Fantasy T maps

[Teban54]

Regarding the Green Line Reconfiguration topology and colors: this is one of the major differences between my map and @Teban54's -- I've used two colors and he used four, and we didn't even use Gold for the same purposes! For his map, I think the extra colors make sense for the details he wanted to convey, but in mine, again there was some pressure toward simplification. I disliked the idea of a long set of parallel lines along Huntington, but then I realized that I could bring the two Nubian branches into the Green Line, and that would allow me to simplify things down to these two colors.

For the record, I initially used Gold for Huntington-Seaport and Magenta for Nubian, but @Riverside convinced me to do the Gold/Magenta swap (for the same reason that Gold's contrast is too bad on a white background). So if anyone is irked by the inconsistency, blame it on him.

But yeah, by not drawing nearly as many additional routes, I did have an advantage in being able to use more colors.

1 (orange): Oak Grove - Millennium Park

• OLX thru West Roxbury
• Infills at River's Edge and Edgeworth

I think you meant to have River's Edge and Edgeworth as between Wellington and Malden Center, right? The current map has it between Assembly and Wellington, where there's nothing but Mystic River.

 

[Riverside]

For the record, I initially used Gold for Huntington-Seaport and Magenta for Nubian, but @Riverside convinced me to do the Gold/Magenta swap (for the same reason that Gold's contrast is too bad on a white background). So if anyone is irked by the inconsistency, blame it on him.

But yeah, by not drawing nearly as many additional routes, I did have an advantage in being able to use more colors.

Yeah, that was another thing that was interesting about this whole exercise — whether a color is a right choice for a line definitely is impacted by how large/prominent that line is. For me, small changes in my Gold Line seemed way more noticeable than I expected. And I was surprised at the difference swapping the Gold and Magenta made in yours.

I think you meant to have River's Edge and Edgeworth as between Wellington and Malden Center, right? The current map has it between Assembly and Wellington, where there's nothing but Mystic River.

Womp womp. We’ll just say that the infilling was very aggressive

 

[TheRatmeister]

A few different things incoming here...

First: I redesigned my redesign of the MBTA system diagram from earlier this year. Two versions included at the link, but the "latest and greatest" (which I may have already posted upthread in here, not sure if it was this specific one though) is:

View attachment 45845

Excellent work! The dark background works quite well. I think we have our differences on a general "Vision" (More spider-webby light rail focused vs more concentrated heavy rail) that have been discussed and debated plenty, so I won't focus on that, I'll just touch on the general design:

• I think this map does a good job balancing geographical accuracy with showing accurate service patterns, although I think this goes out the window a little bit the further east you go. I keeping the geographically accurate style might require enlarging the map and shrinking the size of some elements.
• Transfers: The solid black lines for subway transfers work quite well, but I think the smaller dots for buses and especially the way the CR is handled are somewhat lacking. North Station in particular feels quite unclear, and the dots at major bus transfer points like Longwood or Nubian end up too bunched and scrambled to make sense.
• Should the box describing which key bus routes have better than 15 minute service exist? Having good service is what makes a key bus route a key bus route with the BNRD, it feels somewhat redundant.
• Should walking connections be specifically highlighted? On a map focused much more on geographic accuracy than the current map it again feels quite redundant
• On geographic accuracy: I think you've maybe swung a little too far in that direction with the GL branches at the expense of transfers that are made much more commonly along the RL and FL. Showing the connections between the buses at Nubian and the FL/RL would likely be much more useful, and almost certainly better utilized, than connections like Riverway-Brookline Village. Maybe it's better to make some parts less accurate?
• Not having the CR lines continue to the end of the map feels like a mistake to me. At Readville for example it's impossible to tell what CR line(s?) you can actually transfer to.
• If the Fairmount Line is receiving the same treatment as the rapid transit lines on this map I think it deserves a new color. The merge at South Station with the CR lines merging into the FL is somewhat confusing. However, if this is a map of the current situation I think it should be treated like the other CR lines, given the... shall we say, somewhat lackluster service.
• Only having the Amtrak label and transfer points, not on the map itself, make it harder to find for someone not familiar with the system.
• I think the truncated bus routes with arrows are overused. I like them for routes like the 57 or 77 where they just head off into the abyss, but for routes like the 16 or 39 where Forest Hills is right there, it's just needless complexity and text on the map.

And now the real nit-picks

• I really think the rounded of the termini on the current map is better than the square ends, especially with the more rounded look of the current map generally. I think they work better the spider-man inspired version.
• The arrow at Chinatown on the SL isn't mentioned in the legend
• The Hingham/Hull ferries are shown, but not labeled.
• "BrooklineVillage"
• The buses, especially the Logan shuttle, would be easier to see if they had a white buffer around them as they crossed rapid transit lines.
• No line for the 32?

But I don't mean to over criticize, I really like the emphesis on geographic accuracy, it's a different way of doing things that I think can make a truly excellent map if it's fully committed to.

 

[Teban54]

• Should the box describing which key bus routes have better than 15 minute service exist? Having good service is what makes a key bus route a key bus route with the BNRD, it feels somewhat redundant.

The distinction is that BNRD's Frequent Bus Routes (those that start with T) only require 15 mins all day, but @Riverside's textbox lists a subset of them that achieve even better 10-min frequencies during daytime (which I assume include midday). This excludes some of the more borderline (or more peak-oriented) T routes: T7, T8, T9, T12, T15, T16, T22, T31, T39, T47, T71, T73, T77, T96, T101, T104, T109 and T110, some of which are surprising.

(It also omits corridors that give 15-min frequencies by combining two routes: 35/36, 220/222, and 442/455. On a separate note, I feel that any future maps should pay more attention to these corridors, whose only difference from something like T32 is that they split at the end.)

@Riverside, is there a source for your list of 10-min routes? I don't recall the BNRD proposals giving specific schedules.

• On geographic accuracy: I think you've maybe swung a little too far in that direction with the GL branches at the expense of transfers that are made much more commonly along the RL and FL. Showing the connections between the buses at Nubian and the FL/RL would likely be much more useful, and almost certainly better utilized, than connections like Riverway-Brookline Village. Maybe it's better to make some parts less accurate?

I think this question has more to do with the massive geographical distance to the south between OL, Fairmount and RL, and the massive number of Frequent Bus Routes that run there (which itself highlights needs for better transit). The only way to map out all the bus routes with any hope for clarity is likely to expand the "geographically accurate" zone significantly, possibly all the way to Ashmont and Mattapan.

An argument can be made about compressing the Green Line branches and making them not geographically accurate, but the limiting dimension on this map is north-south and not east-west.

 

[TheRatmeister]

@Riverside, is there a source for your list of 10-min routes? I don't recall the BNRD proposals giving specific schedules.

I'd imagine there's a better place to get this information, but if you click on the routes on this map you'll get the frequencies for different parts of the day and on weekends.

 

[Teban54]

I'd imagine there's a better place to get this information, but if you click on the routes on this map you'll get the frequencies for different parts of the day and on weekends.

Thanks for pointing this out. I noticed the headway info when viewing the Remix map in the past, but wasn't (and still am not) sure if they're intended to be accurate. Too many routes had a very similar schedule of 25 min during peak and 50 min midday, so I didn't know if they were placeholders. But looking at the data again, yes, it seems quite plausible to be the source of data that @Riverside used.

 

[Riverside]

@TheRatmeister, agree with most of the points you raise. The concept I was trying to explore with this diagram was to have an inner section with geographic accuracy and visual bus lines, and an outer section that would be more diagrammatic, less geographically accurate, and would mark bus transfers and CR transfers. That idea worked... to a certain extent. I was hoping to create a subtle but distinct visual boundary between those zones, but it didn't turn out to be distinct enough to be obvious why the bus routes (and CR lines) peter out randomly.

But to your point about showing connections to the Fairmount Line and Red Line, that's what these flags are intended to show:

I experimented with drawing the bus lines all the way to the outer Fairmount and Red Lines, but found that it ran into the same problems I have with the current official diagram:

^ I don't feel that there is enough visual structure when it's diagrammatic to this extent.

If I make a new version from scratch, I'd experiment with keeping geographic fidelity down through more of Dorchester, but I think at that point the map will be 70% geographically accurate, so...

The distinction is that BNRD's Frequent Bus Routes (those that start with T) only require 15 mins all day, but @Riverside's textbox lists a subset of them that achieve even better 10-min frequencies during daytime (which I assume include midday). This excludes some of the more borderline (or more peak-oriented) T routes: T7, T8, T9, T12, T15, T16, T22, T31, T39, T47, T71, T73, T77, T96, T101, T104, T109 and T110, some of which are surprising.

(It also omits corridors that give 15-min frequencies by combining two routes: 35/36, 220/222, and 442/455. On a separate note, I feel that any future maps should pay more attention to these corridors, whose only difference from something like T32 is that they split at the end.)

@Riverside, is there a source for your list of 10-min routes? I don't recall the BNRD proposals giving specific schedules.

That is a correct interpretation. Those 8 routes are planned (and mostly currently have today) at very high frequencies even during off-peak. 15-min freqs are amazing, but are slightly outside of turn-up-and-go, while these routes remain squarely in that territory for most of the day. That seemed worth highlighting to me.

But... I'm guessing the BNRD didn't highlight this specific list because they didn't want to create two "tiers" of the 15-min network and invite questions as to why some neighborhoods got the "higher" vs "lower" tier.

I'd imagine there's a better place to get this information, but if you click on the routes on this map you'll get the frequencies for different parts of the day and on weekends.

If there's a better place, I've never found it. This was how I constructed my list.

I noticed the headway info when viewing the Remix map in the past, but wasn't (and still am not) sure if they're intended to be accurate. Too many routes had a very similar schedule of 25 min during peak and 50 min midday, so I didn't know if they were placeholders.

I think they represent some level of accuracy (or at least are intended to). If you look at the Commuter Rail frequencies, they are very specific in a way that makes me think they are drawn directly from real schedules. So my speculation would be that they did indeed come up with tentative schedules and fed those into Remix. (They would have needed to come up with at least some estimated schedules, in order to figure out how many new drivers they'd need, etc.)

But yes -- the one (very small) downside of how they are achieving these higher frequencies is that it won't be clock-facing. I think we can live with that, though.

 

[BosMaineiac]

These maps are all beautiful! I really appreciate the use of a new style of maps. I think that will certainly be the way to go soon as, the way I look at it, the current map is kinda maxed out.

I know these maps were intended to really show off the green line reconfiguration proposals, which I think is a great idea, but I did notice a few HRT extensions, or lack thereof, as well. The three included the most obvious ones (OLX South, Lynn, Arlington, and some form of BL west of Charles/MGH), but I also thought it would be a good chance to imagine some northerly HRT extensions. A map with BL Salem (which @ratmeister did include), OL Reading, and RL Lexington/128 would be nice to see on these masterpieces!

 

[HenryAlan]

3 & 4 (red): Arlington - Mattapan & Arlington - Braintree

I like that you label the Red Line as two distinct lines. It's consistent with how most other systems deal with branching. I've always felt that the MBTA undercounts the extent of its services by pretending there are just four.

 

[Riverside]

I like that you label the Red Line as two distinct lines. It's consistent with how most other systems deal with branching. I've always felt that the MBTA undercounts the extent of its services by pretending there are just four.

Thanks! It’s definitely not an original idea of mine — I think davem or omaja did it on their maps way back in the day.

 

[Riverside]

These maps are all beautiful! I really appreciate the use of a new style of maps. I think that will certainly be the way to go soon as, the way I look at it, the current map is kinda maxed out.

I know these maps were intended to really show off the green line reconfiguration proposals, which I think is a great idea, but I did notice a few HRT extensions, or lack thereof, as well. The three included the most obvious ones (OLX South, Lynn, Arlington, and some form of BL west of Charles/MGH), but I also thought it would be a good chance to imagine some northerly HRT extensions. A map with BL Salem (which @ratmeister did include), OL Reading, and RL Lexington/128 would be nice to see on these masterpieces!

Thank you for your kind words! Very much appreciated.

Yes, the absence of northerly HRT extensions was an intentional choice -- even if tonally a fantasy map, the diagram is still intended to be a (semi) serious proposal with a focus on feasibility.

To the specific points:

BLX to Salem: discussed elsewhere, I think BLX to Lynn is rock solid, and I think it gets progressively fuzzier the further north you go. My preference is to focus on BLX to Lynn and high-frequency regional rail to Salem.

OLX to Reading: I really go back and forth on this; @F-Line to Dudley and I had an exchange on this upthread; his argument was that Regional Rail maxes out once NSRL is built, but is likely sufficient until then, and I tend to agree; it feels like a lot of political capital to spend which I would prefer to focus on other projects. (F-Line, you mentioned pair-matching problems post-NSRL with Reading -- why not pair-match it with Fairmount? To your point, both routes could handle those frequencies and they're similar lengths which keeps things balanced.)

RLX to Lexington/beyond: I struggle with this one. RLX to Arlington Center is short and has density and demand, but, like BLX beyond Lynn, I think this one gets fuzzier the further north you go. In particular, unlike BLX, OLX, or the South Shore extension, or either Orange Line relocation, there is no railroad here. The tracks have been gone for over 30 years. Building an at-grade heavy rail line seems like a big swing, and a subway seems impossible to justify that far out

Ironically enough, though, given that this map is nominally focused on Green Line Reconfiguration: I am much more optimistic about the prospect of a light rail line along the Minuteman. It would be an easy extension from Porter, and capacity should be very manageable even with a couple other northern branches. Light rail also gives you more flexibility if you ever make it all the way to Burlington -- Burlington Mall Road would be fun to run a light rail line down.

I actually decided to not draw any LRT beyond Porter relatively early on when planning this map, but it was a big question to me: being able to fan out the light rail network to Medford/beyond, Lexington, and Watertown is, to me, a pretty cool benefit of the GLR. But there would be a lot of specifics to work out, and I wanted to focus on other things.

~~~

Now I'm already planning for the "bigger" version of this map. The contest (sensibly) limited us to 30" x 30", but if I'm making a bigger version for fun, I'd probably just expand that. My list of potential additions would probably include:

• Gold Line to Watertown
• Gold Line to Lexington
• LRT line between Woburn, Burlington, and the Minuteman
• LRT shuttle between Millennium Park and Dover, maybe down to Dedham as well
• LRT branch from Blue Hill Ave up Columbia Road to JFK/UMass
• Gold Line extension to Wellesley Lower Falls
• Blue Line to Newton Corner or maybe Watertown

I'd also experiment with some strategy for showing high-frequency regional rail. I tried doing it with this version but was unhappy with the results.

 

[KCasiglio]

Ironically enough, though, given that this map is nominally focused on Green Line Reconfiguration: I am much more optimistic about the prospect of a light rail line along the Minuteman. It would be an easy extension from Porter, and capacity should be very manageable even with a couple other northern branches. Light rail also gives you more flexibility if you ever make it all the way to Burlington -- Burlington Mall Road would be fun to run a light rail line down.

I've had similar thoughts but I thought the arguments against were fairly persuasive. In a more blank slate scenario a light rail extension I think would make more sense and be much more politically palatable.

 

[F-Line to Dudley]

Thank you for your kind words! Very much appreciated.

Yes, the absence of northerly HRT extensions was an intentional choice -- even if tonally a fantasy map, the diagram is still intended to be a (semi) serious proposal with a focus on feasibility.

To the specific points:

BLX to Salem: discussed elsewhere, I think BLX to Lynn is rock solid, and I think it gets progressively fuzzier the further north you go. My preference is to focus on BLX to Lynn and high-frequency regional rail to Salem.

Lynn-Salem's got the second-highest studied ridership of any HRT extension after Wonderland-Lynn. I would agree that BLX-Lynn + Regional Rail is probably a good first gear, but saturation comes very quickly after that. Remember...Salem has a good chance of becoming a breakaway bus hub that can substantially increase the frequency, density, and overall coverage spread of North Shore bus routes. So having the HRT extension probably becomes a desired get if we're envisioning Salem as a Quincy-analogue (if not exactly equal heft) hub.

OLX to Reading: I really go back and forth on this; @F-Line to Dudley and I had an exchange on this upthread; his argument was that Regional Rail maxes out once NSRL is built, but is likely sufficient until then, and I tend to agree; it feels like a lot of political capital to spend which I would prefer to focus on other projects. (F-Line, you mentioned pair-matching problems post-NSRL with Reading -- why not pair-match it with Fairmount? To your point, both routes could handle those frequencies and they're similar lengths which keeps things balanced.)

The problem there is that Fairmount is load-bearing for Franklin/Foxboro Line slots in a Regional Rail universe. Not everything is going to be neatly terminating at Readville or 128; thru slots are a big piece of the pie. So that's where the pair matching becomes exceptionally difficult for Reading. It's too ops-brittle with the single-tracking and grade crossings for anything more than a 128-to-128 shortie, but any southside source main you try to pair it up with is going to be carrying some substantial percentage of longer-haul traffic...including Fairmount.

RLX to Lexington/beyond: I struggle with this one. RLX to Arlington Center is short and has density and demand, but, like BLX beyond Lynn, I think this one gets fuzzier the further north you go. In particular, unlike BLX, OLX, or the South Shore extension, or either Orange Line relocation, there is no railroad here. The tracks have been gone for over 30 years. Building an at-grade heavy rail line seems like a big swing, and a subway seems impossible to justify that far out

Arlington Heights is really needed if you're doing any RLX, because there needs to be an end-of-line storage yard and there's not enough footprint to do an Alewife Yard-clone in the tunnel underneath Arlington Center. So if you're extending at all you're going +2 and a rail-with-trail (easy to do given the ROW width and abutting city parks) for 1.3 miles past Mill St. portal. I've written at length about how it won't be hard at all to accommodate a lusly-landscaped Minuteman with rail restoration to AH. Don't forget as well, Arlington Heights becomes a more substantial bus hub absorbing virtually all of the Alewife-Route 2 frontage roads routes. For transfers it's arguably equal heft to Arlington Center.

Lexington...I agree, lots of problems, no easy solutions. But that AH bus hub helps a lot for triaging from there to 128/Burlington with good rubber-tire frequencies that don't get stuck in too much traffic.

 

[Teban54]

OLX to Reading: I really go back and forth on this; @F-Line to Dudley and I had an exchange on this upthread; his argument was that Regional Rail maxes out once NSRL is built, but is likely sufficient until then, and I tend to agree; it feels like a lot of political capital to spend which I would prefer to focus on other projects. (F-Line, you mentioned pair-matching problems post-NSRL with Reading -- why not pair-match it with Fairmount? To your point, both routes could handle those frequencies and they're similar lengths which keeps things balanced.)

Is the idea to remove the OL third track and give it to Haverhill/Reading regional rail? Because otherwise I can't see the line being able to handle 15-min frequency with that long of a single-tracked stretch, much less Fairmount-level. (And I'd say that if we're doing that, it's probably better to just do OLX to Reading.)

RLX to Lexington/beyond: I struggle with this one. RLX to Arlington Center is short and has density and demand, but, like BLX beyond Lynn, I think this one gets fuzzier the further north you go. In particular, unlike BLX, OLX, or the South Shore extension, or either Orange Line relocation, there is no railroad here. The tracks have been gone for over 30 years. Building an at-grade heavy rail line seems like a big swing, and a subway seems impossible to justify that far out

Ironically enough, though, given that this map is nominally focused on Green Line Reconfiguration: I am much more optimistic about the prospect of a light rail line along the Minuteman. It would be an easy extension from Porter, and capacity should be very manageable even with a couple other northern branches. Light rail also gives you more flexibility if you ever make it all the way to Burlington -- Burlington Mall Road would be fun to run a light rail line down.

Question for you and anyone else that are doubtful of RLX to Lexington: What are the engineering challenges for that? Specifically, why do the same challenges not apply to an LRT branch to Lexington?

I can understand about political challenges of removing Minuteman, and the presumed lack of demand for LRT (though the fact that RL almost got to Lexington in the 1970s makes me doubt the latter point). But if we assume Minuteman can be repurposed for transit, then I don't see much issues. There aren't many grade crossings in the first place, and they look easily eliminatable with open cuts of either the railway or the cross streets.

The contest (sensibly) limited us to 30" x 30",

Reference for anyone attempting to draw such a map in the future: My own map is exactly 30" * 30" (300 dpi), and it's equivalent to OpenStreetMap scale 14. I agree that this size limit is not large enough for a geographically accurate map of the whole region, or even a schematic map with extensions further out.

 

[F-Line to Dudley]

Is the idea to remove the OL third track and give it to Haverhill/Reading regional rail? Because otherwise I can't see the line being able to handle 15-min frequency with that long of a single-tracked stretch, much less Fairmount-level. (And I'd say that if we're doing that, it's probably better to just do OLX to Reading.)

The OL third track buys you very little additional double-track. Assembly-Wellington, and that's it. Past Medford St. (where the ex-freight lead spurring off the currrent passing track ends) to Oak Grove you're still doing a heinously expensive widening project because the third track doesn't exist there. Plus you have to eliminate some of the grade crossings for Regional Rail to work well because there are just too many speed-inhibiting clusters of them. Alon Levy did some napkin math for what the great Malden widening + grade crossing eliminations would cost, and it was substantially more for Regional Rail than OLX. So you're doing OLX in the end because it's the cheaper solution to an intractable problem.

The ridership is buff...buff enough for it to likely be justifiable on its own. But the go/no-go decision gets made in favor of OLX because it's flat-out cheaper than trying to make real NSRL pair-matched Regional Rail work well here.

Question for you and anyone else that are doubtful of RLX to Lexington: What are the engineering challenges for that? Specifically, why do the same challenges not apply to an LRT branch to Lexington?

I can understand about political challenges of removing Minuteman, and the presumed lack of demand for LRT (though the fact that RL almost got to Lexington in the 1970s makes me doubt the latter point). But if we assume Minuteman can be repurposed for transit, then I don't see much issues. There aren't many grade crossings in the first place, and they look easily eliminatable with open cuts of either the railway or the cross streets.

The problem is that in Lexington (unlike Arlington), you can't easily make the trail and rail coexist. To Arlington Heights you have zero issue; the ROW is luxuriously wide and you've got the abutting parkland to off-ROW a well-landscaped trail. In Lexington you've got wetlands embankments in various places and a very snug-fitting ROW downtown that functionally preclude rail-with-trail without great engineering difficulty and/or a sub-Minuteman standard trail interface (think GLX Community Path extension at the tight squeezes). It really makes no difference whether you're looking at HRT or LRT out there; the trail and rail are fundamentally at odds. So going past AH becomes a question of whether people are willing to sacrifice the trail altogether for the rail line. It's very tough to see that happening politically in the foreseeable future.

Therefore I think any extension out here needs to be de-monolithed. You're not getting to 128 in one shot. It's got to be a first phase to Arlington Heights where the trail is a non-controversy, and then a much more fraught second phase if you want to get anything built at all.

 

[RandomWalk]

Deep bore doesn’t mitigate the either/or nature of rail or trail in Lexington?

 

[F-Line to Dudley]

Deep bore doesn’t mitigate the either/or nature of rail or trail in Lexington?

No, it doesn't. Because you can't achieve a real-world buildable cost-per-rider ratio by tunneling through Lexington. The topline ridership doesn't come orders of magnitude close to justifying the extreme cost. It has to be surface in Lexington if there's to be any Lexington rail at all. That's not even Crazy Transit Pitching...tunneling Lexington is purely God Mode.

 

[Riverside]

I've had similar thoughts but I thought the arguments against were fairly persuasive. In a more blank slate scenario a light rail extension I think would make more sense and be much more politically palatable.

Red Line to Arlington Center definitely makes sense. Red to Arlington Heights maybe also makes sense -- F Line makes reasonable arguments from an ops perspective (ah, as I see he just summarized here). Red beyond Arlington does not make sense to me, and seems squarely in the realm of LRT to me.

Lynn-Salem's got the second-highest studied ridership of any HRT extension after Wonderland-Lynn. I would agree that BLX-Lynn + Regional Rail is probably a good first gear, but saturation comes very quickly after that. Remember...Salem has a good chance of becoming a breakaway bus hub that can substantially increase the frequency, density, and overall coverage spread of North Shore bus routes. So having the HRT extension probably becomes a desired get if we're envisioning Salem as a Quincy-analogue (if not exactly equal heft) hub.

Yes, and this points to a fair criticism of this particular fantasy map -- inconsistent timelines. To use your analogy in the linked thread, Lynn and Arlington would both be Phase 1A, with 1B coming later... but arguably I have other extensions on that map that are Phase 2 or even Phase 3. So that's tricky.

The problem there is that Fairmount is load-bearing for Franklin/Foxboro Line slots in a Regional Rail universe. Not everything is going to be neatly terminating at Readville or 128; thru slots are a big piece of the pie. So that's where the pair matching becomes exceptionally difficult for Reading. It's too ops-brittle with the single-tracking and grade crossings for anything more than a 128-to-128 shortie, but any southside source main you try to pair it up with is going to be carrying some substantial percentage of longer-haul traffic...including Fairmount.

Ah yes, fair point.

Arlington Heights is really needed if you're doing any RLX, because there needs to be an end-of-line storage yard and there's not enough footprint to do an Alewife Yard-clone in the tunnel underneath Arlington Center. So if you're extending at all you're going +2 and a rail-with-trail (easy to do given the ROW width and abutting city parks) for 1.3 miles past Mill St. portal. I've written at length about how it won't be hard at all to accommodate a lusly-landscaped Minuteman with rail restoration to AH. Don't forget as well, Arlington Heights becomes a more substantial bus hub absorbing virtually all of the Alewife-Route 2 frontage roads routes. For transfers it's arguably equal heft to Arlington Center.

Lexington...I agree, lots of problems, no easy solutions. But that AH bus hub helps a lot for triaging from there to 128/Burlington with good rubber-tire frequencies that don't get stuck in too much traffic.

Yeah I think we're largely in agreement about Arlington.

Question for you and anyone else that are doubtful of RLX to Lexington: What are the engineering challenges for that? Specifically, why do the same challenges not apply to an LRT branch to Lexington?

I can understand about political challenges of removing Minuteman, and the presumed lack of demand for LRT (though the fact that RL almost got to Lexington in the 1970s makes me doubt the latter point). But if we assume Minuteman can be repurposed for transit, then I don't see much issues. There aren't many grade crossings in the first place, and they look easily eliminatable with open cuts of either the railway or the cross streets.

You know, you're right, there definitely are fewer grade crossings than I'd thought. In addition to F-Line's points about the trail, the other reason would be the ability to have smaller station footprints -- shorter platforms, and potentially with grade pedestrian crossings. Again, maybe I'm underestimating how much ridership there would be, but HRT just seems like overkill.

Idk. This much greenspace just seems at odds with heavy rail:

(Compared to Arlington, below)

 

[RandomWalk]

No, it doesn't. Because you can't achieve a real-world buildable cost-per-rider ratio by tunneling through Lexington. The topline ridership doesn't come orders of magnitude close to justifying the extreme cost. It has to be surface in Lexington if there's to be any Lexington rail at all. That's not even Crazy Transit Pitching...tunneling Lexington is purely God Mode.

That makes sense. However, it still is frustrating because RLX to 128 could go a long way toward unbefuggling Alewife.

 

[Teban54]

Idk. This much greenspace just seems at odds with heavy rail:

View attachment 45872

(Compared to Arlington, below)

View attachment 45873

FWIW, I think this much green space means that in a very very speculative far-future world with proper zoning, a transit extension to Lexington has higher potential for TOD than Arlington. (I know, I know.)

Regardless, I think this discussion from both yourself and F-Line illustrated that engineering feasibility is definitely not a distinguishing factor between HRT and LRT for Lexington - political feasibility and ridership are. In other words, there's no world in which LRT to Lexington is feasible but HRT using the exact same design is not.