Updating my MBTA Commuter Rail modeling for the Worcester Line

On Friday, the MBTA quietly released the results of its 2018 in-person passenger counts. I’ve been waiting for this numbers since I started modeling service on the Framingham/Worcester Line last fall, and apparently everyone else has been waiting for them since late spring. I first learned about the release on Saturday, when I saw a retweet by an advocacy organization of a Friday tweet by Laurel Paget-Seekins of the MBTA’s Office of Performance Management and Innovation, and of course I had to take a look at the numbers and rerun my ridership model. The new figures represent a 40+% increase in F/W ridership over 2012, and include the effects of the “Heart to Hub” morning superexpress and the opening of the very popular Boston Landing station in Brighton.

My model is a kind of static demand model: it simply maps the existing ridership onto a new schedule, without any consideration for whether the attractiveness of the schedule would induce more ridership, or indeed for constraints like connecting bus schedules and parking availability at stations that might limit the willingness of riders to alter their schedules. The Rail Vision program is running a dynamic model that hopes to address some of these issues, and indicate where investments in first-mile facilities are necessary to maximize ridership. But with the new figures, I wanted to rerun the analysis I did last year and figure out what the passenger loading looks like when mapped onto an all-electric system with single-level articulated EMUs.

My preferred schedule from last time around involved running two different service patterns: an all-local short-turn pattern in shoulder, reverse peak, and midday, and a zone-express pattern in peak, with four trains per hour (two Worcester local, two Framingham local) middays and eight trains per hour (four Worcester express and four Framingham local) in morning peak. (I don’t model the PM peak, but it’s more spread out so the morning rush is the stronger scheduling constraint.) I demonstrated that this schedule can be operated with 24 75-meter, 260-passenger articulated EMUs using no more than two EMUs in a consist. With 2018 ridership, even at 8 trains per hour, there are two express trips that absolutely require three EMUs, because we don’t want to have more than 120 standees on the non-stop segment from West Natick to Boston. The problem with running “triples” is that Yawkey station, which discharges about a hundred passengers from every train in AM peak, is substandard and lacks the real estate to platform a 750-foot train. But suppose you resolved that, either by erecting signs at all stations directing Yawkey passengers to the front two cars, or (at considerable expense) lengthening the platform: does that open up any additional scheduling possibilities?

More specifically, does allowing three-EMU consists yield a lower overall equipment requirement if you slightly reduce the service frequency? I constructed a service model that runs only six trains per hour in the morning rather than eight: such a service might conceivably reduce the vehicle requirement. (I did not redo the original equipment schedule for the new ridership numbers, but I’m assuming based on the increased traffic that it will require around 30 EMUs.) The unfortunate result of the simulation is that this doesn’t help: as soon as you reduce frequency in the peak, you start requiring four-EMU consists, which are just plain impossible (they would require 1,000-foot platforms). It’s worth noting that the Rail Vision team are not planning for anything better than four trains per hour, which locks them into either extending platforms for using exclusively bilevel equipment — the former is expensive and the latter is a bad choice for passenger comfort, convenience, and speed of boarding, especially with our 48-inch high-level platforms.

What if, instead of 260 seats per train, you could get 290 seats per train? It seems plausible that an 80-m EMU (about 267 feet) — which is the longest practical single-unit length for the MBTA’s 800-foot platforms — could hold that many (figure 5 m of additional length gives you six rows of 3+2 seating for 30 more seats). So what if you take the same ridership estimates and distribute them over larger EMUs? In that case, the “6/6/4” schedule works out quite well, requiring only 26 EMUs and providing at least 50 open seats on every train to allow for ridership increases — and you still have the option of increasing frequency back to 8 trains per hour, which works given the constraints of the line. (I checked: there aren’t enough additional seats to get you back down to two-EMU consists; there really are that many more passengers.)

Just to review the major constraints: I assume full electrification and two full high platforms at every station; Alon Levy’s operating schedule for fast, light EMUs like the Stadler FLIRT; turnaround times of at least 12 minutes at each terminal; and no more than the currently available overnight layover space. Alon’s schedule requires some additional superelevation, but this is a relatively small expense compared to construction of catenary and high platforms. I assume that some midday layover space is available, although the schedule is flexible with respect to which end of the route that layover space is at. (Having some midday layover space in Boston makes it easier to ramp up for PM peak; obviously, you could also run the same service level all day, although this would result in unfavorable headlines in the Herald.) I assume that trains can follow each other with three minutes’ separation, although the proposed schedule provides somewhat more. Finally, I assume that the traffic doesn’t demand a counter-peak express service: this is important because the schedule assumes that westbound Framingham trains can lead westbound Worcester trains, which only works if both branches run local service in the reverse commute.

In developing the equipment schedule, I planned for the line to be operated with two distinct fleets of identical EMUs — one set of “Worcester” cars and separate set of “Framingham” cars — although the equipment can be swapped around at will when not in service. An actual operating service would have the same cars operating Providence and Fairmount service, so spares could be pooled and vehicles could easily be rotated through the network for preventive maintenance and washing.

All of the updated model run results, as well as the new ridership data and my spreadsheet showing the schedule, is available in my GitHub repository. This specific version of the printed spreadsheet contains the results described in this post (except for the 8/8/4 equipment schedule).

The Rail Vision Advisory Committee and the MBTA board have both expressed interest in service plans that allow for phased implementation. With that in mind, I’m going to put at least an evening’s worth of effort into scheduling a service that runs electric local service from Framingham and diesel expresses from Worcester. That’s in preparation for the real challenge, which is to figure out what the Providence Line looks like, with its challenging mix of Amtrak and MBTA service plus the single-track Stoughton branch. But first, I have to tweetstorm my notes from today’s board meeting — after some exercise.

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1 Response to Updating my MBTA Commuter Rail modeling for the Worcester Line

  1. Jacob Paikoff says:

    This is awesome, thanks for doing it and showing why regional rail is the best way forward for the MBTA. I’m looking forward to seeing your Providence/Stoughton results, since that’s the line that I normally ride.

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