Crazy Transit Pitches

[Equilibria]

This week's post gets into the "fun stuff" -- specifically, where do we go after Kenmore or Kendall?

There are three major ideas that get thrown around, and which all, in my opinion, are somewhat "crazy" but still "reasonable" enough to distinguish them from (for example) replacing GLX with the Blue Line: Blue to Highland Branch, Blue to B&A, and Blue to Watertown & Waltham. I think all of these have significant merit, and I think all present significant challenges.

I confess that the genesis for this series actually came from wanting to avoid repeating myself regarding the challenges of Blue-to-Riverside, which is probably the most common "crazy transit pitch" I come across. And to be clear, sending the Blue Line to Riverside is itself a solid idea, which has been around since at least 1971, from what I can tell.

What I've tried to illustrate in my post, however, are the knock-on effects of such an extension. To put it perhaps provocatively: "Future Commuter Rail riders in New Bedford would rue the day the Blue Line was extended to Riverside."

On a different note, though I spend a good amount of time outlining why such extensions would be challenging, I personally find an extension to Watertown the most promising, at least on a 100-year timescale. It would require a generation of advocacy. Moreover, I think it is even further down the road than "Phase 2", as I believe that an intermodal West Station, with transfers to circumferential service and regional rail, would itself be a logical "second phase" destination point, in that it would provide valuable service, would still leave options open for the future, and would potentially be a modestly low-impact build.

I believe that @Charlie_mta has put forth proposals for a largely-elevated ROW between West Station and Watertown Square, and while obviously very expensive, I do think it's a compelling proposal, but again, on a 100-year timescale. I do think building further to Waltham is hard to imagine, in any century. And, as I outline in the post, I believe a better alternative to serve Watertown is a combination of LRT and Regional Rail. I could also envision an elevated extension along the Mass Pike to a major transfer center at Newton Corner; replace the Boston Landing commuter rail station with a Blue Line stop, and then add extra stops at Blue Line-spacing at Market St, Parsons St and Bigelow St, and allow Regional Rail service to run express between Newton Corner and West Station. I like both of these ideas, but I also don't think either of them is a surefire winner. Better to lay the groundwork with extensions to Kenmore or maybe West Station, and add Regional Rail service, and see where that lands us first.

That all being said -- if we want to talk about truly crazy transit pitches, imagine what a Blue-to-LMA extension would set you up for. Kenmore to LMA to Roxbury Crossing to Nubian to Newmarket to Seaport to Logan to Airport to Chelsea to Everett to Wellington. (Yes, I made a map of this, yes, it is ridiculous, yes, I will post it at some point. I named the file "Project Blue Lace", to rhyme with "shoelace" because the Blue Line looping back on itself looks a bit like a shoelace. Yes, I was way too happy with myself for the pun.)

Your blog posts are great! Might I suggest adding a map of Blue-Kenmore in the Blue-Kenmore post? You have lots of them elsewhere...

 

[Teban54]

A little bit late this week, but the "series finale" for Extending the T's Blue Line west is now live. I have more things in the works, but probably will take a week or so off before the next one.

In this post, I make the case in favor of the Kenmore alignment, largely from the perspective of overall network design. I think this discussion reveals a number of interesting esoteric points about the way the MBTA network functions, and is why I see this as more than just a question of “Kenmore ridership” vs “Kendall ridership” (though I absolutely think that there needs to be a formal study, and I will certainly change my opinions based on the results of such studies).

I spend a long time winding my way through the different topics here, but in one of my last paragraphs, I think I get to The Big Point I’m trying to make:

One hundred years ago, the mainline gateway to Boston’s western suburbs was located in the Fenway at Brookline Junction station. Despite all that has happened in the intervening century, the ROWs that were laid out feeding into that junction have persisted over all these years. Because of that, Kenmore has remained a transit nexus, and remains the strongest “launchpoint” for any future expansion to the west.

(The more things change, the more they stay the same.)

The other Big Idea I introduce here (which will be the topic of further posts at a later date) is a three-tier distinction between “light metro”, “heavy metro”, and “regional metro”. I think the terms “light rail” and “heavy rail” remain useful in certain ways, but also can confuse more than clarify. MUNI Metro streetcars are famously slow (~8 mph on average), operate in mixed traffic, and have numerous stops that are literally just straight up in the middle of the street; LA Metro’s E Line (formerly Expo Line) operates in a dedicated ROW at near 20 mph on average, with full length high platforms for level boarding. These services should not be placed in the same category.

Likewise, if we all get our Indigo wishes, and see EMUs running 7.5 min headways on the Fairmount Line, that is basically mid-frequency heavy rail in almost everything but name. Moreover, heresy though it may be to say, the reality is that certain corridors – particularly circumferential service and radial service outside of an urban core – can be as well-served by true, high-quality BRT as by LRT (and in some cases, even better), with virtually indistinguishable rider experiences between the two.

The terms “light metro,” “heavy metro”, and “regional metro” are meant to give us more precise terms to describe the capabilities and roles of different services, deemphasizing a rapidly antiquating distinction between “light rail” and “heavy rail”.

Once we start viewing the T as three overlaid networks (plus a fourth layer of local feeder networks – i.e. most buses), the gap at Kenmore becomes obvious and we can start to plan a more balanced and efficient system for the decades ahead.

Great post as usual!

One question I wonder: Just how much pressure would Blue-to-Kenmore take off from the Green Line? Current GL branches would likely still prefer a one-seat ride to downtown as they do today, unless their destination is on BL. For any possible GL short-turns at Kenmore, these passengers may still find it easier to transfer to another GL train towards Park on the same platform at GL Kenmore, instead of walking to the BL Kenmore station (depending on BL configuration). Same situation for any proposal or Urban Ring LRT via B/D branches and Kenmore.

I do think passengers boarding at Kenmore, including those transferring from buses, will prefer BL as it's faster with greater capacity. But unlike all other transfer hubs you mentioned which primarily facilitate bus-to-HRT transfers, Kenmore having branches with one-seat rides to the city may, in my opinion, undermine BL's utility in linking the transfer hub to the city. And that's not even considering riders heading to Copley (either from GL branches or the rest of the system), whose location is perfect and not easily replaced by any BL station.

Of course, a BL extension beyond Kenmore can potentially take off huge pressure from specific GL branches depending on alignment.

 

[HenryAlan]

I wonder whether the future for Kenmore HRT is best served by sticking with the original BERY plan. Extend the Comm Ave. subway, convert to a Blue Line style HRT, which would run B&E through the central subway, then out to Union and Tufts branches. Seems like that would be cheaper and more straight forward than building an entirely new subway.

 

[F-Line to Dudley]

I wonder whether the future for Kenmore HRT is best served by sticking with the original BERY plan. Extend the Comm Ave. subway, convert to a Blue Line style HRT, which would run B&E through the central subway, then out to Union and Tufts branches. Seems like that would be cheaper and more straight forward than building an entirely new subway.

Depends on if the Urban Ring gets there first with a Comm Ave. subway out to BU Bridge. The insertion angle for BLX needs to at leave equal-opportunity options to go up Brookline Ave. to the B&A ROW for reaching Allston if Ring LRT is going to be a thing (and be a thing that likely gets there first).

 

[F-Line to Dudley]

Great post as usual!

One question I wonder: Just how much pressure would Blue-to-Kenmore take off from the Green Line? Current GL branches would likely still prefer a one-seat ride to downtown as they do today, unless their destination is on BL. For any possible GL short-turns at Kenmore, these passengers may still find it easier to transfer to another GL train towards Park on the same platform at GL Kenmore, instead of walking to the BL Kenmore station (depending on BL configuration). Same situation for any proposal or Urban Ring LRT via B/D branches and Kenmore.

Lots. The Urban Ring looms huge here. A large share of Allston-to-Cambridge transfer traffic that currently rides thru the gut to Park St. will instead be transferring at Kenmore onto more trolleys operating in a spray pattern. That in turn is going to lengthen dwell times at Kenmore a bit, so it more closely resembles Park St. with the large quantities of alightings each trip. So that change right there is the big opening for a new direct trunk line to shoulder the straight-to-CBD loads, which BLX will do in fewer stops to Red/Orange than Green will. Keep in mind as well that if you do a greater pan-Green Line Reconfiguration like branches to Seaport/Southie, any load relief to Park gets back-filled and then some by people from the Seaport hopping platforms @ Park to get around. So BLX is providing a crucial amount of load-shifting to do other/better things with other wings of Green.

I do think passengers boarding at Kenmore, including those transferring from buses, will prefer BL as it's faster with greater capacity. But unlike all other transfer hubs you mentioned which primarily facilitate bus-to-HRT transfers, Kenmore having branches with one-seat rides to the city may, in my opinion, undermine BL's utility in linking the transfer hub to the city. And that's not even considering riders heading to Copley (either from GL branches or the rest of the system), whose location is perfect and not easily replaced by any BL station.

Of course, a BL extension beyond Kenmore can potentially take off huge pressure from specific GL branches depending on alignment.

If you're going to Copley-Arlington, you're still going to be riding the Green Line one-seat. Which will hopefully be less crowded due to BLX existing. BLX ends up diverting a lot of Park load to Charles, so the Park GL level can absorb more inter-branch transfers with the Seaport hooked in. The straight BLX trip to GC frees up the Green Line level for inter-branch transfers from looping Urban Ring and northern trains. And Haymarket/North Station will get backfilled by transfers from the North-South Rail Link (since the saner NSRL Alts. have headhouses at both), meaning State picks up the slack for the Orange transfers. The system is tons more resilient under tons more expansion if you have an alt spine out to Kenmore specifically because of how the pooling @ Kenmore influences transfer loads Downtown.

 

[Riverside]

So BLX is providing a crucial amount of load-shifting to do other/better things with other wings of Green.

This is what it all boils down to (emphasis mine). The Green Line/LRT network can do things that no other mode can -- not HRT, not BRT, not mainline rail. Blue-to-Kenmore -- even though it doesn't solve all problems -- frees the Green Line up for new possibilities.

I'd also point out that, even with a transfer, the Blue Line may still be faster for some journeys. In my current maps, I put stops at Mass Ave, Hatch Shell, and then of course Charles/MGH, closing Bowdoin. That means Government Center is 4 stops away rather than 6, and that a Red Line transfer is 3 stops away rather than 5. (With an unusually long straightaway between Mass Ave and Hatch Shell -- nearly a mile, depending on stop placement. So those trains will be flying.)

@Teban54 your point about single-seat rides is well-taken, and probably not given its due consideration in my analysis. As F-Line points out, Kenmore's importance increases if you turn it into an Urban Ring node. Perhaps existing riders will still prefer the one-seat, but the added capacity would create new possibilities.

Another fascinating post, kudos again to you for the dedication you've shown to the topic, Riverside. I'm entirely in agreement you, both in terms of preferred destination and, more importantly, in the need to consider the network impacts as much as (or even more than) just the ridership potential at the chosen node-station.

Kenmore was once actively intended as a transfer node, hence the existence of the turnback loop (which I like to think of as the nameless, less-squeaky western counterpart of my namesake at Government Center); as I understand it the plan at one point was for the C (this predating the Highland Branch's conversion to the D-branch) to loop at Kenmore while the B's tracks would be eaten by the HRT-ified Central Subway. (Ironically, or perhaps poetically, given the clearances in the Tremont Street Subway, it might well have ended up using Blue Line-size HRT stock.) So there's a very good historical argument that Kenmore was supposed to be a LRT/HRT (light/heavy metro) transfer node and that the system's simply been suffering from its never having been built all these years, and that Blue (albeit now via Riverbank) would fix the problem that was intended to have been fixed last century.

This is indeed pretty much how I see it. And yes, the plan would've been for the C to be short-turned and probably also the outer half of the B. @vanshnookenraggen may know more from his work on his historical track map.

I look forward to these future posts. That said, while I'm intrigued by the three-tier concept, I do have a few thoughts. One's sort-of a nitpick, which is that I wouldn't call things like MUNI Metro's streetcars, New Orleans' streetcars (much as I like them), or even the surface-running portion of the E-branch as proper light rail, regardless of equipment. I wonder if there's room for either stratifying the classification between the systems operating in significantly mixed-modes (like with street running, which is really not that far off from BRT) and those that aren't.

So, with the caveat that I'm still refining these ideas, my response would be that this is exactly why I think the light rail/heavy rail distinction isn't useful for planning or understanding our systems anymore. The "streetcar vs light rail" dichotomy that you're describing isn't really about the equipment -- it's about the infrastructure surrounding the equipment. If you widened the Green Line tunnels, removed the rails, put down pavement, and then did the same on the B and C Lines, and then ran double articulated battery buses on them, how different would that be from today's Green Line? It's not about the equipment -- it's about the infrastructure.

One point to clarify as well -- I think I am possibly using a stricter definition of BRT than you are? To me, mixed-traffic running (which, yes, is not inevitable with street-running, as you can have transit lanes) does not clear the bar for BRT. At the very least, you need segregated lanes with enforcement, and ideally you have as much infrastructure as I described above for the B and C Line.

(I have considered adding a fourth tier: "Feeder Metro". The problem is that, by definition, that tier has minimal infrastructure, and part of my point here is shifting away from vehicle types and toward infrastructure components, so it becomes a bit of a contradiction in terms.)

The Green Line's an interesting example, because a fair number of its problems come from mixing pure grade-separated LRT (D and the Central Subway), two and a half surface branches running in reservations, and half of a branch street running (resulting in the nasty garbage-in, garbage-out difficulty of scheduling the thing to work in the de facto HRT role the Central Subway has been pressed into). (MUNI Metro has some of the same characteristics with its subway, right down to being the other poor fools to suffer the lemons that were the Boeing LRVs.)

Yes, this mixing of light metro and near-heavy metro is I think one of the fundamental challenges stressing the Green Line.

The other point is that as useful as tiered classifications are for discussions like this in forums like this (even if reasonable people can quibble about the specific definitions), part of me really, really hopes that your tiers don't catch on widely, because I feel like they're ripe for misunderstanding and misuse by moronic politicians who'd happily pick up the "light metro" definition to plaster over the fact that they're building BRT when they should be building LRT. (I can just see the MBTA of the era using "light metro" for the Silver Line just to try and add a bit more lipstick to that particular pig.) Hopefully that's just me being unnecessarily cynical, though

Soooooo I mean........ if it's proper BRT -- something like SL3 in Chelsea -- then I'm not opposed to calling it "light metro". You could argue that by putting it into the same category as (say) the B Line, it raises the expectation for what the infrastructure and service should look like. I'm not opposed to BRT; I'm opposed to bad BRT. And if it's bad BRT, then it's bad light metro too.

I do share your cynicism, but also the T can spin a frequency reduction with a fare hike as an "enhancement of service", so I think if we let the potential for abuse be a ruling criterion, we'll find ourselves very limited very quickly.

The terms “light metro,” “heavy metro”, and “regional metro” are meant to give us more precise terms to describe the capabilities and roles of different services, deemphasizing a rapidly antiquating distinction between “light rail” and “heavy rail”.

Once we start viewing the T as three overlaid networks (plus a fourth layer of local feeder networks – i.e. most buses), the gap at Kenmore becomes obvious and we can start to plan a more balanced and efficient system for the decades ahead.

Here's where I'd push back a little, referencing what I mentioned above. I don't know that I'd necessarily agree that the Green Line from Kenmore-east is as easily classifiable outside of the heavy metro network as it is west of Kenmore. It's certainly being relied upon to do the work of a heavy metro spine, the stop spacing is not that much more dense than the Orange Line, and on a whole it operates far more like a heavy metro than it does BRT; even one of the most significant differences, the vehicles, will be altered by the Type 10s. (Though, as above, that may well all be able to be chalked up to the Green Line being a unicorn hybrid; that it is such a unicorn is, in my view, a very good reason for some of the pressure to be taken off by BLX to Kenmore.)

Yes, I think this is a fair pushback. Certainly the Central Subway operates (and is asked to operate) like a heavy metro service, though I think it falls short in terms of reliability and capacity. If it is indeed "heavy metro" service, then I'd suggest that it is subpar. But yes, as we've discussed above, the unicorn hybrid nature of the Green Line means that it can't really serve either role fully effectively. I'd like to see Blue-to-Kenmore free the Green Line up to better leverage the advantages of a "light metro" role in the network -- which brings us full circle to F-Line's point above.

(Also, spoiler alert: my vision for the Green Line includes extending the Huntington Subway to Brookline Village-ish, and running the Riverside Line through there. With fully separated ROWs, rapid transit stop spacing, and modern vehicles, that could relieve a significant fraction of the current Green Line's "heavy metro responsibilities.")

 

[Brattle Loop]

@Teban54 your point about single-seat rides is well-taken, and probably not given its due consideration in my analysis. As F-Line points out, Kenmore's importance increases if you turn it into an Urban Ring node. Perhaps existing riders will still prefer the one-seat, but the added capacity would create new possibilities.

F-Line's point about Kenmore's importance as a transfer node in an Urban Ring universe (with or without the nifty "boomerang" service pattern discussed in the Green Line Reconfiguration thread) is well-taken and would turn Kenmore into much more of a transfer hub than it is now, increasing the appeal of the Blue Line pipe. That said, it's also worth noting that in addition to the additional speed element you mention, there have been times - some of them very recent - when at least one of the Green Line branches hasn't served one or more of the downtown transfer stations. Until last October the B didn't even hit Government Center; it was literally impossible for anyone on a B train going to the Blue Line to have a one-seat ride, and there's nothing to say that won't happen again (Park Street short-turning being useful for managing subway capacity). That problem wouldn't be a problem, even a potential one, if there was a permanent Blue connection at Kenmore. So even beyond the new network effects, you can effectively gain capacity by using the Park Street loop without dumping anyone who needs to get to Government Center to crowd onto the next trolley at Park to go one stop.

One point to clarify as well -- I think I am possibly using a stricter definition of BRT than you are? To me, mixed-traffic running (which, yes, is not inevitable with street-running, as you can have transit lanes) does not clear the bar for BRT. At the very least, you need segregated lanes with enforcement, and ideally you have as much infrastructure as I described above for the B and C Line.

(I have considered adding a fourth tier: "Feeder Metro". The problem is that, by definition, that tier has minimal infrastructure, and part of my point here is shifting away from vehicle types and toward infrastructure components, so it becomes a bit of a contradiction in terms.)

Yeah, I'm still kinda stuck in Boston-style BRT which is basically "buses with silver paint". I do think that there's still some haziness around things like the Green Line, or more accurately around something like the Silver Line if they'd built Phase III (which would have been not-really-BRT on Washington Street and BRT(ish) from Boylston through the Transitway (and then not again past there), but that's inherently going to be a risk given that buses and LRVs inherently have the ability to operate in various infrastructure in a way that HRT doesn't.

Soooooo I mean........ if it's proper BRT -- something like SL3 in Chelsea -- then I'm not opposed to calling it "light metro". You could argue that by putting it into the same category as (say) the B Line, it raises the expectation for what the infrastructure and service should look like. I'm not opposed to BRT; I'm opposed to bad BRT. And if it's bad BRT, then it's bad light metro too.

I do share your cynicism, but also the T can spin a frequency reduction with a fare hike as an "enhancement of service", so I think if we let the potential for abuse be a ruling criterion, we'll find ourselves very limited very quickly.

I mean, I agree with this, and I was mostly joking in that particular segment. I find the classifications useful, mostly just didn't want anyone to tell the politicians about them because the last thing they need is more material to spin with. So, by all means, let's not limit our discussions, just make clear to tell the politicians things in ways that they can't as easily misuse.

Yes, I think this is a fair pushback. Certainly the Central Subway operates (and is asked to operate) like a heavy metro service, though I think it falls short in terms of reliability and capacity. If it is indeed "heavy metro" service, then I'd suggest that it is subpar. But yes, as we've discussed above, the unicorn hybrid nature of the Green Line means that it can't really serve either role fully effectively. I'd like to see Blue-to-Kenmore free the Green Line up to better leverage the advantages of a "light metro" role in the network -- which brings us full circle to F-Line's point above.

(Also, spoiler alert: my vision for the Green Line includes extending the Huntington Subway to Brookline Village-ish, and running the Riverside Line through there. With fully separated ROWs, rapid transit stop spacing, and modern vehicles, that could relieve a significant fraction of the current Green Line's "heavy metro responsibilities.")

There's certainly a number of things that can be done to help deal with the problem. Shifting E and at least some of D over to the Tremont tunnels really does seem like it would be a big help. I don't know if there's any realistic possibility of ever reactivating the outer loop at Park Street, if they could it'd be theoretically possible to run anything coming through the Tremont tracks in and back out with very limited interaction with the Boylston traffic. Not the end of the world if you can't by any means, but it would be nice to still have that flexibility.

Part of me doesn't really know how much of it is a "light metro doing a heavy metro's job" problem versus how much of it is the Green Line is run atrociously poorly. I know F-Line's discussed it at length elsewhere, but the T's bizarre focus on one-seat rides and fixed service patterns really does the Green Line a disservice. It's anecdotal, I know, but I spent far too much time on an overcrowded and dangerously-narrow (at that time) platform at Government Center waiting for cars to North Station, all the while my namesake Brattle Loop sat empty, just another example of their fixation on running the thing like a pure heavy metro when it's probably more accurate to describe it as an overlapping set of light metros. (Which only speaks more to the potential benefits of the Blue Line to Kenmore; why should all the C's and D's - and B's if you do some track work for that matter - all have to pass Kenmore anyway? There's a perfectly good loop there.)

 

[guitarguynboston]

Can't remember if this was every posted before. Never knew about the Orange split on the south side proposal.

 

[JumboBuc]

Can't remember if this was every posted before. Never knew about the Orange split on the south side proposal.

View attachment 21526

75 years later and we're still talking about many of the exact same extensions...

 

[F-Line to Dudley]

Can't remember if this was every posted before. Never knew about the Orange split on the south side proposal.

View attachment 21526

The Dedham extension was historically favored over Readville, but with I-95 slated to nuke the SW Corridor through Hyde Park and forcing a re-route of thru RR trains to the Fairmount Line the state was planning to reserve 2 tracks worth of ROW in perpetuity to graft on a future branch split. Branching would've been OK this far out because it would've been past the big Forest Hills bus terminal and would not have caused any overt harm to bus transfer frequencies at the outlying stops.

Readville extension remained on-the-books until the T/Boston MPO's 2004 Program for Mass Transportation, but since it would've necessitated a reduction in NEC capacity from 3 to 2 tracks and Amtrak has been claiming since the mid-90's HSR planning that it eventually needs Track 4 back to satiate future growth...it hasn't been practical to mount in 25+ years. NEC capacity would really be left in a bad spot if you did it today. Note that the Mt. Hope and Clarendon Hill intermediates would've had really low utilization, and Hyde Park and Readville are doubled-up by Fairmount + Readville on the Fairmount Line...so there's not too big a coverage gap here that Urban Rail frequencies on the Fairmount can't cover well enough. Keep in mind that had the Fairmount become the Amtrak mainline with I-95 built there'd be no way to do stage enhanced Hyde Park local frequencies on only 2 tracks, meaning Hyde Park would have a pronounced coverage gap that only Orange would've been appropriate to fill. The same need is not there today with Fairmount available as a denser local-service paralleling route to the NEC instead of the uni-line forced by I-95, so in addition to the other issues with pinched NEC capacity a lot of the impetus for that Orange extension has been removed today.


If you really want to get Crazy, you can still bring rapid transit to Hyde Park via a somewhat expensive and low-priority (but overall doable) Red Line trajectory. Just bring full HRT to Mattapan, then tunnel station-less under River St. from Mattapan Sq. to the Fairmount ROW @ Poydras St. (approx. 1/2 mile cut-and-cover), then glom alongside the easterly side of the Fairmount ROW south of Poydras where it used to be quad-track into Readville. Ashmont/Mattapan extension stops @ River St. just outside the portal, Fairmount, Readville...service coexists alongside 2 tracks of the now much more Dorchester-centric Fairmount Line. Hop across the NEC @ Readville, then continue on the grade-separated and landbanked Dedham Branch to Dedham Center. Additional stops at East Dedham (River St. @ Milton St.) and Dedham Center...short Wellington-style box tunnel splitting the High School athletic fields but otherwise on the surface. Not really one to talk about since we haven't so much as figured out an HRT conversion for Mattapan, but in absolute feasibility it's doable (with the River St. subway being less expensive than similar projects closer to the CBD because of the set-back properties and fact that it's stationless). You would be future-proofed for re-creating the essentials of a Hyde Park & Dedham rapid transit line in spite of the NEC and the Dedham Center leg of the West Roxbury extension no longer being available. It just gets punted much further future.

 

[Ayo]

Assuming we had a modernized regional rail network with a North South rail link how feasible would it be to convert the D branch of the green line and any extensions to Needham to regional rail. I think the utility of this would be freeing up capacity on the central subway and creating opportunities to expand the regional rail network to dover or points beyond.

 

[The EGE]

Theoretically possible, but highly undesirable. Infrastructure-wise, you'd have to build high-level platforms at every station plus footbridges to replace the pedestrian crossings at most stations, upgrade bridges and culverts, deal with the 3 level crossings near Lansdowne, completely rebuilt Lansdowne station, and build a new yard/heavy maintenance shop for the Green Line. Getting anywhere close to existing 6-minute headways would eat up a large fraction of NSRL capacity, and the Worcester Line would be hurt by the shortened Lansdowne platforms and the junction there (which would be nearly impossible to make a flying junction). Given the heavier trains, you'd probably have lower acceleration than LRVs, and thus longer running times on the surface. The level crossings in Needham, which probably can't be eliminated, would have to have gates down for every train, whereas light rail can just act as a different traffic phase.

For the same infrastructure price, you could probably build the D-E connector and a new subway (as discussed here previously) connecting Huntington Avenue to the Pleasant Street Portal. That unlocks higher frequency for every Green Line branch with basically no downside. If you built a full subway from Brookline Village to Northeastern, both the D and E (including the GLX branches) would be fully grade-separated save for the Needham crossings.

 

[Riverside]

^ Took the words right out of my own mouth. It's a fun idea @Ayo! And I like the lateral thinking. But I agree with @The EGE.

As you probably know, the Riverside Branch was originally built as a steam railroad (essentially a commuter rail line); and in fact, the initial route that was built looked very different from today -- ran from Brookline Jct (now Lansdowne) to Newton Highlands on the current D ROW, but then continued straight on to Needham. The connection to Riverside and the connection to West Roxbury was built later. So your idea is a fun retro callback to those days!

I like that you are thinking about capacity on the Central Subway, but as mentioned above the NSRL itself will fill up near capacity relatively quickly. For context, 40 tph (trains per hour) in each direction is basically the highest you can go with a two-track tunnel, and that is exceptionally rare, and I've only ever seen it achieved with light rail systems. Assuming a max of 30 tph is a more reasonable bet, although you still need to have very good infrastructure and very good operational discipline to swing it.

The EGE pointed out that you'd need frequencies approaching 6 minutes in order to replace existing D Line service -- that would 10 tph alone right there. Now let's assume that we also send the Fairmount Line and the Newton-Brighton section of the Worcester Line into the NSRL -- we'll give those slightly more modest headways of 7.5 minutes, or 8 tph each.

...And with that, you've used up 26 of your 30 trains per hour through the NSRL. That's what I mean about the NSRL filling up pretty quickly.

As The EGE says, a Huntington Ave subway would solve most of our immediate Central Subway capacity issues. And as for expansion to Dover: there used to be a commuter rail line out that way, but it was discontinued in the 60s due to low ridership. Which isn't surprising, given that the towns it served currently have a total population of ~40K, spread out over 14 miles of rail in very low-density suburbs. (For comparison, Needham alone has 32K people.) Despite their proximity to Boston, those communities form a density cavity, giving them a significantly different character than their neighbors to the north, south, and east. I'd love to see rail service restored, but I think the pros don't outweigh the cons here.

--

Now, if we want to talk about really crazy transit pitches, how about this: restore the Millis Branch as a light-rail interurban pinging back and forth between Medway and Needham Junction (or W Roxbury), with occasional peak service through-running into the subway. You would need to have a massive wellspring of community support, and you would need to string up wires the whole way. But damn would it be a beautiful ride, flying through that forest!

 

[AndrewOnTheMBTA]

I am curious if this is feasible for this thread or if this should go in the God Mode thread...

A connection of a green line SL1/3 conversion under Boston harbor to East Boston. I understand how massively expensive this would be and probably not ever having support - but I am interested how a crazy pitch like this would be achieved.

I picture this as a phase 1: conversion of Silver Line Way to an underground deep station, a deep tunnel to East Boston and a connection at Airport under the blue line. Then a tunnel again under the Chelsea Creek and underground Eastern Ave station. Then rising up to ground level for the remaining RoW.

I think SL1 should just stay bus in the same way we have explored it being moved to bus when SL2 were to become a green line conversion.

This is a Crazy Transit Pitch for a reason...

 

[Brattle Loop]

I am curious if this is feasible for this thread or if this should go in the God Mode thread...

A connection of a green line SL1/3 conversion under Boston harbor to East Boston. I understand how massively expensive this would be and probably not ever having support - but I am interested how a crazy pitch like this would be achieved.

I picture this as a phase 1: conversion of Silver Line Way to an underground deep station, a deep tunnel to East Boston and a connection at Airport under the blue line. Then a tunnel again under the Chelsea Creek and underground Eastern Ave station. Then rising up to ground level for the remaining RoW.

I think SL1 should just stay bus in the same way we have explored it being moved to bus when SL2 were to become a green line conversion.

This is a Crazy Transit Pitch for a reason...

I'd say it's properly a Crazy Transit Pitch because I don't see it needing anything in God Mode territory; with sufficient money it'd be feasible, though it's maybe on the border between the two threads.

The fact that they zeroed-out the possibility of a transit tube in the Ted Williams permanently consigned the Silver Line running through it to some form of BRT, because the feds don't let you street-run LRVs on an Interstate. In addition to the negative impact on the SL1/3 service itself, that also complicates the Urban Ring concept, because there's no way to make it LRT/HRT without building another harbor crossing (i.e. this project).

Previous discussion of converting the SL3 to LRT (essentially the northeast quadrant of the Urban Ring) didn't bother with tunneling (or even grade separating) the Chelsea Creek crossing; the portion of street running over the bridge (and the ship-induced bridge raisings) are low-impact enough that tunneling wouldn't really be cost effective. (If we're talking HRT, on the other hand, it'd be mandatory.) SL3 conversion to the Airport environs can alternately be done at less-Crazy costs via the GLX carhouse, which would require a new CR bridge near the casino as the only hard-and-fast requirement for a water crossing, and that's a heck of a lot easier than another harbor tube.

There's no point whatsoever in doing any of this if it doesn't get something other than at least LRT running from South Station to Airport. Making an undersea bus lane for the SL1, which is what it would be if the SL1 stayed a bus, is God Mode territory. Building the stillborn Silver Line Phase III Boylston-South Station connection (as LRT, which is how it should have been, the project might not have collapsed under its own weight if they'd planned it like that to begin with) is a prerequisite for turning a transit tube under the harbor from God Mode to Crazy Transit Pitch, because it'd fail the cost-benefit analysis if all it did (even as LRT) was dump everyone on the Red Line at South like the Silver Line does now.

That said, while I do think there's some appeal to the Urban Ring running as LRT all the way to South Station, I also don't think a project like this is particularly necessary. The SL1 would be significantly improved by simpler fixes (i.e. permanent use of the State Police ramp and doing something about the idiotic traffic light on D Street), the SL2 is a bus doing an LRVs job which would be fixable with the itself-useful-and-necessary Green Line connection to the Transitway, and the SL3 can much more easily be fed as northern Green Line branch (there's nothing to stop you running some SL3 through the tunnel to keep the one-seat ride if you want, though you'd be better off letting the bigger LRVs handle the SL3 route and using those buses to boost SL1 service so long as a proper Green!SL3-to-SL1 transfer can be established.

 

[AndrewOnTheMBTA]

I'd say it's properly a Crazy Transit Pitch because I don't see it needing anything in God Mode territory; with sufficient money it'd be feasible, though it's maybe on the border between the two threads.

The fact that they zeroed-out the possibility of a transit tube in the Ted Williams permanently consigned the Silver Line running through it to some form of BRT, because the feds don't let you street-run LRVs on an Interstate. In addition to the negative impact on the SL1/3 service itself, that also complicates the Urban Ring concept, because there's no way to make it LRT/HRT without building another harbor crossing (i.e. this project).

Previous discussion of converting the SL3 to LRT (essentially the northeast quadrant of the Urban Ring) didn't bother with tunneling (or even grade separating) the Chelsea Creek crossing; the portion of street running over the bridge (and the ship-induced bridge raisings) are low-impact enough that tunneling wouldn't really be cost effective. (If we're talking HRT, on the other hand, it'd be mandatory.) SL3 conversion to the Airport environs can alternately be done at less-Crazy costs via the GLX carhouse, which would require a new CR bridge near the casino as the only hard-and-fast requirement for a water crossing, and that's a heck of a lot easier than another harbor tube.

There's no point whatsoever in doing any of this if it doesn't get something other than at least LRT running from South Station to Airport. Making an undersea bus lane for the SL1, which is what it would be if the SL1 stayed a bus, is God Mode territory. Building the stillborn Silver Line Phase III Boylston-South Station connection (as LRT, which is how it should have been, the project might not have collapsed under its own weight if they'd planned it like that to begin with) is a prerequisite for turning a transit tube under the harbor from God Mode to Crazy Transit Pitch, because it'd fail the cost-benefit analysis if all it did (even as LRT) was dump everyone on the Red Line at South like the Silver Line does now.

That said, while I do think there's some appeal to the Urban Ring running as LRT all the way to South Station, I also don't think a project like this is particularly necessary. The SL1 would be significantly improved by simpler fixes (i.e. permanent use of the State Police ramp and doing something about the idiotic traffic light on D Street), the SL2 is a bus doing an LRVs job which would be fixable with the itself-useful-and-necessary Green Line connection to the Transitway, and the SL3 can much more easily be fed as northern Green Line branch (there's nothing to stop you running some SL3 through the tunnel to keep the one-seat ride if you want, though you'd be better off letting the bigger LRVs handle the SL3 route and using those buses to boost SL1 service so long as a proper Green!SL3-to-SL1 transfer can be established.

This is a really interesting analysis...

Looking more for the complexity of something like this, while assuming it would 99% never happen. While this is crazy, it also reminds me of something you would do in a city-building video game (thus arguably God mode).

I think an urban ring Northeast extension into Everett/Chelsea is a great alternative. Maybe one day.

 

[Brattle Loop]

While this is crazy, it also reminds me of something you would do in a city-building video game (thus arguably God mode).

Yeah, the border between Crazy Transit Pitches and God Mode can get a little fuzzy at times. My mental shorthand for the difference is that Crazy Transit Pitches basically means turning off the NIMBYs and assuming infinite money (I recall a cheat code to that extent in one of the Sim City games), while God Mode can dispense with other practicalities like usefulness, geologic obstructions, and so forth. That's why I'd call this one a Crazy Transit Pitch; it's obviously useful, it'd obviously improve the transit system (by providing an otherwise-impossible link in the Urban Ring and permitting grade-separated and higher-capacity vehicles for the Silver Line service), and the only major blockers are political support and financing (that said, neither has an easy solution).

I'm not an engineer, so I can't speak to the technical questions, but on the surface (no pun intended) it doesn't immediately look to me like there's any fatal physical/infrastructural blockers to another harbor tube. Silver Line Way is already pointed in the right direction towards the Ted Williams alignment (probably would stick to the east side of that tunnel), and that's sending you in the right direction to hit the Blue Line transfer at Airport. Past Airport it's basically dealer's choice whether you tunnel, elevate, or eat some roads and/or parks to get up to the Chelsea Creek bridge (I'd say eat the bypass road myself). Could build a new bridge for transit, but on LRT it'd be around a thousand feet of street running so not likely worth it. After that you're home free on the SL3 reservation for as far as that goes, then plenty of ROW into Everett. Gets a little trickier and probably requires some CR track shifting (and maybe a few bridge modifications) in Everett, because eventually you need to get to the north/east side of the Eastern Route ROW. LRT takes the existing CR bridge, CR gets a new one (with a less annoying gradient) on the old alignment slightly to the southeast (possibly blowing up Encore's pedestrian bridge if that thing is stupidly allowed to eat the ROW), little overpass over the Orange Line, eating the dinky yard near Sullivan (by this point CSX should have eaten Pan Am so yard space can be found elsewhere if needed), then running up to the GLX carhouse leads. The existing Silver Line Transitway is already large enough for LRVs, so no issues there, and connecting that to the main Green Line (either via the disused Tremont Street tunnels or via Essex Street if you're a masochist) should have been done already and is only a Crazy Transit Pitch on cost grounds considering how useful and necessary it is.

(To me, definitely a Crazy Transit Pitch; a lot of things would need to be done, politically, to support and fund such a project, but it's not particularly out-there in terms of technical feasibility, and really the only significant difference to some pretty-well-supported reasonable pitches around here is the extra harbor crossing, which I think most people would argue would be desirable, though it is of course the most expensive portion and the least necessary given that most of the benefits can be obtained without it, albeit at the cost of SL1 being permanently mode-locked to bus.)

 

[themissinglink]

The fact that they zeroed-out the possibility of a transit tube in the Ted Williams

Was there any serious consideration given to a transit-only tunnel during the planning stages of the Big Dig?

 

[Brattle Loop]

Was there any serious consideration given to a transit-only tunnel during the planning stages of the Big Dig?

That I don't know. I know F-Line has made repeated references to it over the years, so he or someone else could perhaps provide more clarity as to how far that idea progressed (I'd guess not very far).

 

[Charlie_mta]

Was there any serious consideration given to a transit-only tunnel during the planning stages of the Big Dig?

Was there any serious consideration given to a transit-only tunnel during the planning stages of the Big Dig?

No. The BTPR (Boston Transportation Planning Review) Summary Report in February, 1973 recommended a two lane cross-Harbor tunnel, roughly where the Ted Willams tunnel is now. The BPTR recommended tunnel would have been for buses, trucks, taxis, airport limousines, and emergency vehicles only. No rail transit tunnel was proposed.