You might need to dig deeper into the source of the trainset restrictions on that ramp. The North Station to Science Park ramp is quite steep (6.5% grade), near LRT maximum. The restriction there could be safety related, and not solvable with signaling.
I love it. Congress St provides a much faster connection to the Ted that's time-competitive with a non-stop SS-Logan SL1 service (while having some intermediate ridership), and does a reasonably good job at retaining SL3's demand to both Seaport and Airport (further analysis to be done about whether SL3 riders from Chelsea/BL use WTC and SLW).I went down a rabbit hole and found some interesting things under analysis, and sketched out some questionable solutions.
Let’s imagine a future world where:
- Green Line is extended to the Seaport, with LRT services running between Longwood/Back Bay, South Station, and the Seaport
- A third Ted Williams bore is not built, relegating cross-harbor services (e.g. Seaport <> Airport, and Seaport <> Chelsea) to segregated bus lanes in the existing tunnels
- The Piers Transitway is maxed out capacity-wise, and/or we don’t want the dedicated ROW LRT services mixing with the largely-but-not-totally-separated bus services
In this world, where do those Ted Williams bus services go once they reach the Seaport?
Previously, I’ve suggested funneling them into the Summer St bus corridor, and consolidating the various BRT routes running into Downtown & the Seaport under a single “brand” – either a “Navy Line”, or just the good ol’ Silver Line.
And that’s… probably fine. But when did I ever let “probably fine” stop me from fiddling? So, here’s an idea for creating a pair of BRT services for the Seaport, in addition to LRT in the Piers Transitway.
The “Navy Line” (or whatever we want to call it) remains the Congress St/Summer St corridor, extended along the Tobin Bridge to Chelsea (supplemented by non-BRT feeder routes from the T7 in Charlestown and South Boston, the T111 to Woodlawn, and potentially the T116, if we can get reliability across the Tobin high enough). This route terminates around World Trade Center station.
The “Silver Line” is basically today’s Silver Line, but rerouted on to Congress St in the Seaport.
SL1 and SL3 services emerge on to Congress St directly from the highway, and bear left toward downtown. A stop just before A St provides access to Seaport jobs (see below), as well as transfer to SL2 for service to the far eastern section of the Seaport. After crossing the channel, these routes do a loop around the Federal Reserve building before heading back out.
Going outbound, SL1 and SL3 do a slightly roundabout jog to the south to pick up the on-ramp into the tunnel; SL2 service continues down Congress St, stopping outside the WTC stop before potentially continuing on to the Design Center branch, where they could interline with LRT service, though that’s probably overkill.
Why is this better than running along Summer St? Arguably, this alignment lets the cross-harbor services get to South Station as quickly as possible, while still providing some level of access to the Seaport. On the other hand, it’s not clear that the time-savings would be massive, and while I do think the A St stop location serves the Seaport reasonably well, it’s also definitely true that this alignment serves the Seaport less.
As for the question of stop location, here is the On-The-Map rendering of the Seaport (enhanced for legibility):
And here are the overlapping 10 minute walksheds of stops at A St, at Pier Four Boulevard, and in front of WTC station (note that the boundaries are not precise):
And for completeness, here is the A St walkshed on its own:
And WTC on its own:
Somewhat surprisingly, WTC doesn’t actually net you that many more jobs (I think) – you get the WTC itself, that office building on D St, and some smaller job centers out near Silver Line Way and Northern Avenue, but it’s not as big of a difference as I expected.
Separating out the “Silver Line” from the “Navy Line” raises another question: why stop at South Station?
Well, the reason to stop at South Station is that you then have to contend with x many more feet of street-running and y many more traffic lights.
I definitely wouldn’t want to run our new SL1 and SL3 services beyond South Station – their journeys are long enough already.
But an SL2 service, aided by bus lanes and TSP, connecting at Chinatown and Boylston (requiring Avery St to be reversed to one-way the other way), would provide a 2-seat-ride to the Seaport for Park St- and Government Center-terminating Green Lines services. The alignment below is about 4500 feet of street-running westbound and about 2500 feet eastbound.
(If you got aggressive with lane-taking on Essex and built a contraflow lane, you could shorten that westbound journey to be similar length to the eastbound.)
Anyway, this is in the Green Line Reconfiguration thread because it covers potential alternatives if the Green Line ends up consuming all slots in the Piers Transitway, and because this dubious SL2 service would provide a two-seat ride for Kenmore Division <> Seaport journeys, which – even with a transfer tunnel at Back Bay + Copley – still remains one of the annoying loose ends of my recent designs.
(Mostly I wanted to memorialize the analysis of Seaport jobs.)
Yes, this was something I was thinking about, in particular in the wake of your analysis showing that Courthouse had higher ridership than I expected, which then precipitated my jobs analysis.
The reason I want SL2 to still serve Design Center, and why I want it on Congress, is to provide an easy transfer for SL3 commuters to the rest of the Seaport. That's how I feel I can justify the loss of one-seat access to WTC and SLW. Board SL3 in Chelsea, disembark at A St/Congress St, board an outbound SL2 at the "platform" across the street. (And I would just as soon not have the Green Line venturing out onto the street at all, but...)
Looking forward to hearing more!
The one concern might be that the existing subway was built along the south side of Kenmore Sq to leave space along the north side of Kenmore Sq for utilities. If that's the case, then those utilities would have to be accommodated somehow. Maybe build the new subway deeper, with space above it for utilities?
Yeah, it also occurred to me that this new platform go under the existing station, though obviously that would increase construction cost and complexity. One of the things that I like about the "Kenmore North" idea is that it would have a very easy transfer to existing services, so I'd want to preserve that.
You'd still have the concern with a BLX to Kenmore (which is just as needed and has arguably more momentum among transit fans and real-world proposals alike), so I think utilities need to be figured out somehow.
I recall that about 1.5 years ago, there were discussions on how to allocate tph for the Kenmore branches (Harvard, Oak Square/Watertown, Boston College, Cleveland Circle and possibly Riverside/Needham -- but especially Watertown), under the assumption that the Central Subway has limited capacity that cannot support all these extensions. At that time, the inability to short-turn Comm Ave trains at Kenmore became a notable problem:
Your proposals of a new terminal at Kenmore can actually address such problems (if a flyover to the B's tracks is built, which is easily doable under the uber-wide Comm Ave). Ironically, the idea of needing to short-turn Comm Ave trains at Kenmore has fallen out of favor since then, but it can still be a way to have useful Watertown/Oak Sq service without overloading the Park St inner loop.
I personally think crossing under the Mass Pike itself doesn't seem like a big engineering problem. The Pike is a road, just like any other road that people propose tunneling under. You can theoretically even do C&C under it.
I'd say BLX to Kenmore is still quite important especially in an all-ring-routes-end-at-Kenmore world, because:
The existing pedestrian tunnel seems like it intentionally dips under something there, although I have no idea what that might be.
In my opinion, BLX to Kenmore is a very high priority. I would go further, and continue the BL along the D line to Riverside, plus a BL branch to Needham. This would connect the metro west to high jobs areas and Logan.
I think the "minimum build" would just be the second central subway and extended Huntington Ave subway. Anything less than that and you're not really "reconfiguring" the GL, just slightly modifying it. That plus the Washington St LRT (and Needham Extension, I guess, but that's more of a project by courtesy) would make a nice, neat package. I think only then does it really start to make sense to look into more branches to places like Brighton, Cambridge, Southie, Watertown, etc.
As it happens, I actually had a very similar conversation further upthread, about 3 years ago. (I hesitate to include the link because F-Line and I got pretty into it, and my views have changed somewhat since then, but.) And yes, the conclusion was the same: the inability to turn Comm Ave trains makes for a much bigger headache than one might first think.
It's interesting -- I look at the near equal running distances of the "Gold Line" vs "Green + Orange" alignments, and say that it's shocking that a circumferential route could be so competitive and that we shouldn't try to force it to be competitive in a way that circumferential routes almost intrinsically can't be; you look at the same fact, and argue that, since it's already so close to being competitive, we should give it the best shot we can. I think that's a totally valid take, and I think I'd argue for your approach as the Next Gen build, and mine for the Initial Build.
It may not be a big engineering problem, but I still think Kenmore North would be easier. (For one thing, a Mass Pike crossing will also need to underpin the Beacon St Subway, complexity not found at Kenmore North.)
I think I agree with Van here; I don't disagree with any of the points you've raised, but I don't think it needs to be part of the Initial Build.
Really interesting first thoughts! I do think that D-E + Back Bay subway need to be in the initial build, though. More thoughts on this eventually!
Funny you mention this, I've been looking more askance at this lately -- for a while, I've just sorta assumed you'd do some interlining of LRT services from Sullivan and BRT services from Eastie and didn't look that closely at it. The crossing at Chelsea Creek in particular has me pausing -- if we're going to all this trouble to deinterline the Gold Line elsewhere in the system, why would we introduce the variability of a BRT service at the mercy of that crossing? Why not terminate both services at, e.g. the Chelsea Regional Rail station? Not saying I have a definite answer yet, but I've been thinking about it.
In full disclosure, I've proposed a SL57, but with almost zero special consideration. I think the idea was that it would run in the now-vacated reservation on Comm Ave, giving you sufficient justification for the SL label. But that's not particularly well thought-through at all.
I agree with @Riverside that Huntington-Bay Village is high priority, and I'd argue it's more important than NE Urban Ring and perhaps Grand Junction. Arguably, it can even be seen as the prerequisite for Nubian and Needham, not to mention Watertown.
One issue I have with the Chelsea RR station is that it's still quite far from downtown Chelsea and most of the density. Bellingham Square is still far from perfect, but at least it's much closer to the Chelsea City Hall area; likewise, Box District and Eastern Ave are both also adjacent to more homes. So I think there's still value in running LRT to Eastern Ave while overlapping BRT runs from Chelsea RR to Airport and South Station.
