More musings on commuter rail

Earlier this week, I tweeted this:

There are two, largely independent backstories to this tweet. The first is that I’m going back to Helsinki next week to attend the 75th World Science Fiction Convention, and when I was in Helsinki last March and April, I was inspired to write a whole lot on that city’s excellent transit system (see post 1 and post 2). The second reason is the current Commonwealth Ave. overpass reconstruction project in Boston, which was projected to have some deleterious effects on my commute, and which made me take a more serious look at the possibility of taking commuter rail into work — at least for the duration of the construction. I ultimately decided that paying $22.50 a day plus an extra hour and a half of my time was not worth it, given that my car commute is out of peak hours and costs about the same when you factor in parking, tolls, and fuel. But that made me think about the state’s current level of (dis)investment in public transportation infrastructure and what it would take to get me out of the car, on those days when schedule or weather don’t allow for a bike commute (which is more than half the year). I concluded that commuter rail would have to offer sufficiently frequent service, even at the hours I work, and get me from Framingham to Kendall Square in less than 45 minutes — which is not as good as my car commute, 35 minutes parking space to parking space, but is at least in the same ballpark, and if implemented properly would be significantly less variable.

How could you do that, given that the current Framingham-to-South Station run is scheduled to take 49 minutes, and then there’s the Red Line beyond that? The answer, as it turns out, is pretty simple: Electric Multiple Units, or EMUs — a standard passenger rail technology throughout the world, which (when combined with the appropriate investments in track, overhead electrification, and high-level platforms at stations) can significantly reduce travel times by accelerating much faster than conventional locomotive-hauled trains, especially the diesel locomotives currently used throughout the MBTA commuter rail network. Helsinki has such a system (actually the only commuter-rail network in Finland — the rest of the country isn’t dense enough to support it), which clearly demonstrates that a cold climate in a maritime city is no obstacle to successful implementation. Helsinki’s system provides service on multiple lines from the central business district to the airport — a distance similar to my commute — every fifteen minutes. Helsinki uses a customized cold-weather version of the Stadler FLIRT for most of their services, and I know that a number of US transit agencies have ordered FLIRT equipment for their own commuter rail services, so I looked up the performance details and sat down with a simplified line diagram and a calculator to figure out what that service would look like.

The FLIRT is typically configured for a maximum speed of 160 km/h (99 mi/h). At a typical acceleration of 1.02 m/s/s (depending on configuration, this can vary from 0.8 to 1.2 m/s/s) it takes 43.5 seconds and about six tenths of a mile. (Actually, I chose that acceleration value to make it work out to exactly 0.6 mile or 965 m!) I’m assuming that the entire Framingham–Worcester line is rated for 99 mi/h. (It’s not, but remember, we’re what-ifing an investment in better service, and that would involve electrification, trackbed improvements, new platforms, and possibly some grade crossing improvements or eliminations.) I also assume that there’s a “terminal zone” between South Station and the future West Station where speeds are limited by interlocking (junctions with other lines and switching into South Station). I assume that the train can accelerate and decelerate at the same rate, and that this would be done in practice (probably not) just because it makes the math come out easier. Finally, I assume average dwell time at each station is 30 seconds — and since I don’t take the commuter rail right now I don’t know if this is overly optimistic or pessimistic.

So what does this schedule look like? Well, consider, for comparison sake, the current MBTA train 552, which leaves Worcester Union Station at 8:00 AM and arrives at South Station at 9:06, for a scheduled travel time of one hour and six minutes. This train runs express from Worcester to Yawkey, so it only has two station stops aside from the termini — and it creates a huge gap in the schedule for everyone else, because the Framingham–Worcester Line is only two tracks and there’s no way for an express to pass a local train making an intermediate station stop. Now compare that with the following schedule, making all station stops:

Worcester 800
Grafton 804
Westborough 806
Southborough 811
Ashland 813
Framingham 816
West Natick 818
Natick Center 820
Wellesley Square 822
Wellesley Hills 824
Wellesley Farms 826
Auburndale 828
West Newton 829
Newtonville 830
Boston Landing 833
(West Station) 834
Yawkey 836
Back Bay 838
South Station 841

Change ends at South Station and the same trainset leaves for Worcester at 9:00. What’s more, you can start a second trainset at Framingham, also at 8:00, and it gets to South Station at 8:27, so it can become the 8:45 outbound. (In the future, of course, you’ve also converted the Grand Junction branch and it gets Framingham residents a one-seat ride to Kendall in 25 minutes!) Repeat the same pattern every half hour from 6 AM to 11 PM, and you’ve made an enormous improvement in regional mobility and given thousands of people a practical reason to get out of their cars and onto the train. It takes, I think, four trainsets to run this service, not counting spares shared with other lines.

Well, it was a good dream, anyway. We all know that something this useful has absolutely no chance of ever making it through the MBTA bureaucracy or Beacon Hill. Numbers available on request if you want to check my math.

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9 Responses to More musings on commuter rail

  1. Alon Levy says:

    The FLIRT accelerates more slowly than you think. The acceleration rate you give is only the initial acceleration rate – at higher speed acceleration is capped at (train power)/(train mass * current speed). There are videos of FLIRTs accelerating to top speed on YouTube; 0-160 takes 69 seconds over 2 km, for a total acceleration penalty of 24 seconds.

    It’s also not possible to run at 160 on much of the Worcester Line, because of ROW constraints. See speed zones based on ROW geometry here.

    • Thanks, Alon. I figured that I was missing something, but didn’t know what!

      • ofsevit says:

        Yes, as Alon points out, the line is not particularly straight, so there are definitely some slow areas. High levels would be imperative to run this schedule, too. But 60 minute local service—and 45 minute express service from Framingham—is probably possible, and certainly time-competitive with driving even outside rush hour. For Kendall, of course, you’re the target market for a shuttle from West Station. Imagine not taking 25-30 minutes to stop at Yawkey, Back Bay and South Station, and then hoping the Red Line is running. This is very important, and needs to be studied. MassDOT doesn’t think anyone makes this commute, but the numbers beg to differ. And most drive.

      • Yes, and right now the only people who get reasonably direct service to Kendall Sq from the west are those on the Fitchburg line, which is not exactly a hotbed of affordable housing. I have two co-workers in Framingham, one in Millis — all four of us drive. (For the other two Framingham commuters, starting the F’ham local service on the Ag Branch near Framingham Center would be a big win, at least if a parking structure could be built, say at Maple St. where Framingham State currently has a big surface lot. I feel like there’s been a lot of development in Framingham since the last major CR studies were done.

      • The West-North shuttle obviously makes sense if you’re building NSRL, but even if you don’t try to do that, I bet running Framingham local trains to NS via the Grand Junction would be a win for many travelers given the development in Kendall and East Cambridge over the past decade. Would need grade separation, of course, but perhaps two stations, one south of Mass Ave behind ex-Met Storage, connecting to the 1/CT1/CT2, and one north of Broadway? Has anyone studied this seriously?

  2. (Of course, having any sort of frequent service on the Grand junction between NS and WS-to-be could also take a lot of traffic off the various MIT and TMA shuttles. Perhaps MIT could be convinced to help with some of the construction costs, given all the commercial development MITIMCO is spearheading in Kendall — lord knows the existing Red Line really doesn’t have the extra capacity.)

    • ofsevit says:

      Not sure where the reply button went for further threaded comments. A couple of comments:

      1. The TMA is in the business of moving people, not buses. If there was a better connection from North Station, it would probably be fine with it.
      2. With Volpe coming, yes, MITIMCO and whoever else should be held hostage to GJ improvements.
      3. With a decent connection, I think you could run a perfectly good shuttle service from Allston, and just keep running everything in to South Station. Although if you needed to, you might be able to push off the need for SSX quite a bit by running a few peak trains through to North Station. Shorter trains would have less impact on traffic on Mass Ave. I don’t think you need to grade-separate it unless you’re running service every couple of minutes.
      4. I think three stations in Cambridge make sense. One between Mass Ave and Main Street. A second at Cambridge Street in East Cambridge. The third I’d put down in Cambridgeport. There is a ton of underutilized land there (several empty lots) which would spring up with better transit access (sort of a good example showing how land doesn’t get built unless it’s transit-accessible). A potential fourth station over by Northpoint.

      • These all seem pretty reasonable. I’m a bit concerned about the Mass Ave grade crossing, though, given what rush hours on Mass Ave look like already. Main St. and Broadway probably fine. (And a station between Mass. and Main would be great for me since I work across the street…)

      • As regards CRTMA, yes, that was my thought — it would cost them far less if the MBTA could pick up a big fraction of the load on the GJ. Would they be willing to subsidize?

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