It is an absolute reduction in downtown storage needs because the system will be better-distributed to the endpoint layovers and shift changes will be a lot lower-'intensity' than the jarring all-or-nothing peak vs. non-peak of today. But the notion that some transpo advocates who should know better (Ari Osevit...looking immediately in your direction) have erroneously spouted that storage starts getting zeroed-out en masse because "the trains are always in motion" is utterly divorced from all reality. Does NYC not have a whole slew of giant honking subway yards even though they run some of the densest all-day service in the world...
with an overnight revenue shift...because they have so many trains in constant motion? Of course not...the more trains and the bigger the fleet the bigger the staff shift changes are going to regularly be, the more floors there are to pause and sweep, the more onboard toilets there are to empty...and so on. The same Eurozone that the transpo blogosphere loves to lecture us on our inferiority towards has city-size passenger yards for its immense layer cake of hyper-local, semi-local, urban-regional, intercity-regional, and HSR services. That's not born failsons failing to keep the trains forever moving...that's simply the raw-most network effects of their enormous scale showing itself. If we want that kind of scale, we're going to have to support it with matching facilities. That really shouldn't be a hard concept to grasp because we get it intuitively when bus and rapid transit modes are the topic. But bring up NSRL and/or RUR and all of a sudden Boston Engine Terminal becomes this physics-melting 'white hole' where trains go in and high-rent supertalls spit back out. The thought doesn't even follow its own logic to arrive at that endpoint from an ostensibly service-centric point of origin. Some of Ari's recent writing on the subject of yards has bungled this bad by tipping its hand too obviously about a craving for a new real estate canvas to SimCity with rather than any actual concern for transpo network efficiency.
With South Station/South Bay it's simple.
- Red Line is going nowhere, because it cannot physically run 3-min. headways without a maxed-out Cabot firing on all cylinders. But we shouldn't be coveting anything on the interior of Cabot anyway because the Broadway-Traveler block and Traveler-Ft. Point Channel blocks have been pre-provisioned for air rights infill for 49 years and those are 'the' greatest-location parcels of all for knitting SS, South End, Southie, and Seaport together at their crossroads.
- The 3 downtown bus garages are going nowhere if you ever want more BRT-ification of the most overloaded Yellow Line routes within 2 miles of the CBD. The T is already aggressively investing to max out Southampton garage's footprint with expansion to get more 60-footer capable routes running near the CBD. Remember Boston 2024?...this garage was being coveted along with razing half of everything else around Newmarket Sq. for Olympics facilities. The T is very intentionally trying to act faster than City Hall and the BDPA can poke their heads in and interfere it to spit. Albany Garage sits on very highly-coveted property. Unless the state can somehow get interference-free buy of the whole of the ground-level Widett bowl where some of the space (say, by the to-be-relocated BTD tow lot) can be worked in for bus storage, they can't afford to listen to any real estate offers for Albany. And...shit...the Olympics coveted Cabot Garage on Dot Ave., too, an even more mission-critical facility than Albany. But no matter how many times you tell the City that they won't have a functioning bus system without these 3 dead-center downtown garages or equivalents very nearly across the street...pols still buy into magical thinking like everything will be just fine if you parked every Yellow Line vehicle overnight in Weston like that's no big change.
- Amtrak is not going to be running thru NSRL to Woburn or something with every train. Every Boston run of theirs--whether it's an Acela, Regional, Downeaster, Lake Shore Ltd., future Inland Route and Montreal service, or future long-distance trains super-extended up here from New York after the Gateway Tunnel opens--all come with mandatory between-run downtime for crew changes, food service restock, cleanup, and a run around the loop to change directions since the lion's share of their trains (all Regionals + Lake Shore) are run pull-only not push-pull. With NSRL you'll probably see Downeasters (which by that point will probably have been extended outward to Bangor) going through the tunnel just so they can join the rest of the Southampton crowd between-runs, and then a modest share of Portland- and Concord-badged Regionals continuing north Virginia-style (with the necessary caveat that NH + ME ≠ VA + NC on demand, so by no means will it ever be more than a minority share of Regionals continuing up). AMTK needs Southampton Yard forever just to turn around and head back out to D.C. or Albany/Springfield in one piece; it can't practically be done with an on-platform reverse out in the suburbs given the nature of those services and their crews' work hours. So plug all of their 2040 Superduper Regional/HSR growth and the NEC FUTURE study's most acid-fever expansionary dreams into surface South Station. They are already figuring out how to expand Southampton Yard space by reimagining the whole currently non-railed side of the property along Frontage Road: moving employee parking offsite, stacking the collection of sheds and signal bungalows vertically by the main building so they can lay more track, and even trenching underneath the Fairmount Line embankment so they can ram a bunch of new yard tracks straight into the loop while passing underneath Fairmount. Every square inch of that yard is, like RL Cabot, sacrosanct.
- The T right now needs an enormous increase in downtown southside storage because they lack the ability to effectively pair-match train lengths with routes...and that's going to be a problem with RUR because even if headways stay more even-keel there's still big demand spikes and dips to handle at rush. The 3-4 car trains you have rolling out on regular 15-30 minute churns all day aren't elastic enough--even with denser headways--to upshift to 5:00 when Providence can fill an eight-pack to standing room. And conversely it's going to maim operating costs if you have to over-hedge on train lengths for the far emptier off-peak from lack of flexibility. Even EMU sets assigned to NSRL duty are going to need to skip a shift for a yard stop to split/combine into bigger or smaller trains for those shift-related dips and surges. Readville (which the city also covets way too much for redev) is too far away for that; it's got to be nearer to downtown. And Boston Engine Terminal in Somerville is soon to be maxed out for space once they claim the last available strip along the Northpoint property line, with its shop duties becoming all the more intensive the more total trains you run. Further, the tunnel isn't replacing SS Surface so "the trains are always in motion" fantasy deeply held by some doesn't apply at all to NSRL. Systemwide capacity doesn't increase without utilizing both tunnel and surface, and the tunnel's upper limits for mixing-and-matching pretty much constrain all manner of surge service, alt routing, and otherwise non- rote-standard schedule types to choosing the surface rather than trying to worm their way into the churn down below. So even if/when NSRL reduces the storage needs, it won't be by massive amount. And for what substantial amount it does reduce in Purple Line storage, Amtrak and buses have immediate need for gobbling right back up. They really need the Widett 'bowl' and BTD lot. It's 30 trainsets (avg. 6 cars apiece) of space immediately available, where the Beacon Park easement next to would-be West station has already been withered down to 8 trainsets by a land-hungry Harvard and is likely to get zeroed out. And ALL of it would be built with decking provisions, which actually makes it easier than the harebrained Olympics plan to have the developer float the whole cost of building up from the 'bowl' to the street grid on stilts. Then if NSRL reduces the total storage requirements for Purple Line trains, a little bit of Amtrak overflow from Southampton could be accommodated and you can change over some of those storage tracks to bus parking bays for 100+ Yellow Line vehicles. Maybe that's what ultimately lets them barter Albany Garage for redev.
However it works out, ain't no way the total acreage needs for all-modes transpo storage will ever decrease. And that's after it substantially
increases to plug the dire downtown storage shortfalls facing Purple, Yellow/Silver, and Amtrak in the immediate term. It'll shape-shift with changing needs, but always have to be there. Fortunately, nearly all of it except for the tall structures like actual Cabot Carhouse, Cabot Garage, Southampton Terminal, etc. is pre-designed for air rights. So again, the problem is that our civic planners can't seem to stop perennially pwning themselves like Stooges on the air rights opportunities we've already had in-hand for 50 years...not that there isn't so little golden land available in the CBD for playing real-life SimCity that we somehow have no choice but to shoot all our transit networks square in the head with eviction notices.