I remembered the T12 soon after the comment. My concerns with the T12 are that:
I really like your thought process here! (And I'm glad the blog post was interesting!)
This was back in 2009 right? At what point do we get to move on to other things if this doesn't come to fruition? I know Eastern Seaport and the Marine Park will get built out as much but there is development popping up all around there, particularly close to design center.
My concern with street-running LRT is that you can't go down Northern Ave with the fancy new bike lanes, and going Silver Line Wy > Haul Rd> Drydock with no viaduct is a fine lower-cost solution but most of the GLRC talk I see connects the Piers Transitway on a route that avoids street running as much as possible (Bay Village, Back Bay, Huntington Subway, onto Riverside), so wouldn't the hope be that we avoid street running in Seaport if we can? The only interface with the street would be crossing D St. Alternatively any tunneling around all of the submerged highway stuff would be way more expensive than a 0.5 mile viaduct.
Most ideally yes it would be heavy, but to build heavy UR with full grade separation seems like an absolutely MASSIVE undertaking due to the insane complexity around Ruggles and Longwood especially. Using the flexibility of LRT for UR seems incredibly valuable to me. Additionally, track 61 provides a ROW with very minimal crossings (Cypher Rd, Convention Center garage, and Pumphouse) compared to any other route from Seaport to Melnea Cass. You could run longer trains on the Magenta Line along with good frequency on the UR and you'd move a lot of people.
So I think that could be a strength of this plan. Building the Magenta line bit by itself and ending at Design Center seems valuable to me as a phase 1 by itself. And you can build in the provisions for the future if any of those questions become yes's (track 61 UR or a transit tunnel to the airport), then you have what you need to make it happen.
Yeah, this is an issue in terms of a straight shot down Tide St and Codfish Wy. It's about 1550 ft to Shoreline Rd which gets you 95 ft down from viaduct height at 6% grade. I know the Ted Williams tunnel is 90 ft down so there would have to be some other way. You have even less space to descend on the west side of the highway from ground level.
Massport won't move on. They're still actively developing Marine Terminal, they just spent a mint on the port dredging and are still looking for new and creative ways to take advantage of it, and they still own Track 61 from the Pumphouse Rd. grade crossing points east so it's a strategic freight rail hold for them. The Tide St. spur still appears in long-term planning documents at the state level. There's no "expiration date" on those plans.
Again...Track 61 is being held for freight rail futures in the port that don't have an expiration date. It would take three parties--MassDOT, Massport, and CSX--to jointly file for abandonment to take it off the national rail network (with the Red Line test track only being a temporary user who must restore the corridor to previous status when its job is done). CSX has no interest in abandoning...their trackage rights are free for life, so why would they ever pass up rainy-day prospects. Massport has no interest in doing that because they're the ones with the institutional master plan for port freight. MassDOT's not going to do that because of the politics of starting a turf war with the other two. That limits the potential future modes of the Track 61 ROW to Commuter/Regional Rail only, which has already proven to be scheduling-infeasible because of all the crossing conflicts at Southampton.
I have to disagree with this, especially #2, and agree with @samsongam's subsequent response here. The logic is essentially the same as "Fairmount Line definitely shouldn't be commuter rail, because it deserves HRT vehicles with ample standing room". Both are making perfection in mode choice be the enemy of good.
An interesting proposal. In my year of living in the eastern part of southie, I found that the 7 was the most useful bus for me to get both into the Seaport, and to downtown and beyond. It's a pretty significant commuter route as well, those buses are very full during rush hour. Rerouting all those people to the Red Line might improve network efficiency, but I suspect it would be highly unpopular.
A problem is that part of the T12's intention was probably to connect Seaport, as a destination (employment or otherwise), to residential areas of Roxbury and possibly further west. Stopping it at Andrew would break that, and in general, would make it a "neighborhood to neighborhood" route that I'm usually not a fan of.
Sometimes serving where people live and work more directly is more important than route efficiency. Not always for sure but D St in the Seaport alone has the Lawn, a huge tourist trap, multiple new apartment buildings and hotels that require a sizable staff, and large employment warehouses. And that's not including the Southie catchment.
not part, that is THE intention. get people to have a different/better option than red line/silver line to access Seaport.
In that case, one could split up the T7 at Haymarket Station into 2 routes. The section north of Haymarket could be interlined with the 89. The T7 itself could be extended from Andrew to Nubian and/or Ruggles and replace the T12.
