(continued from above)
One last main point about Nubian that I want to address:
Is Nubian a bus hub because it's the best place for a bus hub, and it will always be one, or is it a bus hub because... it just is? Is it really more suited to the role than Ruggles, Jackson Sq, or Roxbury Crossing, for example? Food for thought, if not super relevant.
If anything, I'd say Nubian is the opposite of what you're saying. It's the natural bifurcation point between two important bus corridors, the 15 and the 23/28, and also combines several other routes that radiate out to different directions (1, 66, 42, etc).
On the other hand, what you're describing sounds exactly like Ruggles and Wonderland. Half of the bus routes at Ruggles are really Nubian routes, but were extended to Ruggles in 1987 solely to provide the rapid transit connection
(with additional reorganizations - can you believe the 28 didn't exist until 1987, and was only launched as a supplement to the 29???), the other half are really LMA routes, and then minor exceptions like 22 and 43. Ruggles is the posterboy of a "man-made" bus hub just because of the rapid transit connection, and offering high-quality transit to Nubian would greatly free up resources from buses running between Nubian and Ruggles. Similar conclusions apply to Wonderland, where half of the bus routes would have loved to terminate at Lynn.
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(not as related to above)
Last note for now: This is a separate problem/discussion mainly about the best way to continue an urban ring into Cambridge. I don't really think it has much bearing on the Washington St LRT or subway to Downtown/Southie.
While the cost of a deep bored subway from LMA to Cambridge is indeed a separate problem, if we assume C&C is cheaper than TBM
(which may or may not be true), then consideration of such a long deep-bored tunnel would indicate a lower degree of emphasis on cost and practicality. This, in turns, would imply that a heated, one-or-the-other debate between Nubian-downtown subway and Nubian-Andrew subway is less necessary, as such a debate only arises due to budget concerns.
Well, for one thing, Nubian is closer than Ruggles or Roxbury Crossing is, resulting in shorter routes. Of course, taken to its logical conclusion, that also points to bus hubs along the Fairmount Line -- which I agree are valuable and often underestimated, though I also think are insufficient to wholly negate Nubian's role.
The issue with relocating bus hubs to the Fairmount Line is that riders want to go to Warren St. The initial BNRD proposal eliminated the 44 and 45 routes, and had the 14 and 19 replace them, skipping Warren St. However, community opposition made the T drop this plan and reintroduced the 44 and 45 in the revised proposal.
As I mentioned above, if riders only care about rapid transit connection, the 29 would have been the winner in the post-SW-Corridor era instead of the "supplemental" 28. I'm inclined to think that most (if not all) Dorchester routes have high turnovers due to local demands, and that's not something that can be easily solved with Fairmount-related integrations.
But I do agree that Fairmount Line can use better bus connections. I had considered it myself, but the conclusion seems to be that what we have today (and BNRD) is good enough - Newmarket has T8/10/41, Uphams Corner has T15, Four Corners has 19/T23 (and maybe T16), Talbot Ave has T22, Morton St has 21/26, and Blue Hill Ave has T28/29/30/T31. A few changes can be made, but given that a lot of the BNRD plans (26, 29) in the Mattapan area were reverted due to community feedback, I'm not sure about feasibility.
I think, though am not at all sure, that it's actually there in
part to collect surface traffic from north of the Mass Pike:
Yes that's what I noticed too, but such traffic can easily continue on Albany St and Frontage Rd (with relatively few intersections) until they get to the Melnea Cass on-ramp. If anything, it may create fewer merging conflicts on I-93.
(Edit: there's also an on-ramp at Lincoln St that eventually merges into I-93 south of Melnea Cass, so it can also handle traffic north of the Pike.)
Looking more carefully at your proposal, one difference from what I was imagining is that you are suggesting an elevated that is at the same elevation as I-93, I think? I was imagining just running above it altogether. But again, that creates problems with the grade changes at the northern end.
Yes, my proposal is at the same level as I-93, or more of an "Albany St El". This is primarily due to grade changes to the north. It should also be feasible to run an El above I-93 until you get to E Berkeley, but that would be a relatively short "above I-93" section and I'm not sure if it'd be worth it.
I was thinking about whether the southern half of the Aldgate junction at the Albany Wye could go under Herald St. The problem with that -- and it's less of an engineering problem, more of a design elegance problem -- is that it makes the (rather expensive) under-Pike tunnel that I propose near Shawmut Ave somewhat redundant; if you're gonna go over the Pike for your northern portal, it's gonna seem silly/wasteful to build a second subway and second underpass for the western portal.
The whole thing looks very alluring but I just am not sure it can work.
While the Herald St subway (with the tunnel under OL) seems redundant, I'm not sure if there's really a better option. Parcels over the Pike will probably be redeveloped (not sure if Albany St is affected, but I do remember one of the parcels further west was to be made a park over Pike), so I don't think running an El over the Pike for any section is feasible. Even if you could, there's no good space for a portal, as you have three close intersections (Shawmut, Washington, Harrison), one of which you'll almost certainly have to cross at grade. Starting your descent west of Shawmut is way too close to the Bay Village interchange.
An El over Herald St faces the same problem - grade crossing with at least one of the north-south streets.
