Category: Transportation

Trains on the Moon

The US government is contracting defense contractor Northrop Grumman to develop a concept for passenger and freight rail on the Moon, the idea being to use this to transport resources and perhaps build rockets for travel to the rest of the Solar System. Upon seeing this, I immediately set to try figuring out design standards, and it looks like such a railway would have a much harder time developing an alignment than on Earth, because of the impact of low gravity.

The issue is that lunar gravity is 1.6 m/s^2, and not 9.8 as on Earth. This turns out to affect how vehicles can round corners. The formula connecting speed, lateral acceleration, and the curve radius is the same everywhere:

v^2 = r\cdot a

The value of a is measured in the horizontal plane; curves are normally banked (canted/superelevated), so that gravity countermands centrifugal force, but normally, trains are run faster than the perfect balancing speed, since some lateral acceleration in the plane of the body of the train is acceptable. For much more detail, see old of posts of mine here and here.

In rail engineering, lateral acceleration is usually measured not in units of acceleration, but in units of distance, corresponding to how far the track is canted vertically (cant), and to how much the track would need to be canted further to achieve perfect balancing speed (cant deficiency). These units follow the formula

a = (e/k)g

Here, e is total equivalent cant (cant plus cant deficiency), k is the track gauge from the middle of the rail to middle of the rail (around 60 mm more than the usual value of track gauge, which is measured from inner rail to inner rail), and g is gravitational acceleration. On Earth, on standard-gauge railways, this reduces to the formula that 1 m/s^2 of lateral acceleration is equal to 150 mm of total equivalent cant.

The issue with all of this is that the safety limits of both cant and cant deficiency are better expressed in units of distance rather than acceleration, as gravitational acceleration changes; equivalently, the limit value of a is proportional to g. The reason is that cant deficiency is limited by the ability of the train to round the curve safely, without toppling; if the combined force vector of weight and centrifugal force points too far off-center, then the swaying of the train can lead to derailment and catastrophic damage, including deaths. Thus, the limit value of acceleration in the plane of the tracks is best expressed as a proportion of gravitational acceleration, rather than in absolute units. The limit value of cant, in turn, is related to the safety limit of the ability of the train to stand still on canted track in an emergency.

This analysis can be seen in two distinct places in existing rail design standards and speed limits:

  • When the train rounds a vertical curve, there is a minimum curve radius too, governed by both safety and passenger comfort. The minimum curve radius is higher on a crest than on a sag, because on a crest the train’s vertical acceleration slightly countermands gravity, and thus the train does not grip the tracks so well, whereas on a sag the vertical acceleration adds to gravity.
  • The maximum values of cant and cant deficiency are usually fairly close for a given train. Two notable exceptions are high-speed rail, and tilting trains. High-speed rail has higher maximum cant than cant deficiency – German standards are 180 and 130 mm respectively – because cant deficiency is a limiting factor when the train is moving at 300 km/h (and thus potentially sways more) whereas cant is a limiting factor when the train sits still. Tilting trains are the exact opposite: the maximum cant deficiency is very high, reaching 270 mm on some high-maintenance Pendolino sets designed to be light enough and have low enough center of mass to be able to round corners safely, because when the train sits still on canted track the tilt system is assumed not to be working.

The upshot is that a standard-gauge railway on the Moon can expect to have a maximum total equivalent cant of 300 mm or somewhat more, same as on Earth – but that is compatible with a value of a of 0.33 m/s^2. In effect, curve radii have to be six times wider, assuming equal technology. The viaducts required to build such a straight right-of-way are easier to build on the Moon, since they don’t need to support as much weight for a given mass, but more and taller viaducts are still needed, and going around obstacles is not easy.

Land Use Around the Interborough Express

Eric and Elif are working on a project to analyze land use around the corridor of the planned Interborough Express line in New York. The current land use is mostly residential, and a fascinating mix of densities. This leads to work on pedestrian, car, and transit connectedness, and on modal split. As might be expected, car ownership is fairly high along the corridor, especially near the stations that are not at all served by the subway today, as opposed to ones that are only served by radial lines. Elif gave a seminar talk about the subject together with João Paulouro Neves, and I’d like to share some highlights.

The increase in transit accessibility in the above map is not too surprising, I don’t think. Stations at both ends of the line gain relatively little; the stations that gain the most are ones without subway service today, but Metropolitan Avenue, currently only on the M, gains dramatically from the short trip to Roosevelt with its better accessibility to Midtown.

More interesting than this, at least to me, is the role of the line as a way to gradually push out the boundary between the transit- and auto-oriented sections of the city. For this, we should look at a density map together with a modal split map.

At the seminar talk, Elif described IBX as roughly delineating the boundary between the auto- and transit-oriented parts of the city, at least in Brooklyn. (In Queens, the model is much spikier, with ribbons of density and transit ridership along subway lines.) This isn’t quite visible in population density, but is glaring on the second map, of modal split.

Now, to be clear, it’s not that the IBX route itself is a boundary. The route is not a formidable barrier to pedestrian circulation: there are two freight trains per day in each direction, I believe, which means that people can cross the trench without worrying about noise the way they do when crossing a freeway. Rather, it’s a transitional zone, with more line density to the north and less to the south.

The upshot is that IBX is likely to push this transitional zone farther out. There is exceptionally poor crosstown access today – the street network is slow, and while some of the crosstown Brooklyn buses are very busy, they are also painfully slow, with the B35 on Church Avenue, perennially a top 10 route in citywide ridership, winning the borough-wide Pokey Award for its slowness. So we’re seeing strong latent demand for crosstown access in Brooklyn with how much ridership these buses have, and yet IBX is likely to greatly surpass them, because of the grade-separated right-of-way. With such a line in place, it’s likely that people living close to the line will learn to conceive of the subway system plus the IBX route as capable of connecting them in multiple directions: the subway would go toward and away from Manhattan, and IBX orthogonally, providing enough transit accessibility to incentivize people to rely on modes of travel other than the car.

This is especially important since the city’s street network looks differently by mode. Here is pedestrian integration by street:

And here is auto integration:

The auto integration map is not strongly centered the way the pedestrian map is. Quite a lot of the IBX route is in the highest-integration zone, that is with the best access for cars, but the there isn’t really a single continuous patch of high integration the way Midtown Manhattan is the center of the pedestrian map. East Williamsburg has high car integration and is not at all an auto-oriented area; I suspect it has such high integration because of the proximity to the Williamsburg and Kosciuszko Bridges but also to Grand Street and Metropolitan Avenue toward Queens, and while the freeways are zones of pedestrian hostility, Grand and Metropolitan are not.

What this means is that the red color of so many streets along the IBX should not by itself mean the area will remain auto-oriented. More likely, the presence of the line will encourage people to move to the area if they intend to commute by train, and I suspect this will happen even at stations that already have service to Manhattan and even among people who work in Manhattan. The mechanism here is that a subway commuter chooses where to live based on commuter convenience but also access to other amenities, and being able to take the train (for example) from Eastern Brooklyn to Jackson Heights matters. It’s a secondary effect, but it’s not zero. And then for people commuting to Brooklyn College or intending to live at one of the new stops (or at Metropolitan, which has Midtown access today but not great access), it’s a much larger effect.

The snag is that transit-oriented development is required. To some extent, the secondary effect of people intending to commute by train coming to the neighborhood to commute from it can generate ridership by itself; in the United States, all ridership estimates assume no change in zoning, due to federal requirements (the Federal Transit Administration has been burned before by cities promising upzoning to get funding for lines and then not delivering). But then transit-oriented development can make it much more, and much of the goal of the project is to recommend best practices in that direction: how to increase density, improve pedestrian accessibility to ensure the areas of effect become more rather than less walkable, encourage mixed uses, and so on.

Is There Room for Optimism About New York Construction Costs?

This year, there have been some positive signs about things changing in New York on subway construction – and yet, I’m uncertain about them. There are some signs that construction costs for Second Avenue Subway Phase 2 are coming under control. The New York Post broke in January that the MTA is eying smaller station designs, to reduce costs, to the tun of $300 million; an article released a few hours ago adds that there may be another $600 million in potential savings. So, in theory, costs are going down, and they’re going down as the MTA implements something we’ve been screaming about at the Transit Costs Project, so we should be happy.

And yet, I’m uncertain – not negative, but still somewhat pessimistic about whether this portends an era in which New York can finally build more subways. The main reason isn’t even some mistrust in the MTA at this point – the reduction in station footprints is a genuinely good thing, and to the extent it’s incomplete, it’s because it’s a longstanding project with older designs. Rather, it’s a combination of what this means for future projects, and how it interacts with federal funding. In brief, federal funding is at the level of the project rather than agency, and this makes it hard for cost savings to be plugged into the most straightforward benefit – namely, being able to build more on the same budget.

How is the money being saved?

The New York Post is relying on an MTA presentation from January that defends the cost structure but talks about how to reduce station costs through reducing back-of-house space. Phase 1 of Second Avenue Subway built two deep-mined intermediate stations, at 72nd and 86th Streets; the platforms are 610′ (187 meters) long, and there are no serious prospects of ever running longer trains since the line is an extension of older lines, but the station caverns are, respectively, 398 and 295 meters long, where the norm in the European comparison cases we’ve seen is that the station dig is 3-15% longer than the platforms, not twice as long.

Both stations have extensive back-of-house space, which New York City Transit demanded so that each department using the station would have its own space; 72nd also has a crossover inherited from older designs that would have permitted some trains from the south to terminate there on a third station track, which was later removed from scope to reduce costs. (The terminal station, the cut-and-cover 96th Street, is a 485 meter long dig, but that’s an artifact of block-level geology: the northern end had to go as far as 99th in order to connect with an older tunnel built in the 1970s, whereas the southern end had to go as far as 92nd because the underground geology changes abruptly there and it was easier to start boring at 92nd than at 96th.)

The plan for Phase 2 initially included much longer digs than the platform, for the same reason. However, it has since changed, and now the digs are substantially reduced. The MTA’s presentation looks like the overage at 125th Street is reduced from somewhat more than 100% in the 2004 plan to about 40-50% in the 2023 plan, and the overage at 106th and 116th is somewhat less than that, maybe 30-40%. While the 125th Street station dig is still as deep as in prior plans, the deep-mined station will also extend less far up, reducing the extent of space required to be outfit with systems.

The MTA could shrink the stations’ footprint further and save more money, but it’s fairly late in the design, and thus the opportunity to take full benefit of this improvement is for future projects. If this establishes precedent for future station construction, then it’s an unmixed blessing.

Money is saved. So what?

The broader issue is that the savings from shrinking the stations’ footprint – totaling potentially $1 billion out of a budget of $7 billion – don’t have much to go. The rub is that the project already has a Full Funding Grant Agreement. If the MTA manages to do it for less, then the most obvious, and most pessimistic, answer to where the money goes is “preventing future overruns.” The savings, in the worst case, then transfer waste from one basket, namely oversize stations, to other baskets, which could be future conflict with contractors, last-minute design changes, or betterments to the neighborhood.

That said, there are plans to spend it on something useful. But the problem is that this is limited by the scope of the project itself. Second Avenue Subway in its current iteration dates to the 1990s, and is reusing some infrastructure from the 1970s. The intention in the 1990s was to do the entire thing, or at least Phases 1 and 2, together, and the project was only chopped into four phases due to high costs. There was design work done 20 years ago or more, and the environmental impact statement is roughly that old.

I suspect the reason the cost saving from shrinking the stations is $1 billion and not much more – we estimated that Phase 1’s cost would have been halved if the stations had been only as long as the platforms – is that the designs are already spoken for, with 20 years of optimization involved. Thus the change is reducing the hard costs of construction, but not the soft costs. It will not surprise me if a postmortem will reveal an elevated ratio of soft to hard costs, purely because the cost savings are happening at such a late stage; in this case, and only in this case, it is important to forgive a high ratio of soft to hard costs, since it portends that future designs will be cheaper, and future cost savings larger. Normally, a high soft-to-hard cost ratio suggests red tape and waste involving consultants, but in this one case, it would suggest something else; I highlight this so that watchdogs for government waste, including the New York Post, realize what is going on and avoid hitting the project if it turns out to indeed have a high soft-to-hard cost ratio as I expect.

Current plans include potentially continuing the tunnel boring under 125th Street. Governor Hochul expressed some interest in a subway extension under 125th Street, extending Phase 2 from 125th/Lexington to the Hudson, with stops at the intersections with the subway lines, at Lenox (2/3), St. Nicholas (A/B/C/D), and Broadway (1 and also potential commuter rail). Such an extension was long on the wishlist of New York-area railfans, and an operations planner mentioned it to me as a future desire more than 10 years ago, unprompted. But there is no way to just reallocate $1 billion to this line; that’s not how federal funding works. At best, it will be possible to continue boring the tunnel all the way to the west, and leave the systems and stations to a future project.

My pessimism is that the cost figure given for the 125th Street extension is $7.6 billion, around $3.3 billion per kilometer. Even taking into account future inflation, it’s costlier than Second Avenue Subway Phases 1 and 2. Now, this is an early number, one that hasn’t really made it into any plans. I hope that the current cost savings are then plugged into the 125th Street extension plan, and that this project is pursued seriously at a much lower cost figure; since all stations would have to be complex digs underneath older north-south subway lines, the benefits of shrinking station footprint are especially large. But I worry that this will not happen; I’ve had hopes dashed before – for example, FRA reform did not lead American commuter rail agencies to start buying alt-compliant vehicles. We’ll see what happens if there’s more detailed work on the 125th Street extension proposal.

Funding projects vs. funding agencies

The current way federal funding works for public transportation in the United States is that the government funds specific capital projects. The MTA can ask for funding for big-ticket items like Second Avenue Subway Phase 1, Phase 2, a future 125th Street subway, the Interborough Express, or any similar such line. It can also ask for a rolling program of improvements, for example installing elevators at stations to make them accessible in line with the Americans with Disabilities Act. But the federal government does not make it easy to move money between such projects.

Phase 2 is just one project, but imagine that there are three subway lines funded concurrently: Phase 2, a subway extension under Nostrand, and a subway extension under Utica. If the MTA finds 25% cost savings, it can’t easily flex the money to a fourth line, say under 125th. It would need to start the planning process early, which is so cumbersome and expensive that it wouldn’t do so for a project it wasn’t certain it wanted to do; there is no shelf of subway extensions that are approved and are just waiting for money.

This makes the incentives for cost savings uncertain: cost savings could be used to establish the agency’s bona fides with a distrustful public, or to establish a warchest guarding against future cost overruns, or to trial new ways of working that could lead to bigger cost savings in the future, but the most straightforward benefit of cost savings – building more infrastructure on the same budget – is not generally available. For Phase 2, the best that can happen is, again, continuing boring the tunnel to the western end of 125th Street, which could be connected with the current project because the geology under the street is the same from Second Avenue to Broadway so might as well future-proof it.

And unfortunately, in the United States, the current examples of funding agencies rather than projects have been lacking. The programs in Los Angeles and Seattle, funded by sales taxes, in effect fund the agencies. There are long lists of projects in both metro areas that are funded from them, but they come from the same pool of money in each region. The situation in Los Angeles is that there’s a decided priority list, with money allocated through the end of the 2050s; if Los Angeles figures out how to cut costs significantly, all of the opening dates will be moved closer and additional lines could be planned and built with the money (the planning and environmental review process takes years, not decades, so by 2050 they will have reviews for the additional subways they could build).

And yet, the same process that’s produced lush agency-level funding in both regions has also led to bad prioritization. New York may have the world’s highest construction costs, but at least what it’s building is what it should be building: Second Avenue Subway Phase 2 is indeed the highest priority right now, and among the next priorities, the Interborough Express and 125th Street are solid choices, according to most area rail advocates two of the top five, and potentially even the top two (the other three are Nostrand, Utica, and an elevated extension of the Astoria Line to LaGuardia). In contrast, Los Angeles is prioritizing the wrong projects. The same ballot proposition process there that produces agency-level funding also requires the agency to bribe local actors who care little for public transportation or for ideological politics with lines to their own subregions of the county, not because they or their constituents will ride the trains, but because they will be able to tell their constituents “I managed to force the county to give us infrastructure money.” This way, each region of the county gets a light rail extension, no matter how lightly-ridden, while the core of the system receives little investment: while the busiest bus corridor in Los Angeles, Wilshire, is getting a subway in the D (Purple) Line Extension, the next two busiest, Vermont and Western, are not getting any rail through the 2050s, despite calls from advocates to built a line on Vermont to turn the B (Red) Line into a north-south line rather than a branch with the Purple Line.

Incentives for the future

The MTA is clearly capable of saving money. The question is now how to incentivize doing more of it. First of all, I urge New York-area advocates to pursue the 125th Street extension, and demand that the cost savings identified for Phase 2 apply to it too. The savings may even potentially be relevant to the Interborough Express, though with at-grade and above-ground stations, the impact is greatly reduced. The Phase 2 savings are reactive; applying them to future lines is proactive.

Second, I urge both the MTA and advocates to look for cost savings in areas where it is easier to flex money – namely, ADA accessibility. Being able to make a station accessible not for the current budget of about $70 million per station with contingency but the $25 million of Boston or $10 million of Madrid would enable New York to have an all-accessible subway system not in the 2050s but in the early 2030s.

Finally, at the federal level, it is useful to figure out how to fund agencies with a positive track record and not just specific projects. Potentially, agencies could be encouraged to submit wishlists of future projects that may be cleared in case money becomes available on short notice; this is useful not just in the case of cost savings, but also in the case of an unexpected infrastructure stimulus – neither the scope of the 2009 stimulus in the early Obama era nor that of 2021 under Biden had been telegraphed until shortly before, and so agencies have not always been able to take maximum advantage of the additional funds.

Northeast Corridor Travel Markets and Fares

I’m optimistic about the ability of fast trains on the Northeast Corridor to generate healthy ridership at all times of day. This is not just a statement about the overall size of the travel market, which is naturally large since the line connects three pretty big metro areas and one very big one. Rather, it’s also a statement about how the various travel markets on the corridor fit atypically well together, creating demand that is fairly consistent throughout the day, permitting trains with a fixed all-day schedule to still have high occupancy – but only if the trains are fast. Today, we’re barely seeing glimpses of that, and instead there are prominent peak times on the corridor, due to a combination of fares and slowness.

Who travels by high-speed rail?

High-speed intercity rail can expect to fill all of the following travel markets:

The key here is that the first two kinds of trips can be either day trips or multiday trips. I day-tripped to the Joint Mathematics Meeting in 2012 when I lived in Providence and the conference was in Boston, about an hour away by commuter rail, but when there was an AMS sectional conference in Worcester in 2011 (from which my blog’s name comes – I found Worcester unwalkable and uploaded an album to Facebook with the name “pedestrian observations from Worcester”) I took trains. I probably would have taken trains from New York to Worcester for the weekend rather than day-tripped even if they were fast – fast trains would still be doing it in around 2:30, which isn’t a comfortable day trip for work.

Non-work trips are the same – they can be day trips or not. Usually recreational day trips are uncommon because train travel is expensive, especially at current Amtrak pricing – the Regional costs twice as much per passenger-km as the TGV and ICE, and the Acela costs three times as much. But there are some corner cases: I moved to Providence with a combination of day trips (including two to view apartments and one to pick up keys) and multiday trips. Then, at commuter rail range, there are more recreational day trips – I’ve both done this and invited others to do so on Boston-Providence and New York-New Haven. Recreational rail trips, regardless of length, are more often taken by individuals and not groups, since car travel costs are flat in the number of passengers and train costs are linear, but even groups sometimes ride trains.

We can turn this into a two-dimensional table of the various kinds of trips, classified by purpose and whether they are day trips or multiday trips:

PurposeDay tripMultiday trip
BusinessWork trips between city centers, usually in professional services or other high-value added firms, such as lawyers traveling between New York and Washington, or tech workers between New York and Boston; academic seminar tripsConference trips, more intensive work trips often involving an entire team, and likely all business trips between Boston and Washington or Boston and Philadelphia
TourismTrips to a specific amenity, which could be urban, such as going to a specific museum in New York or Washington or walking around a historic town like Plymouth, or not, such as taking the train to connect to a beach or hiking trailLong trips to a specific city or region, stringing many amenities at once
Other non-workCollege visits, especially close to the train stations; meetings with friends within short range (such as New York-Philadelphia); advocacy groups meeting on topics of interest; apartment viewings; some trips to concerts and sports gamesVisits to friends and family; some moving trips; some trips to concerts and sports games
CommuteLong-range commutes

Day trips and different peaks

The different trips detailed in the above table peak at different times. The commute trips peak at the usual commute times: into the big cities at 9 in the morning, out of them at 5 in the afternoon. But the rest have different peaks.

In particular, multiday tourism trips peak on weekends – out on Friday, back on Sunday night – while multiday business trips peak during the week. This is consistent enough that airlines use this to discriminate in prices between different travelers: trips are cheaper if booked as roundtrips over Saturday nights, because such trips are likely to be taken by more price-sensitive leisure travelers rather than by less price-sensitive business travelers.

Nonetheless, even with this combination of patterns, the most common pattern I am aware of on intercity rail, at the very least on the Northeast Corridor and on the TGV network, is that the trains are busier during the weekend leisure peak than during the weekday business peaks (except during commute times). Regardless of the distribution of business and leisure trips, leisure trips have a narrow peak, leaving within a window just a few hours long on Friday, whereas business trips may occur on any combination of weekdays; for this reason, leisure-dominated railroads, such as any future service to Las Vegas, are likely to have to deal with very prominent peaking, reducing their efficiency (capacity has to be built for all hours of the week).

But then day trips introduce additional trip types. The leisure day trip is unlikely to be undertaken on a Friday – the traveler who is free during the weekend but not the week might as well travel for the entire weekend. Rather, it’s either a Saturday or Sunday trip, or a weekday trip for the traveler who can take a day off, is not in the workforce, or is in the region on a leisure trip from outside the Northeast and is stringing multiple Northeastern cities on one trip. This day trip then misses the leisure peak, and usually also misses the commuter peak.

The business day trip is likely to be undertaken during the week, probably outside the peak commute time – rather, it’s a trip internal to the workday, to be taken midday and in the afternoon. It may overlap the afternoon peak somewhat – the jobs that I think are likeliest to take such trips, including law, academia, and tech, typically begin and end their workdays somewhat later than 9-to-5 – but the worst peak crowding is usually in the morning and not the afternoon, since the morning peak is narrower, in the same manner that the Friday afternoon peak for leisure travel is narrower than other peaks.

The day trips are rare today; I’ve done them even at the New York-Providence range, but only for the purpose of moving to Providence, and other times I visited New York or even New Haven for a few days at a time. However, the possibility of getting between New York and Providence in 1:20 changes everything. The upshot is that high-speed rail on the Northeast Corridor is certain to massively boost demand on all kinds of trips, but stands to disproportionately increase the demand for non-peak travel, making train capacity more efficient – running the same service all day would incur less waste in seat-km.

The issue of fares

All of this analysis depends on fares. These are not too relevant to business trips, and I suspect even to business day trips – if you’re the kind of person who could conceivably day trip between New York and Washington on a train taking 1:45 each way to (say) meet with congressional staffers, you’re probably doing this even if the fares are as high as they are today. But they are very relevant to all other trips.

In particular, non-work day trips are most likely not occurring during any regular peak travel time. Thus, the fare system should not attempt to discourage such trips. Even commute trips, with their usual peak, can be folded into this system, since pure intercity trips peak outside the morning commute period.

The upshot is that it is likely good to sell intercity and commuter rail tickets between the same pair of stations for the same fare. This means that people traveling on sections currently served by both intercity and commuter rail, like Boston-Providence, New York-New Haven, New York-Trenton, and Baltimore-Washington, would all be taking the faster intercity trains. This is not a problem from the point of view of capacity – intercity trains are longer (they serve fewer stations, so the few stations on the corridor not long enough for 16-car trains can be lengthened), and, again, the travel peaks for multiday trips are distinct from the commute peak. Commuter trains on the corridor would be serving more local trips, and help feed the intercity trains, with through-ticketing and fare integration throughout.

Serving Metro-North Fordham Station

In the Bronx, the Metro-North Harlem Line runs north-south, west of the 2/5 subway lines on White Plains Road and east of the 4 on Jerome Avenue and the B/D on Grand Concourse. It makes multiple stops, all served rather infrequently, currently about every half hour, with some hourly midday gaps, at premium fare. The north-south bus lines most directly parallel to the line, the Bx15 and Bx41, ranked #20 and #24 respectively in ridership on the New York City Transit system in 2019, though both have lost considerable ground since the pandemic. Overall, there is serious if not extremely high demand for service at those stations. There is already a fair amount of reverse-peak ridership: while those half-hourly frequencies can’t compete with the subway for service to Manhattan, they are the only non-car option for reverse-peak service to White Plains, and Fordham gets additional frequencies as well as some trains to Stamford. A city report from 2011 says that Fordham has 51 inbound passengers and 3,055 outbound ones boarding per weekday on Metro-North. Figuring out how to improve service in the Bronx requires a paradigm shift in how commuter rail is conceived in North America. Fordham’s reverse-peak service is a genuinely hard scheduling question, which we’re having to wrestle with as we’re proposing a (much) faster and smoother set of timetables for Northeast Corridor trains. Together, they make for a nontrivial exercise in tradeoffs on a busy commuter line, in which all options leave something to be desired.

Harlem Line local service

The bulk of demand from Fordham is local service, mostly toward Manhattan. The area is a bedroom community: within 1 km of the station at Park and Fordham there are 35,338 employed residents and only 22,515 jobs as of 2019; the largest destination is Manhattan (12,734 commuters), followed by the Bronx (7,744), then the rest of the city (8,069 across three boroughs), and only then Westchester (2,207), Long Island (1,660), and Connecticut (220). But to an extent, the station’s shed is larger for reverse-commute service, because people can connect from the Bx12 bus, which ranked second in the city behind the M15 in both 2019 and 2022; in contrast, Manhattan-bound commuters are taking the subway if they live well east or west of the station along Fordham. Nonetheless, the dominance of commutes to city destinations means that the most important service is to the rest of the city.

Indeed, the nearest subway stations have high subway ridership. The city report linked in the lede cites ridership of 11,521 on the B/D and another 12,560 on the 4 every weekday, as of 2012; both stations saw declines by 2019. The West Bronx’s hilly terrain makes these stations imperfect substitutes for each other and for the Metro-North station, despite the overlap in the walk sheds – along Fordham, Park is 600 meters from the Concourse and 950 from Jerome. Nonetheless, “roughly the same as either of the Fordham stations on the subway” should be a first-order estimate for the ridership potential; better Metro-North service would provide a much faster option to East Harlem and Grand Central, but conversely require an awkward transfer to get to points south, which predominate among destinations of workers from the area, who tilt working-class and therefore peak in Midtown South and not in the 50s:

Adding up all the Bronx stations on the line – Wakefield, Woodlawn, Williams Bridge, Botanical Garden, Fordham, Tremont, Melrose – we get 170,049 employed residents (as always, as of 2019), of whom 62,837 work in Manhattan. The line is overall in a subway desert, close to the 4 and B/D but along hills, and not so close to the 2/5 to the east; several tens of thousands of boardings are plausible if service is improved. For comparison, the combination of Westchester, Putnam, and Dutchess Counties has 115,185 Manhattan-bound commuters, split across the Harlem Line, the Hudson Line, and the inner New Haven Line. The Bronx is thus likely to take a majority of Manhattan-bound ridership on the Harlem Line, though not an overwhelming one.

To serve all this latent demand, it is obligatory to run more local service. A minimum service frequency of a train every 10 minutes is required. The current outbound schedule is 20 minutes from Grand Central to Fordham, and about four of those are a slowdown in the Grand Central throat that can be waived (the current speed limit is 10 miles per hour for the last mile; the infrastructure can largely fit trains running three times that fast almost all the way to the bumpers). Lower frequency than this would not really make use of the line’s speed.

Moreover, using the track chart as of 2015 and current (derated) M7 technical performance, the technical trip time is 18 minutes, over which 20 minutes is not too onerously padded; but removing the derating and the four gratuitous minutes crawling into and out of Grand Central, this is about 14 minutes, with some pad. The speed zones can be further increased by using modern values of cant and cant deficiency on curves, but the difference isn’t very large, only 40 seconds, since this is a section with frequent stops. It’s fast, and to reinforce this, even higher frequency may be warranted, a train every 7.5 or 6 or even 5 minutes.

There is room on the tracks for all of this. The issue is that this requires dedicating the local tracks on the Harlem Line in the Bronx to local service, instead of having trains pass the platforms without stopping. This, in turn, requires slowing down some trains from Westchester to make more local stops. Current peak traffic on the Harlem Line is 15 trains per hour, of which 14 run past Mount Vernon West, the current northern limit of the four-track section, and 13 don’t stop in the Bronx at all. The line has three tracks through past Crestwood, and the stations are set up with room for a fourth track, but a full 10 trains per hour, including one that stops in the Bronx, run past Crestwood. In theory it’s possible to run 12 trains per hour to Mount Vernon West making all stops, and 12 trains past it skipping Bronx stops; this slows down the express trains from White Plains, which currently skip seven stops south of White Plains to Mount Vernon West inclusive, but higher speeds in the Bronx, speeding up the Grand Central throat, higher frequency, and lower schedule padding would together lead to improvements in trip times. However, this introduces a new set of problems, for which we need to consider the New Haven Line too.

Harlem Line express service and the New Haven Line

Currently, the New Haven Line runs 20 trains per hour into Grand Central at the peak. This number will go down after Penn Station Access opens in 2027, but not massively; a split of 6-8 trains per hour into Penn Station and 16-18 into Grand Central, with the new service mildly increasing total throughput, is reasonable.

Today, New Haven Line locals stop at Fordham, and nowhere else in the Bronx. This is inherited from the trackage rights agreement between the New York Central and the New York, New Haven and Hartford Railroad, allowing the latter to make only one stop in the Bronx on the former’s territory; it used to be Woodlawn, the branch point, but has been moved to Fordham, which has busier reverse-peak traffic. The two railroads merged in 1969, and all service is currently run by Metro-North, but the practice persists. This is not necessarily stupid: the New Haven locals are long – Stamford is 53 km from Grand Central, 50% farther than White Plains – and a system in which the New Haven trains are more express than the Harlem trains is not by itself stupid, depending on other system constraints. Unfortunately, this setup introduces all manners of constraints into the system:

  1. Fordham is a local-only station, and thus New Haven locals have to use the local tracks, using awkwardly-placed switches to get between the express and the local tracks. In fact, all stations up to and including Woodlawn are local-only; the first station with platforms on the express tracks is Wakefield, just north of the split between the two lines.
  2. If there are 12 Harlem Line trains per hour expressing through the Bronx, then the New Haven Line is limited to about 12 trains per hour as well unless the local trains make all the Bronx local stops.
  3. The Hudson Line has a flat junction with the Harlem Line at Mott Haven Junction, which means that any regular schedule has to have gaps to let Hudson Line trains pass; current peak Hudson Line traffic is 11 trains per hour, but it was 14 before corona.

This leads to a number of different options, each problematic in its own way.

Maximum separation

In this schedule, all Harlem Line trains run local, and all New Haven Line trains run express in the Bronx. This is the easiest to timetable – the junction between the two lines, unlike Mott Haven, is grade-separated. This also requires splitting the Hudson Line between local and express tracks, so delays will still propagate in any situation unless the Hudson Line is moved to the Empire Connection (6-8 trains per hour can stay on the current route); but in a future with Penn Station Access West, building such service, it does allow for neat separation of the routes, and I usually crayon it this way in very high-investment scenarios with multiple through-running tunnels.

But in the near future, it is a massive slowdown for Harlem Line riders who currently have express service from White Plains to Manhattan. The current peak timetable has a 15-minute difference between local and express trains on this section; this figure is padded but not massively so, and conversely, higher speeds on curves increase the express train speed premium.

It also severs the connection between the Bronx and the New Haven Line, unless passengers take east-west buses to the Penn Station Access stations. It is possible to add infill at Wakefield on the New Haven Line: this is north of the junction with the Harlem Line, but barely, so the separation between the lines is short, and a transfer station is feasible. But it wouldn’t be a cross-platform transfer, and so Fordham-Stamford service would still be degraded.

Locals run local

The New Haven Line locals can make local stops in the Bronx. It’s a slowdown of a few minutes for those trains – the current outbound timetable is 18 minutes from Grand Central to Fordham, two minutes faster than on Harlem Line locals while skipping Melrose and Tremont. Overall, it’s a slowdown of around six minutes; the current speed zones are 60 and 75 mph, and while raising the speed limits increases the extent of the slowdown (most of the track geometry is good for 160 km/h), getting new trainsets with better acceleration performance decreases it, and overall it’s likely a wash.

    From there, the service pattern follows. New Haven Line locals to Grand Central have little reason to run more frequently than every 10 minutes at peak – the local stations are 30-60 minutes out of Grand Central today, and this is massively padded, but with the timetables Devin produced, fixing the Grand Central throat, New Rochelle would still be 20 minutes out on a local train (stopping at Fordham only as is the case today) and Stamford would be 45 minutes out. What’s more, there will be some local trains to Penn Station starting in three years, boosting the effective frequency to a train every five minutes, with a choice of Manhattan station if express trains can be made to stop at New Rochelle with a timed connection.

    Now, if there are six local trains per hour in the Bronx going to Stamford, then the Harlem Line locals only take six trains per hour of their own, and then 12 trains should run express from Wakefield to Harlem. What they do to the north depends. The simplest option is to have all of them make all stops, which costs White Plains 7-8 minutes relative to the express stopping pattern. But if the line can be four-tracked to Crestwood, then half the trains can run local to White Plains and half can run nonstop between Wakefield or Mount Vernon West and White Plains. Two local stations, Scarsdale and Hartsdale, are in two-track territory, but timetabling a local to follow an express when both run every 10 minutes and there are only two local stops’ worth of speed difference is not hard.

    The New Haven Line, meanwhile, gets 12 express trains per hour. Those match 12 express Harlem Line trains per hour, and then there’s no more room on the express tracks; Hudson Line trains have to use the local tracks and somehow find slots for the northbound trains to cross both express tracks at-grade.

    Status quo

    The status quo balances Bronx-Stamford connectivity with speed. Bear in mind, the New Haven Line today has truly massive timetable padding, to the point that making trains make all six stops in the Bronx and not just Fordham would still leave New Rochelle locals faster than they are today if the other speedup treatments were put into place. But the status quo would allow New Rochelle, Larchmont, Rye, and Greenwich to take maximum advantage of the speedup, which is good. The problem with it is that it forces New Haven Line locals to take slots from both the express tracks and the local tracks in the Bronx.

    In this situation, the New Haven Line still runs six locals and 12 express trains to Grand Central per hour. The Harlem Line is reduced to six express trains through the Bronx and has to run 12 trains local. Transfers at Wakefield allow people in suburbs south of White Plains to get on a faster train, but this in effect reduces the effective peak-of-peak throughput from the suburbs to Manhattan to just six trains per hour.

    Express Fordham station

    Rebuilding Fordham as an express station means there’s no longer any need to figure out which trains stop there and which don’t: all would. Then the New Haven Line would run express and the Harlem would either run local or run a mix.

    The problem is that Fordham is in a constrained location, where such a rebuild is hard:

    The line is below-grade, with a tunnel from Fordham Road to 189th Street. The platforms are short and narrow, and partly overlap the tunnel. Any conversion has to involve two island platforms north of the tunnel, where there is room but only if the right-of-way is expanded a little, at the expense of some parkland, and possibly a lane of Webster Avenue. The cost would not be pretty, independently of the inability of the MTA to build anything on a reasonable budget.

    That said, the timetables on the Northeast Corridor require some infrastructure intervention to smooth things, like grade-separating some junctions for hundreds of millions of dollars each. New Rochelle, which has only a local platform southbound, should almost certainly be rebuilt as a full express stop. So rebuilding Fordham is not out of the question, even if the cost is high (which it is).

    In this situation, all New Haven Line trains should use the express tracks. Thus, as in the status quo alternative, the Harlem Line gets six express trains, the other trains having to run local. Potentially, there may be a schedule in which the New Haven Line runs 16 trains to Grand Central and eight to Penn Station, and then the Harlem Line can get eight local and eight express trains; but then the local trains have to be carrying the load well into Westchester, and four-tracking the line to Crestwood is likely obligatory.

    The New Haven Line and intercity trains

    The above analysis elides one important factor: intercity trains. The current practice in the United States is a three-way separation of urban rail, suburban commuter rail, and intercity rail, with fares designed to discourage riders from taking trains that are not in their sector. However, in much the same way the best industry practice is to charge mode-neutral fares within cities, it is also valuable to charge mode-neutral fares between them. In other words, it’s useful to look at the impact of permitting people with valid commuter rail tickets to take intercity trains, without seat reservations.

    To be clear, this means that at rush hour, there are going to be standees on busy commuter routes including Stamford-New York and Trenton-New York. But it’s not necessarily bad. The intercity trip time in our timetables between Stamford and New York is around 29 minutes without high-speed bypasses; the standing time would be less than some subway riders endure today – in the morning rush hour the E train departs Jamaica Center full and takes 34 minutes to get to its first Manhattan stop. And then there’s the issue of capacity: commuter trains on the New Haven Line are eight cars long, intercity trains can be straightforwardly expanded to 16 cars by lengthening the platforms at a very small number of stations.

    And if the intercity trains mop up some of the express commuter rail traffic, then the required service on the New Haven Line at rush hour greatly decreases. An intercity train, twice as long as a commuter train (albeit with somewhat fewer seats and less standing space per car), could plausibly displace so much commuter traffic that the peak traffic on the line could be reduced, say to 18 trains per hour from today’s 20. Moreover, the reduction would be disproportionately at longer distance: passengers west of Stamford would not have any replacement intercity train unless they backtracked, but passengers east of Stamford would likely switch. This way, the required New Haven Line traffic shrinks to 12 local trains per hour and six express trains; half the locals run to Penn Station and half to Grand Central, and all express trains run to Grand Central.

    In that situation, we can rerun the scenarios for what to do about Fordham; the situation generally improves, since less commuter traffic is required. The maximum separation scenario finally permits actual separation – the Hudson Line would run on the express tracks into Grand Central and have to cross the southbound Harlem Line locals at Mott Haven Junction, with predictable gaps between trains. The locals-run-local scenario gives Harlem Line express trains more wiggle room to slot between New Haven Line express trains. The status quo option lets the Harlem Line run six local trains and 12 express trains, though that likely underserves the Bronx. Converting Fordham to an express stop straightforwardly works with zero, six, or 12 express Harlem Line trains per hour.

    Or maybe not. It’s fine to assume that letting passengers get on a train that does Stamford-Penn Station in 29 minutes and New Haven-Penn Station in 57 for the price of a commuter pass is going to remove passengers from the express commuter trains and put them onto longer intercity trains. But by the same token, the massive speed improvements to the other stops could lead to an increase in peak demand. The current trip time to Stamford is 1:12 on a local train; cutting that to 45 minutes means so much faster trips to the suburbs in between that ridership could increase to the point of requiring even more service. I’m not convinced on this – the modal split for peak commutes to Manhattan is already very high (Metro-North claimed 80% in the 2000s), and these suburbs are incredibly NIMBY. But it’s worth considering. At the very least, more local service is easier to add to the timetable than more express service – locals to Grand Central don’t share tracks with intercities at all, and even locals to Penn Station only do on a controllable low-speed section in Queens.

    New York-New Haven Trains in an Hour

    Devin Wilkins and I are still working on coming up with a coordinated timetable on the Northeast Corridor, north to south. Devin just shared with me the code she was running on both routes from New Haven to New York – to Grand Central and to Penn Station – and, taking into account the quality of the right-of-way and tunnels but not timetable padding and conservative curve speeds – it looks like intercity trains would do it in about an hour. The current code produces around 57 minutes with 7% timetable pad if I’m getting the Penn Station throat and tunnel slowdowns right – but that’s an if; but at this point, I’m confident about the figure of “about an hour” on the current right-of-way.

    I bring this up to give updates on how the more accurate coding is changing the timetable compared to previous estimates, but also to talk about what this means for future investment priorities.

    First, the curve radii I was assuming in posts I was writing last decade were consistently too optimistic. I wrote three months ago about how even within the highest speed zone in southern Rhode Island, there’s a curve with radius 1,746 meters (1 degree in American parlance), which corresponds to about 215 km/h with aggressive cant and cant deficiency. At this point we’ve found numbers coming straight from Amtrak, Metro-North, and MBTA, letting us cobble together speed zones for the entire system.

    But second, conversely, I was being too conservative with how I was setting speed zones. My principle was that the tightest curve on a section sets the entire speed limit; when writing commuter rail timetables, I would usually have each interstation segment be a uniform speed zone, varying from this practice only when the interstation was atypically long and had long straight sections with a tight curve between them. When writing intercity timetables, I’d simplify by having the typical curves on a line set the speed limit and then have a handful of lower speed limits for tighter curves; for example, most curves on the New Haven Line are 873 meters, permitting 153 km/h with aggressive high-speed rail cant and cant deficiency, and 157 km/h with aggressive limits for slower trains, which can run at slightly higher cant deficiency, but those sections are punctuated by some sharper curves with lower limits. Devin, using better code than me, instead lets a train accelerate to higher speed on straight sections and then decelerate as soon as it needs to. Usually such aggressive driving is not preferred, and is used only when recovering from delays – but the timetable is already padded somewhat, so it might as well be padded relative to the fastest technical speed.

    The upshot of all of this is that the speed gains from just being able to run at the maximum speed permitted by the right-of-way are massive. The trip time today is 1:37 on the fastest trains between New York and New Haven. Commuter trains take 2:10, making all stops from New Haven to Stamford and then running nonstop between Stamford and Manhattan; in our model, with a top speed of 150 km/h, high-performance regional trains like the FLIRT, Talent 3, or Mireo should do the trip in about 1:15-1:20, and while we didn’t model the current rolling stock, my suspicion is that it should be around six minutes longer. The small difference in trip time is partly because Penn Station’s approach is a few kilometers longer than Grand Central’s and the curves in Queens and on the Hell Gate Bridge are tight.

    What this means is that the highest priority should be getting trains down to this speed. In the Swiss electronics-before-concrete schema, the benefits of electronics on the Northeast Corridor are massive; concrete has considerable benefits as well, especially on sections where the current right-of-way constrains not just speed but also reliability and capacity, like New Haven-Kingston, but the benefits of electronics are so large that it’s imperative to make targeted investments to allow for such clean schedules.

    Those investments do include concrete, to be clear. But it’s concrete that aims to make the trains flow more smoothly, in support of a repetitive schedule with few variations in train stopping patterns, so that the trains can be timetabled in advance not to conflict. At this point, I believe that grade-separating the interlocking at New Rochelle, popularly called Shell Interlocking and technically called CP 216, is essential and must be prioritized over anything else between the city limits of New York and New Haven Union Station. Currently, there’s very high peak traffic through the interlocking, with a flat junction between trains to Penn Station and trains to Grand Central.

    On the electronics side, the timetables must become more regular. There are currently 20 peak trains per hour on the New Haven Line into Grand Central; of those, four go to branches and 16 are on the main line, and among the 16, there are 13 different stopping patterns, on top of the intercity trains. It is not possible to timetable so many different trains on a complex system and be sure that everything is conflict-free, and as a result, delays abound, to which the response is to pad the schedules. But since the padded schedules still have conflicts, there is a ratchet of slowdowns and padding, to the point that a delayed train can recover 20 minutes on less than the entire line. Instead, every train should either be a local train to Stamford or an express train beyond Stamford, and there should only be a single express pattern on the inner line, which today is nonstop between Harlem and Stamford and in the future should include a stop at New Rochelle; this means that, not taking intercity trains into account, the main line should have at most four stopping patterns (local vs. express, and Penn Station vs. Grand Central), and probably just three, since express commuter trains should be going to Grand Central and not Penn Station, as passengers from Stamford to Penn Station can just ride intercity trains.

    Also on the electronics side, the way the line is maintained currently is inefficient to an extent measured in orders of magnitude and not factors or percents. Track inspection is manual; Metro-North finally bought a track geometry machine but uses it extremely unproductively, with one report saying it gets one tenth as much work done as intended. Normally these machines can do about a track-mile in an overnight work window, which means the entire four-track line can be regraded and fixed in less than a year of overnights, but they apparently can’t achieve that. Whatever they’re doing isn’t working; the annual spending on track renewal in Connecticut is what Germany spends on once-in-a-generation renewal. The endless renewal work includes a plethora of ever-shifting slow zones, and at no point is the entire system from New York to New Haven clear for trains, even on weekdays. The excessively complex schedule, on tracks that constantly shift due to segment-by-segment daytime repairs, is turning a trip that should be doable on current rolling stock in perhaps 1:23 into one that takes 2:10.

    The billions of dollars in the Bipartisan Infrastructure Law that are dedicated to the Northeast Corridor and have not yet been spent can reduce trip times further. But the baseline should be that the bucket of money is a few hundreds of millions smaller and the base case trip time from New York to New Haven is an hour and not 1:37; this is what the system should be compared with.

    On Worshiping Foreign Systems

    Tucker Carlson has been wowed by Putin’s Russia as of late and is reporting about how great it is; I wouldn’t normally talk about it, except that among the things he crowed about was Kiyevskaya Station on the Moscow Metro. He described it as clean and drug-free, and showed videos that would not have looked out of place in present-day Paris or London, and all I could think about when I watched it was something that I read in Korean media, more than 11 years ago. The newspaper JoongAng criticized the construction of the infill station at Guryong, by comparing its extravagance with the much more spartan stations of the Washington Metro, without noticing how the Washington Metro’s above-ground infill stations cost substantially more than the underground infill at Guryong, the Potomac Yards station reaching four times the cost of Guryong. In both cases, and in some others, the foreign system is not really described as a real place, but as a tourist fantasy. Little learning can come from this.

    In fact, there are many positive things one can learn from Russia about how to run rail transportation. Soviet metro planning was quite good, and Eastern Bloc successor states (including satellites, not just former USSR constituents) inherited it and have in some cases expanded on it even while rejecting central planning elsewhere, for example in thoroughly neoliberal Czechia. Good features of this planning tradition include all of the following:

    • Clean radial metro network design, with a distinction between city center and outlying areas.
    • Very high frequency on each line. Moscow peaks at 39 trains per hour, the highest number I know of on non-driverless metros. When I visited Prague, planned by the same tradition, I saw higher metro frequency than I do in Berlin, with its rigid five-minute headways.
    • Central planning of routes, with integration with where housing construction is permitted.

    Of note, Carlson’s video doesn’t touch on any of this. He gets the history of the station wrong – he says it was built 70 years ago, when in fact the metro station opened in 1937, and it’s only the two later lines on this three-line transfer that opened in 1953 and 1954. He says he is “just asking questions” and then takes the watcher on a short video trip of the long escalator down to the platform, the ornate details of and art on the station, and the platforms and trains. That’s not Soviet metro design; that’s just metros. The New York City Subway is atypically dirty so that the mosaic art and sculptures there are surrounded by grime, but London and Paris are clean, and some of the stations in Paris have interesting art on the platforms. Stockholm has exposed gneiss rock, which forms a natural arch, and sculptures on some of its platforms. To me, as a regular urban rail rider, all of this looks extremely ordinary, which should not surprise, as good metro planning makes the ordinary last for generations.

    Much of it is the excitement of a tourist. To the American visitor, the ornate finishes of Kiyevskaya are new, but the sculptures on the New York City Subway are so familiar that they go unremarkable. I see this in how Americans speak of Europe in general, especially on matters of urbanism; Marco Chitti pointed out that Italian farmers’ markets are for tourists and politicians, while most Italians do their shopping at car-oriented hypermarkets – tourists don’t see how auto-oriented Italy is, and this influences urbanist thinking about the greatness of traditional premodern city centers.

    I don’t know what Carlson thinks about urbanism in general. I doubt he’s thought about it much. There are other American right-wing populists who have; their views are common enough among architectural traditionalists that The American Conservative publishes Strong Towns and that at one point the Trump administration passed an executive order requiring all new federal buildings to use traditional architectural styles rather than postwar ones like brutalism or postmodernism.

    And Soviet-style metro planning is the exact opposite of that kind of urbanist tradition. It lives off of high-density housing, which are called projects in American parlance and microdistricts in the Soviet tradition, and are ideally placed right next to metro stations so that people can get to work efficiently. In Moscow, the city is large enough to support many radial metro lines, so that districts can be fairly close to metro stations far out of the center; in smaller cities, central planning is required to ensure alternation between high-density housing near the trains and parkland far from them, for which the best examples are Nordic rather than Eastern Bloc.

    Traditional architecture critics loathe that kind of housing. In Sweden, one can find right-wingers who view Million Program housing as a socialist conspiracy to depress people into being pliable subjects. Chuck Marohn is not conspiratorial like this, but still opposes spiky density and prefers uniform density, with rules about how new housing on a street should be of similar size to existing buildings (no more than 50% taller) rather than much taller as is typical of either modern redevelopment projects or project-style housing.

    Carlson himself is not that influential in urbanism, in the grand scheme of things. But urbanists who go on tourist trips abroad and conflate their travelogues for intellectual insights abound. Their views are often idiosyncratic, based on whatever they liked on a trip, which could be a high-speed rail trip, a neighborhood in a tourist trap, a kind of shopping that locals rarely do, or something similar. In all cases, this is fundamentally about leisure: the (usually New Left) tourist is in the city for purposes of leisure and experiences it as such, but the local rarely is. A glimpse of this can even be seen in the video from Kiyevskaya: the Moscow Metro is very crowded at rush hour, but the video does not depict overcrowding.

    It’s possible to learn from abroad, but it does not involve travelogues. It involves interacting with locals in a position of equality rather than in that of a heavyweight who uses taxi drivers as sources. It involves reading what locals say; two years ago, around when Russia invaded Ukraine, I found a list of Russian dissidents and looked at the LiveJournal of an urbanist activist, who was talking about how Russian cities undermaintain public spaces. I think highly of Seung Y. Lee precisely because he demystifies Korean and Japanese urban rail for the Western reader; one can read his complaints about the Seoul subway’s accessibility and still recognize that its 92% wheelchair accessibility is by most global standards very good. It’s possible to, from a position of learning, inform oneself and conclude that a foreign system is superior in most aspects to the domestic one. But that’s not what so many urbanists who speak of their own tourists experience do, and Carlson happens to have provided one political example of this.

    Costs Per Rider and Willingness to Build

    At the Transit Costs Project, we study the costs of urban rail lines per kilometer. This, with our usual controls, is a rough indicator of how efficient a city’s infrastructure construction program is. However, cost-effectiveness is different from efficiency, and is better measured not by just the cost but also the benefits, which are measured by ridership. Thus, cost-effectiveness is best measured by the cost of each project per rider. So what does it mean to compare different cities by their costs per rider, rather than per kilometer?

    The answer is, “not much,” at least not as far as efficiency or good decisionmaking. In fact, while some projects persistently have costs per rider that are too high to be cost-effective (for example, it’s endemic to airport extensions), some cities have costs per rider that are too low, such as Berlin. The issue here is that if municipal or state decisionmaking is healthy, it will build cost-effective lines; if a line under discussion has a very high benefit-cost ratio, or equivalently a very low cost per rider, it means it should have been built long ago, and it speaks poorly to the local decisionmaking that it hasn’t been built already, as is unfortunately the case in Berlin.

    Cost per rider and cost-effectiveness

    As always, let’s start with Second Avenue Subway Phase 1, the project that launched my interest in construction costs and the Transit Costs Project writ large. The projected daily ridership is 202,000; the line came close to it in 2019, reaching about 163,000 (see data here; I’m taking boardings for the three new stations, adding the growth in ridership at Lexington/63rd, and multiplying by two to account for disembarkings), and would have likely reached projection by now but for the pandemic. The cost, in 2023 dollars, was $6.23 billion, or about $31,000 per projected weekday trip.

    For another anchoring number, let’s use the Stockholm Metro’s entire construction from the 1940s to the 1970s. This is useful because in addition to costs per rider, there is a published ex post benefit-cost ratio, thanks to the work of Maria Börjesson. The cost of that system, in 2023 PPP dollars, was $3.7 billion, with a ridership of 1,265,900 per workday in 2019, or $2,900/rider, while the benefit-cost ratio is 6 without taking agglomeration into account, or 8.5 with. This does not mean that the value of a rider is only about $24,900; this was the value in the economic situation of postwar Sweden, a country that was substantially poorer than the Sweden of today. In 2023 PPP terms, Sweden’s GDP per capita in 1965, about midway through the opening of the original system, was about $19,400; today, Sweden is 3.5 times richer, and the US is 17% richer than Sweden.

    The benefits of urban travel are largely proportional to GDP per capita. The economic benefits of agglomeration are proportional to the value of the economy writ large, and so are the benefits of reduced travel time, which in benefit-cost analyses are usually taken to be proportional to the average hourly wage. Conversely, the ability of a government to spend money on desired outcomes is proportional to its tax base, i.e. the size of its economy. All of this is approximate, but all we’re doing is first-order approximate analysis anyway, and so correcting for GDP per capita is valuable.

    As it is, the difference between American and Swedish GDP per capita boils down entirely to working hours. Swedes work shorter hours than Americans, as they, like nearly everyone else in Europe, get much longer vacation time; as of 2022, Sweden’s GDP per hour worked was, by a rounding error, slightly higher than the US’s. However, at the same time, the daily ridership numbers for Sweden are specifically drawn from winter workday ridership, to avoid reporting figures from when ridership is lower during the summer vacation season, and the same is true for daily ridership counts in France. If we give Sweden and France credit by looking at ridership when people aren’t on vacation, we must compare the cost per rider with GDP per capita and not GDP per hour.

    The upshot is that countries should be building metros up to a maximum capital cost per rider that’s about as large as their GDP per capita. The $24,900 computation for 1960s’ Sweden is ex post, and usually the ex ante benefit-cost ratio must be at least 1.2 or 1.3 for the project to go ahead due to risk. For light rail the allowable cost should be lower, and for bus projects it should be lower still, due to the higher lifetime operating costs; but for metros and metro-like urban rail projects (such as largely grade-separated light rail, or commuter rail tunnels like Citybanan), this analysis should hold. Second Avenue Subway Phase 1, which opened in a United States with a GDP of $73,300/capita in 2023 prices, is thus very cost-effective; Phase 2, budgeted at something like $70,000/rider in today’s prices, is marginal but makes it (in 2022, US GDP per capita in 2023 prices was $80,300).

    Some more costs per rider

    Our database of construction costs per km is largely complete, but we don’t have much ridership data. Worse, the costs per rider we do have have some biases. We have better information for the US and Canada than elsewhere, and for Europe than the rest of the non-North American world. Costs are also likeliest to be reported for megaprojects with notable delays or cost overruns and thus an incomplete database will be biased upward; large, international cities have better reporting in English than the rest and this introduces another upward bias in incomplete data (these are typically wealthy and therefore capable of affording a high cost per rider).

    With that in mind, here are some (again, incomplete) examples:

    • Crossrail cost $24 billion in 2023 PPP terms; ridership in late 2023 was 4.3 million a week, which is usually about 700,000/weekday, said to be above projections, with long-term projections rising to a million/weekday; on current ridership it’s $34,000/rider, and on future projections it’s $24,000.
    • Paris Métro Line 14’s original section, opened by 2007, cost $2.44 billion in 2023 PPP terms; ridership in 2019, before more recent extensions and before corona, was 92 million, so around 320,000 per workday, which is $7,600/rider.
    • Grand Paris Express was projected in 2021 to cost (in 2023 PPP dollars) around $65 billion, with a ridership projection of 2 million/day from 2022, and 2.3-2.4 million/day from 2012, for around $32,000/rider, or $28,000 if the older ridership projection is used.
    • Milan Metro Line 5 cost $2.2 billion in 2023 PPP terms to date, and was said to carry 180,000 daily passengers in 2019, for $12,000/rider.
    • Milan Metro Line 4 cost $2.63 billion, and was expected to carry 235,000 riders per day when complete, which would be $11,000/rider; it will be completed this year, but ridership so far is for only the half of the line that has opened so far ans is also still somewhat suffering from corona.
    • The U-Bahn extensions in Berlin that are currently in development hell include U8 to Märkisches Viertel projected at 13,160€/rider (around $21,000 in 2023 PPP terms), a U6 extension to the former Tegel Airport projected at 27,200€/rider (around $43,000), and a U7 extension to the current BER airport projected at 23,000€/rider (around $36,000), among others brought up by the new coalition.

    Willingness to build and Berlin’s problem

    The above numbers should not be taken to mean that Italy and Germany are more cost-effective about metro construction. To the contrary, they indicate that they are leaving value on the table by not building.

    Germany has a GDP per capita of $66,000 in PPP terms. The benefit-cost ratios of the U-Bahn extensions in Berlin that are being discussed but not actually brought forward and built are very high, and the U8 extension to Märkisches Viertel is scratching a ratio of 4. It is irresponsible that there isn’t a massive construction plan not just under discussion but in design and soon physical construction. This must include not just those lines but also others to be added until the benefit-cost ratio of the marginal line falls to slightly more than the minimum that deserves funding.

    Italy has the same problem. No matter how pessimistic one’s view of the future of the economy of Italy is, the metro lines it is currently building, at least in Milan, are so cost-effective that there have to be more of them. In the 2010s, Italy was in a budget crunch and ended up using public-private partnerships to keep debt off-books, at very high implied interest rate based on the rate of payment to the concessionaire, about 8%. Today, fundamentally, even a stagnant economy with a GDP per capita of $55,000, which may finally overtake its 2007 peak this year, should be building more if the current extensive margin of Milan Metro construction is not even in the teens of thousands of dollars. Perhaps the benefit-cost ratios for Sweden rely not just on Sweden’s GDP per capita of the 1960s but on that of today, after 60 years of growth; but then even absent any of this growth, 55/3.5 > 12.

    Paris showcases a healthier situation: the success of M14 endeared the region to driverless metros with longer interstations than the older metro lines but shorter ones than the RER, and with further growth in the region, the state decided to build the 200 km Grand Paris Express to improve circumferential rail service and add more fast radial connections from the suburbs to the city not along the RER. France’s GDP per capita is around $58,000 in PPP dollars; some elements of GPE may be marginal, but the project writ large has a solid benefit-cost-ratio starting with a 2.

    Spain is like France in that when it can build, as it could before the Great Recession and as it can now after having recovered, it does. This is the right way to do it: low costs per km should translate to massive subway expansion. If you’re Madrid, you can build lines that would be completely ridiculous anywhere else in terms of land use, like MetroSur, because it’s cheap.

    A Paris or Berlin cannot be so profligate as Madrid. Building a line like MetroSur here, which in the Spanish context looks silly but does pass cost-effectiveness muster, would be an economic albatross. But medium-cost cities can still cover most of the built-up area with subway and commuter rail lines; Paris is doing so but Berlin is not.

    The problem for Berlin is not quite austerity, which afflicted Southern Europe last decade, producing negative economic growth. In the last coalition, it was the two most left-wing parties, the Greens and Die Linke, which opposed U-Bahn construction. In their view, trams are preferable; they complain about the high construction costs of subways, but don’t meaningfully engage with why they’re still necessary for fast urban transport beyond the range of the handful of inner neighborhoods where people vote for the Greens.

    That said, in the current coalition, there’s no real political left. SPD is in it, but under an atypically conservative leader in Franziska Giffey, and the more left-wing faction in the party, including the youth league Jusos, is sidelined. Both parties in the coalition, CDU and SPD, are committed to building those U-Bahn extensions. But then nothing is happening; Giffey is not competent enough to do it, and CDU is too wrapped up in anti-environmental populism to do something that pisses off some environmentalists but makes others happy.

    This way, the low costs per rider projected for Berlin U-Bahn expansion are not a testimony to cost-effectiveness. They’re a testimony to political unwillingness to build, for largely petty reasons. It is wasteful to build a subway line with a very high projected cost per rider relative to the country’s wealth, but it is equally wasteful not to build one with a low projected cost per rider, and the latter is what is happening in Berlin, unfortunately.

    Security Theater on Metros

    In comments, Sarapen asked me about security on urban rail. It’s common in developing Asia to require people to go through metal detectors to get to the platforms; I’ve seen this in Bangkok, she mentions this in the context of Manila, and it’s also the case on Indian metros and Chinese ones. Seung Y. Lee, a BART digital media worker and indispensable commentator on American and Asian metro history who sadly doesn’t blog enough, has an excellent post about it, talking about the use of security as a tool of social control, for example in Hong Kong.

    But Sarapen is asking about the need for security to deter terrorism and violence, which do exist in the Philippines.

    For this, I naturally went to the country facing terrorism and violence that I know most intimately. I haven’t visited in more than 11 years, and so I’ve never taken the light rail in either Tel Aviv or Jerusalem (which was open on my last visit but I didn’t visit the city then). So I went ahead and asked on my Discord server, and got this:

    The person covered up by the two shorter white rectangles also posted a picture of a platform in Tel Aviv, with a vault for bomb disposal:

    Israel Railways does have security theater – one has to open one’s bags in front of a security guard and go through a metal detector, and this being Israel, there is extensive racial profililng. But the light rail, including the underground portions in Tel Aviv, do not. There’s a lot of visible security presence, including cameras, security personnel, and K-9 units, but no metal detectors. This is in a country that, in the 1990s and early 2000s, underwent a wave of suicide bombings on buses, and still didn’t put metal detectors on them, because it’s infeasible to install such technology on surface transit, and too expensive and frankly not too useful on metros (a security line is an attractive bombing target).

    This shouldn’t be too surprising, in a way. Western Europe did not install security theater on trains in response to far-left terrorism in the 1970s and 80s. Israel’s way of building and running public transportation is intended as a pan-European medley, using consultants who have done work in Europe, and with media discourse that looks up to Europe’s urban transportation systems (on other matters Israel looks up to the United States, but Israelis understand American public transportation is not good). If nobody in Europe (or at least Western Europe) does something, it’s unlikely Israel will do it, not on civilian public infrastructure.

    Worthless Canadian Initiative

    Canada just announced a few days ago that it is capping the number of international student visas; the Times Higher Education and BBC both point out that the main argument used in favor of the cap is that there’s a housing shortage in Canada. Indeed, the way immigration politics plays out in Canada is such that the cap is hard to justify by other means: traditionally, the system there prioritized high-skill workers, to the point that there has been conservative criticism of the Trudeau cabinet for greatly expanding low-skill (namely, refugee) migration; capping student visas is not how one responds to such criticism.

    The issue is that Canada builds a fair amount of housing, but not enough for population growth; the solution is to build more – in a fast-growing country like Canada, the finance sector expects housing demand to grow and therefore will readily build more if it is allowed to.

    Vancouver deserves credit for the quality of its transit-oriented development and to a large extent also for the amount of absolute development it permits (about 10 units per 1,000 residents annually); but its ability to build is much greater than that, precisely because rapid immigration means that more housing is profitable, even at higher interest rates. The population growth coming from immigration sends a signal to the market, invest in long-term tangible goods like housing. Thus, Vancouver deserves less credit for its permissiveness of development – large swaths of the city are zoned for single-family housing with granny flats allowed, including in-demand West Side neighborhoods with good access to UBC and Downtown jobs by current buses and future SkyTrain.

    The rub is that restricting student immigration is probably the worst possible way to deal with a housing shortage. Students live at high levels of crowding, and the marginal students, who the visa cap is excluding, live at higher levels of crowding than the rest because they tend to be at poorer universities and from poorer backgrounds. The reduction in present-day demand is limited. In Vancouver, an empty nester couple with 250 square meters of single-family housing in Shaughnessy is consuming far more housing, and sitting on far more land that could be redeveloped at high density, than four immigrants sharing a two-bedroom apartment in East Vancouver.

    In contrast, the reduction in future demand is substantial, because those students then graduate and get work, and many of them get high-skill, high-wage jobs (the Canadian university graduate premium is declining but still large; the American one is larger, but the US is also a higher-inequality society in general); having fewer students, even fewer marginal students who might take jobs below their skill level, is still a reduction in both future population and future productivity. What this means is that capital owners deciding where to allocate assets are less likely to be financing construction.

    The limiting factor on housing production is to a large extent NIMBYism, and there, in theory, immigration restrictions are neutral. (In practice, they can come out of a sense of national greatness developmental conservatism that wants to build a lot but restrict who can come in, or out of anti-developmental NIMBYism that feels empowered to build less as fewer people are coming; this situation is the latter.) However, it’s not entirely NIMBYism – private developmental still has to be profitable, and judging by the discourse I’m seeing on Canadian high-rise housing construction costs in Toronto and Vancouver, it’s not entirely a matter of permits. Even in an environment with extensive NIMBYism like the single-family areas of Vancouver and Toronto, costs and future profits matter.