Crazy Transit Pitches

[F-Line to Dudley]

Somehow my Allston-Brighton I-90 corridor map got mentioned here. Anyhow, moving the thread here since it's more suited to this purpose.



The ROW within Newton Corner would have an issue of how many stops are needed to adequtely serve the entire corridor.

The Boston Landing and the proposed Beacon Yard stations have poor connectivity to existing bus routes, although they are located in areas that may be easier for TOD. Lansdowne is halfway between Kenmore and the D's Fenway station, but it's utility is limited without NSRL and low frequency/connections (see the GL operator's comments).

If stops are added along all potential nodes for demand within the corridor, without removing existing stations, it would result in a total of 10 stations in between Newton Corner and South Station, with some stops quite close to one another, especially around Allston. At this point, I'd be going full "god mode sandbox" and not "crazy transit pitch".

View attachment 49366

Origin Station	Destination Station	Walk time (minutes)	Comments	Connections at Origin Station
Newton Corner	West Brighton/Charles River Loop	29 min	33 if the station is located on Parsons St. instead of Brooks St.	57/553/554/556/558 - Newton Corner
West Brighton/Charles River Loop	Brighton Depot	23 min	16 if using Parsons St. location.	64 - Oak Sq
Brighton Depot	Boston Landing	14 min	Quite close stop spacing, especially for RUR, and quite tucked in if it were a god mode sandbox HRT line.	64/86 - Brighton Depot
Boston Landing	Allston Depot	11 min	Stop spacing is too close. However, it Boston Landing were skipped, it would be a 25 minute walk to get to Brighton Depot from Allston Depot, meaning the Boston Landing TOD would have poor connectivity with a 13 minute walk to get to either station.	64 Boston Landing - lengthy detour (not useful)
Allston Depot	Beacon Yards/West Station	13 min	Better connections with the 66 and 64 bus.	66/64 - Allston Depot
Beacon Yards/West Station	Cottage Farm/BU West/BU Bridge	9 - 11 min	Excessively close stop spacing for RUR and probably HRT too. May be better if the station is shifted ever so slightly east to balance the distance to BU Bridge. The area around the BU Bridge is in the throat, so space is probably too tight for a station, bridge, railway junction, and highway.	no bus connections
Cottage Farm/BU West/BU Bridge	Lansdowne	20 min	Seems reasonable, most of BU is covered by one of the two's walksheds.	47/57 - BU West, Grand Junction Railway to Cambridge (railway junction)
Lansdowne	Hynes Convention Center/Mass Ave. (I-90-B&A station)	17 min	I'm going full "god mode sandbox" here. For a "Green Line relief valve", I much prefer a routing to Back Bay station, as Storrow Drive, while Storrow's ROW could be repurposed, the walkshed of Storrow just sucks with half of it being water, plus Back Bay provides connections from west to south.	60/65/8/19 - Lansdowne, 6 minute walk to Kenmore Station or GL D Branch (Fenway)
Hynes Convention Center/Mass Ave. (I-90-B&A station)	Back Bay Station	16 min	"Green Line relief valve" (ditto)	1/GL B/C/D - Hynes Convention Center,
Back Bay Station	South Cove (Washington St.)	16 min	Mostly to provide service to Chinatown and South End, and a more direct connection to the Silver Line and points south from the west. Primarily rationale and my ideal "god mode sandbox's Green Line relief valve".	OL, Commuter Rail, Amtrak - Back Bay Station
South Cove (Washington St.)	South Station	19 min	Overlaps with SL4	SL4/SL5/9 - South Cove & Herald St. & Washington St.

If all of the stops are used as actual stops (with about 1.65 - 2 mins per stop), Such a trip from Newton Corner to South Station would take about 19 - 22 minutes. A trip from Newton Corner to Back Bay would take 16 - 17 minutes, a transfer to OL to continue downtown, would be 29 minutes (7 mi/11.3 km) from Newton Corner including transfer time at Back Bay. Such a travel time and trip length would be more suitable for LRT or HRT, and such stop spacing could allow for a reduction of bus routes in the area, as most of the utlity of the bus routes would be covered by such line, but RUR would not suffice.

So my thoughts are, how many stops are needed between Newton Corner and South Station, and what would be appropiate travel times to Back Bay, South Station, and DTX, from Newton Corner?

The 1945 expansion map had the B&A rapid transit line doing stops at Broadway (South Cove-ish), Trinity Place (Back Bay-ish), Cottage Farm, Allston, Brighton, Faneuil, and Newton Corner. The pronounced gap between Back Bay and Cottage Farm was probably ripe for an extra stop near Kenmore, but there was a small freight yard at the former junction with the Highland Branch so siting of a Landsdowne analogue was uncertain at the time. Except for Broadway those were the B&A station locations verbatim.

I think the only way you could mount this as rapid transit is if a Blue Line extension from Charles MGH to Kenmore went along a torn-down Storrow Drive, then banged a right at the B&A at Brookline Avenue in a subway to pick up all the stops Cottage Farm thru Newton Corner...then probably turn under Galen St. to Watertown. You definitely can't do that many stations on RR. The need for 1 set of crossovers every 2 stations to mix expresses with locals places an upper limit on how many stops you can cram in before the whole works on the B&A slows down to a crawl. You're probably only looking at Newton Corner as an infill all the way out to 128...*maybe* Faneuil, but that might even be pushing it.

 

[CheapLeak]

Unrelated to current discussion but i want to ask. I found this post and was curious if anyone knew the title of the book and where to find it.

 

[Teban54]

The ROW within Newton Corner would have an issue of how many stops are needed to adequtely serve the entire corridor.

The Boston Landing and the proposed Beacon Yard stations have poor connectivity to existing bus routes, although they are located in areas that may be easier for TOD. Lansdowne is halfway between Kenmore and the D's Fenway station, but it's utility is limited without NSRL and low frequency/connections (see the GL operator's comments).

If stops are added along all potential nodes for demand within the corridor, without removing existing stations, it would result in a total of 10 stations in between Newton Corner and South Station, with some stops quite close to one another, especially around Allston. At this point, I'd be going full "god mode sandbox" and not "crazy transit pitch".

View attachment 49366

[...]

A first high-level principle that I would propose: Anything beyond just West Station and Newton Corner necessitates rapid transit, not regional rail. Unlike all my other "pseudo rapid transit" corridors like Fairmount, the B&A experiences strong demand from both urban (in-128) and suburban (outside-128) segments, and it's the only such case in the entire system. A clear tradeoff exists between the needs of Allston, Brighton and Newton and those of Natick, Framingham, Worcester etc. The latter group is important not just important for the suburban riders, but also for regional connectivity given the prominence of Worcester. The two aforementioned infills already result in 7 stops between 128 and Back Bay (exclusive), and that number is only exceeded by Fairmount Line; I feel anything beyond that will slow down Framingham and Worcester trains too much.

Spoiler: How to bring rapid transit here?

My own pick would be: a Blue Line extension to Auburndale via the B&A, as a surface route whenever permitted and elevated whenever not, with a branch to Watertown from Galen St.

From a network design perspective, this is a vast area that lacks HRT (or any grade-separated transit spine even with the D considered). GL is already borderline incapable of dealing with the demand at Kenmore, much less with such extensions further west. BL is the easiest way to introduce HRT here, and also solves the inelegance of it being a "half-line", which I feel is a bit of a waste of resources. Moving to rapid transit also has substantial benefits for regional rail service, by eliminating the need to make as many as 7 stops here.

As for engineering, while the ROW is very squished next to the Pike, it seems that most segments have enough room for 4 tracks, at least. Some sections do not, which is why I mentioned Els to go around these points; a few of these bottlenecks may also be dealt with by shortening the westbound emergency lane on the Pike, if possible. An El along the entire corridor may also be considered if the political challenges can be solved; a subway is always feasible if the costs are deemed reasonable. Regardless, my preliminary assessment is that it's more of a political problem than an economical one.

Spoiler: Is this the right corridor for rapid transit?

A natural question that arises: If we're sending rapid transit here - especially if a subway ends up being required - why not deviate from the railroad ROW? The section east of Newton Corner in particular is a bit underwhelming in density due to neighboring Charles River, while parallel corridors, especially the 57 corridor, serve much more residents.

My current thought is: A subway is absolutely required if we're tunneling under the 57, but that may not be the case when following the B&A. Surface and elevated alternatives may play out in theory, if the political challenges can be solved. This will result in significant cost savings that make the extension much more realistic and competitive.

In the event that a subway is required even for the B&A corridor, then I'm not sure which option will be cheaper. On one hand, burying the 57 likely means either TBM, or C&C while closing off the entire corridor (whose local impacts will likely be too much), while also probably having to deal with utilities (hopefully better mapped since I can't imagine the street being dug up before the streetcars discontinued). On the other hand, tunneling under the Pike may be C&C-able in theory, but in practice that means closing off either highway lanes or commuter rail for years, neither of which sound likely. (Correct me if I'm wrong.)

 

[Teban54]

(continued)
Now, my comments on the individual stations, from most to least crucial in my opinion.

[Commuter rail territory IMO]

1. West Station: Already happening.

2. Newton Corner: This is the one station that's most universally agreed upon, with strong bus connections, decent walk-up density, and proximity to Watertown Square. The only questions are about implementation, as I had seen some concerns about it; though I always thought there should be no problem with commuter rail platforms east of the hotel.

[Rapid transit territory IMO]

3. Cambridge St/Allston Depot/Allston Village: Definitely makes the strongest case among the remaining sites.

• Highest density by far on both sides of ROW, strong connection to the 66 (and 64) buses, and a 5-min walk away from most of the commercial and restaurant districts of Union Sq Allston. There's even an existing pedestrian footbridge that can be incorporated into the station, and the ROW is wide enough for 4 tracks + 2 platforms.
• The only problem is that it's too close to the adjacent stations. The footbridge is 1950' from the center of Boston Landing and ~2150' from West Station, on the shorter side even by rapid transit standards (southside OL and GLX are typically 3000'). While I do think a rapid transit station here is absolutely justified despite the distance, it may present issues for commuter rail, with acceleration concerns and adding to the sheer number of stops in general. But if these are not huge problems, I'm happy to move this into the commuter rail territory.
• Note that commuter rail and radial rapid transit may not be the only two options here. For example, my GLR map included an extension of Grand Junction LRT to Boston Landing (with the Boston Landing LRT station east of CR station), with an intermediate stop at Allston Village. This seems easily implementable with surface tracks.

(I'm torn ranking the next two, so I'll list them as 4a and 4b, instead of 4 and 5.)
4a. Faneuil/Brooks St or Parsons St: The unideal "Oak Square" stop or possibly "Arsenal Mall" stop.

• Pros: Covers a good chunk of the residential Oak Square; good stop spacing; a footbridge to Arsenal Mall can possibly be constructed.
• Cons: Half of the walkshed is blocked by the river, and the other half may not be quite enough for a stop, as it's a rather long walk to most residents. I also have some doubts about the utility of the footbridge: it's about 1800-2100' to Arsenal St, similar to the distance from Assembly to Encore, or about a 10-min walk. No bus connections.
• ROW is enough for 2 tracks + platforms.

Spoiler: Brooks St vs. Parsons St

Regarding @Delvin4519's question of "Brooks St or Parsons St":

• It appears that demands from Brighton slightly lean towards the west (Oak Square), in terms of both residential density and the 57's inbound ridership.
• Arsenal Mall is closer to Parsons St on paper, but that requires you to construct a longer footbridge. Vice versa for Brooks St.
• Another merit of Parsons St may be a better "Brighton Center substitute": it's an 18-min walk to Brighton Center, similar to Market St's 16-min walk. You can think of Parsons St as a compromise between Oak Square and Brighton Center, while Brooks St specializes in Oak Square.
• Given all this and stop spacing concerns, I would lean towards east (Parsons St) if Market St is not built, or west (Brooks St) if it is.

Nevertheless, the two streets are 1100' apart, so for a commuter rail station it's perfectly reasonable to put the platform between them, with exists in both sides.

4b. Market St/Brighton Depot: The unideal "Brighton Center" stop, if 4a is built at the western location or not built.

• Pros: Better pedestrian and bus connections to both sides of the ROW than Faneuil, and better bus connections than Boston Landing. Closest stop to Brighton Center on the ROW.
• Cons: The main issue is stop spacing. About 2400-2700' to the center of Boston Landing, which is a little bit close for rapid transit, much less commuter rail (even if not as "bad" as Allston Village). There are also overlaps with Boston Landing's walkshed, both in the TOD area to the south, and perhaps even to the north. From here to Faneuil station is more reasonable for rapid transit, but still too close for commuter rail.
• Since the ROW curves at Market St, any platforms need to be to the west. Seems enough for 2 tracks + platforms.

[Probably only worth it for a brand new rapid transit line, not BLX or CR]

5. Comm Ave/Cottage Farm/BU: I understand the rationale which seems tempting, but I can't find a station site that's feasible and achieves the intended purpose well.

• Firstly, my BLX proposal doesn't need this station at all, as it can instead use Comm Ave between Kenmore and BU Bridge with a much more central station at BU Central/East. So this really only applies to either commuter rail, or a brand new rapid transit line that follows B&A throughout.
• Even then, the main concern is that: (1) The space is tight; (2) Connecting to the B branch isn't as easy as it seems.
  • You can't put the station too far north, as it interacts with the throat, the BU College of Fine Arts building to the NW. Even under Comm Ave may still have issues, this time with the Peter Fuller building and support pillars for Comm Ave overpass itself. (There's plenty of space under Comm Ave to the north of the Pike, but not to the south.) So I see the only feasible solution as east of BU Bridge.
  • While there's enough length east of BU Bridge, the problem is width to the north of existing tracks. Looks like it requires shifting the tracks south while on a curve here, which may present issues. It also interferes with potential BU air rights development in the future.
  • To make things worse, connection with the B is complicated. The B doesn't have a stop at BU Bridge, so you're looking at a walking connection to BU Central (most likely) or Amory St wherever the commuter rail platform is.
• The best bet may actually be to center the station at St Mary's St, which is a short walk from BU Central even if an unpleasant one. This is similar to @Riverside's proposal for his Urban Ring route. But even then, I feel this is only if you really want to have a station that serves BU, and its benefits are otherwise marginal, especially when such a location gets close to Lansdowne.

6. Mass Ave/Hynes Convention Center: Insufficient ROW for commuter rail, and while it's a must-have on a brand new B&A rapid transit line, that's the only scenario where the station is realistic.

7. Washington St/Bay Village/South Cove: Same as above, but even more marginal (pun unintended) for anything other than a brand new line.

 

[Delvin4519]

(continued)
Now, my comments on the individual stations, from most to least crucial in my opinion.

5. Comm Ave/Cottage Farm/BU: I understand the rationale which seems tempting, but I can't find a station site that's feasible and achieves the intended purpose well.

• Firstly, my BLX proposal doesn't need this station at all, as it can instead use Comm Ave between Kenmore and BU Bridge with a much more central station at BU Central/East. So this really only applies to either commuter rail, or a brand new rapid transit line that follows B&A throughout.
• Even then, the main concern is that: (1) The space is tight; (2) Connecting to the B branch isn't as easy as it seems.
  • You can't put the station too far north, as it interacts with the throat, the BU College of Fine Arts building to the NW. Even under Comm Ave may still have issues, this time with the Peter Fuller building and support pillars for Comm Ave overpass itself. (There's plenty of space under Comm Ave to the north of the Pike, but not to the south.) So I see the only feasible solution as east of BU Bridge.
  • While there's enough length east of BU Bridge, the problem is width to the north of existing tracks. Looks like it requires shifting the tracks south while on a curve here, which may present issues. It also interferes with potential BU air rights development in the future.
  • To make things worse, connection with the B is complicated. The B doesn't have a stop at BU Bridge, so you're looking at a walking connection to BU Central (most likely) or Amory St wherever the commuter rail platform is.
• The best bet may actually be to center the station at St Mary's St, which is a short walk from BU Central even if an unpleasant one. This is similar to @Riverside's proposal for his Urban Ring route. But even then, I feel this is only if you really want to have a station that serves BU, and its benefits are otherwise marginal, especially when such a location gets close to Lansdowne.

I think it's also worth noting that even the connection between the 47 bus and the B branch of the Green Line is also not direct, even though the 47 and the B overlap at BU Bridge/BU West.

Looking at the connection between the B and the 47, shows recommendations to transfer at BU Central or Amory, even if travelling/coming westbound on the B branch towards/from the suburbs. In such a case, if it's not possible to optimize a connection with the B branch, I'd like to see how possible would it be to optimize a transfer from the B & A line with the 47 bus around the BU West area. (i.e. the best site to place such a station). Such a connection with the 47 would provide more direct connections/transfers/access to the Longwood Medical Area from the I-90 corridor of Allston-Brighton (barring digging new tunnels, instead focusing on connecting existing ROWs with existing bus lines). The B branch connection is not as necessary, since one can transfer at Allston Depot or Brighton Depot to the 66 or 86 bus lines to access destinations along the B branch. Whereas, a connection with the 47 provides more unique connections.

The throat seems too tight due to the highway, and unfortunately as such, impractical, for 4 way connection of Grand Junction, B & A mainline, the 47, and the 57/B branch anyways, so the Grand Junction railway would have to travel all the way to Beacon Yards to join the B & A line for a connection.

Showing recommended directions from the 47 to the B branch gives the following results:

 

[ritchiew]

Unrelated to current discussion but i want to ask. I found this post and was curious if anyone knew the title of the book and where to find it.

The link in that post is dead, but you can still find the whole document in the Wayback Machine

The Transportation Plan for the Boston Region - Volume 2 - Nov 15, 1993

 

[as02143]

They're linked with something north of the river, but that something will never be Cambridge. That's the problem. These riders are disproportionately using their one-seat rides to get to/from Cambridge.

NSRL is not going to be a perfect panacea for transfers. At 100 feet underground, the stations are going to have significant vertical transportation penalties to get to the rapid transit transfers upstairs because of the sheer length of the escalators. It's definitely on the order of 3-5 minutes worse than the current Red-Silver, Red-Orange and Red-Green transfers.


Red Line Transformation is shrinking Braintree headways to 6 minutes at peak. That's quite likely better than RER is ever going to be able to do.

If we're going crazy rather than god-level - seems like an idea would be to go full Tokyo and operate some (or all?) of the old colony lines as through-running into the subway.

 

[CheapLeak]

The link in that post is dead, but you can still find the whole document in the Wayback Machine

The Transportation Plan for the Boston Region - Volume 2 - Nov 15, 1993

Thank you! I have to ask though, does volume 1 exist?

 

[KCasiglio]

Thank you! I have to ask though, does volume 1 exist?

Per the MPO's website, their archives go back to 1990, so they should still have it. It doesn't appear to be in the digital archive but you can request it by calling them.

 

[CheapLeak]

Per the MPO's website, their archives go back to 1990, so they should still have it. It doesn't appear to be in the digital archive but you can request it by calling them.

Thank you as well.

 

[ritchiew]

Thank you! I have to ask though, does volume 1 exist?

Yeah, what @KCasiglio said. I didn't know you could do that.

One other suggestion for you (or anyone) is contact the Boston Public Library, or go ask in person. They have researchers on staff, available to anyone, and they're awesome. It's an incredible public service.

 

[F-Line to Dudley]

If we're going crazy rather than god-level - seems like an idea would be to go full Tokyo and operate some (or all?) of the old colony lines as through-running into the subway.

Different loading gauges = no-go physical clearances in the Red Line tunnels, even for the smallest domestic EMU's like LIRR's. Amongst other modal incompatibilities.

 

[Riverside]

A natural question that arises: If we're sending rapid transit here - especially if a subway ends up being required - why not deviate from the railroad ROW? The section east of Newton Corner in particular is a bit underwhelming in density due to neighboring Charles River, while parallel corridors, especially the 57 corridor, serve much more residents.

My current thought is: A subway is absolutely required if we're tunneling under the 57, but that may not be the case when following the B&A. Surface and elevated alternatives may play out in theory, if the political challenges can be solved. This will result in significant cost savings that make the extension much more realistic and competitive.

In the event that a subway is required even for the B&A corridor, then I'm not sure which option will be cheaper. On one hand, burying the 57 likely means either TBM, or C&C while closing off the entire corridor (whose local impacts will likely be too much), while also probably having to deal with utilities (hopefully better mapped since I can't imagine the street being dug up before the streetcars discontinued). On the other hand, tunneling under the Pike may be C&C-able in theory, but in practice that means closing off either highway lanes or commuter rail for years, neither of which sound likely. (Correct me if I'm wrong.)

I think if the Blue Line is going to be extended beyond West Station (or Boston Landing), it should be TBM at least under the 57. I'm more agnostic about what happens west of Newton Corner.

The way I see it, there are two possibilities: A) high frequency Regional Rail service sees explosive ridership and is a runaway success, in which case there will be clear demand and therefore justification for TBM; or B) high frequency Regional Rail sees good but not explosive ridership, suggesting it is sufficient for the corridor.

I think your assessment of the potential station sites between Newton Corner and West Station is illustrative of the need for the 57 corridor vs the B&A -- the river eats up your walkshed, and the cross-streets (and lack thereof) reflect that the B&A corridor itself has always been somewhat remote to the neighborhood itself.

^^ This is part of a larger point I'm coming to appreciate: most proposals for new transit in Greater Boston are constrained to the ROWs that were first "claimed" by railroads in the 19th century. (As early as 1850 in some cases.) Beyond the obvious fact that the region has changed since then, it's also worth noting that those railroads were, in many cases, built specifically to avoid existing settlements. Most if not all of the existing settlements in 1850 are still major neighborhoods today, so are going to be chronically underserved if transit remains constrained to its historical ROWs.

 

[Teban54]

I think if the Blue Line is going to be extended beyond West Station (or Boston Landing), it should be TBM at least under the 57. I'm more agnostic about what happens west of Newton Corner.

The way I see it, there are two possibilities: A) high frequency Regional Rail service sees explosive ridership and is a runaway success, in which case there will be clear demand and therefore justification for TBM; or B) high frequency Regional Rail sees good but not explosive ridership, suggesting it is sufficient for the corridor.

I think your assessment of the potential station sites between Newton Corner and West Station is illustrative of the need for the 57 corridor vs the B&A -- the river eats up your walkshed, and the cross-streets (and lack thereof) reflect that the B&A corridor itself has always been somewhat remote to the neighborhood itself.

^^ This is part of a larger point I'm coming to appreciate: most proposals for new transit in Greater Boston are constrained to the ROWs that were first "claimed" by railroads in the 19th century. (As early as 1850 in some cases.) Beyond the obvious fact that the region has changed since then, it's also worth noting that those railroads were, in many cases, built specifically to avoid existing settlements. Most if not all of the existing settlements in 1850 are still major neighborhoods today, so are going to be chronically underserved if transit remains constrained to its historical ROWs.

I like that idea in principle (and indeed, my analysis was virtually leaning towards that idea), but my concerns are:

• Cost, obviously. I think there may be an intermediate between your two possibilities: The ridership is enough to justify a surface or elevated rapid transit extension along B&A and the Pike, which sees 5-min frequencies instead of 10-15, but not a deep bored subway.
• The 57 alignment (even if starting after West Station) omits Boston Landing, which I feel has potential to become a major node or even destination on its own thanks to the TOD (with even greater future potential as currently discussed here).

If we're using the TBM card anyway, I suppose you can do something like this:

 

[KCasiglio]

That jaunt up Market Street is a pretty steep grade. I remember that being a reason why replacing the C line with blue was considered impractical.

 

[Riverside]

I think there may be an intermediate between your two possibilities: The ridership is enough to justify a surface or elevated rapid transit extension along B&A and the Pike, which sees 5-min frequencies instead of 10-15, but not a deep bored subway.

I agree that that is an intermediate option -- tbh I tried to articulate something like that but couldn't put it as succinctly as you did. In any case, though, in that scenario my first thought would be to look at triple (if not quad) tracking the mainline in strategic locations, with the aim of squeezing out the maximum frequencies possible -- see if you can bring the frequencies into consistent SUAG territory, if not <10 min headways outright.

That said, if full quad-tracking will be required to get those max frequencies, then it might just make more sense to use those two new tracks for the Blue Line anyway.

If we're using the TBM card anyway, I suppose you can do something like this:

I like this design! Certainly seems reasonable enough for a crayon map.

 

[Teban54]

That jaunt up Market Street is a pretty steep grade. I remember that being a reason why replacing the C line with blue was considered impractical.

That may indeed a concern. Based on Google Earth Pro, it looks like the B&A at Market St is 22 ft above ground, and rises to a whopping 93 ft at Brighton Center. The climb starts near Faneuil St, with an average grade of 3.1% in 2100 ft; the grade for the last 2/3 of the slope is 3.4%.

However, I don't think that's infeasible. As noted here on my website, there are a few 4% grades on our Red and Orange lines, albeit for only half as long (the Red Line's 4% grade spans 1200'). NYC subway has grades of 5.4-5.5%. Plus, there's technically no limit as to how deep Brighton Center station is, especially since the elevation goes down to 40-50' halfway from there to Oak Square. Putting the station deeper underground can buy you a gentler grade (I think 3% would be reasonable).

 

[Delvin4519]

I think if the Blue Line is going to be extended beyond West Station (or Boston Landing), it should be TBM at least under the 57. I'm more agnostic about what happens west of Newton Corner.

The way I see it, there are two possibilities: A) high frequency Regional Rail service sees explosive ridership and is a runaway success, in which case there will be clear demand and therefore justification for TBM; or B) high frequency Regional Rail sees good but not explosive ridership, suggesting it is sufficient for the corridor.

I think your assessment of the potential station sites between Newton Corner and West Station is illustrative of the need for the 57 corridor vs the B&A -- the river eats up your walkshed, and the cross-streets (and lack thereof) reflect that the B&A corridor itself has always been somewhat remote to the neighborhood itself.

^^ This is part of a larger point I'm coming to appreciate: most proposals for new transit in Greater Boston are constrained to the ROWs that were first "claimed" by railroads in the 19th century. (As early as 1850 in some cases.) Beyond the obvious fact that the region has changed since then, it's also worth noting that those railroads were, in many cases, built specifically to avoid existing settlements. Most if not all of the existing settlements in 1850 are still major neighborhoods today, so are going to be chronically underserved if transit remains constrained to its historical ROWs.

Don't most railway ROWs have much gentler curves than existing bus routes? Such sharp curves that follow the street grid, such as the Harvard curve on the RL, or the Boylston Curve on the GL, require severe speed limits for such significant curves. Such limitations would make for longer travel times, or in some cases, frequency limitations (like that of the RL's Harvard curve, which IIRC seems to be capped at 3 min intervals in the trunk). Many ROWs tend to avoid such twisty streets and high grades, which allows quick travel to the outer terminals (Oak Grove (5.2/5.7 mi) in 17 minutes from Downtown, and West Roxbury HRT in 27 minutes (7.5/8.2 mi) on the OL), but today's built environment and rising seas would mean costly tunneling is the only way to reach today's hubs the same way the old historical ROWs did.

To tunnel under existing streets, would suggest that some bus routes/transit routes should first be straightened to run in more straighter paths to avoid the speed restrictions seen in the Harvard, Boylston, or Prudential curves in the subway system. (I do get the concern though, running street level transit from Ruggles or Lansdowne to LMA would leave LMA without direct service, so a subway following Huntington and Brookline Aves would be needed to directly serve it, but that Prudential curve severely limits the speed for the more "direct" ROW/tunnel routing to LMA, compared to OL being a lot faster to Ruggles)

The 57 routing requires a turn at Union Square in Allston, plus some more hard turns in Oak Square and Newton Corner (the turn at Oak Square is particularly sharp), following the route of the streetcar tracks. Only the turn by St. Elizabeths seems to be a more gentle one. Straightening such a sharp turn (like that of the Market St. crayon map), may end up tunneling under buildings instead of tunneling beneath the road itself.

A Mass Pike routing on the B & A mainline could allow for rapid transit metro to still have a top speed of 50 or 55 MPH (80 or 90 KMH) for much of the route, especially for the stretch just east of Newton Corner, meaning even with stops spaced ~3000 ft (1km) apart like GLX, it would still have an average speed akin that to GLX (20.5 MPH, 33 KMH w stops, but GLX has a 40 MPH/64 KMH speed limit), and get from Newton Corner to Back Bay in a little over 15 minutes, and Downtown in 20 - 25 minutes.

Many of the express buses 501/504/505, are timetabled to get from Newton Corner to Downtown in 34 minutes (the 501/503 and 502/504 were combined as such the express portion ends at Copley instead of South Station). If a rapid transit line results in curtailing of the express buses, a straightened route could speed commutes by 40% from Newton Corner. Such sharp curves and deviations along Market St. could penalize the travel times quite a bit.

It may also be possible to reconfigure and straighten the buses at Brighton Center significantly if the B & A routing is used for rapid transit (plus the same if Reservior - Brookline Village is converted to HRT). Brighton Center could get direct bus connections to 3 HRT lines via a frequent 86, plus a direct link to Central Sq. Cambridge, and a frequent 65 extension to Watertown or Boston Landing.

 

[Teban54]

Don't most railway ROWs have much gentler curves than existing bus routes? Such sharp curves that follow the street grid, such as the Harvard curve on the RL, or the Boylston Curve on the GL, require severe speed limits for such significant curves. Such limitations would make for longer travel times, or in some cases, frequency limitations (like that of the RL's Harvard curve, which IIRC seems to be capped at 3 min intervals in the trunk). Many ROWs tend to avoid such twisty streets and high grades, which allows quick travel to the outer terminals (Oak Grove (5.2/5.7 mi) in 17 minutes from Downtown, and West Roxbury HRT in 27 minutes (7.5/8.2 mi) on the OL), but today's built environment and rising seas would mean costly tunneling is the only way to reach today's hubs the same way the old historical ROWs did.

To tunnel under existing streets, would suggest that some bus routes/transit routes should first be straightened to run in more straighter paths to avoid the speed restrictions seen in the Harvard, Boylston, or Prudential curves in the subway system. (I do get the concern though, running street level transit from Ruggles or Lansdowne to LMA would leave LMA without direct service, so a subway following Huntington and Brookline Aves would be needed to directly serve it, but that Prudential curve severely limits the speed for the more "direct" ROW/tunnel routing to LMA, compared to OL being a lot faster to Ruggles)

The 57 routing requires a turn at Union Square in Allston, plus some more hard turns in Oak Square and Newton Corner (the turn at Oak Square is particularly sharp), following the route of the streetcar tracks. Only the turn by St. Elizabeths seems to be a more gentle one. Straightening such a sharp turn (like that of the Market St. crayon map), may end up tunneling under buildings instead of tunneling beneath the road itself.

A Mass Pike routing on the B & A mainline could allow for rapid transit metro to still have a top speed of 50 or 55 MPH (80 or 90 KMH) for much of the route, especially for the stretch just east of Newton Corner, meaning even with stops spaced ~3000 ft (1km) apart like GLX, it would still have an average speed akin that to GLX (20.5 MPH, 33 KMH w stops, but GLX has a 40 MPH/64 KMH speed limit), and get from Newton Corner to Back Bay in a little over 15 minutes, and Downtown in 20 - 25 minutes.

Many of the express buses 501/504/505, are timetabled to get from Newton Corner to Downtown in 34 minutes (the 501/503 and 502/504 were combined as such the express portion ends at Copley instead of South Station). If a rapid transit line results in curtailing of the express buses, a straightened route could speed commutes by 40% from Newton Corner. Such sharp curves and deviations along Market St. could penalize the travel times quite a bit.

It may also be possible to reconfigure and straighten the buses at Brighton Center significantly if the B & A routing is used for rapid transit (plus the same if Reservior - Brookline Village is converted to HRT). Brighton Center could get direct bus connections to 3 HRT lines via a frequent 86, plus a direct link to Central Sq. Cambridge, and a frequent 65 extension to Watertown or Boston Landing.

View attachment 49459

A few quick comments:

• I think the curvature of tracks only plays a rather small part of travel speed, especially if the curve is also relatively gentle like those on the 57 (which can be done theoretically with TBMs). If anything, the number of stops matters a lot more for travel speed.
• In many cases, the time savings from a more direct route gets eliminated by the extra time it takes to get to the station in the first place. (This alone does not speak against a B&A routing entirely, but it does play a part.)

 

[Delvin4519]

A few quick comments:

• I think the curvature of tracks only plays a rather small part of travel speed, especially if the curve is also relatively gentle like those on the 57 (which can be done theoretically with TBMs). If anything, the number of stops matters a lot more for travel speed.
• In many cases, the time savings from a more direct route gets eliminated by the extra time it takes to get to the station in the first place. (This alone does not speak against a B&A routing entirely, but it does play a part.)

Comparing the travel times for the Orange Line from Roxbury Crossing to Back Bay, gives a travel time of 4.5 minutes to go 3 stops (1.5 miles, 2.5 km). The E branch of the Green Line, which runs on street level in dedicated lanes from Brigham Circle to Copley, takes 9.4 minutes from LMA to Copley, 1.6 miles (2.7 km). A similar distance, but twice as long on the Green Line E branch than the Orange Line, with 5 stops instead of 3. (Brigham Circle is 11.3 mins, but 1.9 mi, 3.1km). Even during off peak hours, it still takes 9.8 minutes to travel from Brigham Circle to Copley in late nights and early mornings with minimal traffic.

Even with a Huntington Ave Subway extension from Symphony to Brigham Circle, plus elimination of the Northeastern and Prudential stops, it still would be slower to ride the Huntington Ave. Subway from Brigham Circle to Copley, than the equivalent trip from Roxbury Crossing to Back Bay on the Orange. Removing Prudential and Northeastern stops might save 2 minutes of travel time, plus 1-2 minute off peak/3-4 minute peak periods of street running shifted underground and removal of 10 mph/16kmh at switches. The end result being 7 - 8 minutes from Brigham Circle (6 minutes from LMA) to Copley on the Huntington Line, compared with 4.6 minutes from Roxbury Crossing to Back Bay on the Orange.

I suppose the Huntington Ave. Subway would need conversion from LRT to proper HRT (assuming the curves are slightly smoothed to meet the Harvard Curve's turning radii), but even then, following the exact Green Line routing to Copley would still likely be slower from the equivalent GL stops, versus the OL stops at Roxbury Crossing/Ruggles. Roxbury Crossing to Chinatown on the OL is 8 minutes, I not sure how it would be possible, even with a HRT Green Line from Boylston to LMA, can also take 8 minutes, despite having the same # of stops after removal of the NEU/Pru stops.

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Having more circuitous routes would still hurt legibility of the transit system and it's attractiveness (and hurt the viability of bringing HRT west of Newton Corner). In addition, bus routes can easily be reconfigured to bring riders to the train stations (hence why stop spacing on the B & A would be needed for connections with existing bus routes; to push riders from the 57 and onto rapid transit). It's also worth noting that Boston Landing station and its TOD has very little transit connectivity with other local bus routes today.

• Increase frequency on the 86/65 buses to every 8 - 9 min peak/12 - 14 min off peak, gain frequent crosstown connections to 3 RTL lines.
• Extend the 65 from Brighton Center to Brighton Depot/Boston Landing, more than doubling bus service from Brighton Center to Brighton Depot + bringing bus connections to Boston Landing's TOD.
• Eliminate the Union Sq. detour on the 66 bus and stay on Harvard Ave. to bring riders directly to the Allston Depot station on the B & A.,
• Reroute the 64 to Brighton Center, adding additional RTL connections to Central Sq. in Cambridge.

Finally, if bus service on Brighton Ave., is removed, and the B & A subsituting the 57 in Allston, it could make room for dedicated bike paths, as the 57 corridor lacks good cycling routes that take the shortest path downtown (which is today's 57 bus, which is the shortest route by cycling). The Charles River cycle path is closer to much of the B & A route, especially near Oak Sq. and Brighton, and east of Packards Corner, but leaves most of Allston Village and Union Sq. without a cycling connection.

Today, a trip from Brighton Center to Downtown at 8AM rush hour takes 47 minutes on the 501. A 2 seat ride on the 57 and the Green Line, often unreliable to due traffic congestion, bunching, transfers, and delays, takes a minimum of 40-45 minutes if not more. A RTL line following the B & A routing (with all stops) would take approx ~25 minutes from Newton Corner to downtown, and ~21 minutes from Brighton Depot. Assume 6 minute headways on the B & A, and the 86 and 65 running the aformentioned frequencies, for a combined headway of every 4 - 6 minutes, for the 4 minute bus trip from Brighton Center to Brighton Depot. This means that a full trip from Brighton Center to downtown, with a transfer at Brighton Depot to the B & A mainline, would take ~38 minutes at most, 10 minutes faster than the 501 today (20% faster), and still faster than the 57 bus + GL. If the transfer times are short, it is still possible to complete this trip in as little as a halff hour from Brighton Center (Washington St & Chestnut Hill Ave).

Any rail station that gets built in Newton Corner would likely cause the removal and the end of today's express buses. If Watertown doesn't get a branch off Newton Corner, or if a transfer is required to reach Back Bay, it would result in today's one seat ride on the 504 into one with two transfers.