Green Line Reconfiguration

[Delvin4519]

Every transit project pushes other projects further back. By this argument, we should build nothing.

The inability to keep construction costs low is also irrelevant to the discussion for the same reasons. An expansion done at $1 billion per mile is better than no expansions at all, especially when it's not clear whether other projects of similar construction methods can be done at lower cost-to-benefit ratios (and thus may be just as expensive).

If anything, Red-Blue is one of the most equitable expansion projects. Most other extensions (BLX Lynn, OLX, RLX etc) only have localized benefits to specific cities and neighborhoods, but Red-Blue benefits everyone. Blue Line riders get connections to crucial destinations on the Red Line. Red Line riders get much-needed connections to the airport, East Boston, etc. Orange and Green Line riders also see less direct but still substantial benefits, in terms of fewer people using both lines as a tedious Red-Blue connector, fewer people clogging up the downtown transfer stations (including Cambridge riders going to GC and State), and an alternative to MGH.

I suppose Red-Blue is more akin to Boylston Outer in that regard than with a Huntington Avenue Subway.

Red-Blue is only 1,000 feet to 2,000 feet. So Red-Blue is more akin to 2 billion per mile, not 1 billion.

 

[Riverside]

Giving North Shore communities two- instead of three-seat access to Cambridge-based jobs is a letdown?

This is the big one. I have a series of maps I've been working on (slowly) showing what places are 1SR, 2SR etc from a particular job destination. Red-Blue means that all of the North Shore gets the same level of access to Kendall + Harvard as everywhere else in the region -- for example, someone in Melrose could hop on a bus into Oak Grove (first seat), ride Orange to DTX (second seat), and transfer to Red for Kendall + Harvard. Lynn (a similar distance) would need to do a bus to Wonderland (1st), Blue to State/GC (2nd), Green/Orange to Red (3rd), transfer for Kendall/Harvard (4th).

The North Shore/South Shore contrast is even more marked: someone in a quiet residential corner of Quincy can take a local bus (1st) and board the Red Line directly to Cambridge (2nd). Someone at a similar distance on the North Shore will need a 4SR. The current system is largely designed to make any commute doable in at most 3 seats -- but the lack of Red-Blue disrupts that.

 

[Delvin4519]

This is the big one. I have a series of maps I've been working on (slowly) showing what places are 1SR, 2SR etc from a particular job destination. Red-Blue means that all of the North Shore gets the same level of access to Kendall + Harvard as everywhere else in the region -- for example, someone in Melrose could hop on a bus into Oak Grove (first seat), ride Orange to DTX (second seat), and transfer to Red for Kendall + Harvard. Lynn (a similar distance) would need to do a bus to Wonderland (1st), Blue to State/GC (2nd), Green/Orange to Red (3rd), transfer for Kendall/Harvard (4th).

The North Shore/South Shore contrast is even more marked: someone in a quiet residential corner of Quincy can take a local bus (1st) and board the Red Line directly to Cambridge (2nd). Someone at a similar distance on the North Shore will need a 4SR. The current system is largely designed to make any commute doable in at most 3 seats -- but the lack of Red-Blue disrupts that.

Fixing broken downtown transfers is something of course is very valuable. Fixing Kenmore - OL Northside is relatively trivial, since we already have the tracks and turnbacks to do so, we just need streetcars to use the turnbacks. Red-Blue and NSRL require costly tunnels that cost $1 billion to go 1,000 feet.

However, the moment Teban54 wrote:

• "We have so many transit deserts without any service. Why are we replacing a corridor that already has excellent service?" (Most other rail extensions clearly enlarge the transit footprint.)
• "A subway costs billions of dollars. Why spend them just so that some people can speed up their journey by merely a few minutes?"
• "Why not other Green Line branches? Why don't you bury the B which has higher ridership? Or the C? Why not a subway to Watertown and/or Nubian?"

...
it triggered some of my sentiments of Boston, in some senses, having lost or being unable to reach it's transit ambition in a way.

The ability to keep transit costs low may be helpful for a transit agency to be able to carry, perhaps, say 2 transit expansion projects at once (1 big one, and perhaps 1 smaller one simultaneously). It should be possible to carry out both Red-Blue and OLX+1 to Roslindale Square (or perhaps GLX + 1 to Route 16, but maybe not both simultaneously with Red-Blue) at the same time.

In the case of Boston, there is so much unmet transit needs, that the ability to do multiple expansion projects at once is absolutely essential. Red-Blue costing 1 billion to go 1,000 feet doesn't help. If Red-Blue eats all the bandwidth at once, Boston will hardly be able to do any other expansion projects except for 1 major expansion project per generation. The Big Dig's high price tag probably gives people chills about the prospect of needing to dig another costly, expensive, tunnel in the CBD for NSRL, whenever NSRL is discussed.

 

[737900er]

The ability to keep transit costs low may be helpful for a transit agency to be able to carry, perhaps, say 2 transit expansion projects at once (1 big one, and perhaps 1 smaller one simultaneously). It should be possible to carry out both Red-Blue and OLX+1 to Roslindale Square (or perhaps GLX + 1 to Route 16, but maybe not both simultaneously with Red-Blue) at the same time.

Part of the issue, particularly in the context of GLR, is that many of the dominos have to fall in a certain order to make the various pieces worthwhile.

 

[Charlie_mta]

Absolutely. I find Red-Blue to be a letdown and am somewhat disappointed with it. While it is definitely essential for fixing broken color transfers downtown, it doesn't really extend frequent service to new neighborhoods the same way GLX does. Red-Blue, being a huge cost-blowout to build, would still leave befind the same transit deserts coming out of the project, as with before the project. With only 45% (~765k) of streetcar suburbs accessible from at least 1 frequent route, 55% of our streetcar suburbs are still inaccessible on the frequent grid.

Access to Logan from all points along the Red Line would be helped by the Red-Blue Connector. Sure, the Silver Line goes directly (sort of) from South Station to Logan, but a more direct heavy rail line connection is needed, which the Red-Blue Connector would provide.

 

[Stlin]

Access to Logan from all points along the Red Line would be helped by the Red-Blue Connector. Sure, the Silver Line goes directly (sort of) from South Station to Logan, but a more direct heavy rail line connection is needed, which the Red-Blue Connector would provide.

I'd really like to see any analysis of how Red-Blue could impact the Silver Line generally. There's a lot of questions that haven't been asked yet. Such a transformational project is bound to have downstream effects, such as:

What portion of SL1 airport riders would instead take a 3 seat Shuttle-Blue-Red trip? I would, instead of the SL bus and Ted Williams traffic. What if the shuttle becomes a Massport people-mover? Any people mover would include the BL station, and presumably, be even more attractive as a result. What are SL 3 riders final destinations, and would a transfer at Airport to Blue suit their needs equally well, now that Red Line destinations are more readily accessible? Would removing SL 1/3 from the system / SL transitway allow you to run SL2 as a isolated LRT service, which by existing would then create the impetus for a Seaport-Green Connector as envisaged on this forum as part of Green Line Reconfiguration?

 

[Teban54]

I'd really like to see any analysis of how Red-Blue could impact the Silver Line generally. There's a lot of questions that haven't been asked yet. Such a transformational project is bound to have downstream effects, such as:

What portion of SL1 airport riders would instead take a 3 seat Shuttle-Blue-Red trip? I would, instead of the SL bus and Ted Williams traffic. What if the shuttle becomes a Massport people-mover? Any people mover would include the BL station, and presumably, be even more attractive as a result. What are SL 3 riders final destinations, and would a transfer at Airport to Blue suit their needs equally well, now that Red Line destinations are more readily accessible? Would removing SL 1/3 from the system / SL transitway allow you to run SL2 as a isolated LRT service, which by existing would then create the impetus for a Seaport-Green Connector as envisaged on this forum as part of Green Line Reconfiguration?

SL3 will likely still have a good reason to exist, and this is actually something that had been discussed a few times before. There are plenty of people from Chelsea and BL using SL3 to go directly to Seaport, where it remains the most attractive option by far compared to BL-RL-SL2. Then there are also Chelsea - South Station trips, and the less common ones to RL south of South Station (though definitely with a lot less demand than west of downtown). IIRC, a trip from Airport to South Station is still time-competitive compared to the somewhat roundabout Blue-Red transfer.

I also expect some SL1 riders from commuter rail to continue using it, as well as possibly some riders from southside RL. With SL1, it's a lot less clearer whether it needs to remain a Transitway service, however. (There are also various proposals for removing SL3 from the Transitway that @Riverside and others had crayoned in the past.)

 

[TheRatmeister]

What are SL 3 riders final destinations

Of all inbound SL3 riders who start their trip between Chelsea and Airport, 26% get off at or before Airport, 41% get off between WTC @ Congress St and Courthouse, and 33% get off at South Station. Of riders who board at Airport, around 45% go to South Station, and 55% go to Seaport. Given that Blue->Red will definitely be more reliable, generally faster, and allow for easier access to more destinations, riders who currently board the SL3 at Airport and travel to South Station will almost certainly switch over, however for riders who board before Airport the transfer may make this not worth it, although that would depend on how bad traffic is in the Ted and what their final destination is. If 50% of Chelsea-South Station and 100% of Airport-South Station riders switch, SL3 specific ridership (IE, not trips only on the shared Seaport segment) would decrease by about 20%, with ridership in the Ted Williams Tunnel decreasing by around 25%.

What portion of SL1 airport riders would instead take a 3 seat Shuttle-Blue-Red trip?

Potentially a lot, especially with a people-mover. Only around 15-20% of SL1 riders go to Seaport, the other 80-85% go to South Station. However I think the APM is really crucial to realizing this, without it SL1 will probably still be better most of the time due to the extra transfer required at Airport station.

As for removing SL1/SL3 from the Transitway, I would vote yes. The slow speeds of the transitway make SL1/SL3 worse for riders who aren't going to Courthouse or WTC. Using median lanes on Summer St instead would likely shave off a bit over 2 minutes of travel time in each direction.

 

[Aprehensive_Words]

The main issue of Red-Blue is that it's literally a full billion dollars just to extend the tunnel 1,000 feet down the road. Other countries outside the anglosphere can and have done this much cheaper.

I haven't gone looking for a detailed breakdown of the cost estimate, but a chunk of that has to be the cost of mobilizing the construction crews and equipment, which in a longer project could be amortized out over more kilometers of tunnel, no?

 

[JeffDowntown]

I suppose Red-Blue is more akin to Boylston Outer in that regard than with a Huntington Avenue Subway.

Red-Blue is only 1,000 feet to 2,000 feet. So Red-Blue is more akin to 2 billion per mile, not 1 billion.

The cost also includes a new ADA compliant station under an existing century-old road/rail structure with three or four levels of ADA compliant vertical circulation, and a new underground tail yard for trainset cycling.

But sure, it is only a few 1000 ft. of tunnel

 

[jbray]

The cost also includes a new ADA compliant station under an existing century-old road/rail structure with three or four levels of ADA compliant vertical circulation, and a new underground tail yard for trainset cycling.

But sure, it is only a few 1000 ft. of tunnel

I will say that the 2021 redesign really hampers future expansion of the Red/Blue Connector by moving the tail tracks to the east of the station and ending the ROW with the elevator in the way.

 

[JeffDowntown]

I will say that the 2021 redesign really hampers future expansion of the Red/Blue Connector by moving the tail tracks to the east of the station and ending the ROW with the elevator in the way.

Sometimes there are vested interests who have sufficient influence to cause these design changes to happen to ensure there is never a Blue Line extension beyond Charles (perhaps Back Bay interest groups).

The Hyatt Hotel at Logan is an example of a power broker blockade -- it was built in the 1990's to try to prevent construction of Runway 14/32. It's construction resulted in 14/32 being restricted to 14 takeoffs, 32 landings only -- preventing lots of corporate jets from flying over South Boston.

 

[BlazingZack]

One question about this idea (and I prefer the River Rd option), but do the curbside bus lanes they just added along Washington Street affect this at all? I know they're only a pilot, but do you have those running in the outer lane, one lane for traffic, and then the interior transit lane between River Rd and S Huntington? Or do you make the 66 bus also do center running for a portion?

Yes. Via street-running on Pearl St. Here's a diagram showing a multi-directional configuration (i.e. Huntington trains being thru-routeable onto the D, and South Huntington trains being routeable from Kenmore).

View attachment 55294

An E-to-D train would proceed straight from Huntington to Washington, turn onto River Rd. utilizing the existing pedestrian signal, then turn onto Pearl via a driveway easement, crossing Brookline Ave. at a new signal coordinated with the pedestrian signal. Trains would turn onto the D at a universal crossover and proceed into the existing Brookline Village platform. Same in the reverse direction.

A South Huntington/Arborway train being routed from Kenmore would take the universal crossover and turn out onto sidewalk-facing platforms on Pearl. The sidewalk platforms would be a very tight fit for a 2-car Type 10, but it looks feasible. Then turn onto Washington and proceed to South Huntington via a new wye leg. Ditto the reverse direction. This pattern could also support 'circuit' service Kenmore-Huntington-Park/GC if there were ever a need for it.

If you were only going to do one of these patterns, you could build only half the track to/from the universal crossover and omit the other half. So, for example, if you're not keen on roping in Kenmore to potential patterns you could omit the west half of the Pearl loop and sidewalk platforms, as well as everything on Washington between the Pearl signal and River Rd. signal.


As the street grid is never going to go away, all of this should be permanently feasible.



EDIT: I forgot that there are parking garage curb cuts on Pearl where the platforms are depicted. That's no-go for the platforms. Have to see if instead you can fit turnout platforms on the D Line side of Pearl right after the crossover (perhaps move the crossover further back?). 1-car Type 10 should easily fit...the trick is to see if you can get a 2-car platform back there.

 

[Riverside]

Broadly relevant to the Green Line Reconfiguration concept, I've done a brief formal write-up of "the Kenmore Model and the Lechmere Model". In the Kenmore Model, surface routes from beyond the Inner Belt (~2.5 miles from downtown) enter a subway to run express into the core. The Lechmere Model describes the otherwise common practice on the T, of rapid transit lines that serve Inner Belt transfer hubs, where surface route riders transfer to express rapid transit services.

As an illustration of the two concepts, here's what the T might have looked like if the Kenmore Model had been deployed across the system:

(Don't look too hard at the details -- this is meant to provoke imagination, and isn't a rigorous alternate history exercise. Case in point, there almost certainly would've been a "Red Line" branch to the North Cambridge carhouse off of Mass Ave; I chose to depict something different in order to confound expectations further.)

There are many ways to describe the Green Line Reconfiguration, but I think one way to describe a key tenet is to separate the "Kenmore Model system" from the "Lechmere Model system".

 

[TheRatmeister]

The Lechmere Model describes the otherwise common practice on the T, of rapid transit lines that serve Inner Belt transfer hubs, where surface route riders transfer to express rapid transit services.

I would argue that this model isn't necessary accurate anymore. I would propose a third model, let's call it the Medford model after GLX, where rapid transit is extended/expanded to serve more areas directly. I think the clearest difference between these models can be seen on the Orange Line, with the shift in 1987 from a route highly focused on surface transfers at Forest Hills, Egleston, and Dudley, to one focused more on local demand at stations like Roxbury Crossing, Jackson Sq, and Stony Brook. I think the Alewife, Haymarket North, Wonderland, and of course GLX extensions are all more along these lines. With the BNRD spreading out transfers to many rapid transit stations, I think the importance of some hubs could start to diminish.

That's not to say these models are mutually exclusive, at stations like Harvard and Maverick the "Lechmere" model is alive and well, but the Lechmere and Kenmore models aren't/haven't been mutually exclusive either, the GL branches coexisted with the El previously and with the GLX today.

 

[Riverside]

I would argue that this model isn't necessary accurate anymore. I would propose a third model, let's call it the Medford model after GLX, where rapid transit is extended/expanded to serve more areas directly. I think the clearest difference between these models can be seen on the Orange Line, with the shift in 1987 from a route highly focused on surface transfers at Forest Hills, Egleston, and Dudley, to one focused more on local demand at stations like Roxbury Crossing, Jackson Sq, and Stony Brook. I think the Alewife, Haymarket North, Wonderland, and of course GLX extensions are all more along these lines. With the BNRD spreading out transfers to many rapid transit stations, I think the importance of some hubs could start to diminish.

That's not to say these models are mutually exclusive, at stations like Harvard and Maverick the "Lechmere" model is alive and well, but the Lechmere and Kenmore models aren't/haven't been mutually exclusive either, the GL branches coexisted with the El previously and with the GLX today.

Oh, to be clear, each "model" is only meant to refer to the setup of any given terminal/transfer hub/node. Yes, the two models have coexisted for over a century.

It is also true that the Lechmere Model encompasses a few different varieties. And I agree that GLX actually doesn’t fit either model — none of GLX’s stations are significant transfer hubs, so I agree that it should be distinguished as the “Medford Model”.

I don’t think Wonderland or Haymarket North really fit the Medford Model, though. Wonderland, like Forest Hills, is pretty strongly an Outer Belt "Lechmere" node, anchoring the end of the corridor; GLX doesn't have anything like that.

Which I guess points to the role of surface transit in these model definitions:

• Kenmore Model: subway transforms into (a) surface route(s)
• Lechmere Model: subway connects to a hub of surface routes
• Medford Model: subway lacks surface route anchors

(I'd argue that the extension from Quincy Center to Braintree is the closest pre-GLX example of the Medford Model, as it isn't a major bus transfer hub, although I think the 128-Suburb context complicates that a bit.)

You are right that BNRD's distribution of transfer points may make these terms less useful in a Boston context. As I mention briefly in my blog post, I think the terms are pretty directly relevant to other systems such as San Francisco and Philadelphia. Kenmore Models are otherwise pretty rare in the US, and I think it's useful to have an articulation of that -- it's not that the Green Line is unusual because it's light rail (see St Louis Metrolink or LA Metro), it's not because it has street-running segments (see New Orleans or San Diego), it's because it has this unusual combination of characteristics that arise from the Kenmore Model.

Also worth noting: the Green Line isn't the only Kenmore Model in Boston; the Silver Line Waterfront also fits this definition. It's less readily apparent because the main trunk is so much shorter, but it's there. It even now features a similar heterogeneity among its branches: modest ridership surface running (SL2 and C), high ridership surface running with atypical infrastructure (SL1 and E), longer distance with dedicated ROW and rapid transit stop spacing (SL3 and D).

 

[JeffDowntown]

Oh, to be clear, each "model" is only meant to refer to the setup of any given terminal/transfer hub/node. Yes, the two models have coexisted for over a century.

It is also true that the Lechmere Model encompasses a few different varieties. And I agree that GLX actually doesn’t fit either model — none of GLX’s stations are significant transfer hubs, so I agree that it should be distinguished as the “Medford Model”.

I don’t think Wonderland or Haymarket North really fit the Medford Model, though. Wonderland, like Forest Hills, is pretty strongly an Outer Belt "Lechmere" node, anchoring the end of the corridor; GLX doesn't have anything like that.

Which I guess points to the role of surface transit in these model definitions:

• Kenmore Model: subway transforms into (a) surface route(s)
• Lechmere Model: subway connects to a hub of surface routes
• Medford Model: subway lacks surface route anchors

(I'd argue that the extension from Quincy Center to Braintree is the closest pre-GLX example of the Medford Model, as it isn't a major bus transfer hub, although I think the 128-Suburb context complicates that a bit.)

You are right that BNRD's distribution of transfer points may make these terms less useful in a Boston context. As I mention briefly in my blog post, I think the terms are pretty directly relevant to other systems such as San Francisco and Philadelphia. Kenmore Models are otherwise pretty rare in the US, and I think it's useful to have an articulation of that -- it's not that the Green Line is unusual because it's light rail (see St Louis Metrolink or LA Metro), it's not because it has street-running segments (see New Orleans or San Diego), it's because it has this unusual combination of characteristics that arise from the Kenmore Model.

Also worth noting: the Green Line isn't the only Kenmore Model in Boston; the Silver Line Waterfront also fits this definition. It's less readily apparent because the main trunk is so much shorter, but it's there. It even now features a similar heterogeneity among its branches: modest ridership surface running (SL2 and C), high ridership surface running with atypical infrastructure (SL1 and E), longer distance with dedicated ROW and rapid transit stop spacing (SL3 and D).

One could argue that the Kenmore and Lechmere (and Maverick) models are really the same network structure -- it simply depends on whether some of the surface street cars survived, or got converted to buses. Even Kenmore is a partial bus conversion fan out. Historically all supported some street running cars entering the tunnels.

North Station was another historical subway to street car fan out point -- feeding Charlestown, Chelsea, East Boston and Revere via the Charlestown and old Mystic River bridges. Bus replacement remaining is largely the fan out from Haymarket.

 

[TheRatmeister]

One could argue that the Kenmore and Lechmere (and Maverick) models are really the same network structure -- it simply depends on whether some of the surface street cars survived, or got converted to buses. Even Kenmore is a partial bus conversion fan out. Historically all supported some street running cars entering the tunnels.

North Station was another historical subway to street car fan out point -- feeding Charlestown, Chelsea, East Boston and Revere via the Charlestown and old Mystic River bridges. Bus replacement remaining is largely the fan out from Haymarket.

Some bus hubs (Lechmere and Maverick) originate in this way, but most didn't. Harvard, Sullivan, Ruggles/Dudley/Egleston, Ashmont, etc didn't. They were built as transfer points where it made sense to collect several surface routes, with providing a local service a secondary priority.

 

[JeffDowntown]

Some bus hubs (Lechmere and Maverick) originate in this way, but most didn't. Harvard, Sullivan, Ruggles/Dudley/Egleston, Ashmont, etc didn't. They were built as transfer points where it made sense to collect several surface routes, with providing a local service a secondary priority.

Heavy Rail -- transfers were mandatory; versus Light Rail Streetcars that were compatible with the Street Car Tunnels.

 

[HenryAlan]

Kenmore Models are otherwise pretty rare in the US, and I think it's useful to have an articulation of that -- it's not that the Green Line is unusual because it's light rail (see St Louis Metrolink or LA Metro), it's not because it has street-running segments (see New Orleans or San Diego), it's because it has this unusual combination of characteristics that arise from the Kenmore Model.

I think you could make the case that LA has the Kenmore model at 7th & Flower, where street running trains converge from the west (E-Line) and south (A-Line), then portal down to the connector for express through downtown. On the other end, at Arts District, it's a bit more like the Medford model, as the A-Line to the Valley and E-Line to East L.A. largely follow grade separate ROWs (with occasional street running or grade crossings).