F-Line to Dudley
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*NOW* isn't realistic. There is heavy-duty design work to complete before first shovel can go in ground, and it's not tasks that private involvement can hurry along all that much.
The ancient first UR study affirmed the ridership and mission statement with nice exclamation points, but was unfortunately way too vague about actual build items. So there's major need for a comprehensive re-study. For example, nothing was said before about how a busway is going to get up from the BU Bridge onto Mountfort St. for the jog into Kenmore with the giant hillside, Pike, railroad, and bridge structures all standing in the way. And there's nothing yet said about how a busway is going to get around spaghetti junction at Brickbottom without making time-costly on-road detours. Those are utmost-importance design decisions that have to be drafted, because the Ring operates as quadrants anchored to nodes. So Kenmore is where the NW (Kendall) and SW (Longwood) quadrants tie together, and Lechmere/Brickbottom is where NW and NE (Sullivan-Airport) quadrants tie. It won't work if you half-ass it as a busway fragment that skirts the BU-side dilemmas by just dumping out at Waverly St. then spending a half-hour in bridge/rotary traffic like the godforsaken 47 does.
With LRT it's the things they waved the placeholder wand at the first time around. Things like extending the subway from Blandford to BU Bridge to square the level difference with the Grand Junction bridge, and accommodating the B with a new underground junction + new portal in the BU West area. Straightforward, yes, but needs to be firmed up with things including how much of a tunneling discount they'll net from digging under the utility-few B reservation. Also need to factor things like sitings for 1-2 power substations in Cambridge to chain between the B/subway ext., Red Line @ Kendall, GLX @ Brickbottom interconnects on the rest of the route...and which existing substations on the interconnecting lines might need a boost.
Then there's the things universal to either modes. Like design of an overpass of Mass Ave. w/ elevated station to zap the problematic grade crossing. Prior study didn't do anything there, but years of Mass Ave. traffic counts scream "Problem!"...so they've got to spell that piece out. There's work to do on how traffic signal preemption at the remaining crossings (Main + Broadway are un-eliminable) will work. There's decisions on whether Kendall should have 1 station on the mid-block between Main-Broadway or 2 flanking stations--1 @ Main under the air rights overhang and 1 @ Binney St.--to cover the spread of the area and ensure that one of the stops (Main) is in direct eyesight of the Red Line entrance for wayfinding. There's scheduling of the actual service patterns, which are intended to be mixed (e.g. alternating downtown vs. quadrant-to-quadrant slots if it's LRT) but have never been fleshed-out before for either mode by prior studies.
It's a whole ton of busywork before turning a shovel. Much of it important enough not to try to cut corners on before the crucial details are spelled out and benchmarked, because once this thing gets built out into full NE, SW, and SE quadrants + the Allston & JFK spurs it's going to become its own living beast needing good decade-in/decade-out bloodflow. Unintended consequences are going to sting if the implications of UR-as-developing-system aren't fully thought out beforehand.
Railbuses *were* a thing. Unfortunately they are hilariously, cosmically unsafe in crossing collisions--front and sides--because most makes are no stronger than a city bus. They're illegal here outside of rail museums. The T evaluated one in 1980 and SEPTA shopped around the same model a couple years later. Both agencies were too skittish of the crashworthiness to give it second thought...and those were pretty much the last times they were ever considered here.
The Brits have the largest installed base in the world and still use out in the hinterlands on marginal branchlines far away from electrification where the biggest collision risk is a herd of sheep on the tracks. But they're on rapid phase-out there in favor of more rugged DMU's and probably will be wholly extinct in the Western world within another 5-7 years.
Because of the daily freight switching right in the gut of North Station at Boston Sand & Gravel, there's no way of buying any non-FRA compliant DMU for the Purple Line. The waivered "DLRV's" like the NJ Transit RiverLINE uses are still too light. And unfortunately the market for FRA-compliants has (temporarily) collapsed with Nippon-Sharyo's retreat due to internal turmoil. It'll take 3-4 years for that pump to re-prime, so there's nothing physically available right now for instant gratification deployment.
