Crazy Transit Pitches

Notwithstanding F-Line's response, doesn't that only work from the north, since there's no ability to make the Boyston->Tremont turn?
Well, Boylston could become a major transfer station for GL from the West to GL to Seaport, but that only seems practical, IF there is some way to link the Boylston platforms inside fare control. Boylston platforms could certainly handle the people volume, but the separate directional stations are an issue.
 
Notwithstanding F-Line's response, doesn't that only work from the north, since there's no ability to make the Boyston->Tremont turn?
Yes. But for me the point is that Bolyston-Park is 4-track and so it makes the most sense to turn back at the "Far end" of the 4 tracking (far end from whichever direction you came from).

From the North/East it makes the most sense to turn back at
Gov Cen...because it has 4 tracks on its North side but only 2 going to park
Boylston...because it have 4 tracks on its North side but only 2 going to Arlington
Kenmore...with a pocket track on the surface so you don't have to slog out the B or C

From the West it makes the most sense to turn back at
Kenmore, on the loop, if you wished you had more service on a branch than the central subway can handle
Park...because demand has tapered off and you've got plenty of platform

Government center...I have a hard time justifying short turns here from the South/West...seems like future demand and current capacity favor turning anything you could have at Gov Center by going to North Sta instead.


And if you 've made it past North Station, going 3 stops to Union Sq seems a fine turnaround.
 
What's the tph capacity of the new terminals? If they've only got the two station tracks to turn on, wouldn't they be limited to some function of
Code:
60*2/(time it takes to turn a train)
tph? Does that start to impeded sending multiple branches to each terminal?
 
TPH trains per hour.
Alewife on the Red (which is a longer walk, end to end) turns everything on 2 station tracks and runs a train every 4 to 5 minutes (15 to 12 tph)
Physically, that should be doable on shorter GL trains at center-platform termini.

The Red with transformation wants 20 tph.
To sustain a train every 3 minutes, you've actually got 6 minutes to turn a train at Alewife

- switch onto the right station track
- berth
- discharge
- cycle/end change (the other track departs at about this moment, at the 3m:00s mark)
- load
- set switch
- depart

Assuming 2 termini for the Green, each doing "a Transformed Alewife" of 20tph, that means you could turn 40 tph at the termini. I think your sticking point would be inter-spacing them as they come together, rather than the turns at the end. And, yeah, you probably want to turn some back at North-GC-Park if there's no reason to send all that capacity all the way out north.

Admittedly: Alewife is better than Union or Tufts/Mystic will be because it has a yard beyond the end where a disable train can be just told to "keep going" and not have to backtrack to a pocket track (maybe Tufts has a pocket? I forget)
 
TPH trains per hour.
Alewife on the Red (which is a longer walk, end to end) turns everything on 2 station tracks and runs a train every 4 to 5 minutes (15 to 12 tph)
Physically, that should be doable on shorter GL trains at center-platform termini.

The Red with transformation wants 20 tph.
To sustain a train every 3 minutes, you've actually got 6 minutes to turn a train at Alewife

- switch onto the right station track
- berth
- discharge
- cycle/end change (the other track departs at about this moment, at the 3m:00s mark)
- load
- set switch
- depart

Assuming 2 termini for the Green, each doing "a Transformed Alewife" of 20tph, that means you could turn 40 tph at the termini. I think your sticking point would be inter-spacing them as they come together, rather than the turns at the end. And, yeah, you probably want to turn some back at North-GC-Park if there's no reason to send all that capacity all the way out north.

Admittedly: Alewife is better than Union or Tufts/Mystic will be because it has a yard beyond the end where a disable train can be just told to "keep going" and not have to backtrack to a pocket track (maybe Tufts has a pocket? I forget)

Openstreetmap seems to imply that there will be tail-tracks at College Ave but not Union Square. It's been a while since I looked at the station designs but given the whole "Substation in front of the tracks" thing I would doubt they're there.

So this probably isn't too big of an issue, then. Each branch runs, what, 10 tph? So you could honestly maybe run the entire green line out to the new termini if you're okay with absolutely no redundancy and having even the most minor hiccough throw the line into chaos (leaving room for more trains to terminate downtown?).
 
(Asking for a friend 😳) Maybe this has been asked before but, how many billions would it take to complete the Circle Line from Medford/Tufts to Riverside through Arlington/Belmont/Waltham????????
I figure this can get an answer here in Crazy Transit Pitches.
 
Notwithstanding F-Line's response, doesn't that only work from the north, since there's no ability to make the Boyston->Tremont turn?
Yes, hence my last sentence about Medford and Union Square services. However, elsewhere on this site, there are some fairly detailed proposals that would bring some of the West side Green Line routes through the same tunnel.
 
College Ave (ahem, Medford/Tufts) has space for tail tracks. Earlier work on Mystic Valley (Rt 16 @ Boston Ave) went right up to the precipice of the bridge-that-wont-get-built, and so has no room for tail tracks.


Oh, right. Medford/Tufts. So assuming neither terminal has room for anything to go wrong, I'm a bit more dubious that we can send multiple full schedule branches to the ends of the lines.
 
Union doesn't have tail tracks, but it's so close to the Brickbottom carhouse it doesn't need them as deadheads can make it between the carhouse-branch flyover switch and the crossovers to either platform slot faster than the next 6 min. headway. It saved them the trouble of having to punch underneath the Prospect St. retaining wall.

Route 16 won't have tail tracks, but they are looking at shoving a third pocket track a few feet inbound right before the crossover for picking platform berth that'll end up backstopping the supply. Note as well that if Green Line goes OPTO with only one operator in a multi-car train, they can stage an inspector at the pocket to help speed up that set of end changes for moving the spare train into platform position. Design is still not finalized for that, as they're still debating whether to have 16 up on the embankment or inclining down at-grade into the UHaul parking lot for cheaper digs (and a de facto temp station if the line is ever extended, since it would then have to be rebuilt on the embankment). Parking lot option will either attempt something similar or do real tail tracks. TBD.

GLX traffic modeling has been thoroughly vetted for the end changes. They are not anywhere near scraping against the headway margins on the end changes, so these turnbacks will have ample time to complete themselves on both branches.


If Union is extended to Porter, then you would need tail tracks because the branch would be 2-4 stops long and out of fast deadheading range from the carhouse.
 
GLX traffic modeling has been thoroughly vetted for the end changes. They are not anywhere near scraping against the headway margins on the end changes, so these turnbacks will have ample time to complete themselves on both branches.

Do we know what the expected headways are?
 
Well, Boylston could become a major transfer station for GL from the West to GL to Seaport, but that only seems practical, IF there is some way to link the Boylston platforms inside fare control. Boylston platforms could certainly handle the people volume, but the separate directional stations are an issue.

That's why there needs to be an effort to avoid having to ever build a "Boylston Under" like SL Phase III. If you're just reactivating the fence tracks, transfers are as dead-ass easy as they are at Park St. You just re-excavate the filled-in underpass between inbound and outbound sides (closed 1975-ish so the trackbed over the ped tunnel could be strengthened for the weight of Boeing LRV's) and ADA it like the Park IB-OB underpass.

As per my previous reply, if you envision the Tremont St. tunnel reactivation and new Tufts station as a multi-stage buildout, you end up getting most branch patterns covered in the end by eventually using that 4-tracker pipe to relocate the E off the Copley Jct. chokepoint. Which in turn gives you a chance to route a subset of D service off Brookline Village-Riverway connecting trackage. You can have any of the following patterns represented with one-seat service: Heath/etc.-Boylston/etc., Riverside-Boylston/etc. via Huntington, Needham-Boylston/etc. via Huntington, Kenmore Loop-Brookline Village-Boylston/etc. via Huntington, Boston College-Reservoir-Boylston/etc. via Huntington. With Urban Ring Park/GC-Lechmere 'circuit' service and UR Harvard/West-Lechmere having full access from the north.

What does that actually leave out. C's...unless you do some convoluted Kenmore Loop thru-route back out onto the D via Brookline Village and the Huntington connector. But that's slower on a one-seat than just crossing platforms, so isn't a real-world consideration. And B's past the BU East subway station on the UR built, excluding Chestnut Hill Ave. to BC which can be alt-routed via Reservoir and Huntington. Within the scope of a MUCH bigger system, that is not very much left out at all. So when construction costs for a Tremont tunnel reactivation w/Tufts and some TBD South End routing for SL Phase III replacement are factored, both that and the later-phase E relocation cost less than trying to re-mount the original SL III tunneling on a westbound hook-in and impaling itself all over again on the Common. No...you probably won't have all those routing options from Day 1 because the E-relocation cog is probably a second independent project. But given how utterly brutal it is going to be to attempt any sort of Boylston Under whatsoever or anything that SL III attempted to touch in that vicinity, you may indeed get E's-n'-friends aligned for north-south thru-running sooner and cheaper playing the hookup options at Tufts rather than getting target-fixated on monolithic builds.

Play the sequence of cog plug-ins @ Tufts with due diligence and the answers get pretty self-contained. Say Tufts is built as the Transitway light rail link-up replacing SL Phase III. Don't think of it as "well, I'm using one pair of tracks and one Tufts platform for the Seaport...the other one is complete surplus." No...what's the next cog? Is it converting Silver Line-Washington to streetcar for Dudley Sq.? Is it the E relocation, and mixed patterns ? Eventually you are going to plug the other track pair and other Tufts platform with other cogs.

Yes. But for me the point is that Bolyston-Park is 4-track and so it makes the most sense to turn back at the "Far end" of the 4 tracking (far end from whichever direction you came from).

From the North/East it makes the most sense to turn back at
Gov Cen...because it has 4 tracks on its North side but only 2 going to park
Boylston...because it have 4 tracks on its North side but only 2 going to Arlington
Kenmore...with a pocket track on the surface so you don't have to slog out the B or C

From the West it makes the most sense to turn back at
Kenmore, on the loop, if you wished you had more service on a branch than the central subway can handle
Park...because demand has tapered off and you've got plenty of platform

Government center...I have a hard time justifying short turns here from the South/West...seems like future demand and current capacity favor turning anything you could have at Gov Center by going to North Sta instead.


And if you 've made it past North Station, going 3 stops to Union Sq seems a fine turnaround.

Following on from above re: the Tufts "cogs", seeing the other 2 tracks and their other platform as strictly "the short-turn" is probably very shortsighted.

How many southbound cogs could there eventually be @ Tufts?
Platform 1
  • Boylston/etc.-Silver Line Way w/ SL2 replacement to Black Falcon (6 min. peak headway)
  • Boylston/etc.-Silver Line Way w/streetcar to City Point (6 min. peak headway)
Platform 2
  • Boylston/etc.-Dudley Sq. via Washington St. (6 min. peak headway)
  • Boylston/etc.-Huntington Ave (≤ 6 min. peak headway; primary E pattern + supplemental headway augmentation via Brookline Village)
Should the E alt-route potpourri get especially varied you could even filet a few those slots between Platforms 1 & 2 and work the crossovers past the station down to where tunnels diverge 2 x 2 to keep things in balance. Though because it's also likely that a wye at the tunnel split can alt-route some E's/D's straight to South Station and the Seaport most of the capacity for that variety won't need to be at Tufts-proper.


Now what's available for pair-matching on the north end?
  • Medford/etc. via Lechmere
  • Union/Porter/Watertown via Lechmere
  • UR Northwest Cambridge 'circuit': Park or GC Loop <--> Kenmore <--> Kendall <--> Lechmere/GC
  • UR Northwest Harvard/West: Harvard or West <--> Kendall <--> Lechmere/GC
  • UR Northeast: Chelsea/Logan Airport <--> Lechmere/GC


Hmm...do you actually have enough bandwidth to change ends on the Tufts platform anymore with 2 full branch schedules + some fileted augmentation feeding each side. That's not Park St. dense, but it's more than a train per every 3 min. on each of the 4 tracks. Probably too tight for short-turning.

And what's that...a 4-on-5 mismarch of south vs. north patterns unless the alt-ed E's pick up the slack? Hold the phone on retiring Brattle Loop...we're probably going to need that.


You can absolutely start out Tufts with ample short-turning because it's going to take some time to add all the service cogs and pair-match them. But all of the individual matches are high-leverage builds you eventually want, and you are indeed going to build most of them if not all. Your 50-year traffic modeling considerations are thus that you can't really consider Tufts replacing Brattle Loop as the only north-to-south turnback, because Tufts' capacity will be spoken-for on thru runs if even 75% of those desired cogs get built. It would be selling yourself extremely short on future considerations.

However...if you do want to bump that E relocation up on the priority pile just a bit so that cog has a bit more strategic juice behind it, you do ease the pressure eastbound enough that deleting Park Loop looks a bit less risky. But you better damn well be willing to commit to building that Prudential-Back Bay-Marginal Rd. tunnel and get the hell off Copley Jct. in regular service in no less than 15 years if you want to make Park Loop deletion a fail-safe. I don't think they're looking quite far enough ahead right this second to be able to make that level of commitment with certainty.
 
Do we know what the expected headways are?

To Union: thru-routed E's @ 6 mins. peak headway...same as today's E's.

To Medford: thru-routed D's @ 6 mins. peak headway...same as today's D's.

Off-peak headways same as today's D's & E's.


Optional headway augmentation via Brattle Loop usage. Today Lechmere-GC short-turns are done on Garden game nights, City Hall Plaza special events, and other misc. occasions of unusual-size downtown crowds. So you'll probably immediately see that existing practice extended out on a Medford Branch match (Union's too short to bother).

If D's get too difficult to dispatch long-distance under rush-hour load they might part out some Riverside-GC and GC-Medford turns from the run-thrus to keep things sane at peak load. Though that won't change the default headway to either the Riverside or Medford endpoints as it's just a dispatch-under-load relief valve.

TBD on whether there would be any outright above-and-beyond Medford-GC short-turn supplementing. If exploding Somerville ridership gets real hairy at rush hour after the first several years bringing Brattle online for rush extras is the first/easiest/cleanest pivot to addressing it.
 
If exploding Somerville ridership gets real hairy at rush hour after the first several years bringing Brattle online for rush extras is the first/easiest/cleanest pivot to addressing it.
Call Medford-GC trains "G"
I mean, once picking the letter is done, all the other parts are easy :D
 
As per my previous reply, if you envision the Tremont St. tunnel reactivation and new Tufts station as a multi-stage buildout, you end up getting most branch patterns covered in the end by eventually using that 4-tracker pipe to relocate the E off the Copley Jct. chokepoint. Which in turn gives you a chance to route a subset of D service off Brookline Village-Riverway connecting trackage. You can have any of the following patterns represented with one-seat service: Heath/etc.-Boylston/etc., Riverside-Boylston/etc. via Huntington, Needham-Boylston/etc. via Huntington, Kenmore Loop-Brookline Village-Boylston/etc. via Huntington, Boston College-Reservoir-Boylston/etc. via Huntington. With Urban Ring Park/GC-Lechmere 'circuit' service and UR Harvard/West-Lechmere having full access from the north.

How does a Kenmore-Brookline Village-Boylston via Huntington pattern work at BV? Any structural changes needed at BV for trains coming from Kenmore to get onto Washington St? From Google Maps, looks like a flat junction could work for a train turning south at the station down Pearl Street then east onto Washington, but the outbound platform would need to be shifted east. Has the state ever seriously considered this or is it truly crazy transit pitch? For inbound trains arriving at BV, looks like they could also turn south down Pearl if the inbound platforms were shifted west closer to the Washington st. overpass.
 
How does a Kenmore-Brookline Village-Boylston via Huntington pattern work at BV? Any structural changes needed at BV for trains coming from Kenmore to get onto Washington St? From Google Maps, looks like a flat junction could work for a train turning south at the station down Pearl Street then east onto Washington, but the outbound platform would need to be shifted east. Has the state ever seriously considered this or is it truly crazy transit pitch? For inbound trains arriving at BV, looks like they could also turn south down Pearl if the inbound platforms were shifted west closer to the Washington st. overpass.
It's been intermittently considered since the 70's as a quickie project. You wouldn't need to shift platforms. Depending on which end of Pearl (eastern end or both) used the turn direction that missed the regular BV platforms would utilize a curbside-pickup platform on Pearl before the turn wye onto the D. So with a Kenmore-bound pattern the station announcements would just direct next inbound passengers to the Pearl-side platform in X minutes and so on.
 
The DC area is considering a monorail along part of I-270 (see https://www.fredericknewspost.com/n...cle_a93df92b-6125-5b1a-b4c5-1a114e476a3d.html).

So. how about a monorail along I-95/128 linking Anderson Station in Woburn with the Green Line Riverside station. Also move the Auburndale CR station closer to I-95 to line up with the monorail route, creating a multi-modal transit complex at the Riverside/relocated Auburndale/monorail juncture. Monorail stations would be located at the Burlington Mall area (for TOD), and spaced along the rest of the route. Minimal ROW would be needed as the elevated monorail would straddle the shoulder of the expressway roadway on the existing cut and fill slopes.
 
As long as we're in the crazy transit pitches thread why settle for woburn-riverside? Quincy Adams-Salem Center or bust
 
The DC area is considering a monorail along part of I-270 (see https://www.fredericknewspost.com/n...cle_a93df92b-6125-5b1a-b4c5-1a114e476a3d.html).

So. how about a monorail along I-95/128 linking Anderson Station in Woburn with the Green Line Riverside station. Also move the Auburndale CR station closer to I-95 to line up with the monorail route, creating a multi-modal transit complex at the Riverside/relocated Auburndale/monorail juncture. Monorail stations would be located at the Burlington Mall area (for TOD), and spaced along the rest of the route. Minimal ROW would be needed as the elevated monorail would straddle the shoulder of the expressway roadway on the existing cut and fill slopes.

Might have been interesting 20 years ago.
 
The DC area is considering a monorail along part of I-270 (see https://www.fredericknewspost.com/n...cle_a93df92b-6125-5b1a-b4c5-1a114e476a3d.html).

So. how about a monorail along I-95/128 linking Anderson Station in Woburn with the Green Line Riverside station. Also move the Auburndale CR station closer to I-95 to line up with the monorail route, creating a multi-modal transit complex at the Riverside/relocated Auburndale/monorail juncture. Monorail stations would be located at the Burlington Mall area (for TOD), and spaced along the rest of the route. Minimal ROW would be needed as the elevated monorail would straddle the shoulder of the expressway roadway on the existing cut and fill slopes.

I'd post the Simpsons clip, but forget it. Why can't this stupid mode freaking die?

If you ever want to build a monorail, what you're saying is that you might need BRT or HRT, but you're an idiot.
 

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