Coda: commuter-rail modeling and what’s next

Just about a year ago, I went to Worldcon 75 in Helsinki. Because Worldcon 76 in San Jose (which I’m not attending) is about to start, I was reminded that I still have a whole bunch more photos from Helsinki that I’ve never finished editing, and the research that I’ve done in the last few weeks has definitely given me a bit more to say about them (and Helsinki’s brownfields redevelopment and transit construction costs), so I’m going to try to push a final set of Helsinki posts out over the next few days, if I can get a few hours clear for photo editing. (I say “final” because I have no plans to go back, but if someone’s willing to subsidize my travel I would happily return next summer.)

Beyond that, I wanted to wind up my discussion of Regional Rail and the future of the commuter rail service between Worcester and Boston. In addition to the analysis in the previous two posts, I did a lot of modeling of service patterns that I haven’t shared, because they were not sufficiently interesting, or at least sufficiently different from what I’ve already presented. In some cases these models had insurmountable technical problems, mostly due to the lack of storage space in the right places, and in other cases in order to make the model work I had to assume an impractically short turnaround time. (Impractical under current FRA regulations and railroad operating practices, at any rate — railroads elsewhere in the world don’t seem to have a problem turning trains at rapid-transit-like frequencies.) In a few cases it’s not storage space but platform length that is the biggest issue, like the four-trains-per-hour service pattern that requires trains longer than the current MBTA construction standard. Here are a few of my major take-aways:

  • The F/W Line is incredibly busy for a small number of AM peak runs and fairly easy to service at whatever headway you choose the rest of the time. I based my simulations on the 2012 CTPS riderahip audit, and there’s every reason to think that actual ridership (despite the well-publicized problems of 2015–2017) has increased since then.
  • The lack of sufficient storage capacity in Worcester is a serious limitation on any service. In the Regional Rail model, additional storage capacity would be needed elsewhere at least for middays and probably at night.
  • I believe that additional storage should be at Framingham, not Allston or Southampton. The reason it should be there is a simple one: equipment positioning from those other places has no transportation value, even if for some reason you made it “revenue”; scheduled early-morning and late-evening runs from/to Framingham would have substantial transportation value, and there are multiple existing yards at Framingham that either have room or could be expanded (or the freight railroad could be incented to consolidate operations).
  • Extending passenger service via the Agricultural Branch to Framingham State University and Framingham Technology Park would have actual transportation value, but the costs and RoW limitations are such that it is unlikely to happen without capital support from MWRTA, the City of Framingham, FSU and/or the Tech Park tenants (especially Bose and Sanofi, the largest employers). Such a service might be operated as the tail end of Framingham-terminating Regional Rail trains, in which case there’s room in the Tech Park to construct a layover yard, or it might simply be a diesel shuttle from South Framingham that met each train at the existing station. (Either option would require substantial station construction, as there are no historic stations along this four-mile segment of the line.)
  • None of the schedules I came up with can work with fewer than twenty-four 75 m (250-foot), 232-seat articulated EMUs; most of the usable ones require 26 or 27 (plus one more for a Tech Park shuttle, if you want to build that). That’s an equipment cost of about $216 million, in addition to the capital construction (which I’ll detail below).
  • These schedules and car requirements would get substantially easier with a longer trainset. The MBTA’s standard platform length of 800 feet puts a substantial limitation on the number of passengers you can accommodate with a fully accessible, level-boarding, single-level design. Plus there are issues with platform length at Yawkey that I know about and possibly other stations. (And I have assumed that the storage facilities, which the T reports in “consists”, reflect this maximum length and not the actual lengths of trains being stored for the schedule current when the “State of Commuter Rail” report was written.) For 800-foot platforms, with three-trainset consists you’re limited to 80 m trainsets, which depending on the layout could get you another 20 seats, but if you’re willing to accept a maximum of two-trainset consists, you could go as long as 120 m — and then you have a different problem, because then you either have to manage two different EMU equipment types, or waste a lot of energy hauling around a 350-passenger train on the majority of runs that have fewer than 150 passengers. I’d probably spring for the 80 m length if there are no other constraints, just to have the capacity.
  • Another option is to forget about running articulated EMUs and just do New York-style EMUs, which are the same length as regular passenger coaches. Depending on clearances, you might be able to run bilevel cars under wire, although this is probably a bad idea because of steps and fewer doors leading to slow boarding and alighting and taking away the dwell-time advantage of modern articulated EMU designs.
  • My demand model is surprisingly sensitive to the exact timing of the new schedule being simulated, relative to the arrival times of the high-demand trains. There are three things going on here: first, the demand model considers only the arrival time to be important, not the departure time. Many commuters may have a deadline to arrive, hence the high demand trains, but also have nothing in particular to do with the time they would gain from a faster schedule, and so would choose a departure time closer to their current one rather than the latest train that gets in before their deadline. Second, there is no feedback in this model: in the real world, passengers’ expectations of comfort and reliability have an impact on what services they choose, and I don’t know, for example, what fraction of passengers would shift to an earlier or later train in order to be sure of getting a seat on, say, the half-hour trip from West Natick to South Station. Third, the demand model simplistically assumes that the passengers’ desired arrival times are uniformly distributed over the interval between trains (actually slightly offset by a few minutes to attempt to account for satisficing). To get a better demand model would require Actual Survey Research, which I’d be very interested in but am not prepared to fund out of my own pocket — I assume that CTPS has such a model already, and groups like TransitMatters should be regularly surveying commuters in order to justify their policy proposals to Beacon Hill.
  • In particular, one of the scenarios I simulated for multiple schedules was short-turning trains at Framingham. This always makes the loading much worse, but exactly how much depends to a surprisingly great degree on the order of Framingham and Worcester trains, because so much of the model depends so specifically on the exact timing of the few arrivals provided by the 2012 schedule. Even in 2012 the MBTA was operating a local/express pattern during peak periods; this service pattern isn’t compatible with clockface headways because the time gained by the express over a local causes an express to catch up to the previous local. If you’re limited for other reasons to 15-minute headways (four trains per hour), then the local/express pattern could potentially work, but I haven’t simulated any expresses because I think 4 tph is a pretty weak-sauce service on this line, and there’s no practical place to turn a supplementary short-turn train short of Framingham without fouling the line. However, during middays there does not appear to be enough demand to run all trains to Worcester — even at Framingham the current schedule actually has a huge gap that makes it impractical for me personally — so you’d probably want to short-turn at least half of your trains at Framingham (another reason to put the layover facility there and not in Allston).

What is to be done?

So supposing we (the people of Massachusetts) decided that we really wanted to have a modern, reliable, frequent rail service between Boston and Worcester. What would we need to pay for to make this happen?

  • Expansion of Amtrak’s Sharon substation, which powers both the Northeast Corridor and the “Boston terminal district”. The substation was built with the expectation that it might eventually be expanded for commuter service, and because the terminal district is chained off the NEC that additional power will be needed for electrifying the F/W Line. (For other reasons, of course, the capacity at Sharon should be maxed out — you also want to serve Stoughton/Providence and Fairmount trains, and probably at least part of Franklin.) I don’t know how much this costs, but you can search the web for informed estimates and the original Amtrak NEC electrification plans.) This also gives you sufficient capacity for electrification through Newton and Brighton.
  • Construct a new substation in MetroWest. Exactly where depends on the location of sufficient high-voltage distribution capacity.
  • Correct superelevation on the line to allow for increased speed limits. There’s a machine that does this without excavation or rail replacement.
  • Replace obsolete signaling and switch machines. A lot of this is already programmed as a part of the existing state-of-good-repair program and will serve equally well for Regional Rail.
  • Construct full high platforms for both tracks at all stations outside Boston. An upgrade for Natick Center (which is the busiest station on the whole system to not have any accessibility) to a high-level island platform is in process.
  • Obviously, construct the actual electrification infrastructure. In order to maintain freight clearances under the wires, it may be necessary to depress the tracks or alter some overpasses in some locations. (Beacon Street, Boston, is a noted clearance issue: it would be fine for single-level cars but is too low for bi-levels, and so long as there are bi-levels anywhere on the south side system, the MBTA needs to be able to move them under that overpass to get to the Commuter Rail Maintenance Facility on the north side.)
  • Currently, Worcester Union Station is limited to a single platform on the Main Line. (The other platforms at the station serve other railroads that do not currently have any passenger service, although a private operator had proposed to run Worcester-Providence service from one of them.) Currently this is under study with no firm funding or construction date, but in order to support reasonable schedules at Worcester with sufficient recovery and turnaround time for the train crews, this is a firm requirement.
  • Most importantly, the MBTA has to decide to do it. There are several related planning processes doing on right at the moment: the “Focus 40” plan is the T’s long-term plan, and in order for anything worthwhile to be done before we’re all dead or retired it has to get prioritized in that plan. There is also a “commuter rail vision” process, about which there doesn’t seem to be much public information, and the people responsible for that will have to be pushed very hard to make a plan that’s actually forward-looking and not repeating the same defeatist, stuck-in-the-past thinking (which the MBTA is exceedingly good at). And there is a procurement process starting to ramp up now for the new private contractor to actually operate the MBTA Commuter Rail.
  • Finally, we have to have a governor who actually uses transit and is responsive to the needs and aspirations of the communities in the MBTA district — who are responsible for the vast majority of the Commonwealth’s jobs and tax revenue.
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More modeling for the Framingham/Worcester Line

In our last installment, I talked about how I wasted an entire weekend developing a not-very-good model of a way to make the commuter-rail line that serves my city suck less. Well, it’s been another nasty rainy weekend here in Framingham, so I spent even more time (also some nights) trying to make my model sufficiently less not-very-good to be able to simulate more interesting variations than the uniform-headway, 100%-local service that I initally implemented, to see whether they were any better (or any cheaper to operate). This was not especially easy, because I don’t actually know R, but a lot more of the work was done entirely by hand. I’m sure actual railroads have good equipment planning and scheduling software, that they probably either developed in-house or gave huge piles of money to a consulting firm for. I on the other hand have the Mk. 1 human brain, which for a problem of this size is more adept at implementing backtracking search internally than it is at writing that down as code. I’m going to describe my process, and while all of the code and data, and most of the results, are available in my GitHub repo, I’m taking the liberty of simplifying out a number of wrong turns and dead ends, and reordering some things for a more understandable presentation.

Code restructuring

As I presented it last week, the simulator consists of two pieces: a demand model, which predicts how many passengers will board a particular train (given the arrival time of that train and the next train at the final destination), and a supply model, which was just a fixed bit of one-off code that generates the particular schedule I was interested in looking at. This is clearly not a good way to do it, because it means that constants scattered throughout the code, many of which are arithmetically related, all have to be changed in unison in order to change either model. I started out by moving the demand model into a separate function, so that the supply model did not need to have any knowledge of the parameters to the demand model — it becomes a higher-order function that accepts the demand model as a parameter. I ended up completely restructuring the demand model anyway, in order to implement some of the features described in the next section, and also because there were a bunch of bugs that I found when I started simulating trips that don’t stop at every station.

The way the old supply model worked was that it took a fixed schedule, and for each train, it iterated over the stations, invoking the demand model for a random sample of passengers’ desired arrival times, and just counted up the total passenger loading — the actual supply part was done by me visually inspecting the loading across all trains to identify impossible loads. This was totally inside out: the correct way is to compute the entire demand vector at each station, and then divide it up among the trains on the schedule, and the way I had done it was exceedingly slow, even by R standards. The way I had done it before was also statistically bogus, because fetching a new demand vector for every arrival at each station means that some passengers (due to random chance) can be either counted multiple times, or missed entirely. In the new code, all of this is parameterized using higher-order functions, and every run writes to disk not only the model output, but also the predicted number of trainsets required (given a seat count) and the actual station-by-station, train-by-train schedule that was used in the computation (which can be inspected if the model seems to have done something strange).

All of this is wrapped up in a nest of new functions which make actual simulator invocations much simpler — for a uniform, all-local-train service like the ones I looked at last weekend, a single line of R code does all the work and tells the simulator where to save its results:

doit("4tph-local.csv", function () make.local.service(360, 720, 4))

(Yes, I am a bit unimaginative with my function names, so sue me.)

Adding a bit more statistical sophistication

If you read last week’s post, you’ll recall that the demand model I used was a very simple one: assume that the demand for travel from a station to the terminal reflects a set of desired arrival times that are uniformly distributed over the period between “this” train and the next. This is obviously unsophisticated, but not obviously stupid. I wanted to do a little better, without putting a lot of work into learning statistical demand models for transportation, so I added two bits of “fuzz” to the demand model. First, I assume that some people on a train would actually rather be arriving a little bit earlier than the scheduled arrival, and that anyone who really wanted to arrive just a little before the next train would suck it up and take the later train — “a little bit” I defined arbitrarily as 5 minutes, which is much smaller than the interval between any of the arrivals in the 2012 CTPS study. (The minimum headway in the 2012 schedule was 12 minutes.) I also figured that there would be some day-to-day variability in ridership, and again entirely arbitrarily I chose to multiply the CTPS passenger count by a normally distributed random variable (μ=1, σ=0.05) — I suspect this effect is overwhelmed by the uniform distribution of arrivals but I left it in without doing any serious examination.

The other big problem with my original model is that it just took a single run of the model as gospel, rather than looking at the behavior of the system across multiple samples. I fixed that by the good old-fashioned Monte Carlo method: the simulator now runs the model 250 times, and computes the 90th percentile over all of the simulated loadings to come up with a more confident guess of how many seats are needed. (It can also compute the median, or indeed any quantile you happen to like, although this isn’t parameterized — I chose 0.9 because that corresponds to my intuition that an operator probably wants enough seats on the train to consistently seat the maximum load at least 90% of the time.) Given those 90% loadings it’s easy enough to divide by the number of seats in an EMU trainset and round up to get the required number of trainsets. As before, I used the JKOY Class Sm5 trainset from Helsinki, which seats at least 232, and which is part of a family of EMUs (the Stadler FLIRT) that is available for sale in the US.

Results of running the updated model

Having made the model at least look more sound, on Friday night I reran the simple schedules I first simulated last weekend, starting with the simplest, four-trains-per-hour all-local service from Worcester. I got a bit of a nasty surprise: although my initial runs on the old model suggested that you could run 4 tph service with nothing longer than a three-trainset consist, the new model predicts one train (the one that would arrive at 8:45) to require four trainsets — and even three-trainset consists are a problem, for reasons I’ll explain shortly. But four-trainset consists are just impossible on the Framingham/Worcester Line, because the MBTA standard platform length is 800 feet and four trainsets are just under 1000 feet long. That said, the 90% loading is only 45 passengers over the 696-seat capacity of a triple, so maybe the cost savings (if there are any) might justify tolerating more crush loads on that train. It’s possible that such a situation would naturally sort itself out, if enough passengers chose to switch to an earlier or later train, but I’m uncomfortable starting out — without accounting for increases in ridership since 2012 — on the basis of a predictably over-capacity train. So I went on look at other service patterns, first the uniform 5-tph and 6-tph ones that I had examined before, and then some other more complicated service patterns once I had implemented the ability to do that (and fixed the bugs in the model that doing so exposed).

Disappointingly, both the 5-tph (12-minute headways) and the 6-tph (10-minute headways) all-local services require three-trainset consists. The 5-tph service has three triples, and a manual inspection of the loadings made me think it really needs five triples, which is a lot — more, in fact, than the 4-tph service. The problem with these three-trainset consists is that there isn’t room to store them at Worcester overnight, where they’re actually needed to provide the service, so you end up wasting a lot of equipment-hours on what are essentially deadheads (there’s just not that much demand for pre-rush-hour seats to Worcester) and when once they get in to Boston you either have to send them back out or you have to store them somewhere. Also, one trainset in a triple can’t platform at Yawkey, because trainsets are 250 feet long and the platform there is only 650 feet, and rush hour is specifically a time when all-door deboarding is necessary to maintain short dwell times. The 6-tph service requires only one triple, which is still more than my first whack at it last weekend suggested. There is just a huge amount of travel demand to get into Back Bay or South Station before 9 AM.

Next, I started looking at short-turn service patterns, where every other inbound train starts at Framingham rather than Worcester (and likewise every other outbound train stops there). This sort of service pattern uses less equipment, in theory, than the all-local service pattern does, but it has the disadvantage that the outer stations receive half as much service during peak periods — which then doubles the ridership on the outer trains. When I simulated the 6-tph service with this model, I found that it was even worse than the all-local service, because the Worcester trains were leaving Framingham already full, and still had to pick up more passengers on the way. (Why not run expresses, like the current service? That would even out the load, but the Regional Rail service is sufficiently faster that a train that runs express from West Natick will catch up with and get stuck behind the previous local train — and of course the inner stations then lose the benefit of the investment in equipment and infrastructure that supports 6-tph operation, because half the trains don’t stop in Wellesley or Newton. That’s likely to be a big loser on Beacon Hill. Hypothetical expresses might as well stop at Boston Landing because the train they’re stuck behind is going to anyway!)

Finally, I investigated other service patterns that would break up the rush-hour demand, and also included reduced frequencies at other times (such as midday) when there is less need for seats. The one I came up with that I like the most is what I call “rush-hour push”: it starts out with 6 trains per hour, then increases frequency to 7.5 trains per hour (eight-minute headways) right around the peak of morning rush, from 8:40 to 9:20, and then drops down to 3 tph after 10 AM. (I chose 8:40 to 9:20 intentionally since those endpoints are divisible by 10.) This knocks the predicted trainset requirement down to two at the peak (in fact, it moves the heaviest-load point earlier, to 8:10). Remarkably, this schedule requires only one more trainset than the 26 I came up with under the old model for 10-minute headways. The lower frequencies during the late morning and early afternoon can be easily sustained without a lot of extra crew expense, but of course it comes at a cost of having to store those trainsets somewhere, which is one of the most limited resources in the current commuter rail system.


So let’s talk about train storage. There are several places currently used to store trains for the Framingham/Worcester Line (or that could plausibly be so used): Worcester has space for four consists of the current equipment (which I’ve arbitrarily called 3200 linear feet, which should be enough for 12 trainsets of modern EMUs). The rest of the space (in the current service, something like eight consists are required) comes from Amtrak’s Southampton St. yard, which is in South Bay not far from South Station, or in the MBTA’s Readville yard, which is in Hyde Park, 30 minutes away. Last weekend, I looked only at existing facilities, but as I was developing the equipment requirements for this “rush-hour push” service, I found myself thinking, “What about Framingham?” There are three railyards in Framingham: one off the Agricultural Branch west of Franklin Street, one off the Main Line south of Fountain St., and one at the end of what’s left of the old Milford Branch, where it once served GM’s Framingham Assembly plant. Surely some space could be found in one of those — Fountain Street by preference, because it’s right on the Main Line and west of the Framingham station so no reversing is required. Furthermore, having early-morning revenue service from Framingham to South Station has actual transit value, unlike deadheads from Readville or Southampton St., because there are a lot of people who have reason to want to get to South Station between 5 and 6 AM. (Business travelers looking to catch an early Amtrak or a 6:30 flight out of Logan, airport employees, service workers in convenience stores and fast-food places that need to be ready for service by 7 AM, the list goes on….)

So having considered that maybe it might be possible for the MBTA to either rent or construct space at CSX’s Fountain Street yard sufficient for both overnight and midday storage, I reworked the equipment plan some more, and I ended up with a service that adds five early-morning trips from Framingham and requires only two trainsets to be stored at Southampton Street. It does require 1000 feet of space near Worcester Union Station, which may not be available or constructible, in which case those trains would have to deadhead somewhere else (perhaps Grafton or Westborough if not all the way back to Framingham), but all of the remaining midday storage ends up at Framingham rather than in Boston — and because headways are reduced during those same hours, there are plenty of gaps in the schedule for freight moves west of Framingham. Although I haven’t modeled the PM peak at all, those trainsets stored at Framingham would be in the right place to resume 6-tph service in the afternoon, since the reverse-commute demand from Worcester wouldn’t justify ten-minute headways at the time when the equipment would be needed at South Station. Hopefully, this also reduces the number of split shifts for train crews, although I haven’t attempted to model that. (Doing the equipment was hard enough, and of course when you’re running a train every ten minutes, crews can just hop on the next train at whichever station.)

An equipment plan and the fully worked schedule for the AM inbound direction can be found in the spreadsheet in my repository (PDF of the latest version). I also did an equipment plan for a version of the 4-tph service that accepts a crush load on one train inbound, which requires no “storage” at Worcester but does require some place a couple of three-trainset consists can go to clear the platform for the better part of an hour and a quarter; I don’t like it. Someone else could probably come up with a better schedule that doesn’t have that defect; the only advantage of running 4 tph is that it reduces the equipment requirement from 27 trainsets down to 24 — and that’s about $24 million so it’s not peanuts.

So what about that Agricultural Branch, eh?

If we’re going to be storing trains in Framingham at midday, maybe Fountain St. isn’t actually the best place to put them. There are actually three branch lines from Framingham that might serve potentially useful destinations: the Agricultural Branch, part of CSX’s Fitchburg Subdivision (although it doesn’t go all the way to Fitchburg any more), which runs north from the wye at Framingham station; the Milford Branch, which runs south, parallel to Route 126, towards South Ashland and Holliston; and the Framingham Secondary, which runs south through Sherborn and eventually connects to the Franklin Line. The Milford Branch is abandoned south of the yard west of ADESA (the old GM plant, now an auto-auction facility), and in Ashland and Holliston it has now been converted to a trail. The Framingham Secondary is now CSX’s primary freight route to Southeastern Massachusetts, and while the section through Foxborough has a commuter rail station, there is no great travel demand between Framingham and the other towns along the route that would justify even building a station, never mind electrification and double-tracking. So that then leaves the Ag Branch, and that one is very promising indeed. The Ag Branch runs from the Franklin Street yard in downtown Framingham north past the old town incinerator to Framingham State University (three FSU parking lots directly abut the line), and then runs north of Route 9, crosses Baiting Brook, and follows the Turnpike to Framingham Technology Park.

The office park is home to the Sheraton Framingham Hotel and Conference Center, the corporate headquarters of Bose, and a large Sanofi-Genzyme facility, among other important destinations; the corporate headquarters of Staples is not far, on the other side of Route 9, and the park is served by MWRTA buses from Natick and Marlborough. There are oceans of parking, suggesting that most employees at these companies currently drive to work. There are abandoned (and mostly lifted) sidings parallel to the line in the park, suggesting that there is enough right-of-way for two 2000-foot tail tracks (west of the California Ave. grade crossing) and an island platform station with a stub-end track for a shuttle. There are numerous low-rise buildings nearby, including Bose and Nestle Waters distribution facilities, which could be relocated if train service made office development in the park more economically attractive. Finally, the whole complex is just off the Massachusetts Turnpike, an ideal location to intercept commuters who might be coming from the towns north of Route 9 such as Southborough (the Southborough station is at the very southern end of the town and not freeway accessible), Marlborough, and Hudson. I would even suggest not building public parking at a station here: let the landowners decide for themselves whether that’s the best use of their land. Ultimately, from the perspective of this exercise, you could just build the layover facility and not bother with an actual station. But once you’ve built a station, upgraded the tracks, installed switches and signals, and extended electrification (oh by the way, there’s already a substation just south of the tracks), you might as well spring the extra $8 million for a single EMU trainset that can operate a shuttle service during non-pull-in/pull-out periods. The four-mile ride from downtown Framingham to Tech Park would take about eight minutes, a significant improvement on current MWRTA bus service and competitive with driving if the shuttle is timed appropriately to meet through trains at Framingham station.

So what are the issues for implementation? Obviously, the track is in very bad shape, and would need to be improved to at least 39-mph service. (The one freight train a day appears to run at 5 mph; I used to watch it from my old dentist’s office abutting the tracks at the Route 9 grade crossing.) There are remnants of dual-tracking between Mount Wayte and Maple St. that may need to be reinstated, and bridges to replace or renovate. Electrification is obviously required in order to get the EMUs from Framingham station to Tech Park, and you’ll want a side-platform station at either Maple Street (most constructible) or Salem End Road (best location) to serve Framingham State University. A new side platform will also have to be built on the Framingham yard wye, which is complicated by the fact that the wye infield is now used for station parking; probably the CSX westbound leg of the wye will need to be relocated in order to make enough room for the platform. The total cost of this project might be $25-$35 million. Worth it? I’m not sure. Fountain St. would definitely be cheaper, even with takings and construction costs. But it’s worth studying — and it might be worth it to the employers that would be served, if it helps them attract talent.

Thanks for putting up with my transportation rants. We’ll be back to your normally scheduled baking some day soon.

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In which I waste an entire weekend modeling one line of Regional Rail in AM peak

A draft of the MBTA’s “Focus 40” long-term plan was release on July 30, and I spent a little while reading it (it’s rather thin) and sending comments (both officially and on Twitter). If you’ve been reading this blog lately, you’ll know that I’m a strong supporter of Regional Rail, an initiative from the local advocacy group TransitMatters, and of course part of my comments concerned necessary investments in rail infrastructure:

One of the concerns about Regional Rail is how you replicate the existing peak capacity with electric multiple unit trainsets, given that current diesel-hauled commuter rail has quite long trains and bilevel commuter coaches. The Framingham/Worcester Line currently has peak loads of 1600 passengers, which is way more than a single-level, easy-boarding EMU can hold, but of course you can couple trains together, if the trains and platforms are long enough. The number of seats you can deliver on a Regional Rail line is ultimately determined by two factors: platform length and service pattern. The service pattern is profoundly influenced by storage capacity, since you’re not going to be able (or want) to run peak service all throughout the day. So I asked some people who would know what the current shortest high platform on the MBTA Commuter Rail system is — figuring that, if they built high platforms in the first place, there was probably a constructibility constraint that kept any one station from being as long as the rest. That would then influence my idea of how long a consist of EMU trainsets you could operate in peak service, which would then allow me to search for service patterns that would be able to meet that need.

I learned a few things: first, that the MBTA’s standard high-platform length is 800 feet (as compared to Amtrak’s 1050 feet). Second, that the shortest full-high platform in the system is 400 feet at Malden Center and at Oak Grove — these platforms were originally built for Orange Line service, and when the Orange Line extension to Reading was cancelled, they remained in use as commuter rail platforms. Finally, and more relevant for my particular inquiry, Yawkey Station has high platforms that are less than 650 feet long. Since the MBTA decided to have regular trains stop at Yawkey (it previously only served baseball games) it has become a popular stop, with bus transfers to Longwood and Cambridge, and the Green Line nearby in Kenmore Square; more than 400 people get off there during a typical weekday morning (and not all trains stop at Yawkey). That suggests that a Framingham-Worcester service requiring more than about 650 feet of platform is going to run into operational issues (either the trailing trainset[s] won’t be able to platform, or you’ll have to add short turns or local/express patterns to meet the demand in a shorter train). On a two-track main line like the Framingham-Worcester Line, expresses cause scheduling problems, because there are no passing tracks, but short-turns are OK so long as there’s a yard or siding where the train can reverse without fouling the main line — and this becomes more and more important as frequencies get higher.

In order to think about service patterns, I first had to come up with some reliable passenger counts for the existing commuter rail service. Unfortunately, that is quite tricky: the most recent data available was collected by CTPS in the winter of 2012, which predates, among other things, the opening of the popular new Boston Landing station, and the new super-express trains connecting Worcester (and making quite a mess of the schedule for everyone else). There are a lot of reasons to think that Regional Rail would not need any express services, at least on the Framingham-Worcester line, because it is already so much faster. Based on modeling done by Alon Levy in a study of the North-South Rail Link, with proper high-level platforms at all stations, electrification, and full electric multiple-unit trains — the Regional Rail program in a nutshell — a Boston-Worcester train would take only 61 minutes while making all local stops, including several new or restored infill stops that currently have no service at all (also part of the Regional Rail program). By contrast, the current inbound local trains, like P512, are scheduled to take 94 minutes from Worcester to Boston, the regular express takes 80 minutes, and the superexpress takes 66 minutes — so even a local Regional Rail train would beat the fastest current express train (while serving many more passengers).

For the rest of this post, I’m going to be using the 2012 CTPS data — but keep in mind that the peak 2012 loading on any Framingham-Worcester Line train was 1200 passengers, and now that number has increased to 1600; you may want to add 30% to all of the numbers below. (That said, one of the other numbers I don’t have is total boardings: it’s possible that the schedule clearing required to make the superexpress happen has simply concentrated existing demand in a smaller time window, because people still have to get to work at 9:00.)

The question then comes to how to model travel demand, given the passenger numbers. I’m no transportation planner, I haven’t studied this, I don’t know how they actually model these things, but I came up with a really simple way to do it. First, we assume that all travel demand is for people from outlying towns to get into the city. To a first approximation, this is true: in the current service, very few people get off at any of the intermediate stops in Newton, Wellesley, or Natick. One of the goals of Regional Rail is to change this, and encourage trips like Wellesley Square to West Newton to be made by rail instead of by car, but for service planning purposes we’ll start by looking at what people are actually doing today. We’ll model Boston as a point destination at South Station, the end of the line, although in reality about half the passengers get off at Back Bay and Yawkey; since all train schedules we will model will stop at all Boston stations (including the as-yet unbuilt West Station) we’ll treat these destinations as a unit. This allows us to consider only net boardings (which are nearly equal to boardings at all out-of-Boston stations) and makes the model especially simple.

So this is what I did: consider every boarding on the 2012 service as an indication of travel demand to arrive before the next train’s scheduled arrival at South Station (because otherwise they would take a later train). To be specific, for every boarding, we sample a uniform distribution of desired arrival times over [this train’s scheduled arrival, next train’s scheduled arrival). This model is clearly too simple: the distribution is probably not uniform (it should probably be something like a truncated exponential), and some passengers would undoubtedly choose to arrive earlier than the train they’re currently taking, but can’t because the next earlier train leaves too early. But at least this model, while simplistic, is not crazy stupid. So I wrote a bunch of really bad R code to take as input the CTPS data (manually rekeyed from the PDF into a spreadsheet which was then exported as a CSV file for R to ingest) and then, for each station, generate a vector of simulated desired arrival times. Then, for any given schedule (or at least, in the simple case I solved, for any schedule of 100% local trains with no crossing freights or other track fouling) we can compute the number of boardings to expect at each station, and thereby the cumulative loading at the Boston city line.

Once you know the cumulative load at each station, you can calculate the number of EMU trainsets required to serve that number of passengers, based on your preferred model of EMU. I used the JKOY class Sm5 EMU, used in Helsinki’s commuter network; it’s a broad-gauge version of the Stadler FLIRT, and in the middle of the size options Stadler offers for this product line. (The Sm5 is 75 meters or about 246 feet long, and carriers 232 fixed seats and 28 folding seats including wheelchair bays; I’m rounding up to 250 feet and 250 passengers since any Boston EMU will not be this exact configuration. The diesel FLIRT being constructed for TEXRail is 266 feet long but with a much higher seating density, rated capacity 488 passengers; with the same seating layout you could probably get the same capacity in a 250-foot EMU, but with slower boarding and less convenience for passengers with wheeled bags or mobility aids.) Given these numbers, you could carry 700 passengers in comfort on a three-trainset Sm5-equivalent, or over 900 passengers in less comfort on a two-trainset TEXRail-type train. I started doing this modeling before I found the capacity numbers for TEXRail’s FLIRT3 DMUs, so all of the rest of this analysis is based on the Sm5’s capacity. (That said, if you use my analysis but buy Fort Worth’s seating layout, then you’ve effectively accounted for a more than 50% increase in ridership over the 2012 numbers. My bias, however, would be towards boarding doors and bike/wheelchair/stroller space.)

Now finally to get to the point. I modeled three different scenarios, all with 100% local trains serving all stops between Worcester and Boston, with four, five, and six trains per hour. The 4-tph service pattern requires a minimum of five trains with 3 trainsets (peak loadings 541–643 passengers); the 5-tph service pattern requires a minimum of two 3-trainset trains (peak loadings 515 and 541), but for operational reasons you’d probably run five triples on that service as well. That causes a problem, because overnight storage at Worcester is limited to four 800-foot consists, so you end up having to make up three-trainset consists in Boston and send them out empty before the morning rush to be turned around in Worcester and used to make inbound peak service. The extra peak-load trainsets being used in non-peak (or worse, non-revenue) service significantly reduce the equipment utilization compared to a service pattern that uses no more than a two-trainset consist. For what it’s worth, the Helsinki service that the Sm5 was specified for uses to more than that — but they have sufficient passing tracks to run multiple express patterns in addition to their regular 2-tph local service. For my 6-tph scenario, with 30 trains arriving between 6 and 11 AM, the peak load is 464 passengers, for the 9:00 scheduled arrival, which makes sense — there’s another peak (450) that probably reflects people starting work at 8:30.

Having concluded that 6 tph was the best all-local, all-stops schedule, I went on to actually figure out the equipment and storage required to make this service operate. I assume a minimum 15-minute turnaround times (works out to 19 minutes at South Station), which requires at least two platform tracks (possibly you can make it work with as few as that, but the equipment plan does entail making and breaking consists on the platform, in addition to reversing direction, which means doing additional checks before boarding outbound passengers. Overall, the service requires 26 trainsets, of which 12 can be stored overnight in Worcester (more would be better) and 14 in Boston (at Southampton or Readville). At midday, 10 trainsets would be stored in Boston and 1 on the platform at Worcester, with the remaining 15 either in service or being turned at one of the terminals. (Note that the capacity at Worcester is for four 800-foot consists, and likewise 8 consists at Southampton and 12 consists at Readville. Three 250-foot trainsets of EMUs — or indeed three 266-foot trainsets of Fort Worth DMUs — will fit in 800 feet; whether the slack can be used for anything depends on the layout of the yard tracks being used for storage.)

If you look at the simulated boardings, there are no trains that leave Framingham with more than 270 passengers (one trainset’s worth). This suggests a different service pattern, which I haven’t written the code to model but which I suspect makes a lot of sense: instead of running 6 tph all the way from Worcester, run 3 tph from Worcester interspersed with 3 tph from Framingham. Then, you can store trainsets at one of the three Framingham yards (which would have to be wired to make this work), or even implement my idea to upgrade the Agricultural Branch as far as Crossing Blvd. and build a station there with a tail track to store Framingham-terminating trains. I think if you do this, you actually save a substantial number of trainsets (maybe as many as six), but of course the outer towns don’t get as much service in that scenario, which will cause higher loading on the interior segments of those runs. You’ll also notice that there are three early-morning runs in my schedule that have no boardings shown; there’s every reason to believe that people would use these early-morning trains, but 6:30 was the earliest arrival in the 2012 schedule that CTPS audited, so my model doesn’t predict any demand before then.

The crux of my argument to MassDOT and the MBTA is that, with looming procurement projects to replace the ancient and outdated commuter rail rolling stock, it makes sense to commit to building high platforms everywhere now, so that we can then purchase exclusively high-floor multiple-unit rolling stock like the FLIRT3 (which is assembled in Utah and thus eligible for “Buy America”-restricted funding) — specifically with the goal of acquiring a modular system that uses the same components for both electric and diesel-powered trainsets. We wouldn’t get the full benefits of electrification right away — for one thing, the prime mover in the diesel FLIRT only outputs half the power an EMU can draw from the overhead wire, so it accelerates much more slowly — but we would be ready to switch over as quickly as lines can be electrified, starting with the Providence Line which already is electrified aside from a few terminal and yard tracks. We should say “yes, we are going to do this, and we are not going to blow billions of dollars on obsolete unmotorized passenger cars and diesel locomotives.”

Code and data

All of the code and data used for this model is available in my commuter_rail_simulation repository on GitHub. A printable PDF version of a spreadsheet with the results is available at in the repo as well (direct download).

The contents of the spreadsheet are as follows:

  1. The predicted schedule of a local train leaving Worcester, based on Alon Levy’s modeling but with most of Alon’s infill stations zeroed out. Note that he adds a 7% pad to the scheduled arrival time at each station, which adds up to just over four minutes pad in the arrival time at South Station.
  2. Simulated passenger loading, 4 tph
  3. Simulated passenger loading, 5 tph
  4. Simulated passenger loading, 6 tph; I’ve added columns with terminal departure and arrival times as well as the number of trainsets required for peak loading on each run
  5. An actual equipment schedule for the 6 tph service, based on the simulation
  6. Predicted schedule of an express train leaving Worcester, again based on Alon’s numbers but with the stations the current P504 skips zeroed out; note that it gains 9 minutes over the local, which would cause problems for 6-tph operations.
  7. Predicted schedule of a superexpress train leaving Worcester, adding stops at Framingham and Boston Landing over the current P552 schedule; it gains 15 minutes over the local, which would cause problems for any of the scenarios modeled, and is not worth emulating or even modeling, given that the local under Regional Rail is faster at any time of day than this twice-daily express is today
  8. CTPS passenger loads, from the 2012 study, for Framingham/Worcester trains departing in the morning
  9. Net passenger boarding, from the same study
Posted in Transportation | Tagged | 1 Comment

Long time no bake

Earlier this year, I committed to myself that I would not repeat a recipe that I had previously done, as a way of getting out of what felt like a rut. But since then, I have baked almost nothing, and indeed I haven’t done much complicated cooking either. Part of that is because my dishwasher has been malfunctioning since the winter, and I’ve been lazy about getting it fixed or replaced, but a bigger part of it has been that I’ve been quite frankly getting rather fat. Nothing discourages the creation of tasty baked goods quite like stepping on the scale and being unable to comprehend why the number is so much higher than it was three months (or worse, three years) ago. That said, I do have one new baking experience to share, although I have less to say about it than I usually do.

Expecting bad weather all this week, I decided to make a whole-wheat sandwich bread. I had printed out a recipe by Andrew Janjigian from Cook’s Illustrated‘s March/April 2011 issue (on the web, $); the same recipe was also featured on America’s Test Kitchen TV S12E13, “Soup and Bread from Scratch”. (I’m not sure why I printed this recipe out, since I own every issue of the magazine going back to 2006, but it was handy to have as a reminder — otherwise I would probably have just gotten my usual supermarket whole-wheat bread.)

It was an interesting experience, to say the least. The recipe requires three separate wheat ingredients: bread flour, whole-wheat flour, and wheat germ, and dirties a rather large number of bowls: the bread flour is used to make a traditional pre-ferment, but the whole-wheat flour and wheat germ are combined with milk, kneaded, and allowed to soak overnight — then the whole mass is combined together the following day with large quantities of butter, yeast, and salt to form a very wet, sticky dough, which must be kneaded by machine, proofed, kneaded some more, proofed some more, divided in half, shaped (while still extremely sticky), bench proofed, and finally baked off in a steam-filled oven on top of a baking stone. The online version of the recipe text did not even hint at how wet and sticky the dough would be, although I suspect the television version (which I would have seen in 2012) would have done so. I ended up adding about an extra half-cup of flour just to make the dough manageable — fresh out of the first mixing stage it was practically a batter. With all that fat (there’s also some veg oil), flour, and sugar (honey) it makes a very soft and very high-calorie bread, probably better suited to French toast than the sort of sandwiches I can afford to eat when the weather doesn’t allow for bike commuting. I also found it difficult to divide the dough evenly — should have used my scale! — so I ended up with one loaf pan overflowing and one rather undersized after the bench proof.

Overall? It’s good enough, but just comparing the amount of work required to proof, handle, shape, and clean up after this recipe, it’s not enough better than my own whole-wheat bread recipe to justify the extra effort. (On the other hand, the wheat germ is perishable so I may end up making it again a few times, cutting it in half to reduce the bowl-cleaning effort.) And because this bread is so soft, portion control (without a commercial slicing machine) is a complete nightmare. For this reason I’m not providing nutrition information.

Posted in Food | Tagged , ,

Recipe quick takes: sandwich bread and slow-roasted pork chops

In accordance with my pledge from earlier this year, I made two new recipes recently, a whole-wheat sandwich bread I printed out ages ago from King Arthur Flour, and the “deviled” pork chops from next month’s issue of Cook’s Illustrated.

First the bread. The recipe is entitled “Organic Whole Wheat Sandwich Bread” is one of a number I printed out several years ago (copyright 2007!) when I was developing my own whole-wheat sandwich bread. It’s no longer available on their Web site, so far as I can tell, and my printout doesn’t have a URL I can look up in the Wayback Machine, but the the formula is very similar to one titled “A Smaller 100% Whole Wheat Pain de Mie”, but not baked in a lidded loaf pan, and with more fat. So far as I know, I had never done this recipe before, and it has some good and bad points. On the good side, it’s very soft; the added fat, milk powder, and potato starch all combine to ensure that. On the bad side, it’s very soft, and tears easily when slicing or attempting to spread peanut butter or jam. It’s also quite high-calorie: two thin (½ in or 12 mm) slices add up to 275 kcal (minus a little bit for whatever carbs the yeast ate), compared with similar-sized commercial whole-wheat breads which tip the scale at 220 kcal. On the positive side, with all that carbohydrate it toasts very well, and would probably make a good whole-wheat pain perdu or Texas toast. I probably wouldn’t make it again.

The second is the pork chops. This comes from the “May & June 2018” issue of Cook’s Illustrated (pp. 10–11) and I think it’s the first thing I’ve made from the magazine since Christopher Kimball’s partners fired him as editor-in-chief. I actually didn’t make the magazine version, but rather “Deviled Pork Chops for Two”, an online-only extra based on the four-serving magazine recipe. This was quite simple to do, as it merely involves toasting some panko in melted butter, making a flavorful seasoning paste, and using the latter to glue the former to some pork chops. I found while doing this that I had mistakenly defrosted a pair of strip steaks rather than pork loin chops I thought I had, but luckily, my quarterly meat delivery had brought me some pork sirloin chops that I could speed-defrost in the microwave, and this recipe calls for the sort of low-and-slow cooking that pork sirloin requires. (Unlike the loin, pork “sirloin” is composed of a few different muscles, and does not respond well to fast, high-heat cooking methods like sautéeing.) The recipe is simple enough that I did not bother to enter it as a “recipe” in my nutrition app; I just recorded the pork, mustard, panko, and butter (the four highest-calorie ingredients) individually. Recommended.

Posted in Food | Tagged , , , ,

Post-vacation status update

Last year around this time I went to the World Figure Skating Championships in Helsinki and generated a whole bunch of posts about it. I went to Worlds again this year, in Milan, and bookended that trip with train travel in Switzerland. This time, I was accompanied by my parents (who, now both retired and with the big house sold, have more freedom to travel) — which worked out reasonably well, but meant that I wasn’t burning the candle at both ends and couldn’t slam through the photo editing to get some blog posts out during the actual competition. (In all honesty I would rather have been accompanied by one person, for the whole length of the trip, but since that person has yet to be identified, the ‘rents will do, and having someone else worry about the arrangements in Italy made the whole trip a bit less stressful.) The arena in Milan was somewhat inconveniently located relative to our lodging, a short-term private rental apartment, and my impression overall is that Helsinki 2017 was far better organized in addition to being more conveniently located and having better transit access. I finally got back home late on Tuesday evening, and I’ve been spending the last few days digging out from the accumulated backlog resulting from a 13-day vacation. (The folks being retired, they got together with my mother’s older sister and her husband, and are spending an extra week in Italy.)

The practical upshot of this is that I still have about 6,000 photos to edit down somehow into something more like 250, and this process will take a while — starting with working through my shooting logs and hopefully correctly identifying all the skaters this time — but over the month of April you should see photos appearing both here and at Wikimedia Commons where appropriate. Anyone interested in accompanying me to other international sporting events is welcome to apply. ;-)

PS: I’m already planning on not going to the 2019 Worlds in Saitama, but 2020 will be in Montreal, which is well within driving distance for me. Last year I also went to Worldcon, again in Helsinki, but this year’s Worldcon is in San Jose and I’m inclined to skip it as well. (Worldcon 2019 will be in Dublin and Diane Duane is GoH and I’ve already bought a full membership; 2020 isn’t decided yet but will likely be in New Zealand.) Other sporting events I’m considering, besides the usual baseball and hockey arenas, are the IBSF World Cup stop in Lake Placid, maybe some ISU Grand Prix skating events, and perhaps the 2020 Winter Youth Olympic Games in Lausanne — all of this is very speculative right now and might not come to anything.

Posted in Administrivia, sports, travel | Tagged ,

My comments on passenger rail infrastructure to MassDOT

The comment period for the State Rail Plan ends on Friday, the advocacy group TransitMatters just released their report on Regional Rail, and MassDOT is currently in the process of two separate planning exercises related to the MBTA and the commuter rail system in particular, in preparation for the next tender for the commuter rail operations contract (currently held by the French firm Keolis). Yesterday evening I sent in my own comments, inspired by the State Rail Plan deadline, but most of what I had to say was outside the State Rail Plan’s scope, so I also sent it to the people responsible for the MBTA planning process. Here’s what I said, edited slightly for formatting.

I was originally going to send this in regard to the State Rail Plan, since the public comment window was recently extended, but on closer review it seems that most of my comments are more usefully directed at the MBTA-specific planning process, since I live in the MBTA district. However, my points 1 and 2 below are intended to reference all passenger rail corridors in the state, not just the MBTA service area, and in particular the Commonwealth should explore opportunities for cooperation with neighboring states and with Amtrak to investigate the application of these principles to the Connecticut River Line and to future Boston-Springfield intercity passenger service.

Unexpectedly, much of what I have to say has been preempted by the release of a report by the advocacy group TransitMatters, which you will have seen already (for the record, “Regional Rail for Metropolitan Boston“, is the report to which I refer). However, I will make some additional comments on subjects that are not addressed in the TransitMatters report.

I have lived in Framingham for 17 years, and for that entire time, I have commuted in a single-occupancy vehicle on the Massachusetts Turnpike to my job in Cambridge. I would prefer to have an alternative that does not involve driving, but the current MBTA commuter rail service is infrequent, slow, unreliable, and more expensive per marginal trip than my commute. During the summer months I will bicycle to work (on approximately 40 good-weather weekdays between May and September); a better commuter rail service with real provision for bicycle users (not limited to off-peak hours) would substantially increase the number of days a bike commute is practical by enabling bike+train round trips.

To put more precise numbers on it, I pay (employer-subsidized) $10 a day to park in Cambridge, and my shoulder-hours SOV commute (10:25 AM and 7:15 PM) takes approximately 35 minutes parking space to parking space. The current MBTA Framingham/Worcester Line service has a long gap in service after 9:30 AM that makes it impractical for my schedule, but even if I shifted my schedule earlier to take train #512 inbound, the actual time cost of the MBTA service (with the necessity of driving to the Framingham station, finding and paying for parking, the train ride to Boston, the transfer penalty, the subway or bus trip to Cambridge, and then walking to my office) would be well more than double my current car commute. (My bicycle commute, 20.8 miles via two different routes, takes approximately 85 minutes, or about as long as the current commuter rail service, at an average speed of 15 mph — but with much greater health benefits.)

I would be willing to consider commuter rail — indeed, I would strongly prefer it — but for the excessive travel time (which is of course compounded by the system’s current widely reported unreliability). A reliable travel time of not more than 70±10 minutes would be easily within consideration, and with properly optimized schedules and full construction of West Station would make it highly attractive for many commuters from the Metro-West area who currently drive to jobs in Cambridge or Boston. I have heard anecdotally that the Commonwealth currently considers demand for access from Metro-West to jobs in Cambridge negligible to the point of not being worth studying, and I would strongly encourage the planning staff to consider this commuting pattern more seriously, as rising housing costs have made living closer to work impractical for many people who would prefer a transit option.

In the spring of 2017, I took a vacation in Helsinki, Finland, where I had occasion to use the rail system there extensively. The rail network around Helsinki, like Boston, is based on a stub-end terminal station (they only have one, unlike Boston’s two, and it’s correspondingly larger in terms of footprint than is possible in congested downtown Boston). However, Helsinki’s regional transport administration, HSL, has implemented an urban and inter-suburban rail network in the “regional rail” style described by the TransitMatters report, with full fare integration and high frequencies, connecting Helsinki Central Station with both historic suburban and exurban downtowns and new neighborhoods of transit-oriented development. HSL also maintains fare integration with intercity passenger rail services that serve nearby metropolitan areas outside the HSL district, so riders within the region can take a suburban train or an unreserved regional train, whichever is more convenient — this should be a model for intercity passenger service in Massachusetts along corridors such as Boston-Worcester-Springfield, which might be operated by a different agency or contractor than the MBTA.

Metropolitan Helsinki has about a third the population of the Boston MSA and is also slightly less dense; it has only one heavy rail subway line, and for surface transit has only street-running tramways, ferries, and private-tender bus services. The population of the whole of Finland is about that of the Boston MSA and is smaller than the Boston-Providence CSA, and Finland has quite high levels of suburban development and car ownership relative to other European countries. Yet Helsinki sustains substantial investment and substantial ridership in its fast, frequent, reliable, and affordable commuter rail system. I wrote a series of blog posts about it when I returned from my trip, which you can refer to here (fares and network structure) and here (suburban rail). Note that the services described in both of those articles have been realigned and in a few cases significantly expanded since I wrote those posts last April.

My specific recommendations, which are generally in accord with those in the TransitMatters report:

  1. The Commonwealth should adopt as a matter of policy a preference for electrification and high-level platforms on all rail routes currently served or contemplated to be served by passenger trains. In some cases this may require additional state investment to maintain compatibility with freight services.
  2. All projects and studies inconsistent with point (1) should be terminated.
  3. In the Boston region, a priority should be placed on electrification of the South Side commuter rail, improving operating costs, schedule reliability, and environmental justice. As funding becomes available, investment should shift to the North Side lines, which will require more infrastructure to be constructed.
  4. Where possible, labor agreements should be sought that limit excess staffing in exchange for acceleration and simultaneous construction of projects along multiple lines, maximizing useful employment of skilled trades.
  5. As TransitMatters notes, the electrification of the Providence Line is nearly complete and should proceed forthwith, as should electrification of the Stoughton and Fairmount Lines, with the existing diesel locomotives and rolling stock shifted to reduce maintenance pressures on other lines.
  6. Although the North-South Rail Link would significantly improve regional connectivity and the overall utility of the rail network, construction of NSRL is by no means a prerequisite to implementing electrification, high-level platforms, and frequent all-day schedules, and these should proceed at the highest priority, given the current capital expenditures which would otherwise be required even to preserve the existing diesel infrastructure, whether or not a funding mechanism for NSRL can be identified.
  7. The Commonwealth should in particular be prepared to self-fund the entire acquisition cost of electric-multiple-unit trainsets in order to buy global best-of-class equipment at competitive market prices, unless the federal government commits to waiving Buy American provisions. Federal capital funding, if available, could still be pursued for track, platform, station accessibility, overhead wire, and substation construction.
  8. Full build of West Station and development of connecting routes to Cambridge (whether bus, light rail, or a shuttle via the Grand Junction branch) and Longwood Medical Area should be accelerated relative to current plans.
  9. With respect to Framingham in particular, in order to support high frequency service between Framingham and Boston it will probably be necessary to have some trains turn or lay over at Framingham. The Commonwealth should study, in conjunction with the City of Framingham and MWRTA, the potential benefits of exending trains along the Agricultural Branch to Framingham State University and possibly to the office-industrial park area at Route 9 and Crossing Blvd. where there is already a park-and-ride lot and numerous employers that could be served by a reverse-commute service.

You can see more related content in this blog’s category “Transportation” (links below or to the right depending on your screen layout).

Posted in Transportation | Tagged , | 1 Comment

What’s Wrong with Metcalfe’s Law?

In a recent Medium post derived from a talk he gave at private invitation-only event for the IT industry, Dan Hon presents one view of Metcalfe’s Law, the theory espoused by Ethernet inventor Bob Metcalfe that “the value of a telecommunications system increases as the square of the number of participants”. Hon looks at the (no pun intended) value judgment embedded in talking about the “value” of a network, and considers purely market-oriented measures lacking.

I’d like to step back a bit and look at it from a different angle. Instead of “value”, let’s consider “utility”: what benefit arises to the users from their use of the network? Metcalfe’s claim can be restated simply: the global utility (sum over all users) of a network is quadratic in the number of users. You don’t even need graph theory to prove that this is trivially true, if you accept what I take to be Metcalfe’s presuppositions: first, that utility sums linearly over all users (a view which would be understandable to Jeremy Bentham), and second, that each user’s utility is linear in the number of other users on the network.

The real problem with Metcalfe’s Law, as I see it, is precisely in this second presupposition. While it is true to a first approximation, for small networks, once the network reaches a sufficient penetration of that community with which any individual user has an interest in communicating, the marginal utility of additional communications partners diminishes quite rapidly, and ultimately goes negative. We see this even with old technologies like the telephone network: nearly all of the value I get from the telephone derives from being able to communicate with family, friends, and current and potential employers, vendors, and service providers in my immediate vicinity. While connecting a billion people in India or China to the rest of the world is laudable, there cannot be more than a thousand of them that make the telephone network more valuable to me. (One thing that this analysis does not consider, and a more sophisticated analysis would, is economies of scale: do those billions of users actually make it easier or cheaper to provide me with the service that I value. To be left for another day.)

In the social network case, it’s clear how additional users can have negative marginal utility: the additional noise generated can drown out the intended communication (whether that noise is trolls, pile-ons, or just way too many well-meaning people making the same comment in a reply). Twitter is a great demonstration of this; users bearing the vaunted “blue checkmark” — a distinction given out entirely at Twitter’s discretion to a small subset of users, mostly celebrities, journalists, government officials, and corporate marketing departments — are given a variety of tools to screen out communications from the masses. One of the tools which is frequently employed by these “verified” users screens out all notifications from the remaining users, allowing them to give the appearance of using the platform to communicate with others while in actuality paying attention only to a small number of similarly privileged people. This screening was not part of the original Twitter service: it was only deployed after Twitter gained a sufficiently large and noisy user community that it was driving away users Twitter actually had a business reason to want to retain. Of course, even “old tech” had to come up with similar mechanisms: when telephone calls became cheap enough that scammers were willing to spam a thousand people at dinnertime in the hope of finding a single mark, caller ID became a necessity and more and more people began to screen their calls. (Compare also the Eternal September.)

In conclusion: Metcalfe’s Law is wrong because the marginal utility to the existing users of a communications network is not constant: while it is large and positive for small networks, as networks grow beyond the scale of normal human social circles, the utility drops off quite rapidly, and eventually goes negative. When you sum up this function over all users, unlike the linear utility posited by Metcalfe, overall value does not scale as the square of the number of users. (It might not even be asymptotically linear — I leave that analysis to someone with better mathematical chops.)

Posted in Computing, Law & Society | Tagged

Clarifying one particular gender conversation

This post has been percolating in my head since the Worldcon 75 in Helsinki last August. My initial idea was quite a bit more ambitious — I have a note here which reads “Gender: cause or effect?” — but what was going to be the introductory section is probably the only part of it that I have something reasonable to write about.

Gender was, not surprisingly, an important thread in the conversation at Worldcon 75. There was even a panel (which I didn’t manage to attend) talking about how you deal with it in languages that don’t “have” gender, like Finnish, Turkish, and Chinese. But that made me want to write a little bit to try to clarify this discussion, because I think the words we use to talk about this particular aspect often make things more confusing rather than less. So this post is going to explore two questions: What do we mean when we say “gender” in the context of language, and what does it mean to say that a language “has” or “doesn’t have” it?

I should point out that I am coming at this from the perspective of an interested amateur, not a professional linguist by any means — but an amateur who has at least had the experience of trying to learn both French and Finnish. So don’t take any of what follows as gospel, but rather, a jumping-off point for further research if you’re interested in that sort of thing.

So what is “gender”, anyway? In linguistics, “gender” is a specialized form of what is more generally called “noun classification” — it’s just a historic fact that some languages (most but not all of them) divide their nouns up into categories. We generally reserve the term “gender” to refer specifically to those noun-classification systems that align more or less with the binary (masculine-feminine) or ternary (masculine-feminine-neuter) systems seen in Indo-European and Semitic languages (like English, Greek, and Hebrew), as opposed to those with a larger number of categories like the Bantu languages of Africa. It’s important to distinguish gender as a grammatical category from gender as a semantic category: because the “gender binary” is a near-universal part of human experience, all languages have words with semantic gender, words like “man”, “woman”, “father”, “daughter”, and so on (although not all languages have the same set — French distinguishes between male and female cousins, for example, whereas English does not). But even in languages with very strong grammatical gender, it’s by no means given that this will align with the semantic gender — as witness German, where many words that are semantically female (or at least feminine) are grammatically neuter or sometimes even masculine. (Historical linguists tell us that this is because the Indo-European three-gender system had collapsed to two genders before Germanic languages re-developed the modern neuter.)

So what then does it mean to say that a language “has” or “doesn’t have” grammatical gender (or indeed noun classification)? Grammar, roughly speaking, is how words fit together to form phrases and other multi-word structures, and also about how words refer to other words in context. For gender to be part of a language’s grammar, it must have some observable consequence on which words, or word forms, are allowed together in a sentence, or can be used to refer to the same thing. The most relevant property to look at is what English teachers usually call “agreement”, and linguists often call “concord”: the property that words that refer to the same thing must all come from the same class or be otherwise marked in the same way. English makes these considerations much less clear, because English has only the fractured remnants of its historic three-gender system, observable only in pronoun agreement, and not universally even then. But the Romance languages — those descended from Latin, like French, Spanish, and Romanian — all have a robust two-gender system (masculine and feminine) with mandatory concord for pronouns, determiners, adjectives, and participles. Semitic languages go one better: verbs agree in gender with their subjects. Unlike in English, Romance languages have gendered third-person plural pronouns: a group of portes (doors) in French are elles, but a group of stylos (pens), or indeed a group of mixed-gender objects, are ils.

Because of how English historically developed, acquiring pronouns from Old Norse and losing most of its inflectional system as England was invaded alternately from the north and from the south, we have no gender agreement for adjectives or articles any more (except, for a very few writers and the editors of The New Yorker, a very small set of adjectives borrowed from French: naïf/naïve, blond/blonde, brunet/brunette being the principal ones). English does continue to have two forms of gender concord for pronouns: the third-person singular he/she/it, which do not precisely correspond with the historic genders used in Old English or West Germanic, and a simple sentient/non-sentient system seen in the interrogative pronouns who/what and the relative pronouns who/which. (I don’t include “singular they” here because it acts grammatically identical to the third-person plural in all other respects — compare the much earlier “singular you”, which also takes a plural verb form.)

So what about those putative “genderless” languages? The only one that I have any direct knowledge of is Finnish, but I understand that all of the Uralic languages are the same in the most important way: there is no gender concord for adjectives or participles. These languages have no articles, so there is nothing to agree with there. But with pronouns it gets a bit more interesting. Finnish arguably has a two-gender system for personal pronouns: the sentient hän (singular)/he (plural), and the non-sentient se/ne. But (and it’s a big “but”), in regular spoken conversational Finnish (as opposed to newscaster or teach-to-confused-foreign-teenagers Finnish) these two categories are collapsed — to the “non-sentient” se/ne. I never learned the language well enough to express complex structures, but I suspect that there may be similar behavior in some of the relative pronouns. Away from Finnish, I know that there are languages that don’t have pronouns at all, but I don’t know how that set intersects with other means of marking gender or noun classification.

Another interesting part of this conversation here, albeit one that I’m not all that well prepared to discuss, is the question of languages with mandatory gender marking for names. As English users, we are accustomed to the idea that a personal name is just an arbitrary user-chosen token, and might at least in theory refer to any gender. Indeed, numerous names are gender-neutral or have, in living memory, actually changed their default gender. (“Robin” is perhaps the poster child here: previously a diminutive form of “Robert”, today most Robins are female and not a diminutive for anything.) That said, we are still familiar with gender-marked names, whether it’s “Alexander”/”Alexandra” (sharing the gender-neutral hypocoristics “Alex” and “Sandy”!) or “Robert”/”Roberta”. Numerous other pairs of names exist in the repertoire used by English speakers to name their children and their fictional characters. Some other cultures take this to an extreme, however: most or all names in Slavic languages, for example, are gender-marked — both given and family names, not to mention patronymics. Similarly, the patro/matronymics used in Icelandic names have mandatory gender marking, because (as with the Slavic patronymics) they contain an element that means either “son” or “daughter”, regardless of whether they use the father’s or mother’s name as the base.

One of the reasons this specifically came up at Worldcon 75, aside from the panel that I mentioned, is that because Finnish doesn’t have masculine or feminine nouns or pronouns, Finns sometimes have difficulty remembering the correct forms to use when speaking in English or other languages that do make such a distinction. This doesn’t mean that they are confused about the semantic gender of people (they can certainly distinguish miehet and naiset, after all), but rather, that the association of semantic and grammatical gender is weaker when speaking in a second (or third) language when one’s ambient tongue doesn’t make the same distinction. The Worldcon program included a note explaining this and asking attendees to be understanding if their hosts chose the wrong pronoun. (Which is perhaps the best case of all for those badge flags given out at cons indicating the holder’s desired pronoun.) It’s especially an issue for invented or nonce pronouns: it’s probably unreasonable to expect anyone other than the in-group of native speakers who adopted them to actually use or even make sense of them. Those who use such pronouns should take care to check their privilege (as speakers of a global hegemonic language) when dealing with non-native speakers, especially those whose native pronoun system doesn’t correspond to the English one.

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Overdue recipe report: Luisa Weiss’s Christbrot

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This is the third of three recipes I did for the holiday season from Luisa Weiss’s Classic German Baking (Ten Speed Press, 2016). Weiss recounts how she felt that she had to include a recipe for Dresdner Christstollen, the classic … Continue reading

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