The Transit Costs Project will wrap up soon with the report on construction cost differences, and we’re already looking at a report on high-speed rail. This post should be read as some early scoping on how this can be designed for the Northeast Corridor. In particular, integration of planning with regional rail is obligatory due to the extensive track sharing at both ends of the corridor as well as in the middle. This means that the project has to include some vision of what regional rail should look like in Boston, New York, Philadelphia, and Washington. This vision is not a full crayon, but should have different options for different likely investment levels and how they fit into an intercity vision, within the existing budget, which is tens of billions thanks to the Bipartisan Infrastructure Framework.
In Boston, commuter rail and intercity rail interact via the Providence Line, which is double-track. The Providence Line shares the same trunk line into Boston with the Franklin Line and the Stoughton Line, and eventually with South Coast Rail services.
The good news is that the MBTA is seriously looking at electrifying the trains to a substantial if insufficient extent. The Providence Line is already wired, except for a few siding and yard tracks, and the MBTA is currently planning to complete electrification and purchase EMUs on the main line, and possibly also on the Stoughton Line; South Coast Rail is required to be electrified when it is connected to this system anyway, for environmental reasons. If there is no further electrification, then it signals severe incompetence in Massachusetts but is still workable to a large extent.
Options for scheduling depend on how much further the state invests. The timetables I’ve written in the past (for an aggressive example, see here) assume electrification of everything that needs to be electrified but no North-South Rail Link tunnel. An NSRL timetable requires planning high-speed rail in conjunction with the entirety of the regional rail system; this is true even though intercity trains should terminate on the surface and not use the NSRL tunnel.
Philadelphia is the easiest case. Trenton-Philadelphia is four-track, and has sufficiently little commuter traffic that the commuter trains can be put on the local tracks permanently. In the presence of high-speed rail, there is no need for express commuter trains – passengers can buy standing tickets on Trenton-Philadelphia, and those are not going to create a capacity crunch because train volumes need to be sized for the larger peak market into New York anyway.
On the Wilmington side, the outer end of the line is only triple-track. But it’s a short segment, largely peripheral to the network – the line is four-track from Philadelphia almost all the way to Wilmington, and beyond Wilmington ridership is very low. Moreover, Wilmington itself is so slow that it may be valuable to bypass it roughly along I-95 anyway.
The railway junctions are a more serious interface. Zoo Interlocking controls everything heading into Philadelphia from points north, and needs some facelifts (mainly, more modern turnouts) speeding up trains of all classes. Thankfully, there is no regional-intercity rail conflict here.
In some ways, the Washington-Baltimore Penn Line is a lot like the Boston-Providence line. It connects two historic city centers, but one is much larger than the other and so commuter demand is asymmetric. It has a tail behind the secondary city with very low ridership. It runs diesel under catenary, thanks to MARC’s recent choice to deelectrify service (it used to run electric locomotives).
But the Penn Line has significant sections of triple- and quad-track, courtesy of a bad investment plan that adds tracks without any schedule coordination. The quad-track segment can be used to simplify the interface; the triple-track segment, consisting of most of the line’s length, is unfortunately not useful for a symmetric timetable and requires some strategic quad-track overtakes. The Penn Line must be reelectrified, with high-performance EMUs minimizing the speed difference between regional and intercity trains. There are only five stations on the double- and triple-track narrows – BWI, Odenton, Bowie State, Seabrook, New Carrollton – and even figuring differences in average speed, this looks like a trip time difference between 160 km/h regional rail and 360 km/h HSR of about 15 minutes, which is doable with a single overtake.
New York is the real pain point. Unlike in Boston and Washington, it’s difficult to isolate different parts of the commuter rail network from one another. Boston can more or less treat the Worcester, Providence+Stoughton, Fairmount, and Old Colony Lines as four different, non-interacting systems, and then slot Franklin into either Providence or Fairmount, whichever it prefers. New York can, with current and under-construction infrastructure, plausibly separate out some LIRR lines, but this is the part of the system with the least interaction with intercity rail.
Gateway could make things easier, but it would require consciously treating it as total separation between the Northeast Corridor and Morris and Essex systems, which would be a big mismatch in demand. (NEC demand is around twice M&E demand, but intercity trains would be sharing tracks with the NEC commuter trains, not the M&E ones; improving urban commuter rail service reduces this mismatch by loading the trains more within Newark but does not eliminate it.)
It’s so intertwined that the schedules have to be done de novo on both systems – intercity and regional – combined. This isn’t as in Boston and Washington, where the entire timetable can be done to fit one or two overtakes. This isn’t impossible – there are big gains to be had from train speedups all over and there. But it requires cutting-edge systems for timetabling and a lot of infrastructure investment, often in places that were left for later on official plans.