Reasonable Transit Pitches

[F-Line to Dudley]

This is a fantastic idea, and would be so easy to achieve. I think Mattapan quality PCCs for the bulk of things, and then supplement just with cars that actually saw service within the current MBTA catchment area. Easy, low cost, and useful, so it will never happen.

Mattapan's not going to last forever with PCC's. The recent reconstruction got all bridges up to weight spec for modern LRV's and they're planning to build an extra substation to beef up the Red Line Ashmont branch's power draw and separate the M from needing to tether off Red's supply. By 2020 they'll be ready to make a decision on switching the overhead to pantograph, replacing some worn rail, and shipping a few Type 7's down there (which would be ADA-compliant with the new mini-highs). It's inevitable...they really don't want to keep this up forever because there aren't many workers left at Riverside who have experience maintaining the PCC's. They'd be able to repurpose their own PCC's for a historic line and maybe turn over maintenance to a Market St. Rwy.-style volunteer shop, then rotate in the Seashore museum pieces for in-season weekends.

It'll work, but...the politics and complacency.

 

[BostonUrbEx]

Let's say we were to press the Pleasant St Incline back into service in place of SL4 and SL5...

Now could we have a ballpark estimate on the cost or difficulty of utilizing the remaining two tunnels from the flyover/split before the Pleasant portal to continue under that brief stretch of Tremont, and then just cut/cover the Pike all the way to Ring Rd to separate the E Line out of the Boylston subway?

I imagine a stop at Back Bay would be downright necessary, and perhaps there could be provisions made for a future stop at Bay Village underneath that little stretch of Tremont where new tunnel is required.

I imagine it could potentially be one of the cheapest tunneling options in the entire city, on a cost-per-new-mile-of-tunnel.

 

[Commuting Boston Student]

Let's say we were to press the Pleasant St Incline back into service in place of SL4 and SL5...

Now could we have a ballpark estimate on the cost or difficulty of utilizing the remaining two tunnels from the flyover/split before the Pleasant portal to continue under that brief stretch of Tremont, and then just cut/cover the Pike all the way to Ring Rd to separate the E Line out of the Boylston subway?

I imagine a stop at Back Bay would be downright necessary, and perhaps there could be provisions made for a future stop at Bay Village underneath that little stretch of Tremont where new tunnel is required.

I imagine it could potentially be one of the cheapest tunneling options in the entire city, on a cost-per-new-mile-of-tunnel.

Add the cost of an Essex Street Tunnel to those estimations, because Chinatown - South Station is a useful transit link and the only good thing about the SL4 bus. Adding a Green Line stop to Back Bay will increase the value of that Link, not diminish it.

 

[BostonUrbEx]

While there's good reason to suggest Green Line to Seaport via South Station is good, I don't think the would influence it in any way. The line down Essex would be coming off of Boylston, and it would be probably way to difficult to make the hook from Tremont to Essex. Thus, it would still be a two-seat ride from Back Bay to South Station anyway. (By the way -- the commuter rail is free from Back Bay to South Station, with an average frequency at rapid transit headways!)

Also, here's a map of my suggestion, because... well, I like to make these things...

https://maps.google.com/maps/ms?msi...ll=42.349791,-71.078238&spn=0.020838,0.045447

 

[Commuting Boston Student]

While there's good reason to suggest Green Line to Seaport via South Station is good, I don't think the would influence it in any way. The line down Essex would be coming off of Boylston, and it would be probably way to difficult to make the hook from Tremont to Essex. Thus, it would still be a two-seat ride from Back Bay to South Station anyway. (By the way -- the commuter rail is free from Back Bay to South Station, with an average frequency at rapid transit headways!)

Also, here's a map of my suggestion, because... well, I like to make these things...

https://maps.google.com/maps/ms?msi...ll=42.349791,-71.078238&spn=0.020838,0.045447

Commuter Rail isn't free from South Station to Back Bay, though. And even during peak hours, I'd struggle to call the frequency of commuter rail trains at a level equal to that of Rapid Transit.

But even if you could, it still makes more sense to build an Essex Street Tunnel and allow people to transfer to a South Station / Seaport train from a Dudley / Washington Street train in Boylston. Having to transfer once isn't going to kill anyone, and it's guaranteed to be an easier transfer than the ones at Downtown Crossing / Park Street.

 

[BostonUrbEx]

Commuter Rail isn't free from South Station to Back Bay, though. And even during peak hours, I'd struggle to call the frequency of commuter rail trains at a level equal to that of Rapid Transit.

But even if you could, it still makes more sense to build an Essex Street Tunnel and allow people to transfer to a South Station / Seaport train from a Dudley / Washington Street train in Boylston. Having to transfer once isn't going to kill anyone, and it's guaranteed to be an easier transfer than the ones at Downtown Crossing / Park Street.

19.25 hours of service Back Bay to South Station

19.25 * 60 = 1155 minutes

56 trains from Back Bay to South Station every day

1155 / 56 trains = 20 minute headways

And that's the average for the entire day -- including the off peak runnings.

From 8:00am to 9:00am, there's a train every 4.6 minutes.

That's rapid transit frequency.

 

[BostonUrbEx]

I think you're right on BBY-BOS (inbound) not being free though. But it is just $2.

And BOS-BBY (outbound) is free though.


Also, there's Amtrak runs. It's not advertised, but you can easily board Amtrak between the two without tickets (assuming no pre-boarding check at South Station, but going inbound there's no problem).

 

[Commuting Boston Student]

19.25 hours of service Back Bay to South Station

19.25 * 60 = 1155 minutes

56 trains from Back Bay to South Station every day

1155 / 56 trains = 20 minute headways

And that's the average for the entire day -- including the off peak runnings.

From 8:00am to 9:00am, there's a train every 4.6 minutes.

That's rapid transit frequency.

That's an average you took, not an actual indicator of what the real time from one train to the next is at Back Bay. 20 minutes would be barely acceptable by rapid transit standards if it was a regular 20 minutes, all day long - but it's not. 4.6 minutes - which, again, is an average rather than an accurate indicator of times between trains - would be an excellent level of rapid transit service. Unfortunately, good rapid transit service needs to occur for more than one hour a day.

Here's all trains running through Back Bay from 6 am to 10 am, which I would say makes for a good range of times to constitute the morning peak service. Amtrak trains (all one of them) are in blue, even though neither Amtrak nor the MBCR particularly like you freeloading on those trains. I've also taken the liberty of adding the time in minutes between each train:

Inbound to South Station:
#800 @ 6:15 AM
#P500 @ 6:25 AM (10 minutes later)
#802 @ 6:35 AM (10 minutes later)
#P502 @ 6:41 AM (6 minutes later)
#600 @ 6:45 AM (4 minutes later)
#702 @ 6:45 AM (Arrives at the same time)
#902 @ 6:59 AM (14 minutes later)
#704 @ 7:04 AM (5 minutes later)
#804 @ 7:14 AM (10 minutes later)
#602 @ 7:24 AM (10 minutes later)
#904 @ 7:28 AM (4 minutes later)
#P504 @ 7:30 AM (2 minutes later)
#706 @ 7:38 AM (8 minutes later)
#806 @ 7:40 AM (2 minutes later)
#708 @ 7:54 AM (14 minutes later)
#66 @ 7:55 AM (1 minute later)
#842 @ 8:02 AM (7 minutes later)
#604 @ 8:09 AM (7 minutes later)
#P506 @ 8:10 AM (1 minute later)
#808 @ 8:11 AM (1 minute later)
#P508 @ 8:22 AM (11 minutes later)
#906 @ 8:27 AM (5 minutes later)
#732 @ 8:35 AM (8 minutes later)
#606 @ 8:37 AM (2 minutes later)
#P510 @ 8:45 AM (8 minutes later)
#810 @ 8:46 AM (1 minute later)
#710 @ 8:49 AM (3 minutes later)
#P512 @ 8:57 AM (8 minutes later)
#908 @ 8:58 AM (1 minute later)
#608 @ 9:08 AM (10 minutes later)
#734 @ 9:20 AM (12 minutes later)
#812 @ 9:27 AM (7 minutes later)
#P514 @ 9:34 AM (7 minutes later)
#844 @ 9:44 AM (10 minutes later)
#P516 @ 9:54 AM (10 minutes later)

Well, the good news is you're never waiting more than 14 minutes for a train, and most of those wait times are less than 10 minutes. Still, this is hardly a normalized, regular schedule, and the number of 1 minute later arrivals (plus the two trains arriving at the same time) makes me feel a bit worried about that average you came up with...

Well, surely the schedule in the other direction looks better?

Outbound from South Station:
#2153 @ 6:11 AM
#95 @ 6:15 AM (4 minutes later)
#801 @ 6:25 AM (10 minutes later)
#841 @ 6:40 AM (15 minutes later)
#P503 @ 6:56 AM (16 minutes later)
#P505 @ 7:06 AM (10 minutes later)
#905 @ 7:07 AM (1 minute later)
#605 @ 7:10 AM (3 minutes later)
#2155 @ 7:20 AM (10 minutes later)
#803 @ 7:25 AM (15 minutes later)
#607 @ 7:30 AM (5 minutes later)
#P507 @ 7:44 AM (14 minutes later)
#907 @ 7:45 AM (1 minute later)
#843 @ 7:55 AM (10 minutes later)
#705 @ 8:00 AM (5 minutes later)
#171 @ 8:20 AM (20 minutes later)
#609 @ 8:45 AM (25 minutes later)
#909 @ 8:55 AM (10 minutes later)
#P509 @ 9:11 AM (16 minutes later)
#2159 @ 9:20 AM (9 minutes later)
#707 @ 9:30 AM (10 minutes later)
#93/83 @ 9:41 AM (11 minutes later)
#911 @ 9:50 AM (9 minutes later)
#805 @ 10:00 AM (10 minutes later)

Ooh... ouch. That's not better at all! Especially not given the long wait times on either side of a departing Amtrak train. Odds are, anyone trying to take the commuter rail out to Back Bay is going to be waiting a non-trivial amount of time... perhaps that's why it's much less common to see? Well, that and the fact that you probably get charged for the trip.

Okay, so AM peak hour service inbound kind of sort of approximates rapid transit frequencies pretty good. Now let's check out what happens when the morning peak ends and we move into the mid-day, lunch hour and afternoon period service - we'll take another broad sample here and go for 10 AM to 4 PM.

Inbound to South Station:
#712 @ 10:03 AM (9 minutes later)
#610 @ 10:11 AM (8 minutes later)
#910 @ 10:12 AM (1 minute later)
#2190 @ 10:19 AM (7 minutes later)
#814 @ 10:52 AM (33 minutes later)
#190 @ 10:54 AM (2 minutes later)
#912 @ 11:15 AM (21 minutes later)
#612 @ 11:28 AM (13 minutes later)
#2150 @ 11:34 AM (6 minutes later)
#714 @ 11:43 AM (9 minutes later)
#P518 @ 12:19 PM (36 minutes later)
#816 @ 12:20 PM (1 minute later)
#170 @ 12:36 PM (16 minutes later)
#716 @ 1:01 PM (25 minutes later)
#614 @ 1:28 PM (27 minutes later)
#2154 @ 1:34 PM (6 minutes later)
#P520 @ 1:49 PM (15 minutes later)
#818 @ 2:45 PM (56 minutes later)
#914 @ 2:49 PM (4 minutes later)
#718 @ 3:00 PM (11 minutes later)
#172 @ 3:05 PM (5 minutes later)
#2158 @ 3:35 PM (30 minutes later)
#P522 @ 3:39 PM (4 minutes later)
#616 @ 3:45 PM (6 minutes later)
#916 @ 3:53 PM (8 minutes later)

Yeah... those are some pretty huge holes there in the schedule - and if you assume you're not going to be bluffing your way onto any of those Amtrak trains, the time table looks that much worse for it.

I could take a look at the evening peak timetables too, but I think you get my point. A statistical average doesn't necessarily reflect the true frequency. More importantly, rapid transit frequencies aren't rapid transit frequencies if the only time they happen is by coincidence, mostly during peak hours.

 

[BostonUrbEx]

I'd say that even given the potential for a big (20 minute) wait, this is still much more convenient than taking a hypothetical E Line train from Back Bay to Boylston, making a connection via some potentially awkward or lengthy (I consider the distance required to transfer at DTX as lengthy) pedestrian tunnel at Boylston, and waiting for another train to take you to South Station. It's also a much quicker ride, even if it were a one-seat ride by Green Line. I think what really dictates the Green Line via Essex St is demand for transit in the Seaport. That critical demand may not exist for quite some time. As such, I don't think an Essex St Subway is worth bundling in with what I proposed, which could potentially be viable right now.

 

[George_Apley]

Essex St subway isn't going to happen. Too pricey; too much of a mess. You could turn Essex into a transit-way, but goodness knows where the portals will go for SStation and Boylston. That would work better for improved Silver Line service.

The best way to connect SStation and the Waterfront transit-way to the GL is piggy-backing a Green Line tunnel on the N/S-Link, and run under Marginal St alongside the Pike. It could connect northbound via Tremont St to Boylston, southbound to Washington St for street-car service to Dudley, and continue west to BBY and assume the E-line.

Something like this:

 

[F-Line to Dudley]

I'd say that even given the potential for a big (20 minute) wait, this is still much more convenient than taking a hypothetical E Line train from Back Bay to Boylston, making a connection via some potentially awkward or lengthy (I consider the distance required to transfer at DTX as lengthy) pedestrian tunnel at Boylston, and waiting for another train to take you to South Station. It's also a much quicker ride, even if it were a one-seat ride by Green Line. I think what really dictates the Green Line via Essex St is demand for transit in the Seaport. That critical demand may not exist for quite some time. As such, I don't think an Essex St Subway is worth bundling in with what I proposed, which could potentially be viable right now.

You're not digging under Essex. The surface/foundations/utilities/groundwater impacts were prohibitive enough with the bus tunnel. Shaving a few feet's width off it for an LRT tunnel does not change the equation very much. I think even if they revisited the proposal with the mode it should've been from day 1 it's probably pricing out at $5B. Any such digging under downtown streets that haven't previously been wiped clean underneath by 1960's urban renewal are going to turn into a 2nd Ave. Subway mini-me. That's just a fact of life.


Now, a GL-SS connection is buildable if you can build the N-S Link by combining some of the construction.
-- The NEC lead tunnel on the Link will surface somewhere on the Harrison-Washington block. The grades and dancing between various 93 ramp tunnels make that spot a certainty in any design.
-- The Tremont tunnel, if Washington St. ever became a light rail branch, would most easily get extended 1 block down Shawmut from Eliot Norton Park, and surface up the Herald St. wall on the Shawmut-Washington block.
-- The NEC is wide enough that if you did a line split before the Herald portal there is ample room and cleared underground space between Shawmut and Albany to cut-and-cover an LRT tunnel next to the RR tunnel until the RR tunnel reached sufficient depth. Then piggyback the LRT tunnel on top with shared slurry walls for a little economy of scale.
-- Where they diverge right around the bus terminal overpass, cut-and-cover on the grass+brick plaza along Atlantic up to Essex. Then make the turn into the Transitway.



Yes, yes. Misses Chinatown. But Chinatown is physically impossible and costs minimum 3 times as much so fretting about missing Chinatown is a whole lot of spilt milk. This is the only way it can be physically done with full grade separation. And you might easily be able to fund it if punting off the extra Link cruft like the Old Colony and Fitchburg portals to some unfunded later phase as the trade-off for applying those resources towards combined build economy-of-scale and getting the Silver Line finished as the real-deal interconnected LRT system it was originally envisioned.

Looking at 'possibles', that's the only build scenario that could feasibly fulfill the SL's original connectivity goals in-full.



EDIT: Busses beat me to it with the pretty maps.

 

[George_Apley]

-- The Tremont tunnel, if Washington St. ever became a light rail branch, would most easily get extended 1 block down Shawmut from Eliot Norton Park, and surface up the Herald St. wall on the Shawmut-Washington block.

Ah so that's how it would connect to Wash. On my map I continued it down Shawmut to cut under Peters Parkand emerge somewhere south of that on Washington.

 

[F-Line to Dudley]

Ah so that's how it would connect to Wash. On my map I continued it down Shawmut to cut under Peters Parkand emerge somewhere south of that on Washington.

And that wouldn't be hard construction because that Oak-Marginal block next to the school got blown to smithereens by 60's urban renewal (check Historic Aerials...it looks like bombed-out Dresden at the time the Pike Extension went through). All-new and cleaned up utilities underneath there. Same reason if you ever wanted to replace Copley Jct. with a grade-separated E split the easiest way is to go Tremont and shallow-tunnel (i.e. sideways into the Pike retaining wall) underneath Marginal to BBY and Prudential rather than bother with a more expensive and invasive Stuart St. subway.

Your Washington incline would climb the wall where these utility boxes are on the side of the NEC tracks: http://goo.gl/maps/4vXR6. Pre-electrification all that space was used for was the turnout for the Boston Herald's old freight siding. It doesn't serve any possible function for additional SS lead tracks.

 

[George_Apley]

Your Washington incline would climb the wall where these utility boxes are on the side of the NEC tracks: http://goo.gl/maps/4vXR6. Pre-electrification all that space was used for was the turnout for the Boston Herald's old freight siding. It doesn't serve any possible function for additional SS lead tracks.

So would GL trains originating from SStation be able to hang a u-ey to that incline to get to the Washington St track? Or would only trains coming from Boylston be able to head to Wash?

EDIT:

Something like this?

On the way to BBY would intermediate stops be possible? For example, a Tufts stop along with the Orange Line (probably redundant), or a stop at Tremont/Arlington - Chandler Plaza?

 

[F-Line to Dudley]

So would GL trains originating from SStation be able to hang a u-ey to that incline to get to the Washington St track? Or would only trains coming from Boylston be able to head to Wash?

I'm assuming this would all have to be built in phases, with the Washington branch first.

Build 1, Step 1: Reopen the tunnel. Since it's a SL replacement you pretty much need to have a Tufts Med. Ctr. station connected by longish ped passageway to the OL station on the next block. So your first segment of new construction would be a station bore under the park (not hard, since the park is just earthen fill on top of the old wide wedge-shaped incline). This is a 4-track tunnel, so even if you're only laying 2 tracks at the start you have to leave space for 2 island platforms.

Build 1, Step 2: 2-track bore down Shawmut and under the Pike. Stub the other 2 tracks at the station as a turnback or storage space, because if that's ever built it's going to fork down the Tremont side of the block. That's how the surface lines used to diverge here...City Point down Shawmut, Egleston down Tremont.

Build 1, Step 3: Incline up the Herald St. wall to the Herald/Washington intersection. Leave wall cuts underground before the portal for a flying junction akin to the old Boylston St. portal if the SS leg is ever built. Right-turn onto Washington at the Herald-Washington light for Dudley.

--------------------

Build 2, Step 1: Let's go to BBY. Tunnel tracks 3 & 4 from Tufts GL station down Tremont to Marginal. Cut sideways into the Pike retaining wall underneath Marginal and Cortes to Clarendon St. on the Trinity Pl. side of BBY.

Build 2, Step 2: BBY GL station w/ped passageway connecting to the OL and CR/Amtrak.

Build 2, Step 3: Continue up Trinity Pl. to the Stuart/Huntington intersection on the other side of the Pike WB tunnel wall. Rejoin the E tunnel at Prudential curve outside the station. At-grade junction since prevailing traffic is now straight to BBY with Copley Jct. busted down to secondary status. Note: underpinning around the garage might be a little expensive here, so that's the fuzziest part of the plan. But it's not a new idea...the rapid transit line proposed in 1945 along the B&A took this route, so I don't think the post-Pike construction around here totally precludes subwaying around here...just makes it harder.

--------------------

Build 3, Step 1: Now SS. All of this is dependent on the N-S Link getting at least a bare-bones build: NEC/Worcester-to-NH Main/Western/Eastern Route single portals, no Central station, only provisioning tunnel wall cuts for the other portals, and maybe only doing 2 thru tracks and leaving the other berths empty till later phase. Cut all that stuff and you've easily got the money saved to do 100% of the GL-to-Transitway hookup. And nothing's stopping them from adding on all the do-dads they'd ever want to the Link later on when demand and resources merit.

So take those provisional tunnel wall cuts at the Herald portal, complete the flying junction (SS peeling off to the side, Washington portal up the middle) and build a shallow tunnel under the NEC down to the Harrison intersection. This is all the ex-Boston Herald freight siding space so there's plenty of room.

Build 3, Step 2: Build the N-S Link portal. This emerges at Washington 2 tracks in the open space where the NEC and Worcester Line split. So there's side-by-side room to have the shallow LRT tunnel, the top of the Link incline, and the surface NEC and Worcester tracks all converging in one space.

Build 3, Step 3: When the Link tunnel is far enough below ground somewhere around Harrison, veer the LRT tunnel on top of it. Build double-decker with common slurry walls for about 2/5 mile until the Link tunnel diverges to the Dot Ave. side of SS and the underground station. That gets it around the maze of Big Dig tunnels.

Build 3, Step 4: Cut-and-cover underneath the grassy plaza from the end of the 93 HOV ramp along the Atlantic Ave. side of SS. Shallow enough above ground to steer clear of the much deeper 93 tunnel. The only disturbed surface structure may be the bus terminal elevator shaft underpinnings, which may have to be closed and re-poured during construction.

Build 3, Step 5: Veer under thew Atlantic Ave./SS sidewalk at the end of the grassy plaza. Sharp right turn onto Summer and punch through the Transitway wall. Rails buried in the Transitway pavement, dual-mode overhead, turn trolleys back at SL Way.

Build 3, Step 6: Way back at Marginal & Tremont, dig a short connecting tunnel--again, shallow and sideways through the Pike retaining wall--connecting the BBY tunnel to the Washington/SS tunnel with a large underground wye. Now you can thru-route BBY-SS on a totally parallel subway. At-grade junctions OK since the traffic directions will be mixed enough to not overclog any one direction.


--------------------

Build 4, Step 1: Bury the E from Northeastern to Brigham Circle under the reservation. This is an easier dig because of the reservation.

Build 4, Step 2: Bury the E from Brigham to Brookline Village. Harder dig because of the narrower street, but not too long. Now you can thru-route the D or a Needham Branch to BBY & Boylston, BBY-SS-Waterfront, or Kenmore. And run full-blown downtown loop service Boylston-BBY-BV-Kenmore-Boylston-etc. and back. And have enough parallel capacity to the Central Subway to handle the Urban Ring on one unified system + 1 or 2 Southie street-running branches off the Transitway.




Yeah, that's rather grand so pick, choose, and space out your stages accordingly. But that's the full universe of what's possible out that tunnel and via the "easy-dig" urban renewal space on the NEC and Marginal sides of the Pike cut + pooling the $B portion of the build with the $B's tied to the Link megaproject. SL Phase 3 under Essex is way more limited and would cost as much or more than any 2 of the above options options done together.

 

[George_Apley]

Comprehensive.

Would the shallow tunnel beneath Marginal Rd have any effects on future decking over the Pike? Would developers wanting to anchor buildings on solid ground have to worry about the train tunnel?

 

[ErnieAdams]

Quick side note: Matthew asked me in this thread last month to update the board if I managed to get someone from Brookline to look at the light timing at the Hawes St. stop. You hit that set of lights wrong on a car or a C, you'll be sitting there for a full minute waiting for nobody in particular to use turn arrows or come out from the side street. I'm not positive, but I think the Hawes traffic got an absurd 30 seconds for ghost-cars to make the turn onto Beacon.

I used Brookline's online system to file a report on the intersection (making sure to complain on behalf of car drivers first and trolley riders second!), and they didn't close it immediately, an initial good sign. Around 7 last night I went through the light coming from the Hawes direction and tried to count it out as I went through -- 15 seconds, not more than 20. Then I re-checked my online ticket and it had been closed out with a message, "The work has been performed." So while I'm not 100% positive that they even made a change -- or if it's only off-peak, whatever peak is for Hawes St. -- it did feel shorter than before. Maybe they just thought about it, maybe it was just a placebo effect, but they sure do make you feel loved in Brookline. I'm hoping I can take credit for a solid minute-a-day improvement in the C's on-time performance.

 

[Matthew]

Thanks for the update. I was actually curious if you could get a statement on whether or not Brookline is poised to install signal priority for the "C" line.

 

[F-Line to Dudley]

Comprehensive.

Would the shallow tunnel beneath Marginal Rd have any effects on future decking over the Pike? Would developers wanting to anchor buildings on solid ground have to worry about the train tunnel?

No. They'd put the retaining wall back together when they were done. If the tunnel's under Marginal it wouldn't be affected by air rights girders anchored to the retaining wall.

So would GL trains originating from SStation be able to hang a u-ey to that incline to get to the Washington St track? Or would only trains coming from Boylston be able to head to Wash?

EDIT:

Something like this?

On the way to BBY would intermediate stops be possible? For example, a Tufts stop along with the Orange Line (probably redundant), or a stop at Tremont/Arlington - Chandler Plaza?

I'm not sure what depth the Orange tunnel is at the point it crosses the Pike. So if Green-over-Orange at Marginal isn't enough depth separation, then you could move the BBY tunnel up around Tremont to the other side of the park and wye it at the Oak-Shawmut intersection. Orange is definitely way far underground at that point, so there are no impacts to a cut-and-cover under Shawmut. The old Tremont tunnel actually terminates about 1/3 of the way into the park right about where the Google puts the "o" in "Norton". And then the buried incline spreads out in a giant wedge to the corners. So there's plenty of room under there to do something complex for a less-tight wye.

For example, you could set up your Tufts Med Ctr. stop here in some funky wedge setup with 2 x 2 tracks for the BBY-Boylston and Waterfront/Washington-Boylston directions, and an offset wye track platform for Waterfront-BBY. You've got the whole area of the park to play with. That can serve as your intermediate for all directions, since Marginal-proper is kind of a crappy place for a stop and wouldn't leave much underground real estate for anything spacious. The ped walkway to the Orange station would have to be longish since the tunnels don't align, but you can easily do a free transfer between lobbies.


SS-Washington would be the one service pattern you couldn't swing with this. Unless you did a whole separate incline up the wall from the Harrison-Washington side...which is an awful lot of overkill for the relatively limited ridership that would want to make that move. Simple answer: Tufts Med Ctr. cross-platform transfers. Don't forget...SL Phase III would've made everybody disembark at a lower Boylston loop so it never would've been a Dudley-Waterfront one-seat even in the intended configuration.

 

[Commuting Boston Student]

A cross-platform transfer is perfectly acceptable for Washington - Waterfront, and still a vast improvement over the existing situation. For that matter, a long ped tunnel is still OK as well.

It's the idea that we're going to undo this connection or that spiking this connection is somehow a prerequisite for Silver Line LRT that bothers me. It can stay as the #49 bus.