B Line Improvements

F-Line said:
The T has simply resisted doing it despite pleas from City Hall and town of Brookline.
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Any reason for this other than trying to discourage ridership?
 
novitiate said:
I seem to recall reading that the T leadership is skeptical of the benefits of signal priority and want the supporters to pay for a formal study.
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Well that's dumb... if Brookline has already set up the system it would cost the T next to nothing to implement priority on the C as a trial.
 
If the system requires any kind of sensors to be installed anywhere, then it's not even close to being set up.

That having been said, optical sensors as F-Line suggests are pretty awful as far as sensors go. For a stop-gap mechanism or if the cameras are there already, sure, but if we're going to spend anything more than $500 on sensors we might as well do this the right way and have the tracks themselves wired to send a preemption signal every time a trolley passes over the sensor. This is probably less intrusive then throwing up cameras would be, less likely to defeated by false positives or mis-recognition (and god forbid something happens to the camera to obstruct the view...), and on-track sensors will more easily mesh with any CBTC system once one starts getting rolled out.
 
Commuting Boston Student said:
(and god forbid something happens to the camera to obstruct the view...), and on-track sensors will more easily mesh with any CBTC system once one starts getting rolled out.
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As to the former: I imagine that if the signal phases remain the same -- exception to detected trolley forcing all red -- then an obstructed camera will merely result in a trolley having to wait its turn. Nothing catastrophic.

To the latter: Come on. Not happening for ages, if ever.



I have a question as to service frequency... trains would be throughput more rapidly, but the central subway can't really handle much more. Would the result be less frequent trains, but shorter trip times, and possibly more three-car trains?
 
I've heard F-Line mention before that the central subway CAN handle more, and that it's signaling issues holding it back.
 
Commuting Boston Student said:
If the system requires any kind of sensors to be installed anywhere, then it's not even close to being set up.

That having been said, optical sensors as F-Line suggests are pretty awful as far as sensors go. For a stop-gap mechanism or if the cameras are there already, sure, but if we're going to spend anything more than $500 on sensors we might as well do this the right way and have the tracks themselves wired to send a preemption signal every time a trolley passes over the sensor. This is probably less intrusive then throwing up cameras would be, less likely to defeated by false positives or mis-recognition (and god forbid something happens to the camera to obstruct the view...), and on-track sensors will more easily mesh with any CBTC system once one starts getting rolled out.
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Yes, it IS close to being set up. Beacon St. is already wired with pre-emption sensors for emergency vehicles on top of every traffic signal mast. And both Beacon and Huntington have firmware built in--per the city's own specs--for plug-and-play transit preemption of either buses or trolleys. Boston and Brookline paid for it. The literal only installation they have to do is plug in the sensor on top of the existing trackside trolley signal head. Then have a guy with a laptop program the signal box.

Brookline's whole counterargument to the T's reluctance is it's already plug-and-play.


The optical sensors are not "awful" or "stop-gap". They're used on many streetcar systems nationwide, and in lots of cities for buses. They aren't cameras; it's infrared trained to the specific vehicle's shape and trained to ignore anything else or anything discountable as image noise. Detecting a trolley shape in the same fixed position without false positives is not hard; there aren't any other vehicles that look like them. Those trackside reservation signals are staring eye-level at the trolley's headlights and marker lights. If these things work on buses and mixed-traffic streetcars elsewhere they damn sure aren't going to have an issue with the reservation trolleys on the B, C, and E.

The T does not want to have to maintain more maintenance-intensive trackside hardware. Mechanical switches suck in New England weather and wear out fast. Track circuit preemption requires a few million dollars worth of repeaters, insulators, and extra electrical plant that they have to maintain. They don't have to maintain anything with these sensors. Those singals are bought, paid-for, and owned city and MassHighway installations. Some truck plows into a trolley signal...BTD or Brookline DPW are the ones on the hook to replace it. All the municipalities are asking for is for permission that the T will make use of signal preemption if it were installed, a small capital contribution for parts and labor of only the installation of those sensor doohickeys, and to have their traffic engineers talk to the city traffic engineers about recommended timings for the preemption phases. Write a check for a few dozen grand, be done with it. City streets are shared state and municipal responsibility. It's not the T's prerogative to "own" it all, so there's zero reason for them to be installing stuff 10 times as expensive for an entirely duplicate effort that they "own".

This stuff's being served up to them on a silver platter. Their problem is they're pooh-poohing the silver platter.
 
novitiate said:
I seem to recall reading that the T leadership is skeptical of the benefits of signal priority and want the supporters to pay for a formal study.
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And Brookline immediately destroyed that argument by reminding them that they lit a half-mil on fire having a study group for the 39 bus improvements recommend exactly the same signal priority that Brookline installed on Beacon...and spent considerable energy tooting their own horn on how bullish they were on the supposed benefits.

At the time the T wouldn't even send a single official to meet with the town about this. So not only was it a bullshit excuse, but there was no basis for a study because they refused to even discuss what the objective of such a study would be.
 
Matthew said:
Stop consolidation, signal priority, and all-door boarding.
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I think that would drastically improve the B Line. I would go further and get rid of some street intersections around B.U. so that they don't cross the tracks at all which would lessen the frequency of the train waiting in traffic with the cars and buses.
 
Yes, it should be possible to block off the Silber Way intersection to cars, now that Cummington is closed to most vehicles. For walkers and bikers, a simple yield to trolley sign should do, much like along the "D" branch.
 
Matthew said:
Yes, it should be possible to block off the Silber Way intersection to cars, now that Cummington is closed to most vehicles. For walkers and bikers, a simple yield to trolley sign should do, much like along the "D" branch.
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That would never work. Those two crossings in front of Warren Towers are so close to the front door of the CAS building that they are the heaviest-use ped crossings on all of campus. Pedestrians trigger way more light cycles here than cars ever do. Keeping it as-is is the only way to maintain law and order. The crush of students crossing every hour on the hour in a 10-minute burst between classes is enough volume to overwhelm, and leaving one of those unsignaled overloads one side of the BU East platform over the other.

Plus it's an unnecessary safety hazard. The students are going to dart out in front of traffic light or no light...that's a given, like it or lump it. When the Silber Way and St. Mary's lights are green Comm Ave. WB is already a speed trap and a dangerous place to dart across from Marsh Plaza/BU Central. They would not want to create a similar situation at BU East or take down a signal encouraging more kick on the afterburners here. It's a legitimate traffic-calming concern vs. speeders.


The road is set up properly here for pedestrians and cars. The trolley stop spacing is what sucks. And unfortunately they made their bed with that when they decided to rebuild East and Central separately instead of combining mid-block. There aren't any real solutions here beyond fixing the Bridge intersection clusterfuck and re-spacing Central another block west. The only easy fixes are west of the bridge where whacking Pleasant St., signal priority, and fixing the platform pinches when the roadway is rebuilt set up a more efficient/resilient trip through Central/East/Blandford.
 
I don't understand why unsignaled busy pedestrian crossings are a problem for trolleys, honestly... the Opera Place crossing at Northeastern University is very busy with students crossing from one side of the campus to the other, and there is no issue...and that's with the trolleys coming right out of the portal. They ring the bell and at most honk the horn, and I haven't heard of there being an issue.

I mean, you certainly have to stop car traffic (which they do do on Huntington), but it shouldn't be necessary to stop the trolley too if the road crossing is closed.
 
Oh I wasn't suggesting that they get rid of the signal. Just that trolleys should be able to proceed at will when clear. And there's no reason to have cross car traffic here anymore. The intersection could be a kind of mini transit mall.

The students are already treating it as such de facto. Trolleys mixing with people at low speeds is nothing new or strange. It's been standard practice in many places for over a century.
 
Matthew said:
Oh I wasn't suggesting that they get rid of the signal. Just that trolleys should be able to proceed at will when clear. And there's no reason to have cross car traffic here anymore. The intersection could be a kind of mini transit mall.

The students are already treating it as such de facto. Trolleys mixing with people at low speeds is nothing new or strange. It's been standard practice in many places for over a century.
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Can't. The trolley signals are tied to the road signals here. So you can't have the trolley equivalent of a flashing-red or flashing-yellow light when the dependent road signal is on a normal green-yellow-red cycle. That's a conflict verboten by AASHTO rules, which do explicitly cover co-mingled rail and car traffic such as streetcars or grade crossings. And turning all to flashing-red or flashing-red/flashing-yellow doesn't work for road safety at such a crush-load crosswalk. Since there will always be a ped signal here on a green-yellow-red cycle and the track crossing is tied to the signaled crosswalks, the trolley will always be on the same signal. No exceptions allowed.

You really don't have to turn this grade crossing into a pedestrian island. U-turns are illegal here so the only traffic crossing it is off Cummington. That's now limited to BU service trucks, police, and emergency vehicles so it's a de facto private crossing anyway. Blocking it off as a ped island does nothing additional except waste money tarting it up with brick and granite. Unnecessary and superficial. The auto traffic is gone from it except for the very occasional service vehicle, so it's improved as much as it'll ever improve.


Really, it all hinges on a long-term permanent fix for the Carlton/Mountfort/BU Bridge gauntlet of pain. There's nothing more that can be done between Kenmore and BU West until they come up with some concept design that cleans that all-mode dysfunction up.
 
FWIW...here's how I'd respace the stops.


Blandford (approx. spacing to nearest 50' from next inbound station entrance: 1300' from Kenmore entrance) - As-is

BU East (spacing: 900' from Blandford) - As-is

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

BU Central (new spacing: 1600' from BU East) -
Road reconstruction: Reconstruct BU Bridge intersection as single-point, single light cycle with left, straight, right lane setup on Comm Ave. WB, Mountfort NB, BU Bridge SB. Comm Ave. EB still turns onto the Bridge by looping off Carlton St. Block off Carlton St. grade crossing, take down traffic light. Carlton now used only for right turns onto Comm Ave. EB and looping turns from Comm Ave. EB to BU Bridge. Improve thru Carlton traffic at the Carlton/Mountfort intersection since Essex St. thru access may need to be restricted to make the Mountfort reconfiguration work. Make U-turn left-turn lane at St. Mary's for reaching University Rd./Storrow EB from Mountfort/Carlton; delete EB U-turn lane at Cummington (i.e. U-turns @ St. Paul and St. Mary's now equally spaced on opposite sides of the bridge). Additional Storrow access to west via Babcock St. Ext. over Beacon Park reducing load to east.

Transit reconstruction: Move both BU Central platforms to easterly side of BU Bridge intersection. Old station partially cannibalized by EB U-turn lane.

Net benefits: -1 signal cycle. Significant cleanup of the Bridge intersection, much less dangerous weaving, more orderly ped movements from all the weaving disappearing. Significant safety improvements. Slices out significant induced demand traffic, especially to Storrow EB. Better station spacing. Serves future air rights development on the Mountfort-Carlton block.

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BU West - Delete, including traffic light.

St. Paul (new spacing: 1350' from BU Central) - Rebuild platforms directionally on both sides of intersection.

Pleasant St. - Delete.

Babcock St. (new spacing: 1500' from St. Paul) - Rebuild platforms directionally on both sides of intersection.

Packards Corner (spacing: 1000' from Babcock) - Rebuilt on new center median via MassDOT Comm Ave. reconstruction plan; wider platforms. Keep location as-is on SW side of intersection.

Harvard Ave. (spacing: 1800' from Packards) - Rebuilt on new center median via MassDOT Comm Ave. reconstruction plan; wider platforms. Keep location straddling intersection.

Griggs St./Long Ave. (new spacing: 1300' from Harvard Ave.) - Re-space Griggs St. platforms 1 block west to Long Ave.-Scottfield Rd. block. Change station name accordingly. Insert a Blandford-style turnback track to Harvard Ave. to permit regular Harvard Ave. short-turns. Storage for at least 3 three-car trainsets, enough crossovers for each trainset to pull in/out of service from front/middle/back of storage track. Re-space crosswalks out to Harvard Ave. with MassDOT reconstruction to fit pocket track. Locations of all negotiable based on crosswalk spacing needs.

Allston St. - Delete. Larger relocated platform at Long Ave. replaces, provides better station spacing, remains within eyeshot of Allston intersection. Possibly re-name ex-Griggs to "Allston/Long Ave." so it's still primarily associated with this heavier-use intersection.

Warren St. (new spacing: 1450' from Long Ave.) - MassDOT reconstruction relocates outbound platform, gives it more space. Inbound platform stays as-is, but given slightly more room.

Washington St. (spacing: 1800' from Warren St.) - Move inbound platform to opposite side of intersection for more room, widen outbound platform.

Sutherland Rd. (spacing: 1100' from Washington St.) - Move inbound platform to opposite side of intersection for more room, widen outbound platform.

Chiswick Rd. (spacing: 1200' from Sutherland) - Move inbound platform to opposite side of intersection for more room, widen outbound platform.

Chestnut Hill Ave. (spacing: 1250' from Chiswick) - Move both platforms to opposite side of intersection to permit station stop from C/D Lines via Chestnut Hill Ave. connecting trackage. Road improvements to west side of intersection to give platforms adequate room.

South St. - Delete, including light + grade crossing.

Foster St. (new spacing: 1800' from Chestnut Hill Ave.) - New station replacing South St. Add signaled intersection, grade crossing. Platforms on opposite ends of intersection. Delete cemetery crosswalk and relocate here. Better station spacing, better intersection location since Foster serves unique traffic patterns while South is just a lazy shortcut to/from Chestnut Hill Ave.

BC (new spacing: 1650' from Foster) - As-is. I'm not a real fan of the median rebuild planned since boardings are much easier in the yard, but whatever...they're hellbent on doing it, so it'll be done.



Revised B line: 15 stops (-3 stop reduction; -1 BU Bridge traffic signal; traffic signals + platform-vs.-signal locations more efficiently balanced)
Blandford, BU East, BU Central, St. Paul St., Babcock St., Packards Corner, Harvard Ave., Allston/Long Ave., Warren St., Washington St., Sutherland Rd., Chiswick Rd., Chestnut Hill Ave., Foster St., Boston College.
 
You don't care for far-side platforms, I see? What's your plan for signal priority?

BTW, I'm not sure I'm clear about your BU Bridge plan: how can you have Comm EB loop thru Carlton Street to the BU Bridge if you eliminate the Carlton Street grade crossing?
 
Matthew said:
You don't care for far-side platforms, I see? What's your plan for signal priority?

BTW, I'm not sure I'm clear about your BU Bridge plan: how can you have Comm EB loop thru Carlton Street to the BU Bridge if you eliminate the Carlton Street grade crossing?
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Movements at BU Bridge...

From BU Bridge: New/re-striped left-turn lane + protected signal onto Comm Ave. EB. Straight + right-turn configuration stays as-is.

From Mountfort: New left-turn lane + protected signal onto Comm Ave. WB. Straight as-is. Wider right-turn space onto Comm Ave. EB. Clean up interface with Essex and Brookline-side Carlton.

From Comm Ave. EB: As-is. Straight or right-turn onto Mountfort. BU Bridge = right-turn onto Carlton, right-turn onto Mountfort, straight onto Bridge. No need to do a protected left-turn cycle here when this is still a usable traffic pattern for Carlton.

From Comm Ave. WB: Straight + right-turn as-is. Left-turn remains prohibited; most Mountfort/Park Dr.-bound traffic will continue using St. Mary's, so the demand isn't nearly high enough. Keeps the light cycle short with only the Mountfort/Bridge directions needing to get a protected-left cycle.



Carlton @ Comm Ave EB: Right-turn only; stop sign on Carlton. Grade crossing + signal zapped. University Rd./Storrow EB from anywhere but Comm Ave. WB requires a U-turn at St. Mary's. Enough induced demand goes away that I think the impact from the U-ie is negligible. And it probably helps overall flow not having Comm Ave. locked up by an uncleared queue of Carlton-University Rd. cars stopped in the middle of the road and on top of the tracks by students going over the crosswalk in an unbroken chain.

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

As for the platforms:
The only ones that remain directly across from each other are:
-- Blandford (incline, pocket track on opposite block, negligible light cycle)
-- BU East (block-spanning positioning superior to offset platforms)
-- BU Central (spacing is better together on the easterly side vs. offset, more destinations served consolidated in front of the Student Union and BU Academy)
-- Packards (station spacing + more platform space for both directions on relocated median if it stays on its current side of the intersection)
-- Chestnut Hill Ave. (only way to provision for mixed service patterns from B, C/D directions)
-- BC (because that's where they chose to do it).


So all of those have specific ridership or access justifications for staying the way they are.

St. Paul, Babcock, relocated Griggs, Washington, Sutherland, Chiswick, and relocated South all get the offset platform treatment. Griggs has to be rebuilt anyway for MassDOT's project, and thankfully Washington's the only one that's been ADA-modified to-date so they don't duplicate efforts on 5 out of 6 of the in-place reconfigs. Offset's better for managing the traffic signals, and the only way you're going to be able to widen some of those very narrow platforms up the hill is by trading off some space formerly occupied by the opposite platforms. I think that's important enough to do because some of those stops are dangerously narrow.

As for signal priority...trolleys should get it everywhere except for BU Bridge which has a tight schedule to keep to to cycle the car queues, Packards (busy queues), and Chestnut Hill Ave. (busy queues). The tradeoff for the Bridge being non-prioritized being the loss of the Carlton signal and the platform relocation giving them a better starting spot. So that's still a humongous improvement over what we have today. Especially with the Carlton queues no longer blocking the tracks. All of the other offset platforms are ideally situated for transit priority...better than the opposite platforms. The trolley sensors can just watch the blinking marker lights on the front of the trolley when the doors open. When doors close and the lights go steady...that's when the sensor can cycle the traffic lights to give the trolley priority. Not only helps getting them moving on-schedule to have a predictable # of seconds after the doors close before they get a green, but also means they don't have to rush the platform boardings to make a cycle.

For that reason it makes a ton of sense to have offset platforms at all the normal intersections and opposites only at the 3 big intersections least able to handle over-long reds on road traffic + Blandford and East where the intersection traffic has whittled down to pretty much pedestrian-only and a non-factor for the trolleys (though they still get priority anyway).

I think the platform relocations go hand-in-hand with signal priority that actually works really well. So does getting the MassDOT rebuild right at where it spaces signals and crosswalks.



BTW...those Harvard Ave. short-turns? That's only 7 surface stops from Kenmore. 1 less than the E currently makes to Heath. Nice and taut.
 
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Doh! I kept thinking of the forward loop to Carlton that many people make, instead of the backwards loop around Carlton to Mountfort that avoids the "merge of death." Yes, that's much better. They need to reconfigure the concrete at Carlton/Mountfort so that it's a normal intersection where Mountfort (from Park Dr) NW-bound traffic can continue straight onto the BU Bridge. From being on the ground there, I would say that's where the majority of the cars are going, and they all pile into the "merge of death" at Carlton & Comm and block the trolley. It's ridiculous, every day...

Regarding B.C. platform, I wouldn't be so sure that they will make a median station. The community is very much against moving it, and I think they're right to be.

A lot of your plan hinges on reconstruction of Comm Ave between Packard's and Warren... which is still pie-in-the-sky as far as I can tell. Current city plans only extend to Malvern Street at Super 88.

But maybe that can be pitched as capital improvement for the T and rolled into one of transportation funding bills.

In terms of spending priorities on the Green Line, if they got the money, what would you think?

Some ideas:
  1. Design and order Type 9s (many of them, to ditch the creaking Type 8s)
  2. Power system upgrades
  3. Signal system upgrades (but to do it without killing frequency?)
  4. Comm Ave reconstruction
  5. Install modern traffic signals around all Green Line grade crossings
  6. Proof-of-Payment deployment with ticket/verification machines widely installed
  7. ...?
 
Matthew said:
Doh! I kept thinking of the forward loop to Carlton that many people make, instead of the backwards loop around Carlton to Mountfort that avoids the "merge of death." Yes, that's much better. They need to reconfigure the concrete at Carlton/Mountfort so that it's a normal intersection where Mountfort (from Park Dr) NW-bound traffic can continue straight onto the BU Bridge. From being on the ground there, I would say that's where the majority of the cars are going, and they all pile into the "merge of death" at Carlton & Comm and block the trolley. It's ridiculous, every day...

Regarding B.C. platform, I wouldn't be so sure that they will make a median station. The community is very much against moving it, and I think they're right to be.

A lot of your plan hinges on reconstruction of Comm Ave between Packard's and Warren... which is still pie-in-the-sky as far as I can tell. Current city plans only extend to Malvern Street at Super 88.

But maybe that can be pitched as capital improvement for the T and rolled into one of transportation funding bills.

In terms of spending priorities on the Green Line, if they got the money, what would you think?

Some ideas:
  1. Design and order Type 9s (many of them, to ditch the creaking Type 8s)
  2. Power system upgrades
  3. Signal system upgrades (but to do it without killing frequency?)
  4. Comm Ave reconstruction
  5. Install modern traffic signals around all Green Line grade crossings
  6. Proof-of-Payment deployment with ticket/verification machines widely installed
  7. ...?
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Well...other than overly narrow platforms there's not major impact from the Packards-Warren redesign. The intersection traffic lights are at Packards, Harvard, Allston, and Warren...station stops. All remaining track crossings and lights are ped crossings. If nothing happened whatsoever this would still be the stretch of least concern for the B. The short-turn track isn't worth thinking about until MassHighway offers a design supporting it. They are the party paying for it all if the T reservation has to relocate. The T's only responsibility here is being prepared when/if such a redesign gets finalized to lay out the tracks and platforms with max efficiency. That's it. Go/no-go and what actual dimensions they'd have to work with are somebody else's call.

East-of-Carlton does have smart traffic signals today, but it's not worth installing the trolley detectors for Blandford, East, and Central when those have barely any vehicles crossing and ped movements pretty much spike in tandem with an approaching train. The trolleys already shape the light cycles indirectly. The problem is the Bridge. Carlton + Mountfort aren't capable of prioritizing with how fucked up it all is at clearing car queues off the tracks. There is no way to solve that B bottleneck unless/until the intersection is redesigned.

Bridge-Packards is slated for the same lane-drop + streetscaping that east-of-Bridge got. If the T pounced there with a plan to eliminate Pleasant and do the offset platforms at St. Paul and Babcock to max their platform space and max the benefits of signal priority it'll build a minor amount of resiliency for the inevitable Bridge delays and bunching. There's just nothing they can do with West + Central + East without a Carlton/Mountfort reconfig, so it's grin and bear it until MassHighway offers something up.

The rest...Warren-BC is ripe for prioritization if they so choose. The roadway isn't up for reconfiguring. Warren wouldn't be touchable unless the tracks were re-centered east of the intersection, but they could offset and widen the platforms and realign to the signals at Washington, Sutherland, and Chiswick. As well as do the South-Foster relocation. Those stations aren't exactly anyone's idea of high-priority, though. So in the interim the goal should just be re-wiring the road signals for better flow and better B schedule resiliency for when it hits the really tough bottlenecks.

Chestnut Hill Ave. relocation makes a lot of sense, but only if they plan to use it. South-Foster re-spacing is a project dependency because shifting CH outbound to the other side of the intersection makes South even more superfluous. And it would help if they had some idea of what viable C/D-to-BC service patterns they could run before doing that platform relocation. This probably means signal priority throughout the C and stop consolidation of Brandon Hall, Dean Rd., and possibly Hawes first. Otherwise that line hasn't got the flex to stay on-schedule with an extended run. Would help to also bundle in platform offsetting at Englewood, Tappan, and (if it stays) Hawes when those get ADA'd.




PoP is the only other thing that makes a huge difference here. We've beaten to death the insanity of front-door only boarding. Dwell times kill on-time performance. Signal priority helps, but if it takes 4 or 5 minutes at a packed platform the schedule's going to decay and bunching's going to creep in all the same. Open-shut...it must be done.

Modern signal installation are only a concern on the B; C and E reservation already have them. Installing priority-capable signals is MassHighway's and BTD's call. The T can't intervene when it comes to replacing a 'dumb' signal. All they can do is buy the trolley sensors when the smart signals are installed. Something they've obviously resisted doing on the C and E. Open-shut. If they get over their stubbornness on Huntington and Beacon then MassDOT and the City are the ones who need all the remaining pressuring for Comm Ave.

The surface branches don't need much in the way of electrical upgrades. It got boosted for Type 8 and 3-car train loads in the late-90's. Fleet expansion-related power upgrades are mainly going to affect the D and Central Subway. The D is due for a lot of wholesale infrastructure replacement anyway since it's past the 50-year mark without a major trackbed or signal plant rehab. And the ex- A line underground feeder cable that links the Green Line's power supply with the 71 TT's is also up for end-of-useful-life replacement and reliability upgrades. There's not a lot to do on the B- and C-proper. Any boosting on the B such as a short-turn track at Harvard Ave. for denser inner service will probably be provisioned by any MassHighway road reconstruction. The feeders have to get relocated with the reservation. But that's MassHighway's call...out-of-sight/out-of-mind until they offer up a design.

Type 8's are high-reliability right now. Not a concern until they reach age of first overhaul. Then the economics of rehab are going to come into play and retirement has to be considered before they start rapidly decaying. We're a ways away from that point. First priority is securing the money to exercise the option order on the Type 7 rehab to cover all remaining vehicles in the fleet. That's the critical need for fleet reliability. The # of daily available trains increases significantly if there are fewer 7's in the shop for minor aches and pains. They're thin right now because of accelerating numbers of 7's out for rebuild and lots more day-to-day shop malingerers that can't get out for rebuild fast enough. Rehab them all and they're rock-solid until 2025. And potentially good for one more rebuild after that. No concerns at all about any of the existing cars if they don't push them years and years past the time they're due for a rebuild-or-replace decision.


Central Subway CBTC is another ball of wax. Unlike heavy rail where it's tried-and-true and where NYC Subway has been the legacy-retrofit guinea pig for North America, the Central Subway is LRT's worldwide torture test. The first stab at a study was roundly panned. That doesn't mean it's impossible, just that it was the first time they'd ever attempted to study it in detail and wrap brain around how hard it would be. They'll have to continue studying it and gaming out different designs. They can't afford not to because 1 more bad operator-error accident could get the NTSB mandating an auto-stop system...headway-killing or no. So they have to keep digging at scenarios that could work. It means timetable has been set aside, but it doesn't mean they won't eventually come up with something.

And it doesn't mean that they can't CBTC the D, North Station-GLX, or the Huntington Subway where headways will likely remain well below tolerances of a conventional CBTC design. That does a whole hell of a lot of good if the B's and C's surface priority gets them arriving in Kenmore on-time and the D's CBTC has better software anticipation of arrivals at Kenmore and better north-end management of its long, long Riverside-Medford run. So don't think it has to be 100% re-signaled to do a metric asston of good. Accuracy on Kenmore arrivals solves most of the Central Subway clogs due to the 3 western branches. So long as they can avoid more whoopsies like another GC rear-ender it buys them good enough flow to chew almost indefinitely on solutions for the Central Subway. If any exist.
 
Oh, I was making a list for the entire Green Line, not just the "B". And my understanding is that the Type 9 design and order is being funded through the GLX, at least, enough for the new branches to use.

This is somewhat of a "transit pitch" but if they got the money somehow, where to put it for best effect?

  • POP infrastructure (ticket/vending/validation machines)
  • Power system upgrades to central subway
  • Add more Type 9 cars to order
  • Traffic signal upgrades where needed
  • Fund design and study of modern signalling system in central subway
  • Reconstruction of BU Bridge/Comm Ave intersection (in conjunction with MassHighway)
  • Reconstruction of Packard-Warren (centering ROW)

On the topic of CBTC, my understanding is that computer-based moving block safety systems can achieve upwards of 36 TPH, maybe more in practice (and in theory). The GL is currently scheduled for nearly 48 TPH on the most central section. But GL vehicles are much easier to stop than most other railroad vehicles. Does this really require a whole new design, or is it just an incremental improvement to existing ones?
 
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