Regional Rail (RUR) & North-South Rail Link (NSRL)

[Teban54]

I did also provide a potential solution without a flying junction, if we're willing to accept an unconventional track layout.

What about the 2 western tracks being local and the 2 eastern tracks being express? You would still have a flat junction with the Franklin line, but since that would only affect local service it's not nearly as big of a capacity constraint. That would solve the gradient issue at Readville since that area has way more room for an incline, and would also "solve" the platform issue at Forest Hills by reusing the existing not-quite-wide-enough island platform. There's plenty of room on the Franklin Line for double (Or even quad-track) here, so that's not an issue. To avoid a curved platform the station should probably be shifted northwards by about ~300-400ft, but it would be fully level with parallel local/express platforms. (Although without a flying junction there would be no same-direction cross-platform interchange.)

The one big operational hurdle is that to make this work where quad-track turns into triple-track, the Franklin Line would need to run on the left for this section, with a crossover between Readville and Endicott to go back to standard right-hand running.

Spoiler: How the merge works

With an Inbound Local | Outbound Local | Outbound Express | Inbound Express layout, the outbound services would share the middle track for triple-tracked sections.

I can't find any rule that says this is 100% verboten, but I don't think it's done anywhere else on the NEC. Perhaps @F-Line to Dudley has some insight on whether or not this is possible from a regulations perspective.

Sorry that I didn't see this earlier. I think this is a pretty interesting and innovative idea; but one thing to clarify is whether you intend Providence and Stoughton/SCR trains to run on local or express tracks. It appears that local is more likely, even if SCR trains were to skip Hyde Park, so that they don't block Amtrak trains at Ruggles. If that's the case, the majority of NEC's load will be on local tracks, and there will remain merge conflicts between Franklin trains in one direction and Providence/SCR trains in the opposite direction. Not as bad as having additional conflicts with all Amtrak trains on top of them, but since regional rail trains will see much higher tph than Amtrak trains, it's probably only removing a small number of conflicts, as opposed to "not nearly as big of a capacity constraint".

(The other option is to have some NEC regional rail trains run express, but then you're cutting service at Readville and Hyde Park, which is undesirable as we discussed earlier. That sounds even more awkward if the reason is solely to give Franklin riders OSRs to Ruggles and Back Bay.)

I do think it's the best compromise to date for killing two birds in one stone (Franklin Line merge and Hyde Park/Forest Hills platforms), though.

 

[TheRatmeister]

but one thing to clarify is whether you intend Providence and Stoughton/SCR trains to run on local or express tracks. It appears that local is more likely, even if SCR trains were to skip Hyde Park, so that they don't block Amtrak trains at Ruggles

Assuming the existing triple-track between Forest Hills and South Station is not upgraded, the service pattern would be Local inbound | Local and Express Outbound | Express Inbound. In theory this should give enough time for a CR train to leave Ruggles before the following Amtrak train catches up, but if blocking at Ruggles does become an issue the clockface schedule can be made slightly imperfect by a couple minutes during peak hours so trains would leave at 00, 05, 12, 15, 20 etc. instead of at perfectly even 5 minute intervals. Obviously if Amtrak does decide to invest in quad-tracking the whole route then this becomes a non-issue.

(The other option is to have some NEC regional rail trains run express, but then you're cutting service at Readville and Hyde Park, which is undesirable as we discussed earlier. That sounds even more awkward if the reason is solely to give Franklin riders OSRs to Ruggles and Back Bay.)

I do think there should be some peak hours express trains, but I think the SCR trains and some Providence trains are better candidates for this than Franklin Line trains. Readville should also never be skipped due to the interchange with the Fairmount Line. If this is a problem with 4 tracks then good news, the Readville site is not particularly size constrained so a fifth or even sixth passing track for Amtrak can be included as part of the rebuild.

 

[Teban54]

Assuming the existing triple-track between Forest Hills and South Station is not upgraded, the service pattern would be Local inbound | Local and Express Outbound | Express Inbound.

This point actually reminded me: How is this supposed to work under NSRL, where the 3 atypical tracks are supposed to merge into two? Although I do see the setup will be complicated regardless with Worcester Line involved.

In theory this should give enough time for a CR train to leave Ruggles before the following Amtrak train catches up, but if blocking at Ruggles does become an issue the clockface schedule can be made slightly imperfect by a couple minutes during peak hours so trains would leave at 00, 05, 12, 15, 20 etc. instead of at perfectly even 5 minute intervals. Obviously if Amtrak does decide to invest in quad-tracking the whole route then this becomes a non-issue.

Fair enough, at least pre-NSRL. Similar to above, NSRL may bring issues with the setup, but that remains a problem even if those Franklin-via-NEC trains are replaced with Providence/SCR trains.

At this point, I think the biggest question with your proposed setup is not so much with its own feasibility (though I maintain that Franklin having flat junctions with Providence/SCR is still a big issue), but whether we should believe that the atypical setup will receive any official recognition. Given that Amtrak has been reiterating on NEC 4-track plans for a while now (more planning than the T has done for its rapid transit system), I'm not sure if that will happen.

 

[Teban54]

One interesting wrinkle here is that, according to the 2018 data (which I think is the most recent we have), the only "major" stop on Fairmount is Fairmount itself:
View attachment 49365
Or we can categorize Four Corners/Geneva, Uphams Corner, and Newmarket as "minor" stops. But in either case, we're talking about significantly longer distances between express stations, which will cause express trains to have more disruption on the schedule. I definitely think there is a feasible solution somewhere here! I just think the ridership profile poses an interesting question.

(Of course, the Fairmount Line has changed a lot since 2018, so this profile has potentially changed radically.)

That's interesting and unexpected data. I don't think it's worth extrapolating the 2018 numbers onto a future Fairmount Line with <=10 min headways, though.

The main reason is that with the exception of Fairmount station, the alternative of bus+subway is simply too strong given the 45-min headways. Most stops other than Fairmount have either a Key Bus Route or multiple bus routes, as listed below, so residents can easily take a much more frequent bus instead of waiting for the once-every-45-min Fairmount Line. Moreover, the closer you are to downtown, the smaller the time difference between bus+subway and Fairmount Line, making the latter even less attractive. Both factors will change once Fairmount Line runs more frequently than every 45 minutes.

Spoiler: List of bus routes per Fairmount stop

KBR indicates Key Bus Route in 2018. T indicates Frequent Bus Route proposed under BNRD that are not KBRs. Frequencies indicated are from Dec 2019.

• Readville: 32 (KBR)
• Fairmount: 24 (20-min AM peak, 50-min midday)
  • Route 32 is a 10-min walk away, but that distance is longer for neighborhoods to the SE of Fairmount station
• Blue Hill Ave: 28 (KBR), 31 (T), 29 (16-min AM peak, 70-min midday), 30 (25-min AM peak, 55-min midday)
• Morton St: 21 (15-min AM peak, 15-min midday), 26 (15-min AM peak, 30-min midday)
  • Note that today's 26 is a unidirectional loop, and BNRD keeps this unchanged. However, I can see it change if Fairmount become rapid transit-worthy.
• Talbot Ave: 22 (KBR)
• Four Corners/Geneva: 23 (KBR), 19 (14-min AM peak, 60-min midday)
• Uphams Corner: 15 (KBR), 41 (25-min AM peak, 40-min midday; removed in BNRD)
• Newmarket: 8 (T), 10 (20-min AM peak, 40-min midday; removed in BNRD)

Fairmount station easily has the worst bus connection on the entire line. All but one of the other stations will have a 15-min Frequent Bus Route; that exception is Morton St, which has two routes to Fairmount's one, and both routes are more frequent than Fairmount's sole bus route.

(Note that if Fairmount Line becomes rapid transit-worthy, the 32 may be amended to loop at Fairmount station in both directions in the middle of its normal route. However, that was not done in 2018, and this discussion primarily aims to explain the line's ridership patterns in 2018 and why other stations will likely overperform in the future, not whether Fairmount station itself can also do so.)

Just by looking at the maps alone, I'd consider the following 3 stops as "express" stops: Fairmount, Blue Hill Ave, Four Corner/Geneva. This gives the same number of stops as Franklin-via-NEC (Hyde Park, Ruggles, Back Bay), making Franklin-via-Fairmount trains even faster than Franklin-via-NEC. There are at most 2 local stops between express stops (3 with infills), so overtakes might not be a big issue -- although I'm not sure about that if we're running 6+ tph on Fairmount Local.

I think there is a similar though weaker argument for similar service levels to Framingham, in terms of density, ridership, and station locations. Like Norwood, assuming a Marlboro branch, Framingham might potentially enjoy 15-min headways anyway.

I wasn't thinking of locations so far out from 128, but if we're consider that, I also nominate Canton. As mentioned earlier, combining Canton Junction and Canton Center makes them the #3 ridership "station" systemwide, on the same scale as Salem or Beverly. Canton Center even has slightly higher ridership than Canton Junction despite seeing half the number of trains. It's also technically at a similar distance from Boston as Norwood is.

(The difference among the three is that Norwood is the only one with a continuous path of decent density leading up to it, via Endicott, Dedham Corporate Center and Islington. Canton is separated from Readville by the Blue Hill reservation, even though Route 128/University Park has similar ridership as either DCC or Islington individually. Framingham gets 15-min frequency itself, but not the intermediate stops like Wellesleys and Naticks.)

I see four tiers for a corridor like this:

• Services with 5-13 minute gaps between trains: show up and go ("SUAG")
  • mimics the rapid transit experience
• Services with 10-20 minute gaps: show up and wait ("SUAW")
  • these can be both viable and valuable, particularly if there is a pleasant cafe to enjoy a cup of tea while you wait 15 minutes for the next train
  • (and IIRC, at least one of the Norwoods already has a cute station building that could serve this purpose)
• Services with 20-40 minute gaps: plan departure, travel whenever ("PDTW")
  • trains are frequent enough that you can be unconstrained in your travel plans...
  • but infrequent enough that you will choose specifically when to leave for the station (station cafes are nice, but no need to hang out for 35 minutes)
• Services with more than 40-minutes between trains: plan travel around schedule ("PTAS")
  • your travel plans are governed (and limited) by the train schedule

These numbers aren't exact, especially in the lower frequency tiers, but are still illustrative.

Historically, the Commuter Rail was PTAS at most times of day, with most services bumping up to PDTW during peak, and a handful rising to SUAW for brief periods during peak. (Historically, the rapid transit system was SUAG; many of the T's current woes result in SUAW service instead -- with some services dropping to PDTW, especially on weekends, but with no public schedule to Plan Departure around.)

The Rail Vision is to move the entire system to PDTW all day. And most of us agree that the goal for Fairmount should be SUAG.

What you and I see in Norwood is the tier between PDTW and SUAG -- the SUAW "show up and wait" model. Now, even if Fairmount reaches SUAG, it'll probably be a low-freq SUAG -- something like 10 or 12-minute headways. If some of those trains continue to Norwood, that creates a SUAW service there, which I think seems pretty well-matched to its character.

Excellent classification of different service standards. Yes, my proposed 15-min frequencies for Norwood was basically implying SUAW.

 

[Teban54]

(continued)
With all these said, now I can come back to this:

I believe half-hourlies to both Fall River and New Bedford would actually create 15-min service all the way to Taunton... which does feel a little aggressive to me, for a city 30 miles away from Boston that hasn't had commuter rail service in 60 years. But hey, if FR and NB have demand for half-hourlies, let's rock and roll.

While I'm not married to the idea of :30 to Fall River and New Bedford, there are two things to consider here. One is what I said earlier about Canton: While ( :30 PVD, :60 FR, :60 NB) already gives Canton Junction 15-min SUAW, additional service can either upgrade Canton Junction to SUAG, or Canton Center to SUAW, or both. The other is that hourly trains to each terminal make them PTAS, which may not adhere with the spirit of regional rail.

Given these, I think it's fine to give Taunton the "by-product" of 15-min SUAW -- not because we intentionally favor Taunton, but as a by-product or "goodwill service" that's primarily due to Fall River, New Bedford, and possibly the Cantons. Another place where this may play out is Walpole with platform mods: Even though the town itself probably doesn't need very high frequencies, if 30-min PDTW is given to both Forge Park and Foxboro, Walpole will see 15-min SUAW anyway. (On the other hand, a real argument can be made that Foxboro doesn't need PDTW, as the branch is almost like a Walpole short-turn. That will reduce service to Walpole, but I'd still advocate for Norwood short-turns to give it 15-min SUAW.)

Having said that, I do realize :30 to each of FR and NB may be overkill. (Looking at the archives, there were times when I was imagining hourly trains to Forge Park, Foxboro, Newburyport and Rockport, too. On the other hand, Rail Vision Alt 6 has 15-min SUAW to each of Fall River and New Bedford, which sounds insane.) So if FR and NB only have demand for hourly trains, I'm fine with it too.

Spoiler: using "SUAG" and "SUAW" to distinguish service character

The other thing to note about these tiers is that they allow us to differentiate among 4 tph services. To go back to the Taunton example: yes, half-hourlies to FR and NB could result in a train every fifteen minutes (SUAW)... if the trains are evenly spaced. If, instead, the northbound departures are at :00, :07, :30, :37, then that moves you into the PDTW tier.

And there's a similar (and probably more common) effect at 2 tph: evenly spaced, this is a pleasant PDTW service. Offset (e.g. :00, :10), this turns into a PTAS service.

This general "wobbliness" was one of the reasons I hesitated to trumpet an "Indigo Line to Norwood" concept: a named service like that should be consistently SUAG (or consistently SUAW), but I don't think it should change midway through. So.... "Indigo Line to Readville, Indigoish-Purplish Line to Norwood, Purple Line to Walpole and beyond"?

This is why I opted for a "Purple Line" vs "Central Regional Rail" model in my latest crayon map. Purple Line is SUAG, Central RR is SUAW. (Although, ironically, I sidestepped the Norwood question in that particular map, and kept it in my PDTW/PTAS tier. But, anyway, the concept is the same.)

I see your concerns, but even though I wouldn't necessarily use "Indigo to Norwood" branding either, I'm not concerned about this issue of irregular headways. For one, Foxboro "branch" already seems to function almost like a Walpole/Windsor Gardens short-turn, so I think it can be used to regulate headways on the Franklin main line with longer holds at the Foxboro terminal. For another, you can run Norwood short-turns.

Funny enough, I don't think irregular headways present issues for SCR and Taunton at all, as the two SCR branches are almost equal in length. Where this does become an issue is Framingham due to expresses (unless we use your skip-stop proposal): irregular headways will happen either at Framingham or the Newtons.

 

[TheRatmeister]

How is this supposed to work under NSRL, where the 3 atypical tracks are supposed to merge into two? Although I do see the setup will be complicated regardless with Worcester Line involved.

Inbound local can merge with inbound Worcester, and then whatever wacky underground flying junction you need to make the merger of the existing NEC and Worcester Line work will still work. It's not really any more complicated than having inner express merge with outer local tracks and then merging those with Worcester.

Given that Amtrak has been reiterating on NEC 4-track plans for a while now (more planning than the T has done for its rapid transit system), I'm not sure if that will happen

I mean, there's nothing else to say here other than that the T needs to get moving, but that's not really unique here.