Reasonable Transit Pitches

[BostonUrbEx]

Well, an overhead bridge needs a much higher clearance and would need to be built to double stack height. That's why I just opted for undergrade bridge instead.

The ROW really is plenty wide, it used to be 4 mainline tracks, at least. Probably some spare room, too.

Davis is not a problem, but poor geometry and another crossing to blow the horn for, with close-by alternatives at perpendicular angels, it seems ripe for complete elimination with no alternatives constructed.

 

[F-Line to Dudley]

The outskirts of the CR system really don't have pressing need for expensive crossing eliminations. The T did a some housecleaning when it re-opened formerly truncated service to Fitchburg and Haverhill circa 1980, then every time it did a cleanroom extension like the Old Colony or Newburyport. Private RR's also did a bunch of mass-eliminations in the 1950's during their last serious SGR spending spree. Boston & Maine zapped 8 or 10 Lowell Line crossings between Wedgemere and Downtown Lowell...everything except for the max-difficulty West Medford pair. They did Waverley. They did the Salem tunnel extension to separate the rest of downtown. Outside of Chelsea (political friction between private co-tenants B&M and B&A) and the maximal-difficulty ramainders all of the mainlines are exceptionally-well separated out to their branch splits. With the lower-traffic branches and exurbs not posing much of a challenge. Go take one look at LIRR and how much density abuts their crossings and see how good the Purple Line has it.


Fitchburg has the most crossings on the system, but it's also the longest line on the system, has those crossings spread very diffusely out, and crosses few unusually high-traffic roads once it clears un-eliminable Waltham Ctr. None of these have any impact on train operations, and very few of them rate as traffic problems for the towns.

I think you could seek some judicious outright closures of fully superfluous crossings, keep a stiff upper lip at the NIMBY's who feel they've got a God-given right to any shortcut they please, and incentivize the towns with more favorable liability rates. But for the most part if it's more expensive than a jackhammer and jersey barrier, there's little compelling reason to do it. Don't waste a single cent studying bridges. If you haven't eliminated the top-priority eliminables like the Chelsea clusterfuck, West Med, and Ashland pair first...don't even think about spending actual money to eliminate any others.


On the Fitchburg, these are pretty much the only low-hanging fruit worth a "what the hell...let's float a closure trial balloon and see if they revolt":

• Davis St., Shirley (duplicated by Center Rd.)
• Walker Rd., Shirley (if re-snaked along the power line ROW/sandpit driveways to meet the industrial access road near Patterson Rd.)
• Groton-Harvard Rd., Ayer (Sandy Pond Rd. is angled, but comes off the rotary so is better-positioned to handle midpoint traffic between E. Main/2A and Central Ave. Maybe S-curve it at the crossing so it's at a 90-degree angle).
• Snake Hill Rd., Ayer (but ONLY if Sandy Pond stays, since spacing becomes an issue otherwise).

I'd consider 2-for-4 success at getting the towns to agree to jersey-barrier these a plenty good haul. But that's it: jersey barrier, jackhammer, and salvaging the crossing equipment. Not one cent more.




Rockport Line is the system-worst for stupid oversupply of superfluous grade crossings that could be jersey-barriered at no loss to mobility. But that's because Beverly, Manchester, and Gloucester NIMBY's have more power than God to cockblock all efforts at judicious trimming. All those glorified driveways crossing the tracks still persist because the rich townies have been pretty much undefeated dating back to the Boston & Maine era at shooting down closure attempts. Of any line on the system, that's the only one that sticks out at having way too many $0-closeable whoppers.

 

[BostonUrbEx]

Well, they do have very real impacts on operations. Especially Snake Hill, Sandy Pond, and Walker. Whereas a train cannot be intentionally held to block a public crossing for more than 5 minutes except in an emergency situation or an active switching move, it makes it more difficult to time out a meet with a freight train that has both no impact to passenger operations and no crossings blocked. Add into the mix intervening stations and it really is a pain in the ass where trains have to hold up far away or crawl along super slow until they're positive they won't be stopped in a crossing waiting on a passenger train making a station stop. Even without passenger trains in the mix, it makes freight-vs-freight meets a hair less fluid when you have to time out how to avoid blocking the crossings. Groton-Harvard, Sandy Pond, and Snake Hill are also routinely blocked for extensive periods by 22K backing into Ayer Yard. Walker Rd is occasionally blocked (not really by the train itself, but by crossing activation) for 23K and certain moves being made on the Camp track. There's also special-case scenarios such as splitting/splicing a grain train, auto train, etc.


Except for places where crossings have direct impacts on speeds, these are really the only PITA crossings.

 

[F-Line to Dudley]

Well, they do have very real impacts on operations. Especially Snake Hill, Sandy Pond, and Walker. Whereas a train cannot be intentionally held to block a public crossing for more than 5 minutes except in an emergency situation or an active switching move, it makes it more difficult to time out a meet with a freight train that has both no impact to passenger operations and no crossings blocked. Add into the mix intervening stations and it really is a pain in the ass where trains have to hold up far away or crawl along super slow until they're positive they won't be stopped in a crossing waiting on a passenger train making a station stop. Even without passenger trains in the mix, it makes freight-vs-freight meets a hair less fluid when you have to time out how to avoid blocking the crossings. Groton-Harvard, Sandy Pond, and Snake Hill are also routinely blocked for extensive periods by 22K backing into Ayer Yard. Walker Rd is occasionally blocked (not really by the train itself, but by crossing activation) for 23K and certain moves being made on the Camp track. There's also special-case scenarios such as splitting/splicing a grain train, auto train, etc.


Except for places where crossings have direct impacts on speeds, these are really the only PITA crossings.

Do they really have a destructive impact on operations, though? Look...Fitchburg has pretty robust freight volumes by Massachusetts standards and quite bullish growth prospects, but Massachusetts standards of freight congestion are downright *adorable* compared to Class I intermodal freights in the rest of the country. Just like the total crossing count and total "bad crossing" count on the cumulative Purple Line is downright *adorable* compared to the hell on earth LIRR or Metra have to pass through. Compare these small-town exurb crossing clusters through all of 2 miles of Shirley and 1.5 miles in Ayer with similar crossing clusters out in Chicagoland or SoCal that see mile-long Union Pacific or BNSF trains a half-dozen times a day interspersed with Metra or Metrolink commuter and Amtrak corridor schedules. This so-called problem isn't a real-world problem at all; it's total eye-of-beholder subjecture from a very limited hyper-local looking glass. Subjectively hyper-local even for this parochial state. Do you think the MBTA-assessment paying denizens of Main St., Ashland--population 16,500--are going to be fazed by sad violins playing for freight grade crossing traffic in MBTA-assessment paying Shirley--population 7500? Or the MBTA-assessment paying taxpayers who live along Andover St. in Lawrence?


It also isn't a real-world problem when you consider what a stratospheric upgrade Norfolk Southern is going to be over Pan Am when they inevitably buy out Pan Am's 50% stake in the Patriot Corridor to run the whole thing themselves. The first thing they're going to do is hand pink slips to all the Pan Am staff habitually unable to run their schedules on-time, junk all the Pan Am rolling-ruin locomotives that keep breaking down on T property, and bring in their own in-house reinforcements from out-of-state. NS doesn't fuck around; Pan Am are industry legends for always fucking around. Freight trains that run twice as long but with twice the OTP reliability cause way fewer passenger conflicts than the ones that habitually lollygag it. And freight schedules cause way fewer conflicts when they're day-to-day the same and not stuffed full of slapdash run-as-directeds fetching all the previous day's trains that ran out of crew hours and had to park overnight out in the boonies an hour shy of finishing their runs. We haven't even hit the thrust of the Fitchburg schedule increases that come when Wachusett layover opens, and haven't hit the thrust of the freight carload increases that come when the Patriot Corridor upgrades finish. But there'll be fewer conflicts than today on the same tracks because Norfolk Southern doesn't put up with rinky-dink slop ops.

*Adorable* paste-eating Pan Am isn't any more representative of the big-boy carriers than *adorable* Massachusetts-size freight trains through few-and-far-between Massachusetts grade crossings are representative of big boy-size freight trains elsewhere that run totally at-grade through many more small-town grade crossings at no discernible ill effect. You don't shovel money at steel-and-concrete to fill a competence gap. You pressure the incompetents to shape up. Norfolk Southern is doing exactly that by sitting on the buyout for the 50% they don't own, and making their power play in less than 3 years (with rumors of it being much, much sooner). The incompetents are long gone by the time Fitchburg starts to slug its weight on post-Wachusett schedule density.


The only universe in which those particular crossings constitute a real and intractable problem is one with such a limited view of the outside world that it's never seen a grade crossing or freight train beyond a latter-day Pan Am job going through those 5 crossings in Shirley and 3 in Ayer. Since crossing elimination has never been the persistent burning topic at Shirley and Ayer town meetings like it has in, say, Framingham or Medford...one can assume that even a lot of the folks who've never in their lives spent time outside of Shirley and Ayer aren't much bothered by those *adorable* New England-sized freight trains blocking their crossings to make an advocacy out of it.

 

[BostonUrbEx]

Do they really have a destructive impact on operations, though?

Destructive? No, not at the moment. But with prospects to grow both passenger and freight traffic, there is clearly some modifications to keep operations fluid. Yes, the problems will be mitigated by competent management keeping things fluid on the road and in the yards, but it certainly won't solve the greater problem. Is it the highest of priorities that anyone is facing? Certainly not. But it makes sense and is reasonable to do at some point to allow for an increase in operations for both parties.

Things that someone, at least PanAm/NS, should be thinking about are the other points I made about an interlocking at OX and the switching/yard lead from AY to WL. If they intend to expand autorack operations when the CSX lease on the Ford Yard expires (soon), then they're going to definitely need the lead. The passenger schedules aren't going to be modified to meet their needs, and as it stands under the new schedules, there's now a few meets in the Ayer vicinity.

 

[Upstruk]

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The Summer Street Concourse

https://en.wikipedia.org/wiki/Winter_Street_Concourse

I have posted several alternate schemes to create better connections to South Station from the Green and Orange Lines and by extension creating better connections to the Seaport District.

This pitch takes the existing DTX concourse (tunnel) which extends from the station to Devonshire Street above the Red Line and continues it 2 blocks to the Outbound Red Line Platform. From here there is convenient escalator, elevator and stair access up to the Silver Line Platforms. Currently the existing concourse has entrances to Roche Bros and Macy's and also includes MBTA back of house space.

The back of house space would be removed and moving walks ways would be installed in the existing tunnel. At Devonshire Street escalators and an elevator would be installed up to the surface somewhere around 100 Summer Street. https://www.google.com/maps/@42.3535384,-71.0577858,3a,60y,33.32h,82.16t/data=!3m6!1e1!3m4!1s_iYk-efcYR6P2W-hbxccDQ!2e0!7i13312!8i6656!5m1!1e2?hl=en

This would create a great midway connection to the surface and would serve the 111 Federal Street Tower (if built) and Winthrop Sq. Back under ground a new pedestrian tunnel would be dug down beside the Red Line Subway tunnel to the level of the Red Line. If the Red Line tunnel takes up the full width of the street from building foundation to building foundation this could be the one major challenge which moves this out of the "reasonable" category.

With this connection South Station to Park Street can be walked completely underground (one long super station). With South Station potentially being expanded, a new signature tower being built along this route and the Seaport in desperate need of better transit connections, this may be a reasonable solution.

Anecdotally, I often walk from the Orange Line at DTX to South Station. It is a fairly short and pleasant walk, however I enjoy walking and I know my way around Boston, I recognize most people would transfer to DTX and take the Red Line one stop to get to South Station. With this new Summer Street Concourse, once one enters DTX or South Station (subway) there would be signs directing to the other station. Now make this walkway covered from the elements and include a moving walkway like at the Airport and I bet most people take the concourse instead of crowding onto the Red Line.

 

[F-Line to Dudley]

There is zero way to do this.

Unused tip of the Winter St. Concourse was severed by the Dewey Square tunnel built at exactly the same level in the mid-50's. The highway tunnel had to slip over the Red Line, and is taller than the transit bores...so it had to block the upper tunnel entirely and eat all of the 'sandwich' layer below-street to stay on top. There is no means of going upstairs over 93 because upstairs is Surface Rd. with not enough vertical height left for a ped tunnel. Downstairs is blocked by abutting structures pinching off all sideways wiggle room to slip off the back of the Red Line below and snake below. And even if you could snake below the depth required completely kills all pedestrian mobility by essentially requiring two sets of direct-facing Porter Square-length escalators going down then immediately up. It would be twice as fast to walk down Summer headhouse-to-headhouse than stay in the ped tunnel on the slip-under.

They made their choice in 1955 when neighborhood opposition got the Central Artery changed from elevated to tunneled through Dewey. The DTX-SS concourse connection was completely, 100% precluded by that change in highway plans. They were quite explicit about it at the time that future use of that then-unused tunnel was forever blocked by choice of tunneling the highway. There aren't any alternate routings to snake around, because slipping to the side off the Red tunnel piggyback is also physically impossible. Trajectory is pinned in on top by building foundations to High St., and then blocked by the Big Dig ramps remodeled onto the side of the Dewey on the High-Purchase block.


Concentrate on the DTX-State walkway. That one can happen and has been officially advocated many times over the years. Basic engineering feasibility isn't a question there, just uncertain expense from what they may encounter next to the 1908 Orange tunnel making budget evaluation a crapshoot.

 

[stick n move]

Heres a reasonable transit pitch nobody has heard of....... Dont cancel the fucking DMU's. I knew it was too good to be true, made too much sense for it to work.

 

[Matthew]

Might be a blessing in disguise -- gives the FRA time to get its shit together so that non-insanely-heavy DMUs can be ordered (like those used here).

We also need some time to drag the operations into the 21st century so that they don't try to staff every DMU with 4 crew-people. That would make it completely unaffordable straight away.

But really they should electrify. It's a shame that won't happen anytime soon. DMUs, unfortunately, bring all the problems of diesel air pollution along with them, and while it's better than having everyone drive a car, it's still pollution that can be avoided easily.

 

[F-Line to Dudley]

Heres a reasonable transit pitch nobody has heard of....... Dont cancel the fucking DMU's. I knew it was too good to be true, made too much sense for it to work.

The plug was only pulled on the RFP about 3 weeks before the due date, which strongly hints to no manufacturers submitting a bid. That's not canceled so much as truncated. Doesn't make much sense why that was the case, as the vehicle specs differed very little from other recent FRA-compliant orders and didn't throw any red flags. Maybe Nippon-Sharyo's five-star meltdown on the Amtrak bi-level corridor coach design and collision course with a messy contract penalty fight got corporate circling the wagons around the big profit centers and taking a one-time pass on chasing small stuff.

At any rate, this was only an RFP. It's the new normal with the actual manufacturing contract that comes after the RFP that any newfangled computer-heavy 21st century rolling stock design takes no less than 5 years from contract inking to get a new full fleet in full service with uninterrupted availability. Even when they arrive for first revenue trials it's an agonizing 18 months of testing the pilot vehicles before the rest of the units get released en masse from the factory, then an uneven debugging and warranty period to pound out the bugs on-the-fly. It's as true with new-tech vehicles that 'just work' as it is with the ones that are moderately tortured (HSP-46's) or irredeemable junk ('Brokems). So it's not like this would ever go down with pomp-and-circumstance for "Day 1" of full Indigo service displacing shitty old Fairmount commuter rail paper schedules. There would be a period of years where the service would have to scale up with a boring old locomotive hauling 4 coaches and a modicum of extra schedule padding...then a gradual handoff to the new fleet with push-pulls still holding down the reserve slots...then a shedding of the schedule padding and general tightening-up after the MUs' warranty period.

So the fact that there was zero, nada detail given about the actual final service plan and timetable for scale-up, plus pronounced aversion in the year after Gov. Patrick's 2024 fantasy map announcement to answering any questions on the matter when pressed for specifics by the public...is all you really need to know. It was always the service plan, never the vehicles that was going to determine if Indigo was real or a tease. You can't even plot the logistical deployment of vehicles with a 5-7 year planning gestation period without knowing what/where/how often they're going to run and what the transition plan is. Doesn't even work with a "We'll slip these on the midday and evenings on regular CR schedules for some TBD period until we've (maybe) ready, and then we'll announce a 'Save The Date' for full...on...Indigo...LAUNCH!" What lines get capital $$$ appropriated to equip their outer layovers so the MU's can be tested out to I-495, which lines' crews get qualified on them, etc. etc. all influences the deployment timetable. And influences to some degree what contract clauses the manufacturer is going to be held to on warranty.

No enumerated service plan or transition timetable sketched out 5-7 years in advance, pointless exercise to try to bid out a real-money manufacturing contract 5-7 years in advance. So paper RFP is about as far as one can go on nothing but TBD's, a 12-year-old Fairmount operations study, and a 3-year old set of Keolis bid docs on how they theoretically would run Indigo headways if they won the operator contract.



The whole "The vehicle is the service" line of BS was all about Boston 2024 and impressing some very rich and very corrupt kingmakers. Once that motivation went away, lowly little Dorchester was the only thing holding the gnat's attention span. They knew all along that implementing the service would take a several-steps interim scale-up that started with push-pulls, blended, then ended with DMU's. And knew that D-Day on that service plan had way, way less to do with getting under 10 minutes on the stopwatch for vehicle turnaround time and WAY, WAY more to do with fare portability between modes and sticking to their guns on keeping all-day headways consistent for a committed period of years knowing full well that it would entail a lot of empty off-peak trains before ridership growth unevenly filled out the clock. Achieving the minimum possible vehicular headway was never the bar for "full...on...Indigo...LAUNCH!" Equitable fare, easy or free transfers to Red, and not having to keep a paper schedule because the headways were predictable counting up or down to an interval like a local bus was the value proposition. 25- or even 30-minute headways at kickoff is a fantastic deal for attracting riders if it keeps those intra-city transit promises of equitability and consistency, and sheds the isolating effects of that peak-skewed CR paper schedule. Pounding that headway down to 15 minutes, undercutting push-pull operating costs at a certain high-frequency threshold, and having intra-city optimized onboard seating are just the final follow-throughs for sustainable lifetime service momentum. Giving that sales pitch ass-backwards and overly 'shiny things'-centric was a great big red flag.

 

[winstonoboogie]

The plug was only pulled on the RFP about 3 weeks before the due date, which strongly hints to no manufacturers submitting a bid. That's not canceled so much as truncated. Doesn't make much sense why that was the case, as the vehicle specs differed very little from other recent FRA-compliant orders and didn't throw any red flags. Maybe Nippon-Sharyo's five-star meltdown on the Amtrak bi-level corridor coach design and collision course with a messy contract penalty fight got corporate circling the wagons around the big profit centers and taking a one-time pass on chasing small stuff.

.

No, there was one bid being put together before the RFP was pulled:
http://www.bulletinnewspapers.com/23469/173758/a/high-frequency-rail-at-risk-for-fairmount-line

"Holmes said the reasoning behind the assessment was the fact that Massachusetts Secretary of Transportation Stephanie Pollack said they had only received one bid for the construction of the new DMUs, and didn’t feel the technology behind them was up to snuff.

“Pollack said the DMUs are not reliable enough to go out on one bid,” he said"

 

[Upstruk]

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The Summer Street Concourse

https://en.wikipedia.org/wiki/Winter_Street_Concourse

I have posted several alternate schemes to create better connections to South Station from the Green and Orange Lines and by extension creating better connections to the Seaport District.

This pitch takes the existing DTX concourse (tunnel) which extends from the station to Devonshire Street above the Red Line and continues it 2 blocks to the Outbound Red Line Platform. From here there is convenient escalator, elevator and stair access up to the Silver Line Platforms. Currently the existing concourse has entrances to Roche Bros and Macy's and also includes MBTA back of house space.

The back of house space would be removed and moving walks ways would be installed in the existing tunnel. At Devonshire Street escalators and an elevator would be installed up to the surface somewhere around 100 Summer Street. https://www.google.com/maps/@42.3535384,-71.0577858,3a,60y,33.32h,82.16t/data=!3m6!1e1!3m4!1s_iYk-efcYR6P2W-hbxccDQ!2e0!7i13312!8i6656!5m1!1e2?hl=en

This would create a great midway connection to the surface and would serve the 111 Federal Street Tower (if built) and Winthrop Sq. Back under ground a new pedestrian tunnel would be dug down beside the Red Line Subway tunnel to the level of the Red Line. If the Red Line tunnel takes up the full width of the street from building foundation to building foundation this could be the one major challenge which moves this out of the "reasonable" category.

With this connection South Station to Park Street can be walked completely underground (one long super station). With South Station potentially being expanded, a new signature tower being built along this route and the Seaport in desperate need of better transit connections, this may be a reasonable solution.

Anecdotally, I often walk from the Orange Line at DTX to South Station. It is a fairly short and pleasant walk, however I enjoy walking and I know my way around Boston, I recognize most people would transfer to DTX and take the Red Line one stop to get to South Station. With this new Summer Street Concourse, once one enters DTX or South Station (subway) there would be signs directing to the other station. Now make this walkway covered from the elements and include a moving walkway like at the Airport and I bet most people take the concourse instead of crowding onto the Red Line.

1969 Aerial

Enlargement of connection from Summer Street Concourse to Red Line Platforms

Here is a more detailed look at how the existing Summer Street Concourse would be connected to the Outbound Red Line platform (with existing convenient connection to the Silver Line). I have marked the location of the Red Line under Summer Street. On this image I have also marked in yellow an area to the south of Summer Street and the Red Line which does not have building foundations.

In the current aerial below you can see that the driving area of Summer Street has shifted slightly to the south into this yellow area (the Red Line runs mainly under the current sidewalk location). The rest of the yellow area is a small park. On this aerial I have indicated the location of the proposed pedestrian connection point. Also shown is a diagrammatic section through the area.

 

[CSTH]

I like it a lot. I remember reading somewhere though that the Dewey sq tunnel has something like a 10 ft concrete foundation (except directly over the red line) to keep it from floating with the tides...devil definitely in the details on this one...

 

[Upstruk]

If there's 10 ft of concrete completely around the red line platform that would certainly make this tough. However, I believe the platform was extended further under the Dewey Sq tunnel in 1985 for the longer train sets, so that would be somewhat encouraging that continuing further under the tunnel is possible.

 

[Charlie_mta]

I think it can be done.

 

[F-Line to Dudley]

The Winter St. concourse is not intact any further east than Devonshire. It never totally reached Dewey in the first place, so the spacious Red Line lobby is not in fact related to the rest of the Park-DTX upper level. The 1912 construction stopped shy of the station awaiting some TBD continuation plan from BERy on next move that never materialized. The stretch of tunnel past the end of the public concourse that currently hosts MBTA offices off-limits to public access had its end point demolished and chopped back slightly for under-street utility relocation related to the Dewey Square tunnel construction and surrounding urban renewal. So even though the stretch of old Summer St. out to the High St. intersection remained undisturbed at the surface from any mid-50's urban renewal, that truncated end of the tunnel was very much disturbed.

Therefore, the uncertainty factor and devil-in-details variables stretch 500-600 ft. further back of the Red Line lobby. Not nearly as close as the 2D renders would indicate.


Agree with CSTH on this. While theoretically possible and eventually worth a scoping look-see, you need a whole lot more than theory and theoretical renders to prove feasibility because the potential blockers are much more numerous, extensive, and further back than meets the eye. It's a very low-percentage play whose odds shouldn't be overinflated, and isn't something you can front-load in the near-term as any sort of meaningful congestion mitigator because the low odds of success impose a low ceiling on the priority pecking order where too-dogged a pursuit starts becoming a waste of resources distracting from SS's real mobility issues.

In short, this is orders-of-magnitude below the DTX-State ped connector that's a reliably known high-percentage engineering play (if a little hard to peg a $ figure on) and very much worth scoping out. Wouldn't be responsible at all to shotgun the two ped connections as a combo build or Phase I/Phase II expansion of the concourse. It's probably something you conduct a feasibility study on after the Transitway-Downtown Green Line connector gets built to South Station and initial sticker shock of that build is digested a little to start looking at complementary touches. Not as a prelude or buy-time tactic for that megaproject. After-build is where the ped link-up to DTX gets about as good as it's ever going to get on cresting demand to merit the scoping study for a definitive thumbs-up/thumbs-down on whether the low-percentage play can be executed in real life.

Beware the spurious logic in overstating feasibility of the theory. There's an awful lot of variables to conclusively prove first before pursuit of the low-percentage play becomes par-or-better wisdom for resource allocation. It's at risk for going down the 'bad transit' wormhole if superficial simplicity of the theoretical renders causes one to start digging-in on a higher build priority than is supported by known evidence. This is one where it'll take money for test bores, not merely maps of under-street structures, to prove real-world feasibility.

 

[The EGE]

I can't seem to find the actual picture, but somewhere out there there's a ca. 1955 photo of the Dewey Square tunnel being constructed. The Red Line tunnel is clearly visible in profile in it. Rather than being rectangular like most tunnels in the system, it has a sort of half-cylinder on top, probably 3 feet high at most. That half cylinder was being shaved off to fit the auto tunnel on top. There was no second level as there was from Tremont to Devonshire.

Edit: Here's a 1914 view of the tunnel under construction.

 

[Shepard]

Here's a small and underwhelming proposal: North Station to South Station BRT through the CAT (switching to surface streets when peak congestion is reported). Should be an 8 minute trip. 5 minute headways at peak times. No stops in between.

I, for one, would use this service. I could see many commuters using it as well. It could potentially relieve pressure on downtown connections.

 

[The EGE]

Here's the tunnel roof being shaved in March 1957:

And here's what the tunnel looked like with the new lowered roof:

Images are from Boston's Central Artery, copyrights owned by Peter Vanderwarker and the Barletta Company.

 

[BostonUrbEx]

At present, the concourse definitely ends about halfway between Otis and Devonshire. The emergency egress is roughly -- perhaps exactly -- at the end of the concourse, at 80 Summer St. As you come east, you eventually just face a massive wall with a stairway to the left (egress) and a very small crawlspace dead center at the floor. Immediately inside of the perhaps 3x3x3 crawl space it drops straight down to the Red Line tunnel (so basically it is just for ventilation).

While I think a headhouse at 80 Summer (built into one of the buildings as if a storefront) is worth consideration, there's surely a mess of utilities, I-93 vents and egresses, and more utilities between 80 Summer and South Station.