It's unfortunate that the Needham Line's best replacement option effectively precludes the option of HRT on the Highland Branch, at least without screwing over at least one of the other CR services. That said, if SCR Phase II gets killed off by Phase I collapsing under the weight of its born-brokenness, or if the Corps of Engineers never allows a solution to the lunatic trestle through the wetlands, might there be enough spare NEC capacity to keep the Needham Line and therefore permit Blue-to-Riverside? (I kind of doubt it, but someone might know more.)
In my opinion, if there ends up being excess capacity on the NEC (for whatever reason), it should be reallocated to regional rail services -- to Westwood/128, to Dedham/Norwood, and to Providence. For example, Franklin Line services (both commuter services past Walpole as well as higher-frequency services to Dedham and Norwood) will likely be the first to be rerouted off of the NEC, instead traveling via Fairmount. Excess NEC capacity could be used to route a greater number of those trains back on to the NEC, providing better access to Longwood and Back Bay. Hardly a must-have, but to me a more efficient use of the available resources.
I love it as a Crazy Transit Pitch, though it's bringing flashbacks of F-Line's epic dismantling of LRT tunneling for the southern half of the Urban Ring in the Green Line Reconfiguration thread. I'm guessing the same infeasibility and absurd cost would presumably apply to this pitch as well (but of course we don't need to bother as much with those considerations in this thread).
Fascinating post as usual, Riverside, I look forward to the conclusion of the series.
Oh yes, it's not so much a Crazy Transit Pitch as it is a Fever Dream Transit Pitch. I have a map, but I'm not even going to post it in this thread -- it'll go into the Fantasy T Maps thread instead. The costs would be tremendous, and if we were going to spend those monies, we would be much wiser to invest it in a modern LRT subway along the same corridor. (The other major downside -- to do the full "shoelace", you need to build a new transit tunnel across the Harbor, and it would be lunacy not to use that tunnel for service to downtown. An HRT tunnel that's being used for an Urban Ring South would largely preclude that possibility, or require a four-track tunnel. It looks cool, but isn't remotely justifiable or sensible.)
And thank you! I appreciate the words of support.
No, Needham conversion is a necessity no matter what. West Roxbury and Needham desperately need the frequency, and the line is always going to have an outsized impact on NEC operations. Inbound Needham trains either have to run on the west track - thus effectively turning the Southwest Corridor into a two-track line for Amtrak + Providence + Franklin + Stoughton (and heavily limiting Needham frequency) - or they have to cross over at Forest Hills and block other traffic.
The Highland Branch wouldn't be the right choice for the Blue Line regardless. Past Brookline Village, there's not that much density - it's mostly small village centers save for the Cleveland Circle area, which is also served by the B and C. It does great as a light rail line, and there's simply not the population to need heavy rail. All the other western possibilities - Allston, Brighton, Watertown, Waltham, and the north part of Newton - have much more population and all-day demand possible.
You have to convert every station - not just building high platforms, but a lot of crossover bridges to replace the current crossings - and find a new Green Line yard and maintenance facility to replace Riverside. All that cost and disruption, for what? Brookline and Newton don't have a significant improvement in their service, they lose direct North Station service, and trade Copley for a station further from the High Spine. Needham gets nothing. The only real win - elimination of a transfer to Longwood and Brookline Village - is equally achievable with D-E connector and Blue to Brookline Village, and it's pretty minor anyway.
+1 for your summary of the challenges the Needham poses for the tri-track NEC. One of my favorite games -- Transport Fever -- has a pretty rudimentary signaling system, but it still can be a useful simulator for gaming out -- pun slightly intended -- the design ramifications of the current track layout. The old Commuter Rail track chart
is illustrative: south of Back Bay, the only crossovers are at the Plains interlocking just north of Forest Hills, which is why we get what you describe -- either a bidirectional single track operation for Needham, or a number of disruptive crossings.
While I'm a little less pessimistic about the prospect of heavy rail in southern Newton, I think you do a great job of outlining the additional costs and disruptions, and for modest benefits (at best) at that. For what it's worth, as I understand it, when the 1945 proposal was made to convert the Highland Loop to rapid transit, I believe it was imagined as light rail stock all around at that point. Which does reflect the density a bit better, as you point out.
@F-Line to Dudley
, great to see you back. Yeah, I'm pretty agnostic about tunneling under the Pike versus elevating over it, or nearby streets; both options will be disruptive in different ways, so pick your poison. Yes, you are right that BLX-to-Watertown (and, one has to admit, there is poetry to the "Blue" Line going both under the ocean and to "Water"town) is a pretty good compromise between the 1945 proposals for the Red Line (to Arlington via East Watertown) and the B&A. It seems doable, but also easily two generations of projects away -- and to me, a much stronger case after we see Green-to-Watertown and proper rapid transit frequencies to Newton Corner demonstrating significant demand.
, splitting Blue at Kenmore was something I went back and forth about when writing this series. In my opinion, Kenmore is too close to the core to branch a heavy rail line. (I actually think that JFK/UMass is also a bit too close to branch, but that's a topic for another time.) I don't know if you saw my previous post, but I describe Kenmore as being located at the "Inner Belt" of Greater Boston
, similar to Sullivan, Kendall, or Ruggles, all of which I think would be unreasonable locations to introduce branching in their heavy rail lines. In particular, it's important to remember that Longwood is a major employment center, arguably on par with downtown. A new heavy rail line would see very strong ridership and would likely induce additional demand. If you are going to build a heavy rail subway, I think it's best to do it so it can be used for maximum effect.
-- good catch! I actually watched a video about the Singapore system just a couple of weeks ago, and learned about that line. Not exactly something I would intentionally design into my system, but certainly an interesting approach.