Crazy Transit Pitches

[F-Line to Dudley]

Can't be sure without design level data, but I'm thinking elevators could be squeezed in to meet ADA requirements, with ramps/stairways/escalators for non-ADA traffic. It looks like the service road between the tracks and the casino building would need to be preserved, It's currently 2 lanes and maybe could be narrowed to one lane in places to make room for a passenger station platform on the east side of the tracks. This is all speculation without a topo site survey and determination of the casino/hotel operations, but looking at Google Earth I'm thinking squeezing a set of platforms with stairs/escalators/ramps/elevators at the south end of the platforms may be possible.

For the nth time...NO.

The slope of the tracks here is 3%, and that is 100.0000000% illegal for a platform under federal law. There is no "looks" test to be had here. That's the slope...and you do not get a legal permit to build a platform at that slope.

How many times does this need to be stated before it sinks in???

 

[jklo]

For the nth time...NO.

The slope of the tracks here is 3%, and that is 100.0000000% illegal for a platform under federal law. There is no "looks" test to be had here. That's the slope...and you do not get a legal permit to build a platform at that slope.

How many times does this need to be stated before it sinks in???

Flatten it?

 

[F-Line to Dudley]

Flatten it?

For a whole fricking half-mile. Because not only does the 800 ft. platform need to be level, but so do the Everett Jct. switches so freight trains numbering up to 90 cars can switch tracks to/from the Everett Terminal leads without loading issues. And so do the gauntlet track switches you need to install prior to the platform for high-and-wide freights passing a full-high.

Then go get a wetlands permit for putting in all that fill. And get that permit while working not to disturb the preexisting soil cap for one of the country's more notorious Superfund sites directly adjacent.

And stage all the backfill construction half-and-half so all of Rockburyport service isn't cut off for the entire duration of the filling project.


That's going to be into the 9 figures just in permitting and landscaping costs...which is crazy when Wynn fun bux are not going to cover any of that tab far-flung from Encore's home property lines. Grading an SL3 ROW extension from Everett Ave. to a casino/Gateway Ctr. loop...which would be a full-on down payment for infinitely more useful UR BRT or LRT service...wouldn't cost nearly as much as pigeonholing a Purple Line stop there. And SL3 extension still entails building not-cheap duckunder or flyovers near Sweetser Circle for changing sides of the ROW.

Moreover, for the only unique audience--North Shore commuters--it would capture without chewing costs far better off allocated to BRT/LRT down payments, it's barely necessary at all when a simple van shuttle pulsed from Chelsea Station via the back driveway of the shopping center to Beacham St. hits Encore's front door in 5 minutes and encounters very little traffic en route.


Yes, it's build-feasible to have a fully legal Commuter Rail platform constructed there if you have no qualms about spending yourself stupid and going through a downright hellish permitting and staging process. Now explain WHY such tactical nuclear strike for that one mode only would ever be an advisable resource allocation vs. some form of--even partial--rapid-transit ROW buildout? Where's the Pitch behind this crazy that says this specific Commuter Rail project should be so expedited in project priority vs. the alternatives? Somebody please moor this thing in a purpose.

 

[Charlie_mta]

F-Line, I actually agree. I'd rather see this area accessed by a phase of an LRV Urban Ring from GLX to Everett, Chelsea and Logan.

 

[F-Line to Dudley]

Explainer...reasons why the grades are an issue for RR but not for rapid transit when the platform still has to be around 1% slope (+/- tenths) to conform to the ADA:

• Maximum FRA-allowable grades for new construction are 1.5%, but the Mystic approaches were granted an exemption for 3% in the mid-80's because this was a fixed-bridge for movable-bridge replacement project. But the exemption comes with strings attached. The Everett Jct. crossovers for the freights were required to be perfectly flat as a tradeoff to nullify the derailment risk from imbalanced freight cars whose contents may have shifted coming off the steep bridge grades that, on the Somerville side, are also curved while steep. They couldn't live with a slight 1.5% or less grade thru the switches; the interlocking had to be perfectly flat. Everett Terminal's highest carload volumes come from scrap metal cars and concrete mix cars at Schnitzer Steel and Climent Cement, so those are loose materials that definitely resettle coming over the bridge. It's why the 1988 span has such extremely wide track spacing and emergency sidewalks on each side; those are allowances for freight crews to stop the train and get out to inspect if a car develops suspension issues from shifting loads on the grade. Can't chance a weight-imbalanced car causing problems over the crossover switches, so Everett Jct. has to be on perfect flat ground clear of the bridge approach. This eats up all the real estate to put a platform close to the casino, and distends the area of backfilling you'd have to do for achieving level-enough platform very problematically out past the T garage towards Sweetser Circle. The crossovers can't be moved onto the Sweetser curve, either, because of the same mis-loading issue of cars whose contents may have shifted coming off the bridge grade...so the switching all has to be done on flat AND tangent land.

• As stated, this is a Plate F freight clearance route where cars that won't clear the side of a full-high platform can get routed to the Terminal. The refrigerated cars to New England Produce Center are the potential offenders there. While the fridge cars wouldn't have any problems with shifting loose loads coming off the bridge, and the problematic scrap + cement cars with shifting loads aren't the high-and-wide cars...a fridge car coupled directly to a scrap car whose load has shifted on the bridge grade may induce more side-to-side suspension rocking, increasing the platform strike risk. Therefore gauntlet track is non-optional install. And you also must have perfect level ground for that leading gauntlet switch for same reason as ^above^ so that's further going to constrain the real estate for a platform adjacent to the casino, complicate the amount of backfilling, and distend the project limits of the backfilling closer to Sweetser where the wetlands berm between the ROW and the Gateway/ex-Superfund soil cap then becomes an extremely delicate operation.

• Don't underestimate just how delicate that wetlands berm is going to be. It's taken DCR over a decade and torturous amounts of review to get its permits in order for extending the Northern Strand Trail through the wetlands to link the rail trail with the Mystic River paths through the Gateway Ctr. parking lot. Repacking the ROW soil in the vicinity of those wetlands and the ex-Monsato Superfund soil cap is manifold complexity. Any transit project in the vicinity is going to want to stay as far away as possible from touching those cap-adjacent wetlands that start right behind the PetSmart loading docks. Rapid transit projects can plausibly stay away from that vicinity; RR requires so distended a backfilling area that it absolutely cannot.

• NONE of those freight-related tradeoffs exist on any rapid transit (BRT/LRT/HRT) mode, and there'd be no need to have any crossovers whatsoever in the vicinity.

• Rapid transit grades can go up to a maximum of 6%, and max platform length for berthing all cars would be 250 ft. instead of 800 ft. Coupled with not needing all that flat+tangent crossover sprawl, that massively condenses the project area for any soil fill to several dozens of feet abutting a (way shorter) platform, instead of distended nearly a half-mile out to Sweetser. Simply ramp up steeper, level out at the graded platform, then ramp up steeper onto the bridge grade.

• The compactness of the fill area for rapid transit means you can get all the filling done you need to get done before the first appearance of the wetlands berm separating the Gateway Ctr. property, behind the T garage. Enormous amount of EIS and permitting pain and suffering saved there.

• Keep in mind that Commuter Rail is already pretty slow between North Station and Chelsea, taking 15 minutes to cover less than 4-1/2 track miles and 2-1/2 crow-flies miles due to the North Station Terminal District extending out to the Sullivan vicinity and the continuous speed restriction imposed by the steep (and curving on the Somerville side) bridge grades and Sweetser curve coming back-to-back. And they already envision infilling the Sullivan Superstation on Commuter Rail, which isn't going to do that schedule any favors (though all points outbound of Chelsea could see trade-in relief if the Eastern Ave. grade crossing were eliminated and Saugus Draw was rebuilt eliminating the very punitive Chelsea-Riverworks speed restriction). It's one reason why the Rail Vision has such a push to divorce Haverhill thru service from the Reading Line: as much as Sullivan CR enhances inside-128 transit, there are some pretty significant clock tradeoffs if you're trying to make time from further out to 495-land. How is this balancing problem going to fare if you plunk yet another intermediate at Encore to go along with Sullivan? It's going to take in excess of 20 minutes to get to Chelsea even with (relatively) faster-accelerating EMU's in the mix. Nobody's going to be relying on the Purple Line--even if scaled up to :15 frequency intervals--as a Downtown-Chelsea shuttle when the 2 intermediates shivved in between make its best-case schedule equal-or-slower than a bus shuttle on a striped Tobin Bridge bus lane. This is, in essence, the ENORMOUS service gap-filler that a proper Urban Ring rapid transit build fills that has no substitute on any other mode. RR geometry is not conducive to stop densification that near the Terminal District. Sullivan CR only exists as a proposal because the future ridership growth at such a mega-transfer node *ever so slightly* outstrips the scheduling downsides to make it worth it. But you probably aren't going to sustain that margin of benefits if you infill yet another stop so closeby that it shoots so much other clock-keeping to spit. The RR mode is singularly ill-suited to multitasking extreme-local transit, so we can't plausibly task it with trying to do that in interim or in lieu of a proper LRT/BRT Ring build.

 

[Stlin]

I apologize in advance if this has been covered before in another thread, but I can't seem to find it. Leaving aside for a moment the onward connections, (SLs 1-3) just how much work would actually be required to convert the existing Silver Line tunnels to LRT, given that was always the plan? would it be as simple as laying track, upgraded catenary and installing signals?

Given that once the type 10s arrive, only half of the type 9s will be sent to Ashmont/Mattapan, and given the 15mph speed limit the SL hits in the tunnels... I would assume that its feasible to set up some system where you hold trams/buses for coordinated transfers at SL way. It could be that actually reduces overall travel time.

(also, how hard would it be to tunnel under Logan to the SL3 / Coughlin Bypass RoW?)

 

[The EGE]

You'd likely lay tracks over the whole SL2 loop (since your maintenance facility will probably be out that direction anyway), and run SL2 + SLW short turns on rail. Extend SL1 and SL3 to DTX (or North Station on a Congress Street BRT) using Summer Street bus lanes.

 

[Charlie_mta]

I apologize in advance if this has been covered before in another thread, but I can't seem to find it. Leaving aside for a moment the onward connections, (SLs 1-3) just how much work would actually be required to convert the existing Silver Line tunnels to LRT, given that was always the plan? would it be as simple as laying track, upgraded catenary and installing signals?

Given that once the type 10s arrive, only half of the type 9s will be sent to Ashmont/Mattapan, and given the 15mph speed limit the SL hits in the tunnels... I would assume that its feasible to set up some system where you hold trams/buses for coordinated transfers at SL way. It could be that actually reduces overall travel time.

(also, how hard would it be to tunnel under Logan to the SL3 / Coughlin Bypass RoW?)

The Seattle bus tunnel was changed into a combo bus and LRV tunnel without too much trouble. I'm not sure if the concrete floor of the Silver Line tunnel would have to be totally ripped up or not to install LRV tracks into the tunnel's concrete floor. It depends on how the original concrete floor was built, and also on the vertical clearance requirements of the LRVs and catenary wires.

As for tunneling under Logan's terminals and other buildings, all the airports that I know of in the US haven't done that, but instead have opted for elevated transit structures above or alongside the terminals. It's really hard and expensive to build shallow tunnels under buildings. Usually deep-boring a tunnel is required under buildings, which could be really difficult at Logan due to its being built on fill.

 

[AndrewOnTheMBTA]

Hi! I am new to the forum and wanted to introduce myself on a post I have some interest in. I am by no means an engineer in transportation or architecture, nor an architect. I am a lifelong Boston resident, a UMass Amherst graduate (2016), I work in Boston / live in Somerville, and have loved the MBTA and its projects for as long as I can remember. I additionally do enjoy developments and architecture that is wholistic to neighborhoods and communities. I think I will pay attention to the transit threads more though.

For this, I think this is an interesting thread to bump up and wonder if this is actually a more Reasonable Transit Pitch, given it might be on the forefront sooner than the Red-Blue or Blue Line extension, etc. The tunnel is there - the electric infra might be? The planning for a street-running LRT is probably the biggest question. I think building the new Silver Line Way Station for conversion to LRT is important, with that Massport parcel up for redevelopment soon. Also, hopefully an underpass under D St would be ideal soon.

 

[Stlin]

You'd likely lay tracks over the whole SL2 loop (since your maintenance facility will probably be out that direction anyway), and run SL2 + SLW short turns on rail. Extend SL1 and SL3 to DTX (or North Station on a Congress Street BRT) using Summer Street bus lanes.

This actually might be crazy too, but if we're thinking about maintenance facilities and keeping costs to a minimum... Presumably the Type 9s will be maintained at Mattapan Yard once they go there. If you're already putting in track for the SL2 loop, why not just connect to Track 61, and get a road/rail shunter or heavy duty hi rail pickup to pull units down the Red Line, via this switch, to Mattapan overnight, when the red line isn't running for anything heavy maintenance wise? Otherwise, just park the fleet at a couple of stations for overnight cleaning etc. If the LRT/HRT wheel profiles is an issue, some sort of flat car and transfer at Ashmont should still work.

Sure, it's a kludge. But it's a need that'll go away as soon as any green line connection is made on the other side of South Station to Boylston etc.

 

[F-Line to Dudley]

This actually might be crazy too, but if we're thinking about maintenance facilities and keeping costs to a minimum... Presumably the Type 9s will be maintained at Mattapan Yard once they go there. If you're already putting in track for the SL2 loop, why not just connect to Track 61, and get a road/rail shunter or heavy duty hi rail pickup to pull units down the Red Line, via this switch, to Mattapan overnight, when the red line isn't running for anything heavy maintenance wise? Otherwise, just park the fleet at a couple of stations for overnight cleaning etc. If LRT/HRT wheel profiles are too different, some sort of red compatible flat car and ramps shouldn't be too hard.

Yes, the wheel profile is a problem. No, there isn't a fudge-factor 'tweener' type of work car that can handle both wheel profiles. And no, 'fileting' on flatcars is entirely too kludgy to work. They've never bothered--since the BERy era--transferring any work equipment between Green/Orange/Red's links to the outside rail network that way because it's simply cheaper/easier to do it on a flatbed truck. The Mattapan Type 9's (and no more than 8 of 24 vehicles at that...the rest stay permanently on the Green Line as extras) will simply get trucked to Riverside for any heavy repair just like they did with the resident PCC's for 5 decades after Mattapan was isolated by rail from the nearest trolley service facility. That is the true path of least resistance means of doing it, unsexy as it seems.


Also think we're vastly overestimating the size of the yard needed in the Seaport. All maintenance for trains thru-running to the Transitway is going to be handled at Brickbottom since GLX and/or the future Urban Ring are the most logical pair-matches, and North Station Yard can be the cut-in/out point for shift change pulsing. The turnback yard in the Seaport can probably suffice being barely as large as Lake St. at the end of the B...probably with no garage or anything whatsoever. You could probably fit it in the Silver Line Way parking lot or some similar-sized asphalt slab elsewhere.

SL2 can be rail-stituted one of several ways. Traffic-friendliest would probably be doing a Drydock + Black Falcon Aves. super-loop, single-track full-separated reservation grafted onto one side of each road at expense of a parking row. Add a mid-block "crossover" on Design Center Pl. and maybe one middle-of-street emergency passing siding on each in case of disablement, and have the end of the line where Drydock wraps around fan out into a 2-track unidirectional island platform to berth 2 trains between-runs a la Heath St. Any train that has to scoot in/out-of-service...just deadhead to/from the end-of-line loop to SL Way (or other similar-size yardlet).

 

[Stlin]

Also think we're vastly overestimating the size of the yard needed in the Seaport. All maintenance for trains thru-running to the Transitway is going to be handled at Brickbottom since GLX and/or the future Urban Ring are the most logical pair-matches, and North Station Yard can be the cut-in/out point for shift change pulsing. The turnback yard in the Seaport can probably suffice being barely as large as Lake St. at the end of the B...probably with no garage or anything whatsoever. You could probably fit it in the Silver Line Way parking lot or some similar-sized asphalt slab elsewhere.

Yeah, fair. Trucks work too.

However... The central premise was what would it take today to convert just the existing silver line Transitway tunnels to LRT, assuming no onward connections. SL2 might be easier to just lump in, but otherwise this would be isolated. (I figure once you've got this segment, you've got more impetus to connect it to the rest of the system)

 

[F-Line to Dudley]

Yeah, fair. Trucks work too.

However... The central premise was what would it take today to convert just the existing silver line Transitway tunnels to LRT, assuming no onward connections. SL2 might be easier to just lump in, but otherwise this would be isolated. (I figure once you've got this segment, you've got more impetus to connect it to the rest of the system)

It wouldn't be an isolated operation, that's why. You'd have to build the multi-billion dollar connector. Remember: the BRT operation was never supposed to be a forever stub-end, either. We were supposed to have SL Phase III 15 years ago. It's a once-binding mandate that was deferred, not a Crazy Pitch. The mode switch to LRT is practically a prerequisite for getting it back on the board as a binding mandate, because BRT-dimension tunneling and all the duplicate underpinning to interline it with something were the engineering flaws that killed the original and thus constitute the direct-targeted fixes for what failed the first time. Absolutely nowhere does "pull a Mattapan" with current stub-end ops address in any way the really enormous primary thing that's broken-by-omission with the whole operation.

Downtown transit loading (Red especially) is fucked because Silver doesn't continue anywhere. That's not going to meaningfully change if make no changes whatsoever except for airlifting in a drop-in LRT replacement for the same old stub. That's not a solution to the problem at hand. The Park/DTX double-transferee swells are still going to clobber the whole Downtown core, and the dwells on the SS Transitway platform are still going to be somewhat of a headway limiter.

There's no half-steps here. To fix the Transitway requires linking it thru to Downtown for transfer load-spreading, which is going to require loading up for megaproject-level funding.

 

[AndrewOnTheMBTA]

I'm curious then - if SL2 rail-stitution is included, how would a stretch along Northern Ave & Tide St work between Silver Line Way and Dry Dock Ave? Would it be unidirectional or two-way? If just one way, it would require taking some portion of lane, bike lane, or sidewalk. My closest similarity to this is the unidirectional loop at the end of the Blue Light Rail on the LA Metro in Long Beach.

 

[F-Line to Dudley]

I'm curious then - if SL2 rail-stitution is included, how would a stretch along Northern Ave & Tide St work between Silver Line Way and Dry Dock Ave? Would it be unidirectional or two-way? If just one way, it would require taking some portion of lane, bike lane, or sidewalk. My closest similarity to this is the unidirectional loop at the end of the Blue Light Rail on the LA Metro in Long Beach.

Probably by bisecting Massport properties on the Haul Rd.-Harbor St. block and right before the Northern/Tide intersection. And/or using Design Center Pl. as the start of the super-loop. Depends on how faithfully they want to recreate SL2's current bus routing block-for-block. There will in all likelihood be some minor deviation from the current route through the Northern/Haul Rd. rotary with the mode switch, within inter-stop spacing tolerances. The Massport Running Track off the end of Track 61 is also proposed to be spurred up Tide St. to hit Marine Terminal for freight rail. Therefore they have to be choosy about where trolley tracks pass over RR tracks with a squared-up diamond crossing, and try to limit it to only 1 diamond instead of multiples.

Fussing around the edges, basically. There are multiple ways to make it work.

 

[JeffDowntown]

Probably by bisecting Massport properties on the Haul Rd.-Harbor St. block and right before the Northern/Tide intersection. And/or using Design Center Pl. as the start of the super-loop. Depends on how faithfully they want to recreate SL2's current bus routing block-for-block. There will in all likelihood be some minor deviation from the current route through the Northern/Haul Rd. rotary with the mode switch, within inter-stop spacing tolerances. The Massport Running Track off the end of Track 61 is also proposed to be spurred up Tide St. to hit Marine Terminal for freight rail. Therefore they have to be choosy about where trolley tracks pass over RR tracks with a squared-up diamond crossing, and try to limit it to only 1 diamond instead of multiples.

Fussing around the edges, basically. There are multiple ways to make it work.

Would there be any hope in trying (again) to push SL service on over into South Boston proper, with light rail out to City Point for example? Or is the resistance to transit there simply too strong to try? My impression is that, before the pandemic, the bus routes out there continued to max out at rush hour.

 

[F-Line to Dudley]

Would there be any hope in trying (again) to push SL service on over into South Boston proper, with light rail out to City Point for example? Or is the resistance to transit there simply too strong to try? My impression is that, before the pandemic, the bus routes out there continued to max out at rush hour.

Probably. The problem with the original SL City Point route is that it stuck to E. 1st St. at a time in the early-2000's when that strip was still blighted as all hell, while the traditional bus (and old GL branch) route was up E. Broadway in the heart of the neighborhood. Ridership sucked because too much of E. 1st at that time was bombed-out moonscape, and the T simply gave the route too little rope to grow into its surroundings. It would probably have come around eventually if the route stuck around through the last 15 years of pedestrian-encouraging redev on that street, but the T was itching for any excuse to get rid of it so practiced no patience or troubleshooting.

Light rail could thrive there because the Summer St. bridge is an easy modification: re-stripe it from 4 to 2 lanes and put the trolleys traffic-separated left of the yellow line. Which in turn makes mixed-traffic streetcar down E. Broadway a dispatching cinch for its very short mixed distance. For maximizing ridership and offsetting the overloaded buses they'd definitely want to stick to E. Broadway even though the environs around E. 1st are considerably improved nowadays.

Then figure that the Transitway has capacity to pair-match 2 interlaid service patterns from Downtown...two 6-min. headway patterns netting 3-min. overall headway. One of those patterns would continue as SL2, and one would short-turn at SL Way and an ends-change at the storage yard unless/until a City Point extension is greenlit.

 

[Stlin]

Probably. The problem with the original SL City Point route is that it stuck to E. 1st St. at a time in the early-2000's when that strip was still blighted as all hell, while the traditional bus (and old GL branch) route was up E. Broadway in the heart of the neighborhood. Ridership sucked because too much of E. 1st at that time was bombed-out moonscape, and the T simply gave the route too little rope to grow into its surroundings. It would probably have come around eventually if the route stuck around through the last 15 years of pedestrian-encouraging redev on that street, but the T was itching for any excuse to get rid of it so practiced no patience or troubleshooting.

Light rail could thrive there because the Summer St. bridge is an easy modification: re-stripe it from 4 to 2 lanes and put the trolleys traffic-separated left of the yellow line. Which in turn makes mixed-traffic streetcar down E. Broadway a dispatching cinch for its very short mixed distance. For maximizing ridership and offsetting the overloaded buses they'd definitely want to stick to E. Broadway even though the environs around E. 1st are considerably improved nowadays.

Then figure that the Transitway has capacity to pair-match 2 interlaid service patterns from Downtown...two 6-min. headway patterns netting 3-min. overall headway. One of those patterns would continue as SL2, and one would short-turn at SL Way and an ends-change at the storage yard unless/until a City Point extension is greenlit.

I'm assuming you're thinking Summer - L - E Broadway, and not via the bus terminal? I would almost prefer it going straight down L to the beach, but I get that the width is prohibitive past 4th. (whats up with Emerson St anyways?) If we assume we get LRT-Silver to L and E Broadway, I almost feel that we might as well commit to more than just 5 blocks of city point to Farragut and/or the dog leg to the bus terminal. Why not some sort of "crossing" service? Either committing to Broadway in its full length to Broadway (Red) or via Dorchester to Andrew as more of a local streetcar-esque service. Bus/tram lanes on Dorchester and take one of the Andrew busways; the 9/10 in this area are pretty busy.

 

[Arenacale]

I think there's a real justification for giving the 9 a dedicated bus lane and cutting back on the number of stops to make it more of a BRT service straight to Copley, similar to the CT routes. I'd advocate for a proper light rail branch, but I don't know where you'd make the connection from Broadway Station westward now that the South Bay Interchange is so massive. There's definitely the ridership to make that a viable and sustainable thing.

Alternatively, I'd also love to see a full Green Line branch that comes off just past Symphony and somehow gets down Melnea Cass, connecting to Southampton Street and ultimately Dorchester Street and E Broadway. Stops at Ruggles, Washington, Mass Ave, South Bay, Andrew, Old Colony, Perkins Sq., I St., L St. and Farragut (or some such). Sort of a first link in the Urban Ring. Might be more feasible as a Silver Line thing, I guess.

 

[F-Line to Dudley]

I'm assuming you're thinking Summer - L - E Broadway, and not via the bus terminal? I would almost prefer it going straight down L to the beach, but I get that the width is prohibitive past 4th. (whats up with Emerson St anyways?) If we assume we get LRT-Silver to L and E Broadway, I almost feel that we might as well commit to more than just 5 blocks of city point to Farragut and/or the dog leg to the bus terminal. Why not some sort of "crossing" service? Either committing to Broadway in its full length to Broadway (Red) or via Dorchester to Andrew as more of a local streetcar-esque service. Bus/tram lanes on Dorchester and take one of the Andrew busways; the 9/10 in this area are pretty busy.

The 7 route. That was the original GL branch and the one most closely conforming to trajectory from the Transitway. It would reshape a shitton of loading off the 9 but isn't a drop-in replacement.

For Broadway and/or Andrew that load-shifting would come from the Urban Ring SE quadrant Nubian-Southie. Which is most likely going to be BRT but *could* be street-running LRT flung off via Melnea Cass and using some substantial amount of Haul Rd. co-running. That project also looms large in helping to decongest Southie's local routes, so ultimately it's a blanket solution.