The Cummins/Blue Hill intersection clusterfuck immediately west of Mattapan isn't what I would exactly call a trivial thing to negotiate. I'd also be concerned about the potential impacts to any future plans for Red Line to Mattapan that this would have.
Debateable. But we're listing easy, low-impact builds...not ranking them by priority. That's a whole different exercise.
This is very easy build. The M's sparse headways don't make negotiating a long light cycle in the Square any issue. Hell, they don't even need to run thru to Blue Hill CR unless it's schedule-coordinated with a Fairmount Line arrival/departure.
Which I don't think they can realistically do without launching into a decidedly difficult Southeast Expressway / Commuter Rail / Red Line overhaul mega-project. Of course, the corridor needs to be overhauled anyway for a variety of miscellaneous reasons - but that's another thread.
Take a stopwatch on your next trip through Malfunction Junction between the portal and the JFK station approach. There have been artificial slow orders in place there for decades because the switches and signals don't fucking work right and treat 24/7 protection of sparse non-revenue moves from Cabot Yard with equal weight to all revenue trains crossing through there every 5 minutes. That minefield is one of the worst schedule drags on the entire Red Line. Supposedly that clusterfuck is partially funded for an infrastructure rehab, but they've been saying that for over a decade so I'll believe it when I see it. Shave half the travel time off the trip through that wasteland of switches and underpasses and you buy half a dwell time for a Braintree infill. Zap some of the equally pointless slow zones around the Neponset River bridge and buy a little more. No CBTC re-signaling required...just make the junction fucking work right for the first time since the late-80's and it's 'found' schedule resiliency that'll support 1 infill on the longest between-station gap of 1 branch.
SE Expressway megaproject/rebuild wouldn't do anything to trip times on either branch. All that is is 'stacking' the infrastructure to free up physical lateral room on the ROW. It's ops-neutral if (fair assumption) only Ashmont's still going to be stopping at Savin Hill station. And no way are they combining the branches into one mainline, third track or whatever, and losing the grade-separated junctions. That's headway-maiming for everything out to Alewife; it won't work.
Not happening without a similarly difficult overhaul mega-project undertaking, in this case, unfucking the Circle of Death. And given that one of the components of the Circle of Death is Exit 17 on the Mass Pike, I somehow doubt that a new station would simply be a new station as opposed to the finest in T Commuter Rail glass palace park and rides. (Especially since building a Riverside/Turnpike park-and-ride station at the 90/128 junction as a joint venture with Amtrak for future B&A Main Line service to Springfield and Pittsfield/Albany or Hartford/New Haven seems like a difficult to impossible proposition in its own right.)
There are 8 bus routes that already traverse the Circle of Death. 1 more frequency, even if it's under wires, does nil for better or for worse for traffic there. And doesn't mess up the 71 schedule at the end of the line.
A new station would be akin to whatever they rebuild the other 3 Newton stops to. The space between the Crowne Plaza air rights and the ramps does not allow for anything more than an 800 ft. platform, an egress, and a street-level bus loop. It wouldn't even be Allston/New Balance grandiose...because it can't.
You
would be able to whack most of the Pike express buses if rail headways were sufficient, so that reduces some vehicle load on Circle of Death.
Wasn't the earth decidedly salted on the Dedham Center ROW with a $1/99 years lease? Sure, it might be landbanked, but given this state's track record on landbanking you'll forgive me for being ever the skeptic. "Save Our Trail!" coalitions or widening the ROW to allow for rail+trail aren't easy propositions, either.
Wrong Dedham ROW. That's the one south from West Roxbury that had been held since 1950 for the Orange Line extension. This is the full grade-separated and well-buffered one running west from Readville that was active for freight until 18 years ago. The one that had commuter rail until 1967. There's no trail plans for it because of the general lack of easy street access from the ROW, which is either in a cut or on a relatively tall embankment most of the way. Plus it's blocked at the east end by the semi-active Readville yard. People in town occasionally propose trails, but nobody wants to pay to grade it because of the very limited access points from the side streets and abutting properties it goes above/below.
That leaves Dedham Corporate or Inner Franklin (Norwood?) short-turns, but Inner Franklin can't get level boarding as of the last time I checked (and it represents an awful schedule drag besides) and reconstructing Dedham Corporate to facilitate level boarding and short-turns seems like a great way to throw money into a black hole with very little to gain on returns.
And there's no need to with Westwood being 1 exit away, having the garage and waiting room, pre-provisioned for triple track, and having extra turnout space on the easterly side for 2 more expansion platforms. That's why I said fork the Fairmount schedule at Readville once it is scaled up to 25 min. headways.
Dedham Corporate gets useful if you do Foxboro and 1-1/2x the schedule density on the main Walpole-north. But at CR headways, not "Fairmounting".
