is not even the line with the best run-thru options, most intercity connections, or a direct and well-positioned hit on Route 128 to anchor the whole metro area. That is not a bug with Logan's location. Logan can only handle the capacity it does because of its location surrounded on 3 sides by water. I don't understand the need to force-fit something that defeats the entire purpose of run-thru regional rail by excluding that much of the system with no viable workaround. Nor do I understand force-fitting something down Track 61 into another cross-harbor bore when that misses South Station and the single-track NEC wye and crossover through the nerve center of Southampton Yard leaves no run-thru capacity for anything but Eastern Route<-->Old Colony. That's not regional rail. You want run-thru regional rail...where is the regional rail part?

-- It is very wobbly to compare airport access between cities because the geography is not the same in any two cities. You couldn't imprint an exact operational replica of ICE or S-bahn on Boston and drastically change Logan's situation. It is still outside the CBD and there is still a "can't get there from here" geographic blocker to hooking all manner of regional rail from its southside converging point to a cross-harbor peninsula, to the northside diverging point on the regional rail system. It is what it is. Sample the 100 largest airports in the world and--conservatively--80% of them get eliminated on geography from the kind of service perfection being sought here. No two airports are positioned alike or thread the needle alike to their city's CBD and transit hubs. A regional rail route that leaves out large parts of the regional rail system by geographic impossibility is not going to generate enough ridership by its limited hook-ins to be worth the disruption of distorting the city's homegrown transit orientation.

-- America ≠ Europe. We don't use public transit to airports the same way. Maybe that is a character flaw in America, but what exactly does anyone plan to do about that? Mass cultural re-education? Compulsory transit ridership? Sorry...our needs for better and 'good enough' CBD<-->Logan access are a hell of a lot shorter-term than changing travel culture in 50 U.S. states. My entire point for those citations in the last post was that a lot of North American cities are wasting tons of money banking on "if you build it, they will come" airport connectors that don't perform so hot on the "they will come" part after all the steel in concrete is sunk cost. Culture doesn't change that easily, and U.S. travelers are U.S. travelers. Not European, not Japanese. My eyes start to glaze over when people cite S-bahn, ICE, TGV, or Shinkansen, etc.--or, worse, some cherry-picked Chinese menu of all-of-the-above to take only the pros with none of each individual system's cons--as something that MUST...BE...REPLICATED here or else we have failed as a society. That blogger I linked, Alon Levy, has a severe blind spot for doing that and getting really indignant about it which clouds his otherwise immaculately-substantiated judgement in some of his posts. Each homegrown system is homegrown for the way its people travel. And they each have pros/cons. Now, the U.S. can adapt a shitload of best practices to reform the country's transportation system. But the country's transportation system is still going to be uniquely American. We have a legacy rail system, a disproportionately large legacy road network that's not going away, we have mature clustered density around a lot of those rail and road corridors that lends itself to mainly evolutionary and not revolutionary rethinking, we have the largest % of freight traffic as function of total rail traffic in the world and like it or not FRA regs are an existential necessity (if not exactly well-executed) for the U.S. economy, our geography is what it is and covers a lot more ground than other countries...and we use the infrastructure to suit our needs. It's pointless Transit OCD to project other countries onto this one, other cities onto this one, and makes apples-apples comparisons with apples-oranges as an indictment of our transit planning. There is PLENTY to indict with transit planning in this country/state/city purely for not serving the homegrown needs of this country/state/city without having to cherry-pick those arguments from unlike regions of the world. We're trying to make the best MBTA the MBTA can be, and best Logan that Logan can be...so they both can serve Boston, Massachusetts, and New England the best they can be. Last I checked the S-bahn didn't serve Massachusetts.

-- Some sanity needs to prevail on this. Tactical nuclear strikes like Big Dig-costly cross-harbor tunnels at the longest-distance possible water crossing or nuking the existing tunnels converging around South Station to peel out at a more convenient place are as pointless as landfilling the whole damn inner Harbor to make a land-bridge to Logan shackling it to the CBD. Want to get something solved? Drop the Transit OCD pretenses and get to work building the Urban Ring, get to work expanding existing service, get to work building the cross-CBD regional rail link between the two regional rail convergence points. Our Logan access will be 10x better for it. Is that more palatable than building nothing for 50 years longer because that something is someone's idea of Transit OCD perfection? What's that wait going to do to the Boston economy?
 
Here's what I don't get about the cost of typical underwater tunnel construction. As I understand it, the general process is:

1) Dredge harbor
2) Float pre-assembled tunnel segments into place, sink them
3) Cover tunnel segments with silt
4) Pump out new tunnel
5) Connect to tunnel segments on either side

I see how #5 can balloon in cost, but dredging a channel has been going on for centuries and at this point is pretty routine, while pre-assembly of the tunnel segments seems like it would drastically cut down on labor and underwater construction difficulties.

So why are building underwater tunnels still such a big hassle?

Everywhere under the Harbor is geologically different from everywhere else under the Harbor. We live on a glacial debris pile scraped off the mountains from Worcester County to New Hampshire to Eastern CT to Maine, and Boston Harbor is another dumping ground for boulders, silt, and other crud that came from umpteen different inland regions. We know that from the unique challenges of building on the east-facing shoreline how the native bedrock is pretty far down and the terra firma we stand on just a pile of mush and rubble. Boston Harbor is exactly the same. What you encounter in the soil on the man-made shoreline is different from what you encounter in the soil 200 ft. into the water, different from what's 200 ft. beyond that, different from what man-made landfill was dumped at a different time in history to create the opposing shoreline.

So it's a spurious assumption that sunk tunnel casings will work on every alignment. The Ted got relatively lucky there. The Pike-to-Ted tunnel was under the wholly man-made Ft. Point Channel, which was uniform landfilling done at the same point in history. Those parts of the Big Dig were easier tunneling than the I-93 cut-and-cover which passed through a bunch of different and poorly-documented generations of landfilling + glacial refuse. We're way different from NYC in that regard where there are a number of unbuilt cross-harbor and cross-Hudson tunnels studied and actively kicking around as proposals. Most of the rock in NYC was original bedrock that the glaciers helpfully scraped off clean. It's a lot more homogenous vs. the over-full dumpster the glaciers made Boston Harbor to be, and they can make better up-front assumptions about engineering and cost than we ever can.

There's a reason why the Blue tunnel, Sumner/Callahan, and Ted all took the shortest possible paths across the water and jumped off in the middle of high-density (or formerly high-density) wharf districts that were wholly man-made out of landfill and were dredged over and over again for shipping channels long before the tunnels were built. Those tunnels spend the maximum possible time in man-made landfill and minimum-possible time in glacial soil. But those 4 tunnels have taken up all the prime alignments, and boxed in new alignments to a pretty limited range (between Ted and Callahan at a much wider point in the Harbor that doesn't intersect any ex- wharf districts or previously-dredged shipping channels at perfect right angles. You can't assume that cross-Harbor tunnel #5 is going to be a cinch for precast segments when the remaining alignments are longer, at more oblique angles across shipping channels, and don't have as much ex-wharf fill to choose from. Some boulder field under open water may be a no-go for precast segments and have to be dug out from below. And your only other alternative for finding an easier alignment is getting on the other side of these pre-existing tunnels, which is going to limit you to deep boring and very expensive underpinning of pre-existing structures.


There might be an easy option if a very detailed geological assessment finds one. But I think we're extremely overestimating how numerous those options are. And how trivial the geological inventory would be on some of those longer oblique-angle alignments. I would say the same about all these proposals to sink the Tobin with a tunnel on an entirely different--and never-before tunneled--part of the Harbor.


You might only be able to build an SL1 replacement tunnel adjacent to the Ted on that precious little 350 ft. of available land to the west of it (since you have to pass directly under the far deeper Ted to get the shallower Transitway on the east side). And that's probably not going to work with sunk tunnel casings because of how perilously close it would be to the parallel active Ted. It would be a delicate job. Delicate and many times more expensive.

They probably do not want to do this until Urban Ring LRT flanking the northern route to Logan is not only built but maxed out to a point where it forces the issue. Nor is there any reason to until they build and saturate an entirely surface UR. So put the energy on that one, because the decision to omit the transit bore from the Ted was done and irreversible 25 years ago and there's no reason to do more radical cross-Harbor surgery until the (quite very good) potential surface options have exhausted themselves.
 
Here's my ideas as stated before, w/ working link this time

https://mapsengine.google.com/map/u/0/edit?mid=zHBKbWS6THfI.kAbqEnxMW1JQ

Tunneling under Eastie is not going to work. Dense residential in Eastie is all landfill mush just like Back Bay, and just as awful to subway under with the required drainage infrastructure (esp. the deeper you go) and unintended/unpredictable impacts to surface structures. There is no way you can slice across property lines at bad angles like that under landfill. All our other landfill tunneling follows the street grid more or less religiously (including I-93 built under old I-93). You must follow the street grid at cut-and-cover level, and the street grid here completely blows for tunneling with how narrow it is and how sharp the turns are for getting across.

That's a good +$3B more than as-designed surface Urban Ring, passing up the high ridership at Sullivan, Everett, and Chelsea, for a direct with hardly any time savings over the designed route. Most of those supposedly advantageous time savings come from omitting all the highest-ridership stops. Which directly hurts ridership. Flunks on cost, flunks on ridership, flunking cost and ridership makes for terrible bang-for-buck vs. the alternatives, it makes the same exact mistake other U.S. airport connectors make (as cited in that blog link) by passing up CBD destinations with much higher general-purpose utilization vs. a single-purpose airport, and it's operationally fugly with how constrained the tunnel has to be in the mush under that street grid.

The as-designed UR alignment is about as good as it gets for balancing all the needs for an airport connector, general-purpose radial collector, and downtown transfer. Shorting any which stakeholder for a more- mapmakers' perfection other alignment serving only one stakeholder leads to worse transit. Like it or not, all of Boston's transit lines and needed transit lines serve many masters. We're not a collection of single-tasking corridors (in fact, that's one of the more common indictments of SL1, though alignment limits it being much more than that). What's the motivation for building more imbalanced transit that doesn't go where all its potential users need it to go?

Perfect is the enemy of good here. A northside airport connector that doesn't scoop up any transfers or any surrounding neighborhoods for the sake of shaving 2 minutes off...is flat-out lousy transit.
 
Most of the rock in NYC was original bedrock that the glaciers helpfully scraped off clean. It's a lot more homogenous vs. the over-full dumpster the glaciers made Boston Harbor to be, and they can make better up-front assumptions about engineering and cost than we ever can.

And that's worked out great for them...

(yea yea, NYC corruption and incompetence is the stuff of legends...)
 
The SL1 could be "fixed" at a much lower cost than a new airport connector.

- Sign a lane in for bus / taxi in tunnel (and anywhere at the airport that would make SL1 faster
- Negotiate for use of the the state police EB ramp
- Dig a new WB offramp from I-90 directly to silver line way
- Figure out how to make buses go faster in the transitway
 
Here's my ideas as stated before, w/ working link this time

https://mapsengine.google.com/map/u/0/edit?mid=zHBKbWS6THfI.kAbqEnxMW1JQ

As far as the LRV system you have; F-Line touched on why tunneling in Eastie is a no-go, same goes for your Dartmouth subway. Imagine the denizens of Back Bay/South End not only putting up with the construction of a cut-cover subway down Dartmouth, but also facing umpteen more opportunities for "Arlington Station elevator" style disruptions to structures on the surface. No-go.

Tunneling under I-93 north to Medford is probably a no-go as well. Really close to the Mystic River, under an active interstate, and completely unstudied.

The Blue Line spur is possible as some sort of transit-way, but your westward expansion is never happening. If any of the Green Line branches get taken over by HRT it will be Riverside, not Boston College.

Orange Line works too, but probably works better as a GLX urban ring segment.
 
I dont see what all the fuss is about the airport... the airport is accessible already... what I wonder about in terms of the Blue Line/Eastie/landfill, is how hard would it be to have Blue Line tunnel branching north under Meridian Street to downtown Chelsea? Seems like it could be done adhering to the street grid pretty easily...

Edit: basically, the whole SL to Chelsea doesnt sound THAT bad, but with waterfront all along East Boston/Meridien that will be developed, plus density to the east, seems like a good corridor (though I know it's not REALLY justifiable quite yet as a tunnel). But bottom line is downtown Chelsea deserves a subway station. Its ridiculous there isnt one now.
 
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I dont see what all the fuss is about the airport... the airport is accessible already... what I wonder about in terms of the Blue Line/Eastie/landfill, is how hard would it be to have Blue Line tunnel branching north under Meridian Street to downtown Chelsea? Seems like it could be done adhering to the street grid pretty easily...

Edit: basically, the whole SL to Chelsea doesnt sound THAT bad, but with waterfront all along East Boston/Meridien that will be developed, plus density to the east, seems like a good corridor (though I know it's not REALLY justifiable quite yet as a tunnel). But bottom line is downtown Chelsea deserves a subway station. Its ridiculous there isnt one now.

Eastie is made up of 5 ex- Harbor Islands that were landfilled into a contiguous landmass (http://dspace.mit.edu/bitstream/handle/1721.1/68733/24917724.pdf?sequence=1, p. 10). Noodle's Island, the biggest, had a west shoreline at Meridian St.; north shoreline at W. Eagle/E. Eagle and Chelsea St. (Eagle Hill basically a rock outcrop sticking into the Harbor); south shoreline at Sumner St. (with Maverick Sq. the "port") with a peninsula sticking east framed by Maverick St., Marginal St., and Jeffries St.; east shoreline at Brennan + Bennington; and NE shoreline at about Addison. Breed's Island was the area of Orient Heights. 3 small islands are buried underneath the Logan Terminals and tarmac. Basically all uninhabited land used only as cow pasture and military installation prior to War of 1812. Company got chartered right before the war to start the landfilling process.

So those are the only places with terra firma underneath. The islands (and later Winthrop) were all connected by a first wave of landfills. The 3 blocks worth of ex-wharves west of Meridian and south of Sumner were landfilled for the port. The area around Global Petroleum was landfilled to create Chelsea Creek as a controllable shipping channel and build roads to Chelsea. And the vast expanse around Suffolk Downs was landfilled to get the railroad into town (for a couple decades there was a primitive sort of people-mover lightweight suspension railway crossing the water into Revere as the only land transportation into Eastie). Logan runways were all 20th century additions, and I think the edges were buffed out 15 years ago by some surplus Big Dig fill.


You've got solid bedrock underneath Eagle Hill for tunneling. Unfortunately getting there is not so easy when Meridian St. on one side and Brennen St. on the other were beaches and that triangular wedge between Bennington, Brennen, and Route 1A at the tollbooths was salt marsh. The Blue Line tunnel, Sumner, and Callahan already picked the only bedrock outcrop on the south end of ex-Noodle's Island for touchdown at Maverick Sq. terra firma. And the Ted touches down at tiny ex-Bird Island, only several hundred square feet and buried under the Logan tarmac (basically where the Ted crosses Harborside Dr. under the building across the street from the Ferry Terminal).

You can see what limited options that leaves. Basically, if you want a Transitway tube you've got to build it just a few feet west of the Ted to anchor on any of the bedrock remnants of Bird Island, with all the delicate construction that entails next to the active Ted. There are no particularly good alignments between the Ted and Blue Line tunnel except for the one crossing maximum distance of water between Northern Ave. and the ex-peninsula east of Maverick. Doable but billions more expensive because it's the longest possible water crossing, and caveat emptor at what you encounter in non-human/glacial fill under the deepest Inner Harbor water. North...you have Eagle Hill to anchor, but how are you going to get between there and a portal-up at Logan Station under old salt marsh that's now all that hyper-dense Bennington-vicinity residential? Or portal-under from the Charlestown side when Moran Terminal and everything east of Sullivan and north of Medford St. is itself landfill (note this well for all those Tobin-replacement Crazy Transit Pitches)? Or fork the Blue Line to downtown Chelsea when the current Blue portal is basically at the outer extent of the bedrock before it turns into salt marsh and the Chelsea Creek crossing on both sides is a particularly wide swath of shipping port-related fill?

The best route you've got other than right on the other side of the Ted wall is Chelsea St. crossing the creek. Which...tada!...happens to be the as-designed UR route that requires no tunneling whatsoever and hits all the big transfer density. And yes, due to what I said above about the maximum amount of under-landfill tunneling the Blue path to downtown Chelsea has around the Creek you'd better be looking at bus transfer-related solutions to the UR stop out of geological necessity.
 
Is there a MBTA sponsered map of the urban ring anyone could link to me? Haven't had any luck in finding it
 
The DOT Urban Ring website has been down for a while. I think F-line posted an image of the state's conceptual routings a while back, but I can't seem to find them.
 
Is there a MBTA sponsered map of the urban ring anyone could link to me? Haven't had any luck in finding it

They did a (now very outdated) DEIR for BRT Phase II with maps. . .

BRT Phase II map: http://www.massdot.state.ma.us/theurbanring/images/LPA_Figure.pdf

BRT Phase II station detail: http://www.massdot.state.ma.us/theurbanring/downloads/Plan_Profile_Drawings.pdf

This is the non-grade separated, BRT "preferred alternative". Not Phase III total/near-total grade separation, not LRT. The mixed-traffic routings and deviations off rail ROW's obviously wouldn't be there on an LRT build, and would go away when it's Phase III time. No tunnels except that real dubious-looking thing plowing through Longwood. The station siting schematics are so old they're almost worthless, as a decade-later reboot of the study is probably going to get the stakeholders asking for completely different things than they did last time.




Notes:
-- Everything's approximate subject to further study...and pretty outdated at this point as you'll see below.

-- The tunnel was studied before their engineering problems mounted on Silver Line Phase III design and killed that project. Hence, streets this narrow and that sharp S-curve under Huntington are 90% likely to be no-go's if/when they pick this back up. That's a condition that's changed with new information in the years since requiring a re-study.

-- In LRT they would not do all that mixed-traffic travel Lechmere-Sullivan-Assembly-Wellington. With no available off-road ROW's to make every single one of those stops on rail, the Wellington jog pretty much has to get dropped in favor of something glued to the Eastern Route all the way. The GLX carhouse final alternative didn't exist at all back then, so the route from Lechmere to Sullivan is obviously locked by GLX onto one alignment they didn't know much about back then. Routings by necessity will differ by rail or rubber tire mode. Don't assume this official map is a straightjacket you can't deviate from on trolleys. It's colored Yellow for a reason.

-- In LRT the Ring wouldn't deviate off the Grand Junction at Main St. for the rest of the trip to Lechmere, loop around the block at Kendall, and go down Land Blvd. It would stay on the GJ all the way. BRT and LRT routings differ by necessity.

-- Obviously that long ago they had no clue what the plan was around Beacon Park. Hence the crazy napkin scribbles on the Harvard spur.

-- They had no idea at the time whether they needed to hit Brookline Village or skip it and cut straight down Brookline Ave. to the Kenmore bus shelter. Brookline Vill. was predicated on creating a parallel busway next to the D tracks. That is probably going to be impossible because:
* You'd have to blow up a chunk of the Landmark Ctr. garage to make it happen. The Landmark and surrounding development have gotten much huger since the study. Changed condition they have to re-study.
* Tall development next to Yawkey Station on the Fenway Ctr. parcel is a near-certainty to permanently narrow the former freight ROW too much to fit buses. If it ain't wider than this at the end of the existing Fenway Station path, there's no way to run 2 lanes of buses. They assumed the UR would be in advanced design before the buildings and that they'd have the property acquisition funded to grab the extra strips of land beforehand. Things have changed.
* Busways next to active rail ROW's are always more complex than anticipated. Connecticut is finding that out the hard way right now with its billion-dollar busway to nowhere mere feet from the Amtrak tracks, which keeps getting its speeds knocked down further and further from the width constraints. New information they didn't have when they did the study and will have to apply new metrics to. I would be mildly concerned about Silver Line Gateway BRT along the Eastern Route running into the same performance problems and related cost bloat...but that isn't anywhere near as constrained a space as the D around the Fenway platforms and the old freight ROW that's been reduced to alley width by new buildings.
* Olmstead would turn over in his grave if his handiwork got sliced up by a road on top of a double-wide (+ BRT buffer) D ROW. And there'll be an army of preservationists--some with very deep pockets--waging war on his behalf. Tall order for BRT.

-- Save for the on-road Sullivan-Assembly-Wellington jog off the rail alignment, the Chelsea-Logan segment is pretty much exactly the same BRT or LRT, exactly the same as Silver Line Gateway, and does build some sort of brand new grade separation at the Logan Terminal stops. So...1:1 with what we've been talking about here in various threads. Obviously with all-LRT it would stay bolted to the Eastern Route all the way to Assembly and omit the L-shaped Wellington detour.

-- Note it doesn't even enter the Transitway and just stops on the surface at WTC. They didn't exactly scope out service patterns too well here or break the patterns into likely segments...it just looks like a neverending one-seat loop. Further study would have to flesh out where the termini truly are. Good chance that they're going to want to tie it into the Transitway here for the direct free SS transfer the way the Seaport's growing now vs. 6-9 years ago when they were modeling this. Which in turn could change the routing of the entire SE quadrant + JFK spur. That SE quadrant was always the least fleshed-out part of the plan under any mode and most subject to change. You can see from all the mixed-running with nothing but a bike lane stripe that there's almost nothing in the way of permanent structures with that part of the build.
 
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Really appreciate the commentary, F-Line. Don't mean to burden you--but if you found the time to put this in a map (or maybe repost one of your older UR maps?) I, and the rest of AB I'm sure, would be much obliged.
 
It pisses me off to no end that the plan is/was BRT with a later conversion to LRV when so much of the existing infrastructure/ROW is already set up perfectly for sticking with green line. It just seems so much more sensible to take advantage whats already in place from the get go than going with a shittier option and trying to save face by saying "we may convert 20 years down the road".
 
Really appreciate the commentary, F-Line. Don't mean to burden you--but if you found the time to put this in a map (or maybe repost one of your older UR maps?) I, and the rest of AB I'm sure, would be much obliged.

Here's a couple versions of UR mapped out.

Version 1 has all the craaazy cross-Brookline/LMA tunneling, plus a highly speculative routing along the Southie Bypass ROW.

Version 2 is the most do-able (particularly everything from the Airport to Dudley). There's also my preferred station placements as well as a likely spur to Harvard.
 
I think the ring service that could be most beneficial operationally would be this:

2ugDXz4.png


Basically it's a loop around the Charles (and therefore through the Boston/Cambridge CBD) using the existing central subway, B line (buried or elevated to the BU bridge) and the Grand Junction, connecting in to and sharing tracks with every other Green Line service.

To me, there's far more ridership potential here than the hypothetical boomerang around Kenmore to link the GJ to the E.

And yes, I'm aware that this really serves the north side of the urban ring only, but that's where I think the demand for the ring comes from more than the south side - for which the F Line Dudley is probably a better investment than a ring route anyway.
 

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