Crazy Transit Pitches

[Equilibria]

Trolleys don't exist to remove cars from roads. They exist to provide transportation for people. The perspective of justifying transit by always forcing it to answer the question "Does it remove cars from roads?" is first of all wrong (it doesn't) and misguided (that's not what it's for).

Where exactly is it you think all that "transportation for people" is happening that doesn't involve cars? Is there some large transit-riding constituency you think is telecommuting because there's no transit option to precisely where they work?

In a city where the predominant (actually, it isn't - it's only around 50%) mode of transportation is the automobile, you must ALWAYS judge transit by how many cars it's likely to remove. That's how traffic and congestion and all of those things you claim to hate are measured. Cluttering the street with unnecessary infrastructure just to stick it to the people who still choose or need to drive isn't good planning any more than ripping up tracks in reservations was good planning.

Back on Centre Street, there is already a public right-of-way dedicated to travel: it is the surface street, and it's no accident that trolleys are also known as "streetcars." The fact that privatized co-option of the street is given higher priority than public use of the public way is a historical perversion, and I fully understand the politics of it, but that doesn't make it right or something that you need to feel obligated to defend.

I feel obligated to defend it when I see it characterized like this. The "privatized co-option of the street" consists of ordinary citizens, like you and like me (neither of whom drive to work, I feel safe in assuming) trying to get around.

Transit publicly-owned, yes. It carries more people per square meter than cars. It is not, however, some populist dream machine pitted against the MAN with his evil private vehicles. Both modes are used by people who need to get around. No one is coopting or stealing anything from anybody. The street belongs to the drivers just as much as it belongs to you, no more, no less.

 

[Matthew]

The street belongs to the drivers just as much as it belongs to you, no more, no less.

Then why do you believe that transit must defend itself by showing how many cars it removes from the street?

Do you ask that of anyone else who moves into the area and brings a car?

Why does transit have a special burden in your view?

In a city where the predominant (actually, it isn't - it's only around 50%) mode of transportation is the automobile, you must ALWAYS judge transit by how many cars it's likely to remove

(Less than 50%, actually, but that doesn't change anything).

The metric that you want to judge transit by must be based on how it helps people, and that includes people who aren't in cars. Judging it by a metric that is based on removing cars from the road is a car-based metric and not a people-based metric, even if it might indirectly help some people, it's not the right approach to get Good Transit.

There is no single metric that encompasses all needs. However I'll give an example real quick: you could ask questions like "how many opportunities does this transit line design open up for how many people within so many minutes of travel?" or some near approximation that is easier to quantify (I didn't say this was easy). Or you could fall back to something as basic as "how many people per hour can be transported along this corridor" although from an urban planning perspective this isn't as useful.

 

[Equilibria]

Then why do you believe that transit must defend itself by showing how many cars it removes from the street?

Dude, this has nothing to do with oppressing transit riders or bicyclists. Those are the people that push for reduced auto VMT to be one of the primary metrics used to defend every single transit project that gets proposed. It has nothing whatever to do with "making it defend itself", it has to do with figuring out if a project is solving the problems it is intended to solve.

People drive where they want to go if they have no other options. Ergo, a project that takes cars off the street is one that goes where people want to go. Transit lines can also be used to create corridors and movements that weren't there before, and that's definitely a consideration. But if the cars won't go away, then the line isn't moving PEOPLE usefully.

That's important because transit lines cost the public a lot of money. Way more than one more person owning a car. The fact that the public must pay to build, operate, and subsidize transit means that yes, it must justify itself. It's a big investment.

The metric that you want to judge transit by must be based on how it helps people, and that includes people who aren't in cars. Judging it by a metric that is based on removing cars from the road is a car-based metric and not a people-based metric, even if it might indirectly help some people, it's not the right approach to get Good Transit.

So you're arguing that taking cars off the road doesn't benefit non-drivers? I would argue it only benefits them. Honestly, when you reach the point where you're against "removing cars" as a metric because the word "cars" is in it, it's time for the discussion to take a break.

 

[Matthew]

Who's saying anything about oppression? If someone makes a claim that reduced VMT is the basis for a transit project, then I have a bone to pick with them, because it's simply not guaranteed to be true nor necessarily productive. Induced demand applies to transit too.

I'm making the case that "reducing VMT" is not a proper metric to judge transit, and that it is a shallow, car-specific answer to a much deeper and broader question: how to make cities accessible? And also, what kind of urban form do we want to produce?

That's not to say that "reducing VMT" might not be a useful metric in some cases. For example, if your goal is explicitly trying to get cars off the road, or reduce pollution, then "reducing VMT" may be a very interesting metric that you try to poke at. But it's not something that transit is going to buy, because that's not what transit does.

 

[davem]

This is what I'd do. It could be all surface, all tunnel, or a combination:

The parts under the parks would have to be a tunnel, and ideally the parts beneath RT-9 and Brookline Ave would be as well. There's ~400' for a portal between the split and the Muddy River.

The added bonus is that you could get rid of the Washington St overpass and the awful hill it creates, as well as redevelop the ROW along Station Street.


If the E's tunnel was extended from Northeastern to Mission Park, you could do this as well:

It would require blowing up the townhouse section there (which should happen anyway, what a suburban piece of crap that is, and the wall along Huntington is gross). Huntington would have to be widened in front of Mission Park to allow for room for the surface running part of the E to portal up.(Thinking further, I suppose the E could remain all surface, with the leg that runs through Mission Park being a brief tunnel to get beneath the Riverway, Muddy River, Brookline Ave, and that playground.

 

[F-Line to Dudley]

This is what I'd do. It could be all surface, all tunnel, or a combination:

The parts under the parks would have to be a tunnel, and ideally the parts beneath RT-9 and Brookline Ave would be as well. There's ~400' for a portal between the split and the Muddy River.

The added bonus is that you could get rid of the Washington St overpass and the awful hill it creates, as well as redevelop the ROW along Station Street.


If the E's tunnel was extended from Northeastern to Mission Park, you could do this as well:

It would require blowing up the townhouse section there (which should happen anyway, what a suburban piece of crap that is, and the wall along Huntington is gross). Huntington would have to be widened in front of Mission Park to allow for room for the surface running part of the E to portal up.(Thinking further, I suppose the E could remain all surface, with the leg that runs through Mission Park being a brief tunnel to get beneath the Riverway, Muddy River, Brookline Ave, and that playground.

Too much extra tunneling there for too little benefit, and I don't know where you'd ever find the space to portal-up on Huntington or South Huntington. I would not fork the E off the tunnel. I would fork it off the BV superstation by retaining the D-to-E surface connecting trackage as the start of the Forest Hills branch.

Try this:

-- I took that ugly-ass gas station on the corner and turned it into a Riverway surface stop. Probably something they'd benefit from doing today.

-- The D-to-E trackage is pretty much as-is. Trolleys slip under the Riverway bridge on a protected signal cycle, onto the grass along River Rd., then split the driveways to a traffic signal, then Pearl.

-- Tunnel realigned slightly so only 2 townhouses are impacted.

-- 1 track merge into the superstation, single-track portals flanking the side of each D track (probably all of it underneath the air rights). A wye to Kenmore misses the station entirely, so I put in a Kenmore-style turning loop here that can be used in revenue service for trains ping-ponging between routes. Since the D here is in a surface cut, loop is an Ashmont-style flyover just west of the air rights garage. Same configuration also used to exist at Reservoir a few decades ago.

-- All trains ping-ponging to/from Kenmore on the "downtown circuit" to/from Huntington ride the loop to switch tunnels. You can maybe do an outer-platform/inner-platform setup at the superstation to facilitate this without traffic conflicts.

-- All trains going anywhere to/from South Huntington ride the loop to get in and out of the station without a traffic-fouling at-grade crossing of any other tracks.


That makes every traffic pattern hit the superstation. The loop doesn't slow down service because it's the linchpin of diverging routes and diverging dispatcher territory (i.e. it's minimal effect on inbound traffic in the Huntington tunnel if an outbound from Kenmore making the "downtown circuit" is late because this is the point where a train is jumping fresh onto a new line). And only a minority of service will have to use it in a thru-and-thru configuration, since I would presume this is going to be the terminal stop for the grade-separated northern UR. Also note the junctions have no Copley-style track crossings to merge and diverge.


Is it the most elegant possible configuration? Probably not. But if you're going to have diverging routes you want every configuration hitting the one big superstation, and you don't have a lot of space at that junction point under the air rights garage to do luxurious amounts of underground wyes or flyover junctions. That takes real estate and you flat-out don't have it here, so some amount of simplificaiton and/or compromise is recommended.

 

[FK4]

Tunneling anywhere around here, excellent as it would be, is definitely way to much cost for too little benefit. I will again argue that the trains on the surface idea will never fly. Crossing Rt 9 with any regular frequency WILL cause a worsening of traffic in a series of intersections that are already very, very backed up during AM and PM. This is independent of my opinion on why traffic exists and who roads are for, etc. The fact is that throwing in a tram crossing at this particular location will slow things down and more importantly it will be perceived as such and so will never happen.

Secondly, you can't just slip in a tram between the stores backing onto River Road. Brookline Ice and Coal won't allow it, and, probably more importantly, the long term hope for this whole area is to create a better crossing and linkage between the broken ends of the bike path/Muddy River park system. If anything ever changes on River Road, I hope it's an expansion of biking and greenspace, not yet another line of transportation vehicles that the cyclist needs to ford.

And to respond to the narrow roads issue mentioned back, yes, Perkins Street is way too narrow to have light rail on it. Sorry. At 6p the cars start on the Riverway and are bumper to bumper right up through Hyde Square to the Forbes St light. South Huntington is wide enough, but that's it. It's never going to work unless you make it tram only, which again, ain't gonna happen. And quite frankly, Hyde Square does just fine without a T stop - just because now it's another hot spot place to live doesn't mean it needs its own transit line by people who look down their noses at taking the 39.

 

[Arlington]

There is no single metric that encompasses all needs. However I'll give an example real quick: you could ask questions like "how many opportunities does this transit line design open up for how many people within so many minutes of travel?" or some near approximation that is easier to quantify (I didn't say this was easy). Or you could fall back to something as basic as "how many people per hour can be transported along this corridor" although from an urban planning perspective this isn't as useful.

Net Travel Minutes Saved is a pretty good measure. Saving 30 seconds for each of 30 people is 900 seconds saved, and worth, for example, signal priority which may impose 60 seconds of delay on a line of 10 cars.

Basically any time you can put 10 to 50 people on a bus or more on a LRV, you can see that you're letting the one with more people cut in front. The reason cars should get a lower priority is simply that they use a lot of road square-feet-seconds to move just 1 person.

 

[davem]

I don't have time for a full response, but quickly:

I used to do deliveries down there all the time. Traffic, even at rush, isn't that bad. Most of the backup is caused by badly timed lights that don't talk to each other, outdated intersection design, and Huntington being a complete and utter disaster. Taking out two lanes for a streetcar reservation wouldn't do much to hurt, or to help traffic. And there is a LOT of room down there to play with, especially after that condemned pedestrian bridge is demolished. Regarding Perkins St, there is 180' of parking lot next to it. I think they could find room.

Regarding extending the E to Hyde Square, it's not some dream aB came up with, there was serious conversation about doing it and the T actually seemed interested. It's dropped off the radar lately, maybe someone can do some digging?

 

[F-Line to Dudley]

No traffic of any kind...car, bus, trolley, bike, moped...is going to perform well on a street where the BTD gives up on performing its basic function to society. JP Center is a farce of illegally double-parked cars and delivery trucks that excruciatingly slows down those articulated 39 buses. That's the BTD provincialism of that neighborhood a la space-savers in Southie and Charlestown.

That didn't used to be the case. The double-parkers didn't double-park back when the trolleys were running. That "we've always done it this way" and neighborhood "tradition" excuse started only when the 39 began running. And is now the most oft-cited reason for not allowing streetcars on Boston streets. Well...what changed? Was double-parking made legal as Article II of the public notice that the streetcars were being bustituted? Or did the meter maids stop doing their fucking job and start hiding behind a bullshit mountain of excuses and neighborhood-specific provincialism because no one at City Hall would hold them accountable? Take a sampling of other corridors around the city, some much wider than this one, and see how many of them have a BTD quid pro quo where DP's are habitually allowed to block travel lanes, bus stops, multiple parking spots, make a total mockery of designated unloading spaces, etc. without the slightest care in the world about ever getting ticketed.

Don't just look at potential streetcar corridors...just any street that's getting its flow killed by lax enforcement (Mass Ave. north of Symphony, I'm casting an extended middle finger in your direction). Count up the flagrant lax enforcement corridors city-wide. Now what are the odds we've got a systemic, institutional enforcement problem hampering all modes of transit from the local bus to your 10 minutes late #1 or other Key Route, to your bicycle, to your own feet dipping around illegally parked vehicles at a bus stop or crosswalk, to your God-given right to drive your own car anywhere you damn please. Yes...Walsh desperately needs to gut the BTD fiefdom like a fish. They got way too fat, lazy, arrogant, and power-hungry during 20 years of Menino looking the other way and letting each neighborhood's tribalism govern itself. That's not a streetcars problem. That's not a buses problem. That's city-wide brainrot, and we truly don't know what the thoroughfares' peak performance is for all vehicles until that gets fixed. I don't think I've ever visited a big city where DP's are the alpha dogs of the street one step above the meter maids on the chain of command like they are here. Not even NYC, which has incredibly higher volumes of delivery trucks and curbside pull-ups.


I think streetcars in Boston is a valid pros/cons debate. I'm of the opinion that South Huntington, Centre, and South can support streetcars in the 2010's. Because restoration was studied to absolute death and thensome commensurate with the evolution of traffic loads on the corridor since 1985, and the crunched numbers showed no significant issues with trolleys getting stuck in traffic or at curbside stops. The con arguments (the official ones, at least) have trended to a lot of F.U.D. with their supporting numbers conspicuous by omission. I would absolutely be convinced "OK...bad idea" if someone could game out likely schedule delays in minutes vs. modern volume counts and corridor characteristics (incl. time of day) differentiated from 1985 characteristics vs. drag effect on the Central Subway. Numbers, numbers...and maybe some of those helpful traffic charts per-block (NOTE: I'm talking T and city officials; I would never hold an AB member to that kind of data collection standard...we're just spitballing here). But that's been lacking.

The restoration plan cut the number of past-Heath stops from 14 (pre-1985) to 9 (calculated on 5-minute walk catchment areas). And that did not include likelihood that excessively-packed low ridership stops (and perennial consolidation candidates whenever that subject's officially breached) like Fenwood and Back of the Hill would get whacked at long last and trim the street-running stops to an efficient dozen. The plan included the signal prioritization badly needed (and which STILL hasn't been implemented for the much-overhyped 39 improvements plan). It included corner parking reconfiguration for the curbside stops. It included a revival of the pre-1985 service plan where Heath short-turns doubled up the inner headways during the day and ran deeper inbound to North Station or Lechmere while Forest Hills had lighter headways, less peak vs. off-peak variance, and inbound short-turns as a control for street-running schedule variance impacting the Central Subway (the B still would've been many times a bigger factor for that given the headway disparity vs. the E). It would've turned most likely at GC or Park instead of running all the way to Union Sq. like Heath is scheduled to. And this is a place where the D-to-E connector and a Brookline Village short-turn replacing Heath could've accentuated the difference further in inner vs. outer service patterns.

Say what you will about the general wisdom of it...those were substantive project design elements directly addressing post-1985 changes on the corridor, backed by data collection and projections. Given that the 39 has had the post-E cancellation improvements plan delayed, delayed, delayed and whittled back to ever more negligible impact...the gap between the restoration plan's substantive justification and the F.U.D.-spreading officials' substantiation is widening. The kindest thing you can say is that they get a very incomplete grade. We don't have the full picture mode-vs.-mode until they start providing more proof. Especially on stuff like making the BTD enforce its own damn parking rules, because that kills the 39 today and un-does most of the benefits of the as-yet-unimplemented improvements. After 25 years of this avoidance game on their part, it's pretty clear they seem to prefer the freedom of never having to substantiate their inaction.

We really could put this streetcar debate to rest if both sides were held accountable for their own evidence. But..."we've always [not] done it this way" and yada yada. So we'll never know for sure.

 

[FK4]

Double parking in the south end is the worst anywhere I've ever seen. Tremont is basically an extra parking lane on each side.. As long as we're talking about streetcars back on the street, I think it would be incredibly unfair to restore the e line when Jp already has very reasonable transit, that could easily be improved further through simple enforcement and light signal changes, as you describe.

We all know how the mbta map distorts the vast gulf of density in Roxbury and Dorchester without any decent service at all... What about a tram running from Dudley down Dudley st, Hancock, to dot ave and fields corner, or Dudley, Hancock, bowdoin, Harvard to mattapan? Or just Columbia road, or the f line corridor to franklin park... Changing the topic here... But some intercity crosstown routes would really help with the isolated and segregated nature of this city.

 

[bigeman312]

Maybe, this belongs in the Reasonable thread, but with all of this talk of tunneling and property taking, my mind turns to less costly, more likely fixes (if there are any):

The stretch of Huntington Ave from Riverway to Brigham Circle hosts the 39 (a key bus route), the 66 (a key bus route) and the "E" branch of the Green Line. It is very likely that this stretch of road carries more public transit passengers than any other ROW shared with private vehicles. Just addressing this 0.4 mile stretch of roadway, what can reasonably be done to improve public transit speed/capacity/reliability? Is it a lost cause? Is there nothing short of at least a cut-and-cover tunnel that can improve service? Is a trolley reservation possible on this stretch? Dedicated bus lanes? Signal priority (if it isn't already implemented)?

 

[F-Line to Dudley]

Maybe, this belongs in the Reasonable thread, but with all of this talk of tunneling and property taking, my mind turns to less costly, more likely fixes (if there are any):

The stretch of Huntington Ave from Riverway to Brigham Circle hosts the 39 (a key bus route), the 66 (a key bus route) and the "E" branch of the Green Line. It is very likely that this stretch of road carries more public transit passengers than any other ROW shared with private vehicles. Just addressing this 0.4 mile stretch of roadway, what can reasonably be done to improve public transit speed/capacity/reliability? Is it a lost cause? Is there nothing short of at least a cut-and-cover tunnel that can improve service? Is a trolley reservation possible on this stretch? Dedicated bus lanes? Signal priority (if it isn't already implemented)?

Signal priority. Hell, the E reservation is already wired for it, and all of the traffic signals east of Brigham Circle are computer-controlled. The T and city just can't agree to install the add-on trolley and bus sensors to make it functional. Everything west of there to Brookline Village and the entire way to Forest Hills is still analog and uncoordinated, and was supposed to have been fixed years ago with this incredible disappearing 39 improvements project. So you have the compounded problems of no transit priority where it's already capable or transit priority, then all manner of traffic hitting the wall past Brigham from the signals not even having a modicum of self-awareness.

For an appropriate comparison, look at Comm Ave. and Kenmore. Smart lights (but likewise no transit priority) from Raleigh St. through the square and out to Carlton St. installed as part of the Kenmore and Comm Ave. rebuilds. Volumes seem quite a little bit lower in front of BU post-rebuild, no? In reality they haven't declined at all, but the computer coordination hardly lets any queues build up in front of BU and certainly flushes Kenmore clean a lot faster than it used to. Where do the 'dumb' signals start: Charlesgate (DCR responsibility) and BU Bridge. Where does the traffic on the Comm Ave. corridor go to absolute shit: Charlesgate and BU Bridge.

Huntington doesn't have Comm Ave.'s volumes. Route 9 got some state signal renewal west of Washington to the Newton town line, and Brookline paid a chunk of change to renew much of Washington. It's those 3 unmodernized blocks at Riverway where everything mashes together and Brigham-Riverway where everything falls apart. You would notice things flowing a lot looser a la Kenmore and BU East Campus if they fixed this analog gap at the worst possible location to have left an analog gap hanging.


When are they going to finish the job? Who the hell knows. Try getting a city official to pin a deadline to it after every deadline to-date has sailed years past with no action. I can't remember the last time they made a statement about this in a public meeting. Even Menino's expressed bitchiness of a year or two ago about the T's opposition to activating the transit signal priority went quickly silent and hasn't raised a peep out of the new administration.

 

[davem]

How much would it realistically cost to tunnel Huntington from Brigham to Heath St? It's less than a half mile, and would probably only have one underground station at the bast of the hill.

 

[F-Line to Dudley]

How much would it realistically cost to tunnel Huntington from Brigham to Heath St? It's less than a half mile, and would probably only have one underground station at the bast of the hill.

Pointless exercise if you're not willing to go under the reservation from Northeastern to Brigham first. Contiguous subway has way higher impact on the line's performance than chopping it up, and if you're going to the pain of ripping up the narrowest 2200 ft. of Huntington for that tunnel why skip the 1 mile under the reservation that has the fewest underground impacts? Yes...you do have to build at least 3 subway stations to replace the 4 reservation stops and that's expensive. But even if you ran out of money and had to portal-up at Brigham straight onto street-running track the line would still operate a hundred times better for it. Copley-Northeastern is a stratospheric difference from Northeastern-Brigham, and where to tunnel first has to get weighted by where the most ridership is.


Also...there's no reason to subway under South Huntington. The ridership falls off a lot at the turn, and that's why the E traditionally had doubled-up peak service patterns on mainline Huntington and not so to JP Center. Demand forks at the Riverway intersection. If any tunneling has to be done it'll connect to the D for multiple service patterns joined together with full grade separation, not dump off onto a single branch. There doesn't have to be a portal exclusive to the Forest Hills branch. If it departs Brookline Village down Pearl and backtracks to South Huntington that's 1000 ft. less street-running overall. And 1 mile of reservation traded in for subway speeding you to the BV split way, way faster.



FWIW, though...I think if anything has to get buried first it's the B from Blandford to the other side of the Pike, portaling up around St. Paul. Only way you've got a hook-in to LRT over the Grand Junction or anything that could sprout west through Beacon Park. And trading in 4 surface stops spread over 8 traffic lights--including the Carlton/BU Bridge clusterfuck--for 2 high-capacity subway intermediates properly-spaced, ends up saving the most problematic and overloaded branch of them all at the point of failure where everything falls apart.

I think you can live with a surface D-to-E for quite a number of years and really don't need the full Huntington burial treatment until you've got the entirety of a Seaport/SS-Central Subway and a Central Subway-Back Bay Station-Prudential subway cued up (and tied together multi-directionally). Then it becomes more or less academic to close the gap to the D and have complete the full-blown parallel subway, and the momentum for doing the dig becomes self-explanatory. B burial to the bridge is more or less a necessity if there's ever to be a rail UR because that cross-Brookline tunnel is as much a nonstarter under Amory St. as the I-695 tunnel was 45 years ago. Necessity's going to force that prioritization well ahead of Huntington.

 

[George_Apley]

I'm not an expert on rail junctions and such, but could the D/E-as-subway connector look something like this:

with Huntington-Newton/Needham trains using the Pearl St junction and Huntington-Fenway trains using the Washington St junction, and existing Fenway-Newton trains going straight through, with one station serving them all in the middle?

 

[vanshnookenraggen]

Washington St is a bridge over the tracks while Pearl St is at grade so you'd have to build a portal and rebuilt the bridge for that to work.

A simple at grade junction along Pearl St what F-Line suggested would be the cheapest route. I think it would be a worth while investment if only for adding flexibility and testing the waters for a Reservoir-Huntington Ave route.

 

[F-Line to Dudley]

I'm not an expert on rail junctions and such, but could the D/E-as-subway connector look something like this:

with Huntington-Newton/Needham trains using the Pearl St junction and Huntington-Fenway trains using the Washington St junction, and existing Fenway-Newton trains going straight through, with one station serving them all in the middle?

Need to avoid building 2 of everything such as that double-flanked junction. That's just too much disruption on a mission-critical block.



Here's a rough sketch, not-to-scale of what might work:




It's a superstation mixing and matching branches, so logic would dictate it be like Kenmore: 4 platform berths, diverging and merging traffic sorted before entering the platforms. So let's take that setup and stagger it a bit with offset platforms so it can all fit...a Kenmore stretched like taffy. Assume that the D and platform level remains in the existing cut and that the air rights overhang can be extended a little bit west to cover over the staggered platforms.

1. Huntington tunnel is dashed teal line. I picked an alignment that underpins the Riverway overpass, splits the parking lot at Brookline/Pearl, and doesn't knock over any townhouses. But assume that this could shift around umpteen different ways on further study.

2. Dashed blue and purple lines are flyover/flyunders for the bi-directional junction. Assume this is approximate configuration too, but you get the general idea. The merging/diverging tunnels pull up alongside the D tracks in a slip ramp-like setup. Assume that that D outbound-to-Huntington inbound track can be widened out a a much wider loop half-loop under the Kent/Station St. intersection and passing under the westerly platforms to avoid the other tunnels and keep this all at ground + shallow duck-under level without stacking tunnels (I should've done that on the drawing, but forgot).

3. The Forest Hills branch is all-streetcar. Basically a negotiable variation of retained D-to-E surface trackage. And an at-grade junction at the surface that simply turns right out to/from Pearl. At-grade is OK because this is the lightest-frequency configuration and grade separated territory stays grade separated.

4. Platform pair 1 is basically the current platforms, shifted maybe a few feet east. All westbound branches feeding in/out of the Huntington tunnel use this pair out of necessity.

5. Platform pair 2 is underneath the current garage air rights, other side of the slip-ramp junction. All Kenmore-Huntington circuit service uses this pair out of necessity, and the inner tracks are free for passing to/from Platform pair 1.

6. Any service patterns that don't have an outright routing dependency on which pair of platforms they have to use, such as thru-and-thru Kenmore<-->D, get divvied up between the two platform pairs in whatever load-balancing setup makes sense.

7. Because of the duck-unders, you can draw a straight-line surface walkway between platform pairs (dotted white lines). Sort of longish, but logical. And then I just added an inbound/outbound overpass that doubles as an exit out of the cut to the Kent/Station St. intersection and whatever's upstairs in the air rights. Full fare-controlled station.



Only thing I haven't figured out is dispatching this so there's no scenario where a train (esp. an inbound) at Platform pair 1 is going to hold up a train bound for Platform pair 2. Since the block narrows a bit here you aren't going to be able to put passing tracks like you have around the other set of platforms, meaning there's a little bit of at-grade traffic management to do here.

That's probably a caveat solved by choosing carefully what service patterns get assigned to which platform pair, and my head hurts trying to do that math so let's just call that a dispatching TBD. "Software", not "hardware" in terms of the build. Any which way you are never stopped behind a train on the Kenmore<-->Huntington circuit through the parallel downtown subways and your probable Urban Ring boomerang routing, and that's the important part and potentially heaviest service pattern. Forest Hills, Riverside, and/or Needham are just plain old branches. FH and Needham likely with lighter frequency and shorter trains than Riverside.

Any way you slice it the volumes are still lower at BV than Kenmore so some partial at-grade traffic management doesn't foul anything important. Remember, the Central Subway just got a heaping shitload more capacity with the Huntington downtown bypass and the equally likely Urban Ring downtown bypass. If 1 every X happenstance trains has to pause because of an unloading train on the platform in front of it, they now have the breathing room to recover that loss en route to downtown instead of compounding it.




It's not perfect, but it solves for the "build 2 of everything" conundrum and doesn't disrupt the footprint of the block too much with this bi-directional junction stacked on itself under the widest point of the that disposable air rights garage. And Forest Hills just uses the dirt-simplest turnout, likely recycled from previously-existing D-to-E surface tracks, for its much-shortened and much sped-up journey to the streets.

 

[vanshnookenraggen]

Re: Seaport Transportation

I never really saw the need for a transit tunnel under the harbor when it would have been so much cheaper just to build a Blue Line loop to the airport.

 

[Charlie_mta]

Here's my proposal. All surface, no tunnel. Yellow shapes are building takes, mostly gas stations. There would be no additional street running LRV; basically all of it is on a separate reservation / right-of-way. The Green Line Brookline station would need to be moved to the west to avoid the track junctions.

The Arborway overpass would need to be redone, but no big loss based on comments about it I've seen on here. Its replacement with a more open structure would help with community connectivity.