For example, the Seattle streetcars cost on the order of $3.2 million each, and Mattapan would likely need five streetcars, and two spares, to run service, so about $22 million overall. Streetcars are spec’ed to last 30-40 years, so it’s a $500,000 investment per year. 10 buses, at $750,000 per bus, would cost $7.5 million, but only last 12 years, so the capital cost would be about the same (30 buses over 36 years = $22.5 million, slightly less given a discount rate, but at least right now, money is cheap). And the cost to convert the corridor to bus transit—given BRT costs of $10-$50 million per mile—the cost of vehicles would be dwarfed by the cost of concrete. The answer for Mattapan is easy: just buy modern streetcars for the Mattapan High Speed Line.

But then what do you do with the PCCs? They’re still sort of useful transit vehicles, and it’s not hard to look at San Francisco to see where PCCs operate as both transit vehicles and as transit and as a rolling museum (and tourist attraction). We won’t run PCCs in mixed traffic on the Green Line any time soon (or probably ever), but there is somewhere that the fleet could provide a useful transit connection and operate in a tourist-friendly location: between Andrew Square and the Convention Center.

Why this route? While older streetcars could conceivably run on surface lines (and did as recently as the late 1990s) doing so with any regularity would have liability and accessibility concerns, and decrease the capacity of the Boylston-Tremont subway dramatically, where a slot using a 45-foot PCC is far less efficient than one with a two- or threee-car LRV. It would also require pantograph conversion. San Francisco gets around this by running the PCCs on the surface of Market Street with the light rail in the tunnel below (which was built in 1982, only 85 years after the Green Line went underground in Boston). Basically, in Boston, the current light-rail lines are out.

So that leaves a purpose-built line. Nearly every rail right-of-way in Boston is used for rail service, or has been converted to a multi-use pathway. (For instance, Minneapolis runs historic streetcars on an old section of streetcar right-of-way, but other than a short portion of the Fells, we don’t have that.) With narrow streets, we can’t easily throw in something Kenosha-style. But there is one stretch of railroad track in Boston which sits unused: the so-called Track 61 in South Boston.

The state currently owns Track 61, but it hasn’t been used for freight service in decades (and other than vague platitudes, there are no plans to do so any time soon.) There have been calls to run DMU service on Track 61, but this is such a risible plan—crossing the Northeast Corridor and Old Colony lines at-grade, at rush hour, in a roundabout route—that it will never happen, even if the T were to acquire the appropriate rolling stock. Recently the City of Boston has proposed using it for a split terminal from the Fairmount Line, which is more feasible, but still requires a diamond crossing of the Old Colony Line, and the desire line of the Fairmount Line almost certainly aims downtown (and where there is a Red Line transfer), not at the Seaport. If freight were ever to run across the line, streetcars would not preclude future freight use at off hours (which is done in several other corridors) if shipping traffic required a daily freight movement on the line.

The route of Track 61 and an extension to Andrew in yellow.

It’s the route of Track 61 which is most intriguing, as it would make a last-mile connection between the Red Line and the Seaport, which currently requires a ride on two over-capacity transit lines (the Red Line to South Station and the Silver Line to the Seaport). For commuters from the south going to the Seaport, a transfer at Andrew would save five minutes of commute time, and (more importantly) it would pull some demand off of the Silver Line at rush hour, when buses run every minute-or-so at crush capacity and leave passengers on the platform. With some minor (seven figure) improvements (stations, overhead, a couple of interlockings), there is an unused rail corridor with mostly-existing rail on which the PCCs (or new rolling stock) could be run in relatively short order.

The key would be to find both funding and possibly a non-MBTA operator. (Power could be acquired from the adjacent MBTA facilities, but it could be run by a different organization. Let’s start with funding: there are mechanisms in place. Capital costs could come from a TIGER-type grant, and operating costs from a transportation management association or perhaps from the Mass Convention Center Authority or even MassPort, especially since they have hundreds of millions of dollars for parking garages in the area (maybe, uh, we shouldn’t build that parking garage, wait, don’t call it that).

Amazing! Trams/streetcars can have level boarding. (Minneapolis-Saint Paul “Metro”)

As for the rolling stock: The current PCCs are inaccessible, but are made accessible with high-platforms along the Fairmount Line. This could be replicated along Track 61, especially since the stations would be built from scratch and fewer in number. (In theory: Andrew, Broadway, Convention Center, Black Falcon.) More likely would be low-platform modern trams (and by modern, I mean “flush with the platform”) to run on the line with PCCs used for supplemental service (weekends, middays, etc). It might be possible to strike a deal with the Seashore Trolley Museum to both use the Seashore-owned 5734 (which likely needs some rehab but ran within the past 20 years and has been stored underground at Boylston) and perhaps relocating some other MBTA equipment from there for an outpost of the Maine facility: a small, San Francisco-style rolling museum showing the transit history of the oldest subway in the country.

DMUs and commuter rail to the Seaport is a round-peg-square-hole issue. The scale is not really appropriate (especially if it is diesel, with more local particulate emissions in a high-density residential community) and the routing certainly isn’t. (There’s also the matter of significant single-track, which is easier to navigate with light rail equipment.) Moreover, with the Red Line adjacent at one end and the Silver Line at the other, it might be possible to simply tie in traction power from each end without building any new facilities, so the power costs would be minimized (overhead is cheap, substations are expensive). Track 61 shouldn’t be let to sit and fester for the next 25 years. But if we do something with it, let’s do something sensible.