No. This is not a Red or Green connecting ROW. Didn't we spend like 3 pages in the Crazy Transit Pitches and/or Green Line Reconfig threads running headfirst into brick walls without a helmet over and over again on Google Maps and MS Paint trying to make this happen? It's not going to happen no matter how many times this gets rehashed and doubled-down upon.
Green can't physically connect here because crossing the South Bay spaghetti ramps/tunnels is no-go. The only way to the Seaport via Green is via the notch in the wall the Silver Line builders left in the Transitway under the corner of Essex & Atlantic. The end. There are no easy answers for that one that serve the ridership demand square-on except to pick up the pieces of SL Phase III, correct the obvious and avoidable fatal flaws that killed the original project (i.e. narrower-profile LRT not BRT, routings/stations that avoid as much structural underpinning as humanly possible, recycling as much pre-existing infrastructure as humanly possible)...and loading up for the $2B and 15+ years that will take to get done. 20 more pages of map doodling trying to uncover that "Eureka!" moment of easy answers isn't going to address the need in any easier way than the next 20 pages of map doodling. It is what it is.
Red can physically get here, in a "technically correct is the best kind of correct" not-very-useful sense. It can't, however, get here AND hit South Station in the process because of those same South Bay spaghetti ramps/tunnels that upended all those Green map doodles make banging a right across the Channel after SS physically impossible. And it can't get there AND hit a Transitway/SL1 transfer at a neat-and-tidy SL Way node because the Pike connector + Ted tunnels cut a gash through the Seaport you can't slip under.
It also can't get there without outright cannibalizing the Haul Road or creating an expensive swath of destruction to widen out the cut for 2 tracks. Cut-and-cover under the road is a grave engineering no-go when that serves to create an unacceptably high risk of storm drain effect channeling
50-year flood runoff from the Harbor through the tunnel into the single most drainage-vulnerable part of the city at South Bay. Cut-and-cover under the road and a slip-under of the Pike cut is doubleplus no-go when it adds a potential breach
into the Pike cut from the tunnel below dumping two sewers' worth of flood runoff gushing back into the South Bay. You will either spend $½B on nuthin' but tunnel flood mitigation on top of all other costs to build this, making it a horrific waste of money compared to putting a down-payment on the Green-Transitway connector...or will have to ditch the Haul Road and send hundreds of big rigs barreling down Southie residential streets. Either choice, the project's deader than dead.
A Red spur that misses South Station also serves no transit constituency except Dorchester-Seaport directs and Quincy/Braintree-Seaport directs. Those are very small slices of the Seaport commute pie because of the big whiff of SS, and happen to be the non-adjacent areas that presently have the
least difficult trip to/from the Seaport because they can make the transfer at SS
without getting bogged down in the Park/DTX dwell congestion that's decaying the commute from everywhere else north and west of SS. There's no demographic basis for building this as a rapid transit line because of what it
doesn't connect to. It's not even a nice-to-have...it's outright bad transit planning to divert Red congestion management resources out to a bottom-priority niche like this. Especially when the solve for the finite width of the Haul Road cut either blows out the costs or sacks a residential neighborhood with crush-load truck traffic.
There's never going to be a scenario where the transit build bucket list shrinks enough that a Dorchester-BCEC / Braintree-BCEC one-seat sans South Station connectivity gets off the bottom of that bucket list; there will always be something more mission-critical to build. That's the difference between low-priority good transit and total waste of mindshare. We know what the final solve is for Seaport mobility: Green-Transitway. We just have to stop wasting our time talking around it in desperation and grasping at straws at things like the latest Track 61 illusion.
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Now, I do agree that Haul Road has a nice alignment for running the Urban Ring from Dudley-Broadway-Transitway. And that's not a coincidence; it was built that way as a possible routing. But unlike the north half of the Ring that sticks to nuthin' but RR ROW's with easy tie-ins to light rail, south half is all on-street thoroughfares with only short chunks of reservation separation possible. It'll either (likeliest) work best as a northern LRT/southern BRT half-and-half, in which case the Haul Road can just get used as is. Or...the south half is near-total mixed-running streetcar and burying the streetcar tracks in the Haul Road pavement between Mass Ave. Connector and Cypher St., then again on the last block to SL Way, is the way it's going to go.
Either way you're using large chunks of the road as the co-mingled transit line and don't have the luxury of lots of grade separation.
