Last summer, I wrote that 2022 marks the (true) centennial of the Green Line, with the 1922 opening of the Lechmere transfer station commencing a transition from the “local streetcar network” model to the “rapid transit” model. I point to the rapid demise of the streetcar network in the ensuing two decades as evidence of an intentional transformation.
Understanding the pre-transformation network
To understand the scope and scale of that transformation, it’s worth looking at what the “subway-streetcar network” looked like immediately before that transformation. One might think that that would be a simple task: simply Google 1921 BERy map boston and this is the first result:
Except… this map doesn’t tell the whole story. A little bit of further digging reveals that many of the surface lines on this map didn’t actually operate into the subway – the far-flung lines in West Roxbury, for example. Moreover, this map omits the foreign cars that weren’t run by the Boston Elevated Railway but still operated into the subway, turning at the Brattle Loop.
Finding the “subway-streetcar routes”
Identifying which routes operated into the subway 101 years ago is actually not a simple task. Again, I believe this is a consequence of how BERy saw the Tremont Street Subway: it wasn’t a rapid transit line and it wasn’t a “trunk” of the network – it was just a way to get streetcars off of congested streets in downtown. From what I’ve seen, it probably never would have even occurred to BERy officials to publish a map of the “subway-streetcar network” – they were all just “surface lines”.
Making matters more difficult is that BERy also did not (to my knowledge) publish public timetables for specific routes. There were internal timetables, though my understanding is that they were very internal indeed, and are difficult to parse a century later. Most notifications of changes in routes, for example, appear to have occurred in newspaper announcements.
The Map
Here I am indebted to the labors of love of numerous local transit historians. Building on their work, I have created what I believe is the first map of its kind: a full diagram of all BERy services that offered one-seat rides into the downtown subways in 1921.
Click to enlarge
Applying the anachronistic visual language of today’s Green Line and Blue Line, I’ve framed the 1921 network with modern points-of-reference, to make it easier to understand its scope and complexity.
Again, it’s important to understand that this diagram does not represent how BERy officials or riders would have conceptualized their system. However, thinking of the streetcar network in these terms is also vital for understanding the decline of Boston’s streetcar network (which began much earlier than we often think of it as.)
List of Routes
The routes operating into the subways included the following (note that many routes had short-turn turnbacks, the same way some trains on today’s E Line terminate at Brigham Circle); I have included some modern comparisons based on today’s routes in parentheses:
Kenmore Portal lines
Watertown (57)
Lake Street [Boston College] via Commonwealth Ave (B)
Reservoir [Cleveland Circle] via Beacon Street (C)
Ipswich Street lines
Chestnut Hill and the Cypress St Carhouse (55 + 60)
Huntington Ave lines
Lake Street [Boston College] via Village Sq [Brookline Village] (E + 65)
Jamaica Plain Carhouse (just south of Jamaica St) (E + 39, but not all the way to Arborway/Forest Hills)
Pleasant St Portal lines
Egleston (43)
Dudley [Nubian] (similar to SL5, but on Dover St [East Berkeley St] from Washington to Tremont)
City Point (9)
East Boston lines
Central Square, Cambridge via Joy St Portal (no equivalent, but somewhat similar to the proposed Blue-Red Connector)
Jefferies Point (120)
East Boston and Chelsea (114/116/117, 112, and 121)
Orient Heights (120)
Revere Beach (paralleling the route of today’s Blue Line on Bennington St and Ocean Ave)
Lechmere lines
Harvard (69)
Davis, and Clarendon Hill, via Somerville Ave or Highland Ave (87 and 88)
Canal Street Incline lines
Sullivan via Main St (92)
Sullivan via Bunker Hill (93)
Foreign streetcars
Beachmont (using part of today’s 119)
Revere Beach (116 and 117)
Lynn (probably most similar to today’s 455)
Salem and the North Shore (450)
Woodlawn (111)
Melrose Highlands via Malden & Chelsea (I believe roughly using today’s 131 north of Malden Center)
Acknowledgements
This has been a gargantuan project, far more perhaps than the map itself would suggest. The details needed to pinpoint the system exactly as it existed in 1921 are numerous and scattered. As in my previous post, I must heartily thank the army of transit historians who have come before me, including Ron Newman, Bradley Clarke, O.R. Cummings, Frank Cheney, and Anthony Sammarco.
I want to extend a special thanks to DAS, who has expertly collated the primary source material upon much of this map is based, enabling us to expand, contextualize, and occasionally correct the work done by Newman, Clarke, Cummings, Cheney, Sammarco, and others. His expert review caught many errors of mine, answered numerous arcane questions of mine, and uncovered the fine details at the margins of this project to ensure this map was as accurate as possible.
When I was a child, reading the copy of Trolleys Under The Hub my parents had given me, my imagination was enchanted by the idea of a “Green Line” that apparently had so many branches. This is the map that I had wanted to see then, so it is a profound delight to finally see it brought to life; as such, I offer my profound thanks to all those who helped me create it.
Notes and Further Reading
As printed in the image:
Services on this map operated into the Tremont Street Subway and the East Boston Tunnel in 1921.
Street names included here are illustrative and not exhaustive; some routes used additional streets not marked.
Additional transfer points existed but are not shown here.
Huntington and Ipswich services ran at street level along Boylston, paralleling the subway below.
Additional surface-only services ran over shared stretches of track, but are not marked here (for example, an Allston-Dudley service that ran through Village Square).
Services intermingled in the Central Subway, and sometimes were through-routed on to new routes once exiting the subway as needed.
Occasional additional suburban services may have been through-routed in the subway (for example, from Arlington), but these services appear to have been irregular.
Some foreign transfers may have been available at additional locations than are marked here (e.g. Watertown, which likely almost certainly had transfers to the Middlesex & Boston Street Railway).
Tracking down which routes were running into the subway in 1921 was surprisingly difficult. When possible, I’ve used primary sources, but in some cases have relied on secondary sources, particularly since some transit historians have obtained access to archive materials that are more difficult to access remotely or as a member of the public.
I did a poor job of cataloguing my references when building this map. As such, I am currently in the process of rebuilding the reference list for this post. My WIP reference list is available as an appendix to this post.
Everything old is new again. The T is, once again, shuttering significant parts of its network this summer, in order to accommodate maintenance and construction. The Red Line is seeing a string of late evening closures, while the Green Line is seeing much longer shutdowns — including over 40 days of closure on the Union Square branch.
Naturally, I have made some maps.
(I didn’t want to sink too much time into this project, so the maps below are not free from imperfection.)
During this period, the Union Sq shutdown will overlap with a bustitution of the B Line.
The T will apparently not be providing a shuttle for the Union Sq branch, instead directing riders to local bus routes with transfers at Lechmere and East Somerville. I’ve tried to illustrate those here. Alas, it is a bit cramped.
Phase 2: July 29 – August 9
Following the resumption of service on the B Line, a complete shutdown of service between North Station and Government Center will be instituted to accommodate demolition work on the Government Center Garage. It appears that no shuttle will be provided, and the T’s advice is simply to walk from one station to the other.
Phase 3: August 10 – August 28
During these two-and-a-half weeks, the core segment will be restored and the only ongoing long-term disruption will be the unshuttled closure of the Union Sq branch.
In an effort to provide more frequent service to the three stations in Newton, I’ve developed a rework of the Framingham/Worcester Line schedule; there are lots of open questions that I can’t answer at this point, but from what information I do have, I believe the rework would be feasible, and would in fact improve service for the majority of riders on the line.
I propose switching from a “zonal express” model to a “skip-stop” model; this would keep travel times under control, while enabling trains to stop more frequently within the higher density suburb of Newton. Based on my analysis, this would require no additional rolling stock, and possibly may be able to use one fewer train than today. Operational expenses would potentially increase mildly, but no capital expenditures should be required to enable this proposed schedule, aside from the already-underway Worcester Union Station platform project.
Here is a tentative draft of my proposed schedule; background, methodology, and details described below.
proposed skip-stop schedule
Background and current conditions
The Framingham/Worcester Line is a difficult line to run. It presents multiple challenges:
It is long: about 43 miles as the crow flies from Worcester to Boston – comparable to the Providence Line (measured from Providence)
But, unlike the Providence Line, which has lengthy straightaway segments, the Worcester Line has curves aplenty, including a pair of modestly tight S-curves as the rails wind their way into Worcester
It has lots of stops: 15 between Worcester and Back Bay (compared to 8 on the Providence Line)
It has operational constraints due to the locations of platforms (see this post by Dave Perry explaining the track numbers, and detailing some of the operational constraints):
“The Newtons” (Newtonville, West Newton, Auburndale) currently have platforms only on Track 2
At Wellesley Hills and West Natick, the parking lots are located next to the platform on Track 2; the platform for Track 1 is only accessible via an at-grade crossing across the tracks
The T therefore runs all peak direction trains on Track 2 through these stations to avoid having large crowds of commuters crossing live tracks
Worcester’s platform is currently only accessible from Track 1, though the T is building a center platform to allow access from both tracks and enable more than one train to occupy the station at once
The T addresses these challenges through two methods.
First, peak direction trains are divided into “Worcester expresses” and “Framingham locals”, where hourly trains depart from Worcester and make all stops to West Natick before expressing to Boston Landing, while offset hourly trains depart from Framingham and make all local stops. A single “Heart to Hub” (or “H2H”) train leaves Worcester and runs express to Framingham and then express again to Lansdowne, to provide Worcester commuters an option that arrives within Boston’s borders in less than an hour. (Journey time to South Station is 1h5m.)
current schedule
Second, to accommodate the single platforms at the Newtons, as well as the pedestrian-unfriendly conditions at Wellesley Hills and West Natick, the T runs all peak-direction trains on Track 2 between Framingham and Boston. In essence, Track 2 acts as the “inbound” track in the morning and transforms into the “outbound” track in the afternoon.
Reaching toward frequent Regional Rail service for the Newtons
This project began with an effort to identify ways to increase the frequency of service to the Newtons, which sit in modestly walkable neighborhoods of similar density to the villages served by the Green Line to the south, but which only see hourly service during rush hour.
What’s more, there are trains running through these stations during rush hour, roughly every thirty minutes; the problem is that those Worcester expresses run non-stop in order to keep travel times down for the longer commutes.
If only there were a way for those Worcester expresses to stop at the Newtons without impacting the commute times for riders west of Framingham.
Then something occurred to me: what about a skip-stop service?
Skip-Stop Services
For those unfamiliar, skip-stop services are a technique to speed up journeys on lengthy routes by dividing trainsets into two groups, with consecutive stations alternating between the two groups, punctuated by periodic “all trains” stops served by both groups.
Skip-stop service was used throughout the 20th century on major American subways. New York, Chicago, and Philadelphia all used skip-stop patterns to varying extents, though today I believe only one set of services remains in use (the J/Z in New York). They have fallen out of favor in part because they make the system more confusing for new riders and because (in my opinion) the time savings on a rapid transit system simply aren’t particularly large. And particularly for “local” journeys on a subway line – e.g. in New York if you’re only looking to go 30 blocks, about 3 stops – skip-stop service is much more disruptive, requiring a transfer.
Skip-stop service potentially can be effective, but it needs to be on a corridor where there are both significant time-savings and minimal intra-corridor (“local”) journeys.
So, I wondered, could skip-stop service patterns generate enough time-savings to “free up” space in the schedule for Worcester expresses to stop at the Newtons?
Assign stations to different service groups (e.g. “A” or “B”)
Set each train’s departure times from Worcester
Assign each train to one of the service groups
And from there, the spreadsheet will auto-generate the schedule for each train. Critically, this spreadsheet takes into account the time-savings from skipping a stop. (It also takes into account the significant speed restriction due to the curve in eastern Worcester, which will slow trains regardless of whether they make the subsequent stop in Grafton.)
To confirm the accuracy of the spreadsheet’s predictions, I provided it with the service patterns and Worcester origination times for the current schedule. (One major limitation of the spreadsheet is that it only supports calculations for trains originating in Worcester, so I used a hypothetical Worcester departure time that calculated a Framingham departure time matching the current schedule.)
The schedule predicted by the spreadsheet matches the current schedule with high accuracy, in most cases deviating from the current schedule by less than 60 seconds. (The deviations are slightly higher for the H2H service, but my spreadsheet overestimates travel times, and only by 3 or 4 minutes.) So, I am modestly confident in the accuracy of my model’s predictions.
current schedule, as inferred by my model, based on inputted stopping patterns and departure times from Worcesteractual current schedule
Presenting: Half-hourly skip-stop service from Worcester
By moving the stops between Worcester and Framingham, and the stops between West Natick and Auburndale, into a skip-stop pattern, we get the following schedule.
proposed skip-stop schedule
This schedule achieves the primary objective: providing more frequent (half-hourly) peak direction service to the Newtons, without requiring additional rolling stock or capital improvements (beyond the new platform at Worcester, currently under construction).
This schedule provides additional benefits.
Benefits to frequencies and journey times
Service from Worcester doubles to half-hour headways. Additionally, coming from Worcester the travel times are equal (or slightly better) to today’s Worcester expresses, at about 1h21m (compared to today’s 1h23m).
Service from Framingham becomes clock-facing with half-hour headways. There is a resulting trade-off: the current schedule offers hourly 43 min journeys in addition to hourly 56 min journeys (offset from each other by about 15 minutes); my proposed schedule sees consistent journey times of 50 min, which is a bit slower for commuters who are used to the current Worcester expresses. On the other hand, my proposal eliminates the 45 min gap between trains, significantly improving commute flexibility.
(And, as I’ll discuss below, it may be possible to run two H2H trains, which would provide an additional express option for Framingham commuters.)
Journey times either remain constant (within 3 minutes) or improve from most stations. Ashland and West Natick see a similar tradeoff to Framingham – journey times increase by 6-7 minutes; in West Natick’s case, that is off-set by a doubling of frequency.
Benefits to rolling stock efficiency
Finally, this schedule requires no additional trainsets, and may in fact require fewer trains than the current schedule. By my reckoning, the current schedule requires about 8 or 9 trains, possibly with one or two intermingled with other lines. My schedule requires 8 trains, which can be reduced to 7 if most reverse services make limited stops (which would be commensurate with the reverse peak demand, which, at least in 2018, was focused on commutes from Boston to Framingham and to Worcester, and to a lesser extent, Natick.)
If even one trainset is freed up, this opens the door to several possibilities.
Additional “Heart-to-Hub” service
First, the newly available sets can be repurposed to provide additional service on the Framingham/Worcester Line. For example, one of those extra sets could be used to add an additional “Heart-to-Hub” express service from Worcester:
potential skip-stop schedule with an additional H2H service
(In the not-too-distant future, I would love to see a second H2H slot instead filled by a MassDOT service from Springfield, ideally using rolling stock that has been sourced externally.)
30-min headways on the Fairmount Line
Possibly most importantly, even just freeing up a single extra set would allow the Fairmount Line to increase from 45-minute headways to clockfacing 30-min headways, which would be a big step forward in getting the Fairmount Line closer and closer to rapid transit service.
half-hourly Fairmount service, requiring only one additional trainset
Higher frequencies to the Newtons
Finally, while it would definitely require at least one additional trainset relative to today, I sketched out a schedule that would add a third stopping pattern, originating at Framingham, expressing to Auburndale and making all stops thereafter, providing 3 tph to Framingham, and providing clockfacing 20-minute headways to the Newtons. This schedule would (I believe) require 8 sets operating from Worcester, and two additional sets operating from Framingham.
schedule concept for service to the Newtons every 20 min
(The schedule generator I built requires trips to “originate” in Worcester, so I’ve included hypothetical departure times from Worcester in italics – trains with the N service pattern would in reality originate at Framingham.)
Overall, I would use the extra trainset(s) to reduce Fairmount headways to 30 minutes as a first priority, and add a second H2H service as a second priority. I don’t see an urgent need to provide 20 minute headways to the Newtons – I offer it more as a fun bit of imagination.
Conclusion
To review, I believe using a skip-stop service pattern originating from Worcester will:
Provide half-hourly service from Worcester at the same travel time as today
Provide half-hourly service in the peak direction to the three stations in Newton
Provide near clock-facing service from Framingham at a consistent journey time comparable to today
Maintain existing frequencies for all other stations
Maintain equal or faster journey times for most stations
Require no additional rolling stock
Potentially free up existing rolling stock to raise frequencies on the Fairmount Line to 30 min
To me, that sounds like a palpable improvement in service — and something I believe would be well worth the MBTA’s consideration.
To be clear, this is a proof of concept; there are a number of small details that need correcting, and while I think the overall concept works, there are some clear areas for improvement in a subsequent revision. But, I think it does prove out the concept.
Background
The current diagram draws clear lineage to the Cambridge Seven Associates’ original diagram (which captured my imagination as a child with its simplicity and elegance, particularly when it looked more like this). Today’s diagram is much more complicated than the original, due to the need to add additional information, including
Accessibility markers
Explicit markers for all stops on the Riverside Line
Explicit labels for all stops on the B, C, E, and Mattapan Lines
The Silver Line
Commuter rail stops (particularly along the Fairmount Line)
Key bus routes
Plus the editorial decision to include the geographic markers of the shoreline.
That last point reveals a fundamental difference between the original and current diagrams: the original made zero effort to appear geographically accurate, while the current makes some effort to hint at accurate geography… in some places.
The right half of the map – the South Shore, South Boston, the Shawmut Peninsula (a.k.a. Downtown), Charlestown, East Boston, and the communities along the Mystic River – is vaguely accurate, albeit somewhat compressed.
The left half, by contrast, is much more diagrammatic: straightening and simultaneously stretching & compressing the four branches of the Green Line, straightening and simplifying the Red Line and Key Bus Routes, while maintaining some suggestion of a geographically accurate Charles River.
Kenneth Dumas, the designer of the current diagram (and its previous iterations going back to 2000 when the shift was made away from a purely non-geographic diagram), has spoken about the process by which we arrived at today’s diagram; it’s a fascinating watch that I highly recommend if you enjoy transit maps. Suffice it to say, the current diagram represents an effort to harmonize the desires of a wide range of stakeholders.
My goals
I have long wanted to design a diagram for the T that includes the following:
Key bus routes, shown as cleanly as possible and designed into the map from the start
All stops on the Green Line branches
(I actually have not particularly wanted to list out all of the surface stops on the B/C/E Lines, but my understanding is that there is user research showing clear preference for their inclusion)
Walking transfers, including
State – Downtown Crossing,
Copley – Back Bay,
Symphony – Mass Ave,
Brookline Village – Riverway, and
Reservoir – Cleveland Circle
All stops on the Fairmount Line (future-proofed for its eventual conversion to near-rapid transit standards)
The design concept: geographically accurate inner zone & diagrammatic outer zone
Achieving my goals, while maintaining the information on the current diagram, posed several challenges. But as I thought about it further, I realized that several of the thornier issues could all be solved by a highly-geographically accurate diagram, including:
Walking transfers,
the Silver Line, and
to a lesser extent, baking the key bus routes harmoniously into the design of the map
The physical paths of the Green and Orange Lines themselves provided a design to show the walking transfers; this was a key revelation for me: use the physical paths as the starting point for the design, rather than abstract ideas such as “I want the Orange Line to be as straight as possible and form a perfect right angle with a Red Line that is also as straight as possible” (see for example Michael Kvrivishvili’s original design).
At the other end of the spectrum, I got to thinking about Harry’s Beck’s use of a “To” box, listing off-map stops on a line. Cameron Booth offers a modern illustration of this in his Tube map redesign. This is probably the most extreme version of a non-geographic diagram: just a straightforward list of stops.
But, I wondered: was the use of the “To” box really that different from the current diagram’s treatment of the B/C/D/E Lines (and to a lesser extent the Blue Line and Braintree Line)?
There’s very little geographic information being conveyed on those outer lines; there are few or no transfers being shown; there are few or no eye-catching bends that might provide implicit visual cues. Especially on the Green Line branches, the current diagram really just uses a list of stations, along a colored line with white dots.
So, I wondered, what would happen if we had a diagram with a geographically accurate inner section and a maximally diagrammatic outer section?
Hence, the map above.
Notes on the map
A few things to draw attention to:
Sizing
This design uses the original map’s labels and other elements at their original size relative to the page. If printed on a piece of paper the same size as the current map, all of the labels (along with the widths of the subway and bus lines) should be the same size. I know there are ADA guidelines around things like sizing and visual contrast; by reusing as much of the original map’s design language as possible, I’m hoping to generally satisfy those requirements, even if I’m unfamiliar with them.
Alignment for bus routes
Stations are aligned so that connecting bus routes (in this design, the highest frequency “all-day-15-min” routes from the Bus Network Redesign) are maximally straight. These include:
T101: Kendall/MIT – Lechmere – Community College
T9: Copley – Broadway
T12: Andrew – World Trade Center
T109: Sullivan – East Somerville – Union Sq – Harvard
T1: the various stations along Mass Ave
Non-geographic diagram in outer zone
Outside of the “inner zone”, the geographic fidelity of the diagram drops so severely that there’s no way it can be interpreted as being anything other than what it is: a list of stations. This is reinforced by the disappearance of the bus routes and the coastline, and the addition of the “transfer labels” at each station. An earlier version of the diagram featured an explicit “box” delineating the inner vs outer zone; this became unwieldy, however, especially when dealing with the Green Line branches, so I opted instead for an implicit transition.
Color-coded bus routes
Instead of using the current diagram’s “light brown” for the Key Bus Routes, or the official brand guidelines’ “Brand Bus Yellow”, the bus routes have been color-coded based on the hub they operate into. This is far from a perfect system, and in some cases I had to make arbitrary choices. (For example, the T7 and many of the routes running through Roxbury Crossing are colored based on running through State St and Roxbury Crossing respectively, e.g. major transfer points the route travels through rather than to.) Still, I think it is a useful way to differentiate the routes, and somewhat inadvertently highlights the new connectivity of the redesigned routes (e.g. the T28 being a Green route, or the T110 connecting Wonderland to the Orange Line).
Fairmount Line
With today’s timetables, the Fairmount Line should not appear on the map using equal visual language to the rapid transit lines. However, increasing frequencies to “turn-up-and-go” levels should be a major priority for the T and the City, and I wanted this diagram to be future-proofed to enable that.
Silver Line, simplified
The Bus Network Redesign has given us would-be transit map designers a godsend: the elimination of the SL4/SL5 reverse branching & loops. Now we have a simple dog-leg that slots nicely alongside the Orange and Red Lines. The only hiccup is (as I interpret the Remix map), Chinatown will receive northbound service only. I have opted to subtly mark this using a directional triangular for the stop, instead of a circle, and excluding a Silver-Orange transfer indicator at Chinatown (compare to Tufts Medical Center). On a “real” version of this map, the Chinatown label would probably get an asterisk with a note in the legend to the effect of, Silver Line stops at Chinatown going northbound only.
Park St, Winter, Summer, and Washington
This probably falls under the heading of “too clever by half”, but I’m still pleased with it. In general, this map does not mark transfers particularly explicitly. I experimented using black circles, or black dots within circles, but the black circles created contrast problems and the black dots were too subtle.
Instead, the indication of transfers is derived from the physical positions of the stops. For example, the Blue-Green transfer at Government Center is indicated by the Blue and Green Lines sharing a stop indicator. As it happens, only two transfers are marked in this manner: Park St and Government Center.
The rest are marked using transfer bars to connect visually distinct stops. In some cases, the visual distance is a design artifact: for example, the Green-Orange transfer at North Station or the SL1/2/3-Red transfer at South Station are in reality basically as proximate as, e.g., the Red-Green transfer at Park St.
But one benefit is that two of the more complicated transfers are visualized accurately: State, and Park/Downtown Crossing.
State
The transfer between the Blue Line and the southbound Orange Line (the platform formerly known as “Milk” after the cross-street above) is, I believe, the longest in-station transfer on the system. From the western end of the Blue Line platforms to the northern end of the Milk Street platform (I believe under the intersection with School St) is about 800 feet, as I estimate. By comparison, the Green-Orange transfer via the Winter Street Concourse is about 550 feet.
All things being equal, I don’t see a particular need to visually indicate this lengthy transfer distance. However, I chose to add it because I wanted to implicitly indicate that the T7 transfer (on Congress St) is more proximate to the Blue Line than to the Orange Line. So I wanted to separate out the Blue Line station from the Orange Line.
The offset Red Line platforms historically haven’t mattered too much from a map-making perspective. However, with the redesigned SL4/5 route, there will be a minor distinction worth making:
In a clever bit of route design, SL4 and SL5 are going to be combined into a single route that serves Tufts Medical Center, Downtown Crossing, and South Station in a linear fashion, with bidirectional service at each stop. However, instead of serving Downtown Crossing at Temple Place, the new Silver Line stop will be flipped over to Chauncy St – directly outside the entrance to Downtown Crossing at the far end of the Red Line platform.
So, I wanted to indicate on the map that Downtown Crossing will provide a good Silver-Red transfer but subtly suggest that Silver-Orange transfers are better taken at Tufts Medical Center. By separating out the Red Line station (nee “Washington”) from the Orange Line stations (“Winter” and “Summer”), the diagram is able to show exactly that. Again, in this case the physical layout of the network in the real-world has provided the needed design specification.
Drawbacks
There are two sets of problems with my diagram: some problems are execution-related and presumably could be remedied by the touch of a professional; others are conceptual and endemic to the idea of the map itself. Of the drawbacks listed below, I’m not sure which are execution-related and therefore “salvageable”, but I’ll make some guesses.
Busy margins and excess inner blank space
This one I think is execution-related and could be ameliorated by some mild tweaking. This diagram is very busy at the margins overall. To a certain extent, this is by design: I always knew that the outer regions of the diagram were going to be busy with station lists. However, I think the “inner map” section could be compressed by maybe 20%, and free up much needed space, especially at the bottom of the diagram. (For example, there really doesn’t need to be that much space between stops on the Southwest Corridor; the SL4/5 stops probably are the limiting factor here, but they too definitely could be closer together.)
Likewise, I think the “inner map” could also be further compressed along the “Red Line axis”, particularly in the northeast corner. Harvard and Central could both be moved in closer to the core, which would free up more space. For example, the T47 does a small bend at Central right now: in a future revision, I would move Central in closer to the core so that the T47 could run in a straight line between BU Bridge and Union Sq, which would “tug” the northern branches of the Green Line and Red Line further in toward the center. (Looking at it now, I think this would also actually place Central in a more geographically correct location, for what it’s worth.)
Ironically, even though I’m talking about freeing up more space in the top left quadrant of the diagram, in all likelihood I would instead use that space to simply relocate the rest of the map upward, in order to free up more space in the bottom half. The centerpoint of the diagram is currently roughly at the Hatch Shell on the edge of the Charles. In a future revision, I would probably shift things so that the centerpoint is at Back Bay Station.
The busyness of Longwood and Dorchester
These are the parts of the diagram where the shape of the bus network is most germane. The criss-crossing lattice of the Dorchester network does not lend itself to simple labels like “to Ashmont” placed just south of Nubian (which would mirror what I did at Harvard and Sullivan). As for Longwood, the Bus Network Redesign will radically increase bus service to LMA, which definitely merits inclusion on the map, but is challenged by:
Fitting in labels for four bus routes on one segment (between Roxbury Crossing and Brigham Circle)
Fitting in a parallel-but-nearby route for the T47
Showing appropriate proximity to the E Line
Showing appropriate proximity to the D Line (farther away from the E Line)
Illustrating connectivity to Kenmore and Ruggles
Fitting in labels for the E Line and D Line
Fitting everything within the obtuse triangle defined by Copley, Kenmore, and Brookline Village/Riverway
I think the busyness can be partially alleviated by adjusting the compression of the inner core and re-centering the inner core a bit higher up in the diagram to open up a bit more space.
That being said, I think this is a conceptual shortcoming of the map: Longwood and Dorchester both represent areas where higher geographic fidelity is needed, in part simply because the topologies are complicated enough that the geographic representation already is pretty close to the maximally simplified representation of the network.
Unfortunately, this diagram is less effective at fitting in geographic accuracy the further away from the core you get. That’s why re-centering the diagram on Back Bay (or even something further south) is necessary – we need to provide more space for Longwood to fit comfortably within the inner zone.
Dorchester, on the other hand, will likely still have to remain within the “diagrammatic outer zone”, although I think it would also benefit from a little more “breathing” room. That being said, this may be where my design concept for this diagram really breaks down: I dislike the current diagram’s treatment of the Dorchester bus network because I think it looks confusing and hard to read, but I’m not sure mine does that much better.
The “starfish” design centered on Franklin Park feels pleasantly clever, but I worry is still too noisy. Likewise, I’m not wild about the physical disconnect: the bus line ends with an arrow, followed by a “To Destination” label, followed by a relatively small amount of blank space, followed by the diagrammatic stop label with the transfer label (e.g. the T16 going toward Forest Hills). Why not just extend the bus lines all the way to their destination?
Look how close the T16’s to Forest Hills marker is to the actual FOREST HILLS label, alas
(The reason I didn’t do that is because I’m using the absence of the bus and regional rail lines as a visual cue to the shift from geographic fidelity to diagrammatic lists. Now, it is true that the visual distortion would still remain so extreme that the transition would probably still remain visible. But, that corner of the diagram is already so busy that I’d be hesitant to layer on additional visuals.)
I suppose it could be possible to redesign the diagram such that the geographically accurate “inner zone” extends as far south as Forest Hills and Ashmont. Looking at the diagram now, that actually might be more feasible than it sounds, particularly with some compression and reduced scale, so I may need to play around with that!
Branches on the Green Line
The Green Line branches pose a problem: there are way more stops on the B, C, and D branches than there are on any other leg of the network (though Ashmont + Mattapan come close). What’s more, they are the only legs of the network that fan out to the side of the map, rather than the top or bottom, which makes the “diagrammatic list of stations” less obviously different in appearance. And on top of that, I ultimately wanted to make sure all three branches terminated “lower” on the map than Kenmore – meaning I couldn’t, say, turn the B Line upwards to fit it in as a list of stations.
I’m not thrilled with how the Green Line branches turned out, but I do think the concept can be sound, particularly if I can free up a bit more space to let me put the B Line labels on the outside rather than the inside (where they mix confusingly with C Line labels).
(One note: this design is meant to be future-proofed for an addition of a Needham branch: flip the D Line labels past Newton Highlands over to the left side, and use an upside-down tuning fork approach to add the Needham labels on the right, similar to the Red Line branches.)
Conclusion
Does the design concept of a geographic inner zone and a diagrammatic outer zone “work”?
Ultimately, I think the answer is “yes”: I think the fundamentals of this concept are sound, and it’s a question of execution.
As the “15-minute Bus Network” is rolled out over the next few years, it’ll be more and more important for the T to update its map to integrate those routes properly into the design. I hope that an approach similar to what I’ve illustrated here can be helpful in such a redesign.
The following is purely a fun exercise for a highly hypothetical scenario. I’m posting it more as an illustration of thought process, and not really in advocacy of the proposal itself. (There are many things I would prioritize above an Urban Ring LRT station in the Seaport!)
The scenario
Let’s assume a few things are true for this scenario:
The Piers Transitway (currently serving SL1, SL2, and SL3) is converted to light rail and connected to the larger light rail network via a subway running from Huntington Ave to Back Bay to South Station — we’ll call this the “Magenta Line”
“T-under-D” has been completed, meaning the subway now extends from World Trade Center station under the current grade crossing at D St to a portal near the current Silver Line Way station
Center-running bus lanes on Congress St in downtown and Summer Street in the Seaport have been built, and the T7 upgraded into a full bus rapid transit service, which we’ll call the “Navy Line”
SL1 service has been transferred to the Navy Line, to provide a one-seat ride connecting North Station, the Financial District, South Station, the Seaport, and the Airport
We’ll loosely assume that a lane in each direction of the Ted Williams Tunnel has been dedicated to mass transit use
An LRT iteration of the Urban Ring has been built on the southside of the network, connecting Longwood, Nubian, and the Seaport, approaching the Seaport via the Track 61/South Boston Haul Road ROW
In short, our starting point looks like this:
The satellite image doesn’t tell us the whole story, however. This is a highly three-dimensional space, where Summer St and World Trade Center Ave sit elevated above the rest of the street grid, and where a slew of highway tunnels sit under the surface.
World Trade Center Ave looking east, as seen from Summer StWorld Trade Center Ave from above, looking north, with Haul Road below and to the rightWorld Trade Center Ave at “elevated street level” looking north, from nearly the same vantage point as above, but lower downTrack 61 and Haul Road passing underneath Summer St, from above World Trade Center Ave, looking west; the Boston Convention and Exhibition Center is visible at the far leftOpenStreetMap showing the tunnels below the surface
Where to place an Urban Ring LRT station?
“The gravel pile”
As visible in the photo above looking west along Summer St, there is a triangular plot of land bounded by Track 61, the embankment of Summer St, and (effectively) the elevated WTC Ave. (There’s actually an access road that cuts off the corner of the plot slightly east of WTC Ave.) That plot currently is occupied by a massive pile of gravel. (Last I checked, the plot is owned by MassPort, though I assume they would sell it off to a developer if/when they could.)
This is probably the most obvious place to plop down an LRT platform. It’s accessible from the current ROW with minimal modification and landtaking required; it provides good access to BCEC and easy transfer to the Navy Line services (including services to the airport); the Magenta Line subway station at World Trade Center is about 400′ away, which isn’t ideal but is certainly manageable, especially if one of the sidewalks can be covered for protection from the elements.
There are some downsides. The plot is a little small; if we leave the access road untouched, it’s just about 230′ along the long edge, which would be barely long enough for a double-set of the 114′ Type 10 “supertrains” that are expected on the Green Line in the next several years. So it’s likely the modifications at the east end, west end, or both would be needed to fit a center platform, two side tracks and a crossover. (Depending on how the Track 61 ROW is converted to double track LRT, some space might already be reclaimed from Haul Road at the western end, which might simplify the design somewhat.)
The other downside is that this location serves the Seaport, but only somewhat so. A lot of the Seaport is located on the other side of the “highway canyon” that Track 61 and Haul Road sit within, so Urban Ring passengers would need to go “up-and-over” for the last segment of their journey. The current World Trade Center station is much more centrally located.
The gravel pile is potentially an adequate location for a station, and would likely be the least expensive option. On the other hand, if we are going to go to the expense of building an LRT Urban Ring, there’s an argument that it should be built for maximum efficacy, rather than just minimal cost.
The underground parking lots
As can be seen in the photos, there are a number of parking lots at the grade level of Track 61, including one parking lot that directly abuts the southern wall of the current World Trade Center station; open that wall up, and you have a strong transfer to the Magenta Line.
The problem here is that you need to cut across Haul Road and the Mass Pike ramps in order to access the lot. And while that’s doable, it’s far from ideal. There actually already is a traffic light directly underneath WTC Ave on Haul Road, so in theory the disruption to traffic flow would not be new. On the other hand, you could only run trains so often if they need to disrupt traffic, probably capping headways at 5 minutes. Again, that is doable, but seems to trigger the same question as above — if we’re gonna build this thing, why not do it properly?
World Trade Center Ave
One thing that bothered me when thinking about mini-project was how to provide good transfers to both Summer St BRT and Transitway LRT. The distance between a stop in front of BCEC and the entrance to WTC station is roughly 650′, which is long for a transfer but not unheard of. (If I recall correctly, it’s roughly the distance of the transfer between Southbound Orange and Blue at State. Of course, State has the benefit of being entirely indoors, while BCEC <> WTC would have significant exposure to the elements, even if the sidewalk were covered.)
Having two Urban Ring stations — one for the Transitway and one for Summer St — seemed excessive. So then I got to thinking more about what the objectives are for stations/connections at each location.
Summer St
Boston Convention and Exhibition Center
Transfer to Summer St BRT toward downtown: South Station, Post Office Square, Haymarket, North Station
Transfer to Summer St BRT toward Logan
Transfer to Summer St BRT toward South Boston
Transitway (World Trade Center)
Seaport core, including Congress St and Seaport Boulevard
Transfer to Magenta Line westbound: western Seaport, South Station, Back Bay, Longwood
Transfer to Magenta Line eastbound: eastern Seaport
On paper, that looks like a lot of reasons for each, and maybe even more in favor of Summer St due to its connectivity, but when you look closer, some are less relevant:
Summer St
Boston Convention and Exhibition Center
Transfer to Summer St BRT toward downtown: South Station, Post Office Square, Haymarket, North Station
By definition, the Urban Ring will have multiple connections to downtown, so this is not a vital benefit
Also, Urban Ring riders will all but certainly be coming from locations that already have direct service to downtown — it’ll be a very uncommon journey to transfer in the Seaport
Transfer to Summer St BRT toward Logan
As you’ll see below, this benefit is in fact not going to be unique to Summer St
Transfer to Summer St BRT toward South Boston
I won’t put strikethrough on this one, but I will point out that most of the previous connection points along the Urban Ring corridor (e.g. Broadway, Mass Ave/BU Medical Center, Nubian) will hopefully have — and will be better served anyway — by direct bus service from South Boston
Again, the Seaport itself wouldn’t be a common transfer point
Transitway (World Trade Center)
Seaport core, including Congress St and Seaport Boulevard
Transfer to Magenta Line westbound: western Seaport, South Station, Back Bay, Longwood
As mentioned above, pretty much all of the Urban Ring stops between Nubian and the Seaport will have better ways to connect to South Station, Back Bay, and Longwood than via the Seaport
Transfer to Magenta Line eastbound: eastern Seaport
So, to me, the goal of an Urban Ring LRT station would be twofold: connect to the Seaport, and connect to Logan. A stop anchored by the Transitway station better serves the Seaport and, as you will shortly see, also serves Logan. So, insofar as we need to choose which connection to prioritize, we should focus on a Magenta Line connection at World Trade Center station.
Getting to Logan
In some alternate timeline, the Ted Williams Tunnel was built with a third tunnel to carry rapid transit rail service to Logan. This would’ve been so much better than today’s system, but alas.
In the scenario I’ve outlined here (and, in my opinion, in any vaguely realistic scenario), service to Logan is provided by BRT. Now, to be clear, BRT can be a lot better than what we have today. For one, a lane in each tunnel could be dedicated to transit and perhaps very-high-occupancy vehicles, with semi-permanent lane protection to ensure speedy and unencumbered journeys.
But our BRT services still need to get in to the tunnel, and the solution to that problem also solves the problem of Summer St vs the Transitway.
Today’s SL1 and SL3 services make a semi-unadvertised stop at street level on Congress St just outside of World Trade Center station; they do this immediately after exiting the off-ramp, which has the benefit of getting travelers from Logan to a stop in the Seaport quickly, without needing to double back from Silver Line Way.
This stop is marked on my diagram from the top of the post (though I am supposing that the simple sidewalk stop has been expanded into something more like a proper BRT platform):
As far as I can tell, absent a major rework of the Mass Pike tunnels, Logan-originating buses will exit from that off-ramp for the foreseeable future. Now, it is true that Logan buses could instead turn left and use Congress St bus lanes to head toward downtown. However, that would duplicate the lanes on Summer St which would still be needed for South Boston service (i.e. the T7), and would be more awkward to connect to South Station. And while Logan -> South Station is mildly more direct via Congress, the journey in the opposite direction is significantly worse, requiring a lengthy diversion down Haul Road in order to reach the on-ramp.
Funneling Downtown <> Logan service through Summer St maximizes frequencies on the shared trunk, minimizes redundant infrastructure, and maintains good Logan -> World Trade Center service. It is somewhat more roundabout, but connects to more places. (And if we are really worried about an express South Station <> Logan connection, using dedicated lanes in the Mass Pike tunnel running direct into the South Station Bus Terminal is probably a stronger solution anyway.)
So we’ve identified a way for our Logan -> South Station service to transfer at WTC station, but what about the other direction? Well, that’s where those parking garages can come in handy.
Running directly parallel to the Transitway is a small side street/alley that runs into the lower level of the parking garage, and which, I think exits on to Haul Road just underneath World Trade Center Ave. Visible in the second Streetview photo are two large metal doors: I am pretty sure that those lead directly into the lobby of the World Trade Center station — meaning that with some modifications, you could put a BRT platform near there, and have buses immediately proceed to the on-ramp.
This would then provide a strong transfer point to Logan-bound services at World Trade Center proper — benefitting Magenta Line riders, but also providing a crucial transfer point enabling an Urban Ring station at World Trade Center.
Placing an Urban Ring LRT station at World Trade Center
So, where to put a new LRT station at World Trade Center?
We can’t put it at grade level without disrupting all the highway ramps, or otherwise settling for a station at Summer St instead.
We can’t put it below grade level because of the highway tunnels.
What about above grade along the World Trade Center viaduct?
Building a short rising viaduct on the gravel pile’s plot and claiming some of World Trade Center Ave (more details on that below) to add a above-grade LRT platform, combined with building an at-grade BRT platform for Downtown -> Logan services by reclaiming some space under the parking garage and adding a BRT platform on Congress St for Logan -> Downtown service, enables all three services to be centralized in a single station for easy transfers between all three.
So how do you reach the World Trade Center Ave viaduct?
Some of this will depend on how Haul Road is reconfigured for double-track LRT, particularly in terms of the horizontal alignment (do you steal a lane, or eat into the gravel pile?), but I think there’s enough open space to feel comfortable that something could fit, even if we don’t work out the details right now.
One area we have less flexibility on is the vertical alignment: there’s approximately 310 feet of horizontal running space between the Summer St underpass and the edge of the World Trade Center Ave viaduct, and we have to fit our rising viaduct in there.
The WTC Ave viaduct is approximately 25 feet high; 25 feet rise over 310 feet run yields a grade of 4.61°, which is well within the comfort zone for LRT grades. Even a rise of 33 feet over that distance would still come in at our 6° threshold. Likewise, rising 25 feet at <6° is doable in as little as 240 feet. Therefore, even with the known limits, it should be possible to rise from the Summer St underpass to the World Trade Center Ave viaduct at a reasonable grade.
Fitting a terminal on the World Trade Center Ave viaduct
The main question facing us here is whether to maintain some level of automobile access through WTC Ave. I believe I’ve come across proposals to fully pedestrianize that street, which, honestly, based on my experience, seems pretty reasonable. Mostly it seems like the street is used to deliver goods to the World Trade Center proper.
If I needed to maintain some level of automobile access, I would use a staggered pair of side platforms to maintain LRT capacity and keep a shared bidirectional lane open for vehicles to pass through on a limited as-needed basis, placing signals/traffic lights at each entry to coordinate passes through the right-of-way.
Obviously, this arrangement is complicated and would create some disruption to the system, depending on the road traffic volume. This option would need to be considered carefully to assess the cost vs benefit.
The key thing to note is that there is horizontal space to fit all the necessary elements:
First 230′ platform (enough to accommodate a doubleset of the 114′ Type 10 supertrains)
90′ to fit a crossover to provide passing access
Second 230′ platform
A 100′ radius curve from the rising viaduct on to WTC Ave
Reasonably short walking distance between platform and current headhouse to streamline transfers
Maintain pedestrian access to the elevated greenspace between Congress St and Seaport Blvd
The second option is more conventional and straightforward: pedestrianize the whole viaduct, and claim part of it for a GLX-style center-platform terminal station.
There are lots of potential variations on this design — adjusting the width, length, and placement of the platform, trying out different methods of pedestrian access — but they all more-or-less look like this.
Keen observers will note that none of these designs feature fare gates or paid-access vs unpaid-access areas. Numerous transit systems, both in the US and around the world, have demonstrated that it is possible to run ticketed transit systems that do not require metal barriers to enforce payment. Eliminating fare gates makes it possible to build transit access more directly into the fabric of a neighborhood. Both station designs, but particularly the staggered platforms alternative, see no clear demarcation of the “edge” of the station, but rather allow the space to be woven together into a seamless whole.
So how do you site an Urban Ring LRT station in the Seaport?
To me, it looks like this:
Add a BRT platform at World Trade Center station for Downtown -> Logan services (under the parking garage just south of the station)
Build a viaduct to connect Track 61 LRT to the WTC Ave viaduct
Add an LRT station at-grade on the elevated World Trade Center Ave viaduct
Should you put an Urban Ring LRT station in the Seaport?
One thing this exercise illustrates is that the Seaport is not very wide. This sounds obvious and trivial, but one result is that there isn’t really space nor need for a “crosstown” service. The Piers Transitway and Summer St already form strong “east-west” transit corridors (whose elevation difference reduces their overlapping walksheds slightly). But they’re still close enough that a perpendicular service between/across them wouldn’t make much sense (particularly since both originate at South Station and come very close to connecting again at World Trade Center).
So a Track 61 LRT service basically needs to choose a particular point along the “linear Seaport corridor” to terminate. That increases the pressure on that station to be located optimally to maximize access to jobs as well as to transfers. World Trade Center does reasonably well on that front, but both the eastern Seaport (e.g. Design Center) and western Seaport (e.g. Courthouse) would require transfers for short last-mile journeys. But this need to choose lies at the heart of why siting an Urban Ring LRT station in the Seaport is difficult in the first place.
A Track 61 LRT service will likely reach the Seaport in part by passing near Broadway station. Regardless of origin point beyond there, a service near Broadway likely could instead be aligned to pass through South Station instead — and then continue to Seaport along one of the east-west corridors. (For reasons I won’t get into here, a Piers Transitway LRT corridor would very likely have excess capacity to absorb Urban Ring LRT in addition to the Magenta Line LRT I’ve described here.)
Sending an “Urban Ring” LRT service down one of the east-west corridors would provide better access to the entire Seaport, and reduce/eliminate the need for transfers. Running LRT service via Track 61 may in fact be unnecessary.
This brings us to a key difference between an LRT Urban Ring and a BRT one: BRT can continue to Logan Airport and on to Chelsea much more easily than LRT. Rapid transit on the Track 61 ROW, with a transfer station roughly at World Trade Center, and continuing service to Logan is able to catch a much broader swath of journeys (in italics below), compared to service terminating in the Seaport:
Longwood <> Seaport
Nubian <> Seaport
Red Line transfer point TBD (e.g. Broadway) <> Seaport
Longwood <> Logan
Nubian <> Logan
Red Line transfer <> Logan
Longwood <> Chelsea
Nubian <> Chelsea
Red Line transfer <> Chelsea
Seaport <> Chelsea
Logan <> Chelsea
The concept of the Urban Ring was to provide circumferential service that bypasses downtown, for speedier journeys and reduced crowding in the core. A route that terminates at Seaport curtails possible destination pairs, and becomes less competitive against transferring downtown via the radial services (especially for long circumferential journeys).
Returning to the point about connecting at Broadway vs South Station: South Station is, to be clear, the bigger fish. Nubian <> South Station journeys surely outnumber Nubian <> Broadway journeys. Urban Ring concepts usually favor a transfer at Broadway or to the south — but can justify skipping South Station because they are providing speedier service to Logan and Chelsea. Track 61 LRT can’t do that.
So I think Urban Ring LRT service via Track 61 presents a weaker case than it first appears. Now, it bears mentioning that capital costs for a Track 61 LRT route would probably be less expensive than a journey via South Station. If given the choice between Track 61 LRT and nothing, I’ll be entirely in favor of the former.
Conclusion
Ultimately, this is a fun thought exercise. The scenario I’ve contrived here presupposes a lot of things, so its “real-world relevance” is somewhat limited. A few final thoughts:
The problems I’ve outlined here will impact any Track 61 proposal; Track 61 will always be on the wrong side of the Mass Pike between Summer and Congress Streets, so you’ll always need to figure out a way to bridge that gap
This conversation becomes radically different if an LRT connection between Seaport and Logan is built — although even then, Track 61 will still be on the wrong side relative to the Transitway
Urban Ring considerations aside, I’d suggest that a Navy Line service to Logan would significantly benefit from the “under-the-garage” platform I propose here, especially if the Transitway is converted to LRT and thus cut off from Logan
The Seaport is centered on two east-west corridors, and there’s an argument to make that almost all services, even circumferential ones, would do well to feed into or otherwise align with those
For all the reasons outlined here, and others, most of my crayon maps going forward will favor both LRT and BRT Urban Ring services that run via South Station, rather than Track 61/Haul Road. At most, I can see Haul Road being useful for express service to Logan that bypasses the Seaport — that, it could do quite well. But for serving the Seaport proper, I think it comes up short.
As a holiday treat for myself, I went on a purely recreational trip to see the new Green Line Extension in action. Truth be told, I had a ball. Sitting in the so-called “railfan” seat, peeking out the front window as we sped along the Medford Branch, all of the politics and the delays could be momentarily forgotten, and I could enjoy the moment and say to myself, “Wow, this is so cool!”
The Green Line Extension has been in the works for decades. Its 2022 opening means that the one-seat ride between downtown and Union Square and other Somerville neighborhoods has returned after almost exactly 100 years. It is truly a delight to see it open at last. And make no mistake: any operational or aesthetic shortcomings notwithstanding, the bones of this extension are solid and will last for another 100 years if not longer. This is what long-term public investment looks like.
I took lots of notes and photos. Presented below are some of my observations. It is undisputable that many aspects of GLX remain in progress – there is still lots and lots of ongoing construction, for example. So I’m going to present my observations largely without commentary. I pay a lot of attention to details, and will share some of the particular details I noticed – I defer to more knowledgeable voices to assess the significance (or lack thereof) of those details.
All photos are dated Dec 26 2022. I’m writing this about a week after the fact, so it is possible that some of things have changed since my trip, though given the holidays, that seems unlikely.
Maps
Many maps across the system do not currently show GLX. By my observation, all four of the core Green Line transfer stations – Park St, Government Center, Haymarket, and North Station – have maps that omit the Green Line extension and physical signage that points to Lechmere.
The map at North Station is a typical example:
On closer inspection, someone (or multiple people, given the different ink colors) had tried to add in GLX by hand:
A similar situation on Park Street’s Red Line platform:
Park Street’s Green Line northbound island platform had a map and diagram with a sticker that read “Open Spring/Summer 2022”:
By contrast, all of the GLX stations had updated diagrams:
The GLX stations also all have those lovely neighborhood maps:
Quincy Adams (undergoing renovations) also shows GLX on its map in the paid lobby:
Maps within Green Line cars themselves were a mix, with some showing the extension and others omitting it. (Probably there was a pattern based on the older Type 7 vs newer Type 8 cars, but I wasn’t paying close enough attention to tell.)
Signage and wayfinding
“Stop Requested”
On my trip outbound on the Medford Branch, the operator came on the PA after departing Lechmere and said something to the effect of, “For stops on the Medford branch, please request your stop prior to arrival.” (She said something slightly clearer and more elaborate, but I don’t remember the exact phrasing.) The Stop Request sign lit up at every stop, and we made every stop.
On the inbound journey, there was no announcement. When we pulled in to Magoun Sq, no one had made the request, so the train came to a complete stop, but the doors did not open, and the train set off again.
In full candor, the Stop Request system seems reasonable on the B, C, and E branches, where stations are about 750-1000 feet apart; it does not seem reasonable to me on the D and Medford Branches, where stations are much farther apart, and where the often 10-min wait between trains means that a missed stop costs you an additional 15 minutes of travel time (whether you walk or double back on a train).
I should also note that there is no in-car signage on the Type 8’s to explain to riders how to request stops. (I didn’t specifically check while on a Type 7.) There also was no physical signage that I saw in any station about the presence of a Stop Request policy on the Medford Branch.
Next train indicators
I didn’t get a good photo, but the dot matrix indicators that display when the next train will come (e.g. “Heath St – 3 min”) often would just show something like “Trains every 8-13 minutes” on the inbound Medford Branch. As I understand it, this is because a specific countdown doesn’t begin until the incoming train departs Medford/Tufts. However, given that the travel time from Medford/Tufts is relatively short, that means that the countdown indicator will only ever give a few minutes’ worth of notice.
A similar problem happened on the northbound platform at Park Street: because the indicators only show the next two trains, there was a Union Square train only 3 minutes away, but it wasn’t visible on the board.
Next departure track indicators
At Union Square (and also at Medford/Tufts, though I spent less time there), hanging above the platforms are a pair of arrows which are intended to light up to tell passengers which train will depart first. I didn’t get a great photo of them, but you can somewhat make them out in this one (under the overhang, bracketing a white lit panel):
I departed Union Square multiple times during my trip, but only tried to use the indicators during one of those departures; as it happened, the indicator pointed to the wrong track that time.
Miscellaneous
A sign from the Aug-Sept 2022 Green Line shutdown sits tucked away next to the fare machines at Union Square:
The ramp appears to remain under construction at Union Square. As you can see, a small printed sign notes, “MBTA Ramp Closed, Please Use Elevator”.
But in fact, the ramp was unblocked and appeared open, and had a series of small placards with details about the neighborhood (including some evidence of a Somerville-Saugus rivalry over the origins of marshmallow fluff):
Returning to that first photo of the ramp, you’ll notice that there is also an open staircase on the left, which appears to offer an alternative to both the ramp and the elevator. When you get to the top of the staircase, however, it is sealed off with a chain link fence; I did not see any signage to note this.
Operations
Travel over the Lechmere Viaduct remains slow (at or under 10 mph). There was a small sign at the western end on the outbound track, saying “Resume speed.” Trains really fly on the Medford Branch, though – I would guess at least 35 mph.
The automated announcement at Union Square said, “Doors will open on the left hand side,” but the train had already switched over to the other track – meaning the doors would open on the right. (Trains arrive and depart from both tracks at Union, meaning sometimes the doors will open on the left, and other times on the right.)
On one train as we entered Lechmere, the automated announcement said something to the effect of, “This is Union Square. The destination of this train is Heath St/VA Medical Center.” (Beyond announcing the wrong stop, this announcement also doesn’t make sense in that Union Sq trains now go to Riverside, not Heath.)
The inbound Medford train I was on got stuck at a “red over red” signal at East Somerville station (i.e. just before entering the junction with the Union Square branch). The driver eventually had to reset it manually. I overheard chatter on the radio later that suggested there was still an issue at that signal.
One of the outbound Union Sq trains I took needed to have its destination swapped to Medford; we pulled in to Lechmere, and the operators directed people out on to the platform where we waited for the next train (itself originally for Medford) to pull in. I wasn’t able to figure out why the first train needed to change destinations.
On the Green Line Extension, the signals before switches say, “Stop, check for proper signal & switch”, and have little labels below – right arrow for Union, left arrow for Medford, that kind of thing; I’m sure that will make for a fun “Easter egg” for young railfans for many years to come.
On a very nerdy note: now that B and C trains both terminate at Government Center, the Park St Loop in theory does not see any regularly scheduled use (perhaps for the first time ever?). However, I saw at least one train getting short-turned on the so-called “fence track” at Park St, meaning that the loop continues to be used to short-turn trains to reduce bunching.
Infrastructure
The labels for platform level in the elevators at Union Square and Medford/Tufts used different styles for writing “Green Line” – the label at Union Square omits the space between the words.
Elevator buttons at Union Square
Elevator buttons at Medford/Tufts
One of the two elevators at Medford/Tufts was out of service.
Both doors to the Pedal & Park at Medford/Tufts had placards reading “Tap Charlie Card Here,” pointing to an empty space along the fence, where unconnected hookups were visible on the other side; I couldn’t see any place to tap a Charlie Card.
You get some really cool views of the Commuter Rail Maintenance Facility (Boston Engine Terminal) and the new Green Line maintenance facility from the Lechmere-to-Union viaduct:
I didn’t get good photos, but you also get a really cool view looking west from the Medford-to-Lechmere viaduct, from which you can see the Fitchburg Line commuter rail tracks, the Green Line’s flying junction tracks to/from Union, and the under construction Community Path that flies over everything:
And from the Lechmere-to-Medford viaduct, you get a cool view of the curved viaduct ducking under to go to Union, with the Green Line Maintenance Facility in the background.
While GLX stations are not unique in this regard, it is always cool to see level low-floor boarding, which I tried to capture in this quick shot:
The elevator at Lechmere has a lovely botanical pattern on its glass:
And finally, just before I was about to head home, I managed to snag a ride on one of the new Type 9 trains – I had tried earlier in the day to catch one but had barely missed it, and so had given up; as I was heading down to the Red Line platform at Park, I happened to turn around and see a Type 9 rolling in; so I delayed my departure in favor of a quick excursion up to North Station:
Earlier this year, I described how Aldgate Junctions can be used to provide additional service along branchlines without impacting capacity on the core. But Aldgate Junctions have their limitations – a lesson that the Boston Elevated Railway (BERy) learned the hard way, 100 years ago.
The original Main Line El network
When what is now the Orange Line was first built, it was very different. In fact, the earliest iteration of the Orange Line did not use a single piece of track, tunnel, station, or right-of-way that the current Orange Line uses.
The Main Line El, as it was called, was opened in 1901, as a collection of three elevateds and one subway: the Charlestown El, the Washington St El, the Atlantic Ave El, and the Tremont St Subway. Yes – despite being opened less than 5 years before as a streetcar subway, the Tremont St Subway was semi-temporarily converted to third-rail and high-level platforms. (The four-track sections of the subway saw the inner tracks maintained for streetcars.)
The infrastructure of the Main Line El when it opened looked something like this:
Single els at the northern and southern ends were connected by a pair of downtown trunk lines, all linked together by a pair of Aldgate Junctions, the northern junction called “Tower C”, and the southern one called “Tower D”. This arrangement allowed all trains to run everywhere. For example, the following array of service patterns would have been readily achievable, with bidirectional service on each “line”:
(Note that I’m not sure a full service pattern like this ever existed; but, as you will see below, it looks like BERy experimented with many permutations, so this one may have been attempted at one point or another.)
Shifting into the Washington Street Tunnel and reshaping the network
The original network was short-lived. Within the decade, the Washington Street Tunnel opened:
As you can see, the Aldgate Junction at Tower C was preserved, but Tower D was modified into a simple flat junction. I argue that the asymmetric presence of the northern Aldgate Junction fatally undercut the Atlantic Ave El’s ability to contribute usefully to the network.
Mapping the lasting impact of the asymmetric Aldgate Junction
In the course of researching another project, I ended up doing a deep dive into BERy’s experiments with different service patterns on the Atlantic Ave El from 1919 to 1924. You can follow the evolution step-by-step below.
Ultimately, I would argue that the problem they were trying to tackle was a geometric one. Without an Aldgate Junction at Tower D, the Washington St El is hobbled by reverse-branching: every train you try to send from Dudley to Atlantic is one fewer train that you can send from Dudley to downtown; as it is today, downtown was the more popular destination and could hardly afford to lose service.
Trying out a shuttle service + deinterlining
This is why it is unsurprising that in 1919, BERy stopped running trains from Dudley to Atlantic via Beach St – all trains from Dudley would run through the Washington St Subway, as detailed in this newspaper announcement:
As you can see, BERy sought to increase frequencies on both the Tunnel and the El by isolating each other’s services; the Tunnel would be served by Forest Hills/Dudley-Sullivan trains, and the El would be served by North Station-South Station shuttles. (Not mentioned here is a dedicated track that existed at North Station, allowing Atlantic shuttles to reverse direction without blocking Tunnel traffic.) Drawing on the style of the Cambridge Seven Associates “spider map”, a diagram of the system at the time might have looked like this:
This was certainly a reasonable idea, and is a technique called “deinterlining” that remains in use to this day. (Every so often, you will see someone put forward a proposal to deinterline the NYC Subway, for example.) Two low-freq services offering dedicated one-seat-rides to multiple destinations are reshuffled into two high-freq services that provide higher frequencies to all stations, improve reliability, and maintain some OSRs, at the cost of turning other journeys into two-seaters.
The push for deinterlining highlights a common pitfall of Aldgate Junctions: it entangles all three branches into a single shared timetable. Trains on one branch need to be coordinated with trains on both other branches. Even if your train is bypassing a branch, delays on that branch will still impact your journey through ripple effects.
Pitfalls of a deinterlined main line + shuttle, and an attempt at remediation
But BERy’s own announcement reveals a fatal flaw in their plan: most of the major destinations on the Atlantic Ave El could be reached by other two-seat rides that were often more direct, especially for riders coming from the south. Why would anyone board a train at Dudley, ride it all the way to North Station, and then transfer to a shuttle and ride it the long way round to disembark at Atlantic (today’s Aquarium)? It would likely be significantly faster to transfer at State/Milk/Devonshire and ride an East Boston train one stop. (And probably would be just as fast to walk.)
And from a convenience perspective: a two-seater is a two-seater, so Washington + East Boston is equally convenient as Washington + Atlantic. At that point, journey time becomes the deciding factor.
Perhaps an Atlantic shuttle service could have been more successful if it had offered a southern transfer at Dover. Unfortunately, the Washington St El’s station construction style meant that significant capital investments would have been required to turn trains at Dover.
As it stood, the 1919 Atlantic shuttle service was useful for three specific things:
Shuttling passengers between South Station and North Station
Perhaps of limited use to long-distance travelers, but hardly a large market
Serving Battery St
Located at the farthest edge of the North End, with half of its walkshed underwater
Serving Rowes Wharf
Faced with declining ferry ridership and likewise only half of a walkshed
That is pretty wobbly, especially given the cost of maintaining the El and the diversion of rolling stock away from more heavily used segments.
(Of note – though I believe ultimately not of very much consequence to this particular topic – is the Great Molasses Flood, a disaster that occurred about two weeks after BERy’s announcement, and which put the Atlantic Ave El out of service for over two months.)
This experiment in pure deinterlining was short-lived. Just six months later (and less than three months into the service actually being consistently run following the flood), a Dudley-Atlantic-Sullivan service was reinstated:
Which would have looked like this (although I am unclear whether the Sullivan-Dudley service itself was weekends-only):
Implementing a “wraparound” service
The Dudley-South Station-Sullivan service – whether it was truly daily or only on weekends – only lasted another six months. In December of 1919, a fascinating “wraparound” service was instituted that essentially turned the Atlantic Ave El into a second northern branch of this predecessor to the Orange Line:
The core stretch through the Washington Street Tunnel would see 24 trains per hour (tph) at peak. To the north, 8 of those trains would head to South Station, while the other 16 would go to Sullivan; in essence, BERy “paid” for a one-seat-ride to the Atlantic Ave El by diverting about one-third of Sullivan trains.
(To the south, it should be noted, the 8 tph from South Station were short-turned at Dudley, again leaving the other 16 tph available to serve Forest Hills, though I’m not sure that they all did.)
Seasonal direct service
Sometime in the summer of 1920, a direct Dudley-South Station-Sullivan service was reinstated, to accommodate increased traffic from summer travelers. It’s unclear to me whether a North Station-South Station service remained during this time.
Wraparound service + shuttle
However, by the end of September, the through-run was canceled, replaced by a return of the wraparound service – now only 6 tph – but now supplemented by a dedicated North Station-South Station shuttle, also running at 6 tph.
Again, we see BERy reducing the frequency of one-seat rides, but adding additional short-turn service to raise frequencies on the El itself higher.
Low-freq seasonal direct service + high-freq shuttle
Once again, the wraparound service was discontinued. This time around, however, BERy reduced the frequency of the direct service lower than I believe they ever had before: only 5 trains per hour. This was again supplemented by a much higher frequency on the North Station-South Station shuttle, which saw 10 tph during rush hour.
I think there’s actually a lot to be said for this arrangement. The lack of wraparound services means that trains aren’t doubling back on themselves; the frequency for Dudley-Atlantic-Sullivan services seems to match the present-but-low demand, sitting at the edge (but still within) the realm of “turn up and go”; and frequencies remain high on the core segments, meaning that riders who are impatient have the alternative of a two-seat journey between services with high frequencies (and therefore short transfer times).
Reverse branching from the south
It’s unclear to me whether BERy returned to a “Winter” service pattern after the 1921 Summer was over, and if so, which Winter service pattern they used.
However, it appears that the Summer pattern was again used in Summer 1922, before being replaced in September 1922 with yet another new service pattern:
This pattern essentially extended the North Station-South Station shuttle – a relatively constant fixture of all these variations – from South Station to Dudley. This again turned the Atlantic Ave El into a second northern branch of the Main Line El, but shifted the split point to the south to avoid the roundabout journeys of the wraparound pattern. This of course came at the classic cost of reverse branching: radial service from Dudley was rerouted away from the core, reducing the number of trains that could run between Dudley and Downtown.
As I understand it, this service pattern remained somewhat stable, though I am unsure how long it remained in place. By 1924, the predecessors to the Blue and Green Lines saw many of their surface routes truncated at Maverick and Lechmere respectively, which leaves us a map like this:
Writing on the wall
In 1926, the Report on improved transportation facilities in the Boston Metropolitan District noted that (p. 26):
At the present time the Atlantic Avenue Elevated loop is utilized principally as a rapid transit connection between the North and South Stations. It also affords a convenient means of reaching the several steamboat and ferry terminals along the waterfront. The total traffic served by this loop is not particularly important in a comparative sense.
That same report called for the demolition of the Atlantic Ave El and replacing it with an “elevated roadway” (p. 41 and on) – essentially proposing the Central Artery, some 30 years before its time.
To be clear, there were a number of factors that put the Atlantic Ave El at a disadvantage. For one, running along the shoreline meant that half of its walkshed was literally underwater. The route also avoided the densest parts of downtown Boston, in favor of serving the docks, which also reduced transfer opportunities to the Tremont Street streetcar services and to mainline railroads at North Station.
(Transfer opportunities to the East Boston Tunnel were available at Atlantic, and to the Cambridge-Dorchester Subway at South Station; I would speculate, however, that passengers would likely prefer the shorter and fully-indoors transfers available on the Washington St Tunnel.)
Serving the docks was an understandable design decision at the time, but became more problematic as time went on. Tunnels under the harbor significantly reduced ferry ridership; for reference, the highly popular Boston, Revere Beach & Lynn Railroad ferried passengers across the harbor from their terminal at Jefferies Point to Rowes Wharf – surely a large source of passengers for the El.
Finally, it bears mentioning that Elevateds themselves quickly became unpopular. They were noisy, unsightly, and brought the noise of transportation up from street-level directly outside residents’ windows. Furthermore, since the Els were a rapid transit service that BERy used to express riders in from streetcar transfer hubs further out from downtown, stops were spaced distantly, and thus provided that much less advantage to residents who endured the costs of living nearby.
What if?
Would things have been different if Tower D had been maintained as an Aldgate Junction? It’s hard to say. Maintaining a central “loop” service as I showed in my diagram above would still mean reducing the number of trains that could run directly between Dudley and downtown.
On the other hand, a loop would have kept frequencies maximally high within the core Washington Street Tunnel, keeping capacity high for transfers from Cambridge, Dorchester, East Boston, and North Station. A loop service would also have created a one-seat ride from South Station to (what is now) Chinatown, State, and Haymarket.
Would it have been enough to save the Atlantic Ave El? In the end, I doubt it. The waterfront routing and probably the mere fact of being an elevated likely would have doomed it anyway. These were the early days of rapid transit – some ideas were simply best guesses, and so some ideas were inevitably wrong.
Lessons for today
It’s clear that the asymmetric availability of an Aldgate Junction following the construction of the Washington Street Tunnel is the fundamental reason BERy kept changing the service patterns seemingly every six months circa 1920. BERy was trying, I would argue, to solve a physically impossible puzzle, experimenting with basically every possible permutation of service on the El, and failing to make any of them work.
The history of the Main Line El offers a lesson, not in the benefits of Aldgate Junctions, but in the perils of reverse branching and doubleback services. A key advantage of an Aldgate Junction is the “branch bypass” service: recall BART’s Orange Line that runs from Richmond to the East Bay without entering the core in San Francisco.
In the case of the Atlantic Ave El, that advantage was negated: the experimental wraparound service was inefficient because it was a doubleback service that was roundabout and not fast enough to compete with more direct two-seat journeys. South Station-Sullivan service avoided the core of downtown, and consumed slots needed for the more valuable Sullivan-Dudley service.
Why does it work in London?
London’s example may be a closer comparison than the BART’s: the eastern end of the Circle Line is also a doubleback service, as can be seen in the 2015 London Connections Map:
Why does it work in London where something similar failed in Boston? I think there are a few reasons:
London has more people – a lot more people. Greater London had about 7.5 million residents in 1920, while Boston had a tenth of that (see pg. 143). Being physically smaller, 1920s Boston may actually have been roughly as dense as London, but you could probably fit (and I’m making a wild guess here) four or five “Bostons” into London’s areas of high density.
With that many people, the numbers game really begins to change. (This is a useful point to remember when comparing [Western] cities to London, New York, and to a certain extent Paris and Los Angeles – those cities are simply different due to their scale and are hard to use for comparisons.)
The northern and southern legs of the Circle Line are a little bit further apart than the El and the Tunnel were, increasing incentive for passengers to ride around the bend even if it is slightly more roundabout.
The Circle Line has fewer “crossing services” than Boston did: recall that riders could use the predecessors to the Red and Blue Lines to access most of the stops served by the El; London by contrast had more stops and fewer crossing services.
If you were coming from Farringdon or points west and wanted to go to Monument, you could alight from the Circle Line at Moorgate and transfer to the Northern Line and go south one stop… but if you were going to Cannon Street or Mansion House, then you’d need to get back on a Circle or District Line train anyway, so why not stay on? The Central Line and Thameslink also presented options, but might have been undesirable for other reasons (see below).
London’s large population becomes relevant when considering transfers; I don’t know what it was like in 1920, but today those segments of the Northern Line and Central Line are extremely crowded, while the Circle Line is noticeably less so. This again incentivizes riders to continue “round the bend”, to avoid an extremely crowded transfer.
Planning and crayoning
So what does all this mean from a transit planning and crayon mapmaking perspective? It means that an Aldgate Junction can solve some problems with branching, but it’s not a cure-all.
It’s still vulnerable to the pitfalls of reverse-branching, diverting radial services away from the core. Every train from Dudley that went to South Station was a train taken away from the more valuable Dudley-Downtown route.
If the branches are close together, then an Aldgate Junction becomes less useful because it won’t be used for through-journeys from branch to branch – there will be other “crossing services” (including walking or biking) that are faster. Someone journeying from Scollay Square to what is now Aquarium was better off traveling via the East Boston Tunnel than going the long way around.
If the branches are long and are corridors unto themselves, then the Aldgate Junction can still be a useful way to increase frequencies within the corridor – but in that case it may be more efficient and reliable simply to short-turn supplementary services within the branchline itself, rather than deal with the logistics of a junction.
In a Boston context, this would be relevant on the western branches of the Green Line: a “wraparound service” that jumps from the B to C Lines while avoiding Kenmore would be a poor alternative to the (idealized, well-running) 66, 65, or 47 buses. If frequencies need to increase within the Beacon or Commonwealth corridors, short-turning trains at Blandford St, St. Mary St or Kenmore would be more reliable and less complex than a junction.
(This also holds true, in my opinion, at the western end of those branches, where there is a true set of Aldgate Junctions at Cleveland Circle and Chestnut Hill Ave.)
Summary
An Aldgate Junction is more useful when as many of the following are true:
Branches are evenly distributed geographically
The region is pluricentric, where key destinations are located across multiple branches
The branches are long and form corridors unto themselves
Direct “crossing services” (such as circumferential routes) are not available between the branches, or are too centralized resulting in three-seat-journeys (such as Farringdon-Moorgate-Monument-Cannon Street)
Even before the elimination of the Aldgate Junction at Tower D, the Atlantic Avenue El failed all of these. Following the relocation into the Washington Street Tunnel, BERy was hamstrung with no way to serve the El without incurring reverse-branching, doubleback services, or both. This is vividly illustrated by the rapid changes and experimentation with service patterns circa 1920.
While the Atlantic Avenue El was demolished over sixty years ago, its history can still teach us lessons today.
Over the past week, I’ve been iterating on modified versions of the T’s official subway map to illustrate the closures and shuttle services that begin tonight and will continue for 30 days. This map will likely continue to evolve, and I will continue to post the latest revision here. As always, please note that this is not an official map — always refer to the MBTA’s website and to the City of Boston’s website for up-to-date information.
Notes for transit and design nerds
This exercise started relatively simple: show the Orange Line and northern Green Line in some alternate manner to indicate the bustituted segments. This was relatively straightforward: I borrowed design language from the Arborway bustitution in the late ’80s, with a colored outline, white fill, and colored circles for the stops.
On the further advice of someone with better aesthetic sense than I, I shifted the white fill to a lightly colored fill, to better differentiate the lines, and avoid the perception of a total absence of service. The light fill seemed to strike a good balance between maintaining the line’s identity, showing the continued existence of service, and also indicating a significant difference in service.
But, as happens with many projects, I kept on thinking of, “Oh, just one more thing I can add!”
Which brings us to the current design, which pushes the original map’s information design to the limits. I wanted to show:
The bustituted segments
The un-bustituted segments
Text notes on significantly relocated shuttle stops
The one-way service at Haymarket
The early-morning/late-night shuttle to Chinatown and Tufts Medical
The bus routes the T suggests as alternatives to the Orange Line (39, 43, 92, 93, CT2)
The suggested walking transfers between Orange Line and Green Line stations
That is a lot of information to cram onto a diagram that was originally designed to be rather sparse. The current official subway map is an evolution of a design from the early 2000s that primarily showed the rapid transit routes, with commuter rail and ferries being shown secondarily, and limited-access highways being shown tertiarily. In the late 2000s, the key bus routes were added, and a subsequent redesign shifted some parts of the map around while maintaining the same visual language overall.
Evaluating my attempts
Was I successful? Ehn.
I was pleasantly surprised when an earlier version of this map gained a small amount of traction of Twitter, so it’s nice to know that at least some people found it useful. But at a certain point, I fear the level of detail hinders rather than helps. Part of the brilliance of Cambridge Seven Associates’ original “spider map” design was in its simplicity; even if you didn’t memorize the whole thing, the visual concept was highly memorable: four lines, crossing each other in a square and radiating out. That basic schema was easy to recognize and recall, and created a foundation to understand the rest of the system, even if it wasn’t put into one single map.
The eventual addition of commuter rail lines, key bus routes, and now all of the additional information I’ve added here is all very reasonable, especially when done incrementally. But I find myself questioning the ultimate usefulness of the diagram I’ve created. Is it really useful enough for journey-planning? Or is it too confusing to parse?
Simple maps and specific signage
Ultimately, I’ve come to believe that clear and specific wayfinding signage in and around stations is much more important than a detailed system diagram, both under ordinary and extraordinary circumstances such as the Orange Line Closure. (This despite my own love for detailed system diagrams.) In that way, perhaps my earlier, simpler diagrams were more effective.
Shuttle routes only
In this simplest version, the shuttle routes are shown and nothing else:
The advantage of this design is how minimally it alters the original, and (hopefully) how starkly clear the changes are: the most important thing is that the Orange Line and northern Green Line are different and need to be planned around. The question all of this hinges on: can the diagram provide enough information to adequately re-plan the journey? And that’s the part I don’t know.
Walking transfers
The second-simplest iteration added the walking transfers:
Including the walking transfers worked better than I expected. Quite frankly, I’d like to see these added to the official map (though hopefully a little more elegantly than I’ve done here). There are a lot of walking transfers that ought to be indicated on the system diagram, such as the ones I’ve included here, but also additionally:
State – Downtown Crossing
Government Center – Park
Riverway – Brookline Village
Reservoir – Cleveland Circle – Chestnut Hill Ave
Kenmore – Lansdowne
These transfers would not be suitable for everyone — and it should be noted that they are not free transfers under the current model — but if you are able-bodied and have a monthly pass that doesn’t charge per ride, these transfers are useful, speedy, and potentially can relieve congestion on key sections of the network.
Adding these transfers to the map is a good idea in general, but does it help in the case of the Orange Line & Green Line Closures? Again, I’m not quite sure. In most of these cases, I would guess that regular commuters are pretty familiar with the areas in question, and likely are well-aware that, for example, State and Gov’t Center are practically a stone’s throw apart. And if you aren’t a regular commuter… well, the pretty clear (and dire) direction from both the City and the T has been, “Please, stay away.”
Concluding Thoughts
Working on this diagram has been fun. It also has been nice to see positive response from numerous folks on Twitter. (Shout out to Jeremy Siegel at WGBH for sharing it with his followers!) And at least some of those positive responses have made comments to the effect of, “This is easier to understand than the materials the T has put out.” A few comments on Twitter aren’t necessarily a representative sample; however, the negative reaction to the T’s materials have been widespread and resounding — the Boston Globe going so far as to publish a parody of the official closure diagram.
That negative reaction suggests that there is room for improvement in how the T communicates these closures. I’d argue that the positive reaction to my diagram has been driven by its recognizable similarity to the “normal” map, combined with the clear-and-obvious differences that are blatant and draw attention to themselves.
With rumors swirling of partial shutdowns of the Green and Red Lines later this year, perhaps the T might consider adopting a similar strategy to what I’ve presented here.
“Wait”, you say, “that’s not right. The Green Line turned 100 in 1997, with the centennial of the Tremont Street Subway’s opening.”
True enough. But the Tremont Street Subway, for its first quarter-century of operation, looked quite different from the modern Green Line. It was only in the early 1920s that it began to resemble the system we know today, and it was only in 1922 – not 1897 – that the modern Green Line was born.
An Underground Street
BERy (the Boston Elevated Railway Company, the MBTA’s primary private predecessor) saw the tunnel more like a substitute for the crowded street above than as a proper rapid transit subway.
Streetcars funneled in from all over the city and distant suburbs, squeezing into the subway and crawling along at the speed of a modern bicycle. Contemporary accounts describe crowds surging down the platform at Park Street when the boarding location of the next trolley to such-and-such suburb was announced. The destination board at Park Street in 1899 resembles a departure board at a mainline station like South Station or Grand Central much more than that of a rapid transit station:
The streetcar subways draw a clear contrast with the services which BERy did consider rapid transit (the predecessors to today’s Red and Orange Lines). Beyond the difference in rolling stock (high-platform third rail vs low-platform wired), the rapid transit lines were also distinguished by their use of transfer stations.
A Tale of Two Transit Trips
Compare these two rider experiences:
A commuter from Somerville boards a trolley at the intersection Highland Avenue and Willow Avenue.
The car trundles down Highland, stopping every couple of blocks to pick up passengers.
After 2.7 miles, the car reaches Lechmere Square…
…where it departs from the street and enters the streetcar-only Lechmere Viaduct…
…which snakes over the Charles and around the West End before…
…diving into the subway just north of Haymarket.
After another 1.5 miles, the commuter disembarks at Scollay Square
Vs.
A commuter from Dorchester boards a trolley at the intersection of Blue Hill Avenue and Seaver Street (equidistant from downtown to the Highland/Willow intersection in Somerville).
They actually have a choice of trolleys – bound for Egleston, or bound for Dudley (now Nubian).
They travel by streetcar for 1 to 1.7 miles, stopping every couple of blocks to pick up passengers,
before arriving at their rapid transit station where they get a (free) transfer to the Elevated.
The Elevated speeds into downtown, with stops roughly every three-quarters of a mile.
The commuter disembarks at State Street.
The Somerville commuter takes a long slow ride from the suburb to the core, while the Dorchester commuter takes a short slow ride followed by a short fast ride, enabled by a transfer station.
A Tunnel Filled With Buses
For BERy, in those first 25 years, the Tremont Street and Boylston Street Subways were just ways of getting the huge volumes of streetcars off of the streets in downtown. In today’s terms, those tunnels were essentially filled with buses. This was useful transit service, to be sure, but it wasn’t rapid transit.
The same was true of the East Boston Tunnel. Extended from its Court Street terminus in 1916 to a portal on Cambridge Street (with a turnback loop at Bowdoin, still used today), the tunnel’s primary use was to bring East Boston trolleys under the Harbor into downtown. In fact, early in the planning of the East Boston Tunnel, one option that was considered was to have trolleys exit the tunnel from Maverick through a portal in the North End, and continue on street-level into downtown – similar to today’s Sumner & Callahan Tunnels. The primary use of the tunnel was to get trolleys (or “buses”, if you will) under the harbor – not to create rapid transit service.
In the early 1920s, that all began to change.
Conversion to Rapid Transit
Birth of the Blue Line
The 1924 conversion of the East Boston Tunnel to rapid transit is well-known and offers a clear example of how a streetcar tunnel can be transformed into a rapid transit subway. The vestigial surface route on Cambridge St was converted to bus, and the half-dozen streetcar routes to the east were cut back to terminate at a new transfer station at Maverick. Thereafter the local streetcar services fed into a dedicated rapid transit service, mirroring similar designs at Dudley, Harvard, Sullivan, and others.
This, I would argue, marked the birth of the modern Blue Line; while it is true that today’s State (f.k.a. Devonshire) and Aquarium (Atlantic) stations opened some 20 years prior, it was only with the 1924 conversion that the service became anything like its modern form.
(There’s also an argument to be made that the true birth of the modern Blue Line actually occurred a bit further to the east, during the early and highly successful years of the Boston, Revere Beach & Lynn Railroad, which was essentially running Indigo Line-style service 100 years before its time.)
As a matter of comparison: mainline rail service with today’s rapid transit stop spacing had been running along both the Highland Branch and what is now the Southwest Corridor for 70 years and 100 years respectively before their conversion to rapid transit; but I don’t think we would say that either the modern Green Line or Orange Line were born circa 1888. We would consider those to be predecessor services, and I would argue that we should view the streetcars in the East Boston Tunnel as a similar predecessor service (albeit of a different character).
Birth of the Green Line
Less well-noticed – but I would argue equally important – was the 1922 construction of the transfer station at Lechmere. Like at Maverick, local streetcars were now short-turned at a rapid transit station where passengers transferred to service that was dedicated to bringing riders downtown at high speed.
In fact, in those early years, BERy ran a dedicated service to Lechmere for this purpose; a “shuttle” service ran from Lechmere to the Pleasant Street Portal for the first six months, which was rerouted to Kenmore in early 1923. Note the similarity to the East Boston Tunnel’s rapid transit service – “shuttle” services whose sole purpose is to run between downtown and a transfer station. More information in a contemporary newspaper account here.
Over the following ten years, BERy experimented with extending Lechmere service on to the Commonwealth and Beacon branches, which eventually both through-ran to Lechmere until the early 1960s. With their dedicated medians, the Commonwealth and Beacon branches were indeed the most “rapid-transit”-like of the various services feeding into the Central Subway at the time. They still intermingled with “local bus”-like services to Watertown, Huntington, Egleston, Dudley, City Point, and Sullivan, but the clear intent was to create a “rapid transit” service, as much as possible.
The efforts to replicate the success of the “rapid transit transfer station” model were originally envisioned to go even further. As discussed previously in my Blue Line series, plans were made for another transfer station in Allston, which is why Kenmore station – not constructed until 1933 – was built with a loop for the Beacon line; the hope had been to convert Kenmore into a transfer station for a Beacon streetcar and a Commonwealth rapid transit line, Maverick-style. You can see a 1926 proposal for such a network here:
The construction of the Lechmere transfer station marked the turning point from BERy treating the Tremont Street Subway as a collection of independent streetcar routes into BERy treating the Subway like a trunk line with multiple feeder branches – in short, the modern Green Line.
Death of the Streetcar Network
Following the cutback of the Lechmere services, the once-expansive network of streetcar routes running into the subways (a subject for a later post) started a rapid winnowing in which the same story played out again and again: a transfer station was constructed and the streetcar route was cut back to the transfer; once a route no longer needed to travel into the subway, bustitution almost always quickly followed.
This is one place I want to draw our modern attention to. I’d always thought of bustitution as a phenomenon of the latter 20th century, driven by the post-war embrace of the automobile. In fact, the vast majority of bustitutions happened between 1922 and 1941. If anything, the pace rapidly slowed following the war, and it is in fact remarkable that Arborway survived all the way to 1985.
1922: Lechmere Network cut back once transfer station opens
1924: East Boston Network cut back once Maverick opens
1925: the Ipswich Street Lines (the predecessors to today’s 55, 60, and 65) were truncated at Massachusetts (now Hynes) station
1932: the routes along what is now Route 9 to Chestnut Hill were bustituted and redirected to Kenmore’s surface station
1935: last year that foreign streetcars from the North Shore ran into the subway, halted by the loss of the bridge over the Mystic River
1938: the local streetcar running below the El along Washington St between Dudley and the subway was substituted with a bus (described here)
1941: the Huntington Avenue Subway opened, and streetcars stopped using the Public Garden Incline.
At this point, the winnowing slowed significantly, and the system had largely transformed into the modern Green Line we know today, with a few extra branches (to Egleston, City Point, and Charlestown) hanging around.
Late ‘40s: the two Charlestown branches are eliminated, just barely outliving BERy itself
1953: the City Point branch is eliminated by the MTA
1956: the Egleston branch is cut back to Lenox Street
1959: the Riverside Line is converted to light rail, expanding the MTA’s reach to Route 128
1961: the Lenox Street branch (formerly running to Egleston) is cut back to the Pleasant Street Portal, and briefly runs as a shuttle service between Boylston and Pleasant Street
1962: the shuttle to Pleasant Street is canceled, and the Pleasant Street Portal – once an anchor of the streetcar subway – falls into disuse
1969: the “A Line” – having survived long enough to actually be called “the Green Line” – is eliminated
And in this context, we now see that Arborway’s survival all the way to 1985 almost seems improbable by comparison – the last in a 60-year effort to remove all streetcars from the subway.
The cruel irony is that this effort – originally intended to speed up service and improve reliability in the subway – contributed to an overall degradation of transit access in the region over the following century. Once streetcar routes were taken out of the subway, they were very easy to replace with buses, and once they were replaced with buses, it was very easy to quietly degrade or eliminate service.
Conclusion: 100 years of the Green Line
In writing this, I read a lot of old reports written about Boston transit in the early twentieth century. One thing that struck me is that the reports written in the 1920s have much more in common – in terms of priorities and perspectives – with today’s approaches than they do with the reports written by their predecessors a mere 30 years beforehand.
By the 1920s, recognition had set in that the streetcar subways could and should be converted into rapid transit, using the same transfer hub model that had been successfully deployed at Sullivan, Dudley and Harvard.
(Interestingly enough, it had also become clear by this point that those elevated railways – built barely twenty years earlier – were awful and needed to be replaced as soon as possible; both the Southwest Corridor alignment and the current Haymarket North alignment to Sullivan were explicitly described in the 1926 report.)
The 1922 opening of the new Lechmere transfer station marked this pivot point, after which every single capital exercise carried out on the streetcar network was done with the aim of turning the subway service into a rapid transit service – or getting it as close as possible.
This continues to this day! The Green Line Extension project is undeniably a rapid transit project, and not just a resurrection of the former Lechmere streetcar network, and the same will be true if the Green Line is ever extended to Needham. Moreover, it seems all but certain that a Green Line extension to Nubian Square would need to find ways to make itself as “rapid transit”-like as possible – or else face a century of institutional inertia to overcome.
The notion of a “Green Line” with branches feeding into a trunk – as opposed to an urban streetcar network whose density called for a tunnel in key locations – arose in the early 1920s. Today’s Green Line is much more closely related to the LRT subway service of the 1920s than of the 1900s, in structure, operation, and public branding. It arises out of 1920s ideas about hub-and-feeder networks, which had previously been applied on other routes, and were then brought to the streetcar networks following their success.The creation of the rapid transit line that would become the Green Lineoccurred not in 1897, but in 1922.
And so, that is why, this summer I’m celebrating the Green Line’s (true) 100th birthday.
Acknowledgements
I am indebted to a host of transit historians, who have produced reams of carefully researched accounts detailing the stories of Boston’s transit system over the decades; most of them did so as volunteers, producing labors of love that exemplify the root of the term “amateur”. I want to specifically mention the names of Ron Newman, Bradley Clarke, O.R. Cummings, Frank Cheney, and Anthony Sammarco, as well as the volunteers who maintain the Wikipedia pages on Boston’s transit network.
In a previous post, I described the mathematical inevitability of decreased frequencies on branchlines. But I also alluded to a particular feature that certain systems have that allows them to bypass this particular pitfall. And that brings us to today’s post.
Introduction
Let’s take a simple trunk-and-branch system, which sees 10 tph six-min headways on the core and 5 tph twelve-min headways on the branches:
If those branches are out in the suburbs, those lower frequencies may be justifiable. But what if your system needs to branch within the core?
Introducing the Aldgate Junction:
(“Aldgate Junction” is a term I’ve coined to describe this kind of infrastructure and service pattern; there are other related terms, but I think the way I’ll be using this term is a useful addition to our vocabulary.)
An Aldgate Junction enables a second layer of service to travel in one branch and out the other, without touching the core and (usually) without a reverse move. Sometimes this can be created via a relatively minor infrastructure change, such as adding a third leg to create a wye junction, but sometimes a more significant capital project is required.
The original Aldgate Junction
The original “Aldgate Junction” is actually a trio of junctions and is located at the interchange of the District, Metropolitan, Circle, and Hammersmith & City lines:
The Aldgate Junction concept is deployed here to create a triangle of one-seat rides:
Liverpool St to Aldgate East via the H&C
Aldgate East to Tower Hill via the District Line
Tower Hill to Liverpool St via the Circle Line
Modifying my original diagram above to match the colors allows us to see how the Tube’s topology maps on to the generic model I’m discussing here:
The downside of the original Aldgate Junction in London is that it’s a level crossing, meaning trains block each other as they pass through, which creates a bottleneck. Some Aldgate Junctions utilize flying interchanges to avoid conflicts and increase capacity.
Real-life examples of Aldgate Junctions
There are lots of ways to deploy an Aldgate Junction. It can provide distributed service to decongest central transfer points, or can be used to serve pluricentric regions with multiple “downtowns”. It can also be used to increase frequencies within the corridors of the branchlines, which is valuable for local trips as well as cases where the branch line is unusually long.
Northern California
In my previous post, I mentioned that BART – a rather exceptional rapid transit system due to its enormous reach and mid-low frequencies on each branchline – uses an Aldgate Junction to increase frequencies on its East Bay services.
BART’s Orange Line (also still sometimes called the verbose “Richmond-Berryessa/North San Jose Line”) plays the role of the “branch-to-branch bypass service”. For example: without the Orange Line, stations like Fremont would only see 15-min headways; Fremont is about 30 miles away from San Francisco, so 15-min headways might be appropriate for that service. But Fremont is only 15 miles away from San Jose, and there is a steady level of density running all the way up the East Bay – there are plenty of local journeys that sit squarely in “Rapid Transit Land”, and 15-min headways underserve that.
Providing the Orange Line overlay raises headways to less than 10 minutes throughout the entire West Bay, without impacting capacity in the San Francisco core. Key to this is the Oakland Wye, a three-way flying junction to enable crossovers without interference. This is an example where an Aldgate Junction required significant infrastructure.
There are numerous other systems that use variants of the Aldgate Junction.
First, we see that the Orange County, Inland Empire-Orange County, and 91/Perris Valley lines form an Aldgate Junction in Anaheim. This creates a three-way link between Orange County, LA County, and Riverside County.
But there is a second, more abstract Aldgate Junction, formed by the Orange County, Inland Empire-Orange County, and San Bernardino Line, between LA County, San Bernardino County, and Orange County.
In both cases, these exemplify the use of Aldgate Junctions to serve distributed areas of density. Los Angeles is the core of the system, but Riverside and San Bernardino are major urban centers in their own right, and the use of the Aldgate Junction model creates two sub-networks based in Riverside and in San Bernardino.
The “Riverside Network”
The “San Bernardino Network”
These examples, it should be noted, are cases where an Aldgate Junction is not functioning to increase frequencies; Metrolink’s frequencies are pretty poor, usually only about 1 tph at peak, and little-midday service. In this case the focus is on providing one-seat-rides across a decentralized network, enabling transit journeys to non-Los Angeles destinations that otherwise simply wouldn’t be possible.
New York & New Jersey
Finally, the reigning North American monarch of the Aldgate Junction is New York City.
The New York City Subway has several physical Aldgate Junctions, a notably consistent design feature of the old IND network, highlighted below.
PATH and the HBLR offer an additional lesson about the operational realities of Aldgate Junctions; the maps above represent the daytime versions of those networks. On weekends (and in PATH’s case, at night), the Aldgate Junctions functionally disappear.
All journeys remain possible, but some require transfers.
PATH offloads its HOB-WTC journeys into a two-seat journey with transfer at Grove St; meanwhile, its two routes out of 33rd St are combined into one, with a reverse-move at Hoboken as part of the revenue service pattern. (Functionally, Hoboken is serving as a transfer point in the same way as Grove St; PATH just does the transfer for the passengers by throwing the switches rather than swapping out trains.)
HBLR maintains weekend service to Hoboken, but riders from the north must transfer at Pavonia/Newport and backtrack.
Summary
Aldgate Junctions provide a way to distribute service across a larger area and offer a way to increase service levels on branches without being constrained by trunk line capacity. Their physical form and implementation vary widely, from level wye junctions to complicated flying interchanges to dispersed routes spread across miles. These forms defer in capacity, reliability, and cost.
Despite these differences, Aldgate Junctions are united by consistent contributions to network topologies, and are a valuable tool when designing (and future-proofing) complex systems.
