Crazy Transit Pitches

[ulrichomega]

Picking up on the "Aqua Line" discussion from the Unbuilt Roads thread... There's always the question of where the Blue Line heads after the "Reasonable" expansion to Kenmore, and I'd like to make my crazy pitch for BC.

Blue would tunnel under Brookline Ave with new stops replacing the D line at Park Drive and Longwood Ave. Portal up to the existing D line at the baseball field/parking garage, continue to upgraded BV, BH, and Beaconsfield until tunneling off the ROW and into a Chestnut Hill Ave/Comm Ave tunnel to BC/Lake St station location with space to reverse under the existing yard (assuming this would be feasible/similar to the proposed Longfellow tail tracks?).

This, of course, requires massive changes to the Green line.
The outer D line would connect over to the existing C, which is tunneled all the way under Beacon from Kenmore to the baseball field where it gets back on the D ROW to Chestnut Hill and beyond. Cleveland Circle serves both Blue and the C in an underground transfer station. Remaining C stops are at Washington Sq, Coolidge Corner, and Audubon Circle with bus lanes on Beacon replacing the closed stops. B line would run to Cleveland Circle on the surface.

Combining C and D frees up space for restored Brighton/Oak Sq services, a new Harvard branch, or Grand Junction/other Urban Ring service (all merging in a Comm Ave tunnel before Kenmore). Would also improve trip time for Needham/Riverside riders with a straight shot into Kenmore. Having to transfer for Longwood/Fenway would be negated by improved station locations in the Brookline Ave tunnel. D ROW from east of BV to Kenmore could be preserved for future service or returned to parkland.

Maybe this could happen if BC wanted to seriously buy-in to a project that dramatically speeds their access to Longwood, downtown, the Airport, and an easy transfer to Cambridge? Or if Brookline ever wants to give up on having surface stops every 500ft :lol:. Lotta $$$ for no real expansion of service, but the reliability and redundancy improvements could make it an intriguing option at some point in the next 150 years or so.

I'm curious as to why BC is the destination here. I feel like their transit needs are fairly well met by the B line (and potential C line extension if Chestnut Hill Ave is returned to revenue service) if the B Line can be saved. I'm not saying it's a bad proposal, just that I've never heard BC as the target of a Blue-eats-D before.

I will say I'm a fan of continuing out of Kenmore along Brookline Ave. It's wide enough for a subway, there's room for platforms at Longwood Ave (assuming nothing is built there in the meantime), and Longwood will need more transit if it continues to grow. You would probably run into trouble with the Muddy River going over your Emerald Necklace station, though.

 

[George_Apley]

I'm curious as to why BC is the destination here. I feel like their transit needs are fairly well met by the B line (and potential C line extension if Chestnut Hill Ave is returned to revenue service) if the B Line can be saved. I'm not saying it's a bad proposal, just that I've never heard BC as the target of a Blue-eats-D before.

I will say I'm a fan of continuing out of Kenmore along Brookline Ave. It's wide enough for a subway, there's room for platforms at Longwood Ave (assuming nothing is built there in the meantime), and Longwood will need more transit if it continues to grow. You would probably run into trouble with the Muddy River going over your Emerald Necklace station, though.

This is the trouble with "Blue past Kenmore". The *easiest* destination (though not as easy as it looks) is taking over the D to Riverside, but it's not a good candidate because it screws up the Green Line irreparably. The best destinations are to the northeast (i.e. Watertown), but also the most troublesome to get to (tunneling from Kenmore to Watertown Sq). Anything else is either super redundant for too much money, or doesn't serve demand.

 

[ulrichomega]

This is the trouble with "Blue past Kenmore". The *easiest* destination (though not as easy as it looks) is taking over the D to Riverside, but it's not a good candidate because it screws up the Green Line irreparably. The best destinations are to the northeast (i.e. Watertown), but also the most troublesome to get to (tunneling from Kenmore to Watertown Sq). Anything else is either super redundant for too much money, or doesn't serve demand.

As much as it would kill connections, I've always been a fan of keeping the Blue Line closer to the Charles on it's way past Kenmore and then shoving it off onto the B&A once you get past the BU Bridge. I know the opportunity for any sort of ROW preservation is quickly leaving even as far as West Station (meaning far less benefit since leaving West Station is tricky), but it saves so much on project costs. A concourse under Deerfield St wouldn't be too bad if you can put a station under Storrow at the end of it.

Once you get to West Station, as mentioned, it becomes more difficult. You're pretty much left with some of the often-mentioned Green Line routings out, since continuing along the B&A isn't terribly possible. I'm not familiar with the plan for that area, but it looks like there's maybe room as far as Boston Landing for some Blue Line tracks if you're willing to eat a three-track section of the Worcester Line. Getting out there doesn't gain you much, though, so you're pretty much stuck continuing along under the Worcester Line tracks in a tunnel, at which point you're still stuck with finding a way over the Charles.

So basically, I don't see a good place for the Blue Line out past West Station. Sending it down the D Line has all the usual problems that get brought up. I think the Green Line is a better candidate for taking over the West Station surface slots, though (given the Grand Junction uses), so maybe we'll just be tunnelling it anywhere we want anyway.

EDIT: I apologize for how rambly that got.

 

[F-Line to Dudley]

As much as it would kill connections, I've always been a fan of keeping the Blue Line closer to the Charles on it's way past Kenmore and then shoving it off onto the B&A once you get past the BU Bridge. I know the opportunity for any sort of ROW preservation is quickly leaving even as far as West Station (meaning far less benefit since leaving West Station is tricky), but it saves so much on project costs. A concourse under Deerfield St wouldn't be too bad if you can put a station under Storrow at the end of it.

Once you get to West Station, as mentioned, it becomes more difficult. You're pretty much left with some of the often-mentioned Green Line routings out, since continuing along the B&A isn't terribly possible. I'm not familiar with the plan for that area, but it looks like there's maybe room as far as Boston Landing for some Blue Line tracks if you're willing to eat a three-track section of the Worcester Line. Getting out there doesn't gain you much, though, so you're pretty much stuck continuing along under the Worcester Line tracks in a tunnel, at which point you're still stuck with finding a way over the Charles.

So basically, I don't see a good place for the Blue Line out past West Station. Sending it down the D Line has all the usual problems that get brought up. I think the Green Line is a better candidate for taking over the West Station surface slots, though (given the Grand Junction uses), so maybe we'll just be tunnelling it anywhere we want anyway.

EDIT: I apologize for how rambly that got.

Getting on the B&A is not a problem. The angling of the Blue tunnel through Kenmore takes it straight from Beacon to Brookline Ave. Another 400 ft. of tunneling from where the Kenmore extension's tail tracks stub out and you're under the B&A all the same and can choose your adventure. There's no reason to skip a catchment as gigantic as Kenmore when you can get the same place.

Another thing to consider is that the most flood-prone place in Charles Basin is right by BU Sailing Pavilion. East of Mass Ave. the Lagoon absorbs most of it and Storrow itself rarely floods, so the tunneling (with retaining wall -placement flood reinforcements) from Charles to Charlesgate is relatively safe and inexpensive for waterproofing. West of Charlesgate it gets dicier because the water regularly gets on the roadway, and that'll probably heighten waterproofing costs a lot because the same passive-wall construction that was so easy to the east wouldn't work well here. For that reason, why engage that stretch of Storrow to begin with when Kenmore + B&A westbound to BU Bridge are all dry spots.

 

[George_Apley]

I don't believe he was proposing to skip Kenmore in favor of a river-routing, but rather swinging back up towards the Charles after Kenmore as you describe. The "choose-your-own-adventure" is the tricky part, as you know.

 

[Tysons2]

I'm curious as to why BC is the destination here. I feel like their transit needs are fairly well met by the B line (and potential C line extension if Chestnut Hill Ave is returned to revenue service) if the B Line can be saved. I'm not saying it's a bad proposal, just that I've never heard BC as the target of a Blue-eats-D before.

I will say I'm a fan of continuing out of Kenmore along Brookline Ave. It's wide enough for a subway, there's room for platforms at Longwood Ave (assuming nothing is built there in the meantime), and Longwood will need more transit if it continues to grow. You would probably run into trouble with the Muddy River going over your Emerald Necklace station, though.

The argument for BC is that a 45+ minute trip downtown doesn't constitute good service. The trip from Attleboro to downtown in the morning rush is just as fast. How much is GLT and Comm Ave re-build expected to improve travel time? I'm not saying it's BC-or-bust, this could just as easily dead-end at Cleveland Circle or connect at Brookline Village with no change to Green Line service whatsoever. But while I've got my crayons out...

I really like the Brookline Ave subway for station location improvements and the political support you'd get from the North Shore. But it does seem to lock the Blue Line into a service that terminates in the core, instead of other post-Kenmore routings which present the opportunity for connections across the metro area. That's probably something to be decided in our grandchildren's version of Focus 40.

As far as station locations, my thought was to build an entrance into the inevitable Shell gas station redevelopment. Or perhaps move it a block back to the Kilmarnock/Fullerton intersection, which is more centrally located for the neighborhood but misses any potential crosstown connections at Park Drive and Boylston.

 

[Tysons2]

Nice first post.

Long-time listener, first-time caller

 

[F-Line to Dudley]

BC can get a fast trip by routing D to Reservoir, Chestnut Hill Ave. connector, and B. That's doable today with some state-of-repair upgrades to the CHA trackage and doing a beneficial relocation of the CH station platforms to the west side of the intersection where it'll be accessible to all 3 branches. Figure if they end up doing D-to-E connecting trackage that Reservoir is a possible endpoint for that Huntington service booster. Nothing stopping you from going further to BC.


Really, this is all Reasonable Transit Pitches stuff you can mount very soon with the stet Green Line. I wouldn't waste a riddle in Blue-past-Kenmore on an easy reach when things like the triple-junction of branches at CHA and an under-capacity D are in-play.

 

[George_Apley]

Yeah, I'd say that the crazy transit pitch for Blue past Kenmore is getting it to Watertown Square. Even that is more cheaply accomplished by bring Green down from Porter.

 

[bigeman312]

We're in the crazy thread, so I like the idea of tunneling under Beacon with stops at Audubon Circle, Coolidge Corner, Washington Square, and Cleveland Circle. Then, remove the C-Branch and replace it with a multi-use trail. With the freed up capacity on the Green Line from not having a C-Branch anymore, either reopen the A-Branch, or add an F-Branch to Dudley.

 

[F-Line to Dudley]

We're in the crazy thread, so I like the idea of tunneling under Beacon with stops at Audubon Circle, Coolidge Corner, Washington Square, and Cleveland Circle. Then, remove the C-Branch and replace it with a multi-use trail. With the freed up capacity on the Green Line from not having a C-Branch anymore, either reopen the A-Branch, or add an F-Branch to Dudley.

Tunneling up a steep hill is not a fun time construction-wise. Honestly, if you have the urge to bury something Green tunneling the ex- A Branch (glomming onto the Kenmore-BU Bridge Urban Ring + B tunnel) is going to be the easiest one to do because the ground is level and uniform throughout.

We're having enough trouble figuring out how to get Blue out to Newton from Kenmore with the quantity of tunneling required under the B&A, so a Brighton subway is not exactly feasible. But it is more feasible than scaling the entire elevation of Beacon St. (or, for that matter, the Comm Ave. summit in Allston).

 

[jbray]

How about crazy-impractical? With the Huntington Ave subway in place, take over the D to Longwood, follow Longwood ave into Coolidge, then either follow Harvard to Brighton Ave/N. Beacon or run it under the C to Washington St and send it up to Watertown. It crosses all but the D and E lines, removes Van's shuttle service between the Huntington and Tremont, and connects the Blue (higher capacity) to both sides of the Fenway and Longwood. The alt would be to run the blue all the way to BV and run it up Washington to Watertown (eventually).

 

[ulrichomega]

Getting on the B&A is not a problem. The angling of the Blue tunnel through Kenmore takes it straight from Beacon to Brookline Ave. Another 400 ft. of tunneling from where the Kenmore extension's tail tracks stub out and you're under the B&A all the same and can choose your adventure. There's no reason to skip a catchment as gigantic as Kenmore when you can get the same place.

But how much more does that cost versus simply continuing along the shoreline (with the flood mitigation needed) and building a concourse connecting the two? I'm aware a concourse would limit ridership, but if we're talking the savings of a few billion dollars from not needing to bore the Blue Line under the B&A then it's something to consider.

Ultimately, though, I agree that building to Kenmore is the far better solution in terms of ridership and resiliency. What do you see as the most likely ROW out of Kenmore that the Blue Line would be taking?

 

[ulrichomega]

The argument for BC is that a 45+ minute trip downtown doesn't constitute good service. The trip from Attleboro to downtown in the morning rush is just as fast. How much is GLT and Comm Ave re-build expected to improve travel time? I'm not saying it's BC-or-bust, this could just as easily dead-end at Cleveland Circle or connect at Brookline Village with no change to Green Line service whatsoever. But while I've got my crayons out...

I really like the Brookline Ave subway for station location improvements and the political support you'd get from the North Shore. But it does seem to lock the Blue Line into a service that terminates in the core, instead of other post-Kenmore routings which present the opportunity for connections across the metro area. That's probably something to be decided in our grandchildren's version of Focus 40.

As far as station locations, my thought was to build an entrance into the inevitable Shell gas station redevelopment. Or perhaps move it a block back to the Kilmarnock/Fullerton intersection, which is more centrally located for the neighborhood but misses any potential crosstown connections at Park Drive and Boylston.

I believe that GLT is supposed to greatly help the B Line, but I don't think it's going to meaningfully drop the 45 minute number (helping more with reliability). People are always talking about how we should bury the B Line out to at least the BU Bridge, and I think that would do wonders for travel time at a cheaper price (though obviously not quite the same benefits).

For some reason I now have visions of a South Huntington Ave subway on my mind. Continue out on Brookline Ave to the Riverway, cut across to Huntington, and then continue as far south as you need. It covers a much denser catchment, and would serve as a renewal of service for residents there assuming that we're moving the E-Line over to the current D-Line if the North Huntington Ave subway gets built. If it can get down to Forest Hills you have relief for an already stressed Orange Line that will surely be overly stressed from a West Roxbury extension.

 

[F-Line to Dudley]

I believe that GLT is supposed to greatly help the B Line, but I don't think it's going to meaningfully drop the 45 minute number (helping more with reliability). People are always talking about how we should bury the B Line out to at least the BU Bridge, and I think that would do wonders for travel time at a cheaper price (though obviously not quite the same benefits).

Signal priority and all-doors boarding will help bring travel time to BC down substantially. It's fair to say >5 minutes is a guarantee, and more if MassDOT ever reconstructs the BU Bridge clusterfuck as a single-point intersection with turn lanes eliminating the two-light Carlton St. sprawl that is the biggest time chew on any B schedule. But there's no way with all of the above it's going sub-30.

One thing Comm Ave. Phase III reconstruction can do--IF the City goes with a design that centers the reservation instead of cheaping out--is serve up enough room for a turnback yard past Harvard Ave. a la Blandford Yard. And that can allow some service segmentation where headways are kept stiffest Harvard-inbound, with the shorter schedule ensuring additional reliability and tighter packing in the subway. Then you can throttle-down service up the hill where the ridership craters and sparser headways will suffice for most of the day so long as the GLT package of improvements are shorting the trip. And finally, you use the Chestnut Hill Ave. trackage to throttle-up service to BC via the C or D.

Varying up service is an old BERy idea we have an opportunity to re-embrace for the future with very reasonable things like building that Harvard Ave. turnback with the Phase III road reconstruction and better leveraging Chestnut Hill Ave.


As for the BU Bridge subway, the *only* reason to consider building that is if Urban Ring goes LRT, because tunnel is the mechanism for squaring the level difference with the Grand Junction on the bridge hillside. But by bypassing the BU Bridge lights and compressing 3 stops into 1 it's a cosmic speedup and capacity increaser for the B in its own right. What's now 18 surface stops will drop to 14 minus the planned consolidations and TBD future consolidations. That's right in line with the C's 13 surface stops (with 2-3 likely future consolidations) in manageability.

For some reason I now have visions of a South Huntington Ave subway on my mind. Continue out on Brookline Ave to the Riverway, cut across to Huntington, and then continue as far south as you need. It covers a much denser catchment, and would serve as a renewal of service for residents there assuming that we're moving the E-Line over to the current D-Line if the North Huntington Ave subway gets built. If it can get down to Forest Hills you have relief for an already stressed Orange Line that will surely be overly stressed from a West Roxbury extension.

South Huntington definitely does not have the ridership to float subway construction. It can float a trolley because that ridership trends greater than what 60-footer buses can hold, but not a subway. Consider that there'll eventually be E-to-D connecting trackage to Brookline Village, and if the junction is configured bi-directional that means you not only can surge service on Huntington-proper but also defray any concerns on South Huntington about street-running schedules being affected by traffic by spreading out the points of origin. You could even run Hyde Square/Forest Hills to Kenmore Loop as a throttle-up.

Now, if you bury Huntington-proper in a subway to the D w/ bi-directional junction for that alt-spine magic, you can still manage the Forest Hills branch very easily by running it on the surface connector vestige...which is now 'the' branch itself. Surface stops outbound of Brookline Vill. would be:

1. Riverway
2. Heath St.
3. VA Hospital
4. Bynner St.
5. Perkins St.
6. Hyde Square
7. Beaufort Rd.
8. JP Center
9. Monument
10. Child St.
11. FOREST HILLS

That's really not bad considering all the service throttles available. Silver Line-Washington, which majorities would agree is better off as a streetcar, is 9 surface stops at more total ridership. So if we aren't subwaying that one and its characteristics look fine for surface light rail, the South Huntington branch looks to be a near-twin.

 

[F-Line to Dudley]

But how much more does that cost versus simply continuing along the shoreline (with the flood mitigation needed) and building a concourse connecting the two? I'm aware a concourse would limit ridership, but if we're talking the savings of a few billion dollars from not needing to bore the Blue Line under the B&A then it's something to consider.

Ultimately, though, I agree that building to Kenmore is the far better solution in terms of ridership and resiliency. What do you see as the most likely ROW out of Kenmore that the Blue Line would be taking?

Everything Kenmore-west is on bedrock; the literal square is the 1630 shoreline. The only landfilling left is Bay State Road + Esplanade and part of Beacon Park. Tunneling under the B&A from Kenmore requires no waterproofing, which will keep the costs down.

Where uphill tunneling chews costs is from the effects of gravity. It takes much more mitigation to pour and dry concrete because in slurry form it's got a natural inclination to flow downhill and set out-of-place or weighted wrong. The water used in construction (concrete mixture, pressure blasting or cleaning, fill removal, utility triaging) becomes a royal pain to keep from channeling downhill and/or leaking into seams on an unfinished wall segment into under-street cavities...where it could get into adjacent buildings. And the fuel/energy usage for all the tunneling equipment is much more expensive when working a graded tunnel vs. working a flat tunnel.

It doesn't affect build feasibility at all, as a completed tunnel should be able to perform just fine. But it's a significantly longer and more bogged-down construction stage because of all the extra steps needed to keep downhill material flow in-check, how much slower progress goes having to keep the force of gravity in-check, how many potentially more do-overs there are on minor things, and how much day-to-day cost/labor chew there is. So if you're comparing the C up the summit to Cleveland Circle vs. doing something level up the old A route, it's going to be significantly less and significantly faster to build the level route.

Problem is, to get anywhere special with Blue-from-Kenmore you've got to tunnel anywhere from 5-8 miles, which is just bonkers in sheer quantity of concrete. NSRL (all of it...2 two-track bores + all the leads) and Silver Line Phase III could both be build with less quantity of raw materials than this even if their methods are much more complex than a shallow cut under a couple of RR tracks. I don't think I can ever see a universe where a five-plus mile single tunnel--to anywhere--occupies anyone's planning mindshare in this region.

 

[ulrichomega]

Everything Kenmore-west is on bedrock; the literal square is the 1630 shoreline. The only landfilling left is Bay State Road + Esplanade and part of Beacon Park. Tunneling under the B&A from Kenmore requires no waterproofing, which will keep the costs down.

Where uphill tunneling chews costs is from the effects of gravity. It takes much more mitigation to pour and dry concrete because in slurry form it's got a natural inclination to flow downhill and set out-of-place or weighted wrong. The water used in construction (concrete mixture, pressure blasting or cleaning, fill removal, utility triaging) becomes a royal pain to keep from channeling downhill and/or leaking into seams on an unfinished wall segment into under-street cavities...where it could get into adjacent buildings. And the fuel/energy usage for all the tunneling equipment is much more expensive when working a graded tunnel vs. working a flat tunnel.

It doesn't affect build feasibility at all, as a completed tunnel should be able to perform just fine. But it's a significantly longer and more bogged-down construction stage because of all the extra steps needed to keep downhill material flow in-check, how much slower progress goes having to keep the force of gravity in-check, how many potentially more do-overs there are on minor things, and how much day-to-day cost/labor chew there is. So if you're comparing the C up the summit to Cleveland Circle vs. doing something level up the old A route, it's going to be significantly less and significantly faster to build the level route.

I'm not sure of how this connects to my post (other than the first paragraph). Which potential routing involves more hilly-tunnelling?

Problem is, to get anywhere special with Blue-from-Kenmore you've got to tunnel anywhere from 5-8 miles, which is just bonkers in sheer quantity of concrete. NSRL (all of it...2 two-track bores + all the leads) and Silver Line Phase III could both be build with less quantity of raw materials than this even if their methods are much more complex than a shallow cut under a couple of RR tracks. I don't think I can ever see a universe where a five-plus mile single tunnel--to anywhere--occupies anyone's planning mindshare in this region.

This is part of why I'm not a fan of the Kenmore tunnel (let me rephrase, I think it's a better implementation of the idea but potentially far more expensive). It involves an extra two miles of tunnelling on top of all of the other costs of the project. As compared with a Charles-route that potentially involves almost no tunnelling and gets you to West Station far easier, and with fewer build impacts. Unless we're murdering the Green Line for the sake of the Blue it's miles of tunnels once you're out of Kenmore. My proposal is to minimize costs and send the Blue out to West Station via a Kenmore concourse instead.

 

[ulrichomega]

South Huntington definitely does not have the ridership to float subway construction. It can float a trolley because that ridership trends greater than what 60-footer buses can hold, but not a subway. Consider that there'll eventually be E-to-D connecting trackage to Brookline Village, and if the junction is configured bi-directional that means you not only can surge service on Huntington-proper but also defray any concerns on South Huntington about street-running schedules being affected by traffic by spreading out the points of origin. You could even run Hyde Square/Forest Hills to Kenmore Loop as a throttle-up.

Oh, I'm absolutely in agreement that it makes no sense to consider such a thing. But we're so far out in the potential future at the point where we've built the Blue Line to Longwood that I don't know if we can make real proposals anyway. But in the possibility space of where to send the Blue after Kenmore I think there's far more ridership down there than there is along the D.

 

[jbray]

I'm not sure of how this connects to my post (other than the first paragraph). Which potential routing involves more hilly-tunnelling?

He's going back to Tyson2's conversation starter about replacing C or B with Blue.

I think that Kenmore is the logical hub connection to also get the Blue line to the B&A so that it could head to West Station. Not making the connection would be seen as nearly as foolish as not connecting the Red line to Park once upon a time. It makes the Blue line more valuable to have it go to hubs than to skip them because it's easier. I've always wondered what the impediment was to cut and cover the B&A to replace the local stations and improve Worcester headways. Was not the plan back in 1945 to go all the way to Riverside with a line?

 

[F-Line to Dudley]

He's going back to Tyson2's conversation starter about replacing C or B with Blue.

I think that Kenmore is the logical hub connection to also get the Blue line to the B&A so that it could head to West Station. Not making the connection would be seen as nearly as foolish as not connecting the Red line to Park once upon a time. It makes the Blue line more valuable to have it go to hubs than to skip them because it's easier. I've always wondered what the impediment was to cut and cover the B&A to replace the local stations and improve Worcester headways. Was not the plan back in 1945 to go all the way to Riverside with a line?

The B&A/Riverside rapid transit line was pre-Pike and would've taken Tracks 3 & 4 of the mainline from Back Bay. All-surface, no tunneling. The Pike Extension wasn't constructed until a decade after the rest of the highway outside 128. The final 1965 Alternative cannibalized B&A Tracks 3 & 4, but other rejected Alts. would've left more trackage intact and possibly kept the rapid transit proposal alive. As is, no ROW width survived except through Beacon Park so we're left with a total-tunneling build way more severe than the all-surface routing of '45 and the mostly(?)-surface routings of the pre-'65 Pike alts.