Category: Regional Rail

Free Public Transport, Fare Integration, and Capacity

There’s an ongoing debate about free public transport that I’m going to get into later, but, for now, I want to zoom in on one aspect of the 9€ ticket, and how it impacted public transport capacity in Germany. A commenter on the Neoliberal Reddit group claimed that during the three months of nearly free public transport fares, there was a capacity crunch due to overuse. But in fact, the impact was not actually significant on urban rail, only on regional trains, in a way that underscores the importance of fare integration more than anything.

What was the 9€ ticket?

Last year, in the wake of the Russian invasion of Ukraine, fuel prices shot up everywhere. This created populist pressure to alleviate the price of fuel through temporary tax cuts, which further exacerbated last year’s high inflation. The center-right element within the German coalition, FDP, moved away from its traditional position as deficit scold and demanded a cut in the fuel tax; as a compromise, the Greens agreed to it on condition that during the three months of reduced fuel tax, June through August, public transport fares would be cut as well. Thus the 9€ monthly was born.

The 9€ ticket applied throughout Germany. The key feature wasn’t just the deep discount but also the fact that on one ticket, people could travel all over Germany; normally, my Berlin monthly doesn’t let me ride the local trains in Leipzig or Munich. This stimulated massive domestic tourism, since people could travel between cities on slow regional trains for free and then also travel around their destination city for free as well.

What now?

The 9€ ticket clearly raised public transport ridership in the three months it was in effect. This led to demands to make it permanent, running up against the problem that money is scarce and in Germany ticket fares generate a significant proportion of public transport revenue, 7.363 billion € out of 14.248 billion € in expenses (source, p. 36).

One partial move in that direction is a 29€ monthly valid only within Berlin, not in the suburbs (zone C of the S-Bahn) or outside the system; unlike the 9€ ticket, which was well-advertised all over national and local media and was available at every ticketing machine, the 29€ monthly is only available via annual subscription, which requires a permanent address in the city, and the regular machines only sell the usual 86€ monthly and don’t even let you know that a cheaper option exists. The subscription is also not available on a rolling basis – one must do it before the start of the month, which is not advertised, and Ant6n‘s family was caught unaware one month.

Negotiations for a nationwide 49€ ticket are underway, proceeding at the pace of a German train, or perhaps that of German arms deliveries to Ukraine. This was supposed to start at the beginning of 2023, then in April, and now it’s expected to debut in May. I’m assuming it will eventually happen – German trains get you there eventually, if hours late occasionally.

What’s the impact on capacity?

The U- and S-Bahn systems didn’t at all get overcrowded. They got a bit more crowded than usual, but nothing especially bad, since the sort of trips induced by zero marginal cost are off-peak. Rush hour commuters are not usually price-sensitive: whenever one’s alternative to the train is a car, the difference between a 9€ monthly and an 86€ one is a fraction of the difference between either ticket and the cost of owning and using a car, and at rush hour, cars are limited by congestion as well. Off-peak ridership did visibly grow, but not to levels that congest the system.

But then the hourly regional trains got completely overcrowded. If you wanted to ride the free trains from Berlin to Leipzig, you’d be standing for the last third of the trip. This is because the regional rail system (as opposed to S-Bahn) is designed as a low-capacity coverage-type system for connecting to small towns like Cottbus or Dessau.

The broader issue is that there is always a sharp ridership gradient between large cities and everywhere else, even per capita. In some places the gradient is sharper than elsewhere; the difference between New York and the rest of the United States is massive. But even in Germany, with a smaller gradient than one might be used to from France or the UK or Japan, public transport ridership is disproportionately dense urban or perhaps suburban, on trams and U- and S-Bahns.

The regional trains are another world. Really, European and Japanese trains can be thought of as three worlds: very high-use urban and suburban rail networks, high-use intercity rail connecting the main cities usually at high speed, and low-usage, highly-subsidized regional trains outside the major metropolitan regions. Germany has relatively good trains in the last category, if worse than in Switzerland, Austria, or the Netherlands: they run hourly with timed connections, so that people can connect between them to many destinations, they just usually don’t because cities the size of Dessau don’t generate a lot of ridership. The 9€ ticket gave people a free intercity trip if they chained trips on these regional trains, at the cost of getting to Leipzig in a little less than three hours rather than 1:15 on the ICE; the regional trains were not expanded to meet this surge traffic, which is usually handled on longer intercity trainsets, creating standing-room only conditions on trains where this should not happen off-peak or perhaps ever.

The issue of fare integration

The overcrowding seen on the regional trains last summer is really an issue of fare integration, which I hope is resolved as the 49€ gives people free trips on such trains permanently. A cornerstone of good public transport planning is that the fare between two points should be the same no matter what vehicle one uses, with exceptions only for first-class cars if available. Ein Ticket für alles, exclaims the system in Zurich, to great success. Anything else slices the market into lower-frequency segments, providing worse service than under total fare integration. Germany understands this – the Verkehrsverbund was invented in Hamburg in 1965, and subsequently this idea was adopted elsewhere until the country has been divided into metropolitan zones with internal fare integration.

The regional trains that cross Verkehrsverbund zones have their own fares, and normally that’s okay. Intercity trains were never part of this system, and that’s okay too – they’re not about one’s usual trip, and so an intercity ticket doesn’t include free transfers to local public transport unless one pays extra for that amenity. The fares between intercity trains and chains of regional trains were not supposed to be integrated, and normally that’s fine too, because any fare savings from chaining trips on slower trains are swamped both by the headache of buying so many tickets and by the difference in trip time and reliability.

The 9€ ticket broke that system, and the 49€ ticket will have the same effect: for three months, trips on slower trains were free, leading to overcrowding on a low-capacity network that normally isn’t that important to the country’s overall public transport system.

Worse, the operating costs of slow trains are higher than those of fast trains: they are smaller and so have a higher ratio of crew to passengers than ICEs, and their slowness means that crew and maintenance costs per kilometer are higher than those of fast trains. Even energy costs are higher on slow trains, because high-speed lines run at 300 km/h over long stretches, whereas regional lines make many stops (which had very little usage compared with the train’s volume of passengers last summer) and have slow zones rather than cruising at 130 or 160 km/h over long stretches. So the system gave people a price incentive to use the higher-cost trains and not the lower-cost ones.

This is the most important thing to resolve about any future fare reductions. Some mechanism is needed to ensure that the most advantageous way to travel between two cities is the one that DB can provide the most efficiently, which is IC/ICE and not RegionalBahn.

Edge Cities With and Without Historic Cores

An edge city is a dense, auto-oriented job center arising from nearby suburban areas, usually without top-down planning. The office parks of Silicon Valley are one such example: the area had a surplus of land and gradually became the core of the American tech industry. In American urbanism, Tysons in Virginia is a common archetype: the area was a minor crossroads until the Capital Beltway made it unusually accessible by car, providing extensive auto-oriented density with little historic core.

But there’s a peculiarity, I think mainly in the suburbs of New York. Unlike archetypal edge cities like Silicon Valley, Tysons, Century City in Los Angeles, or Route 128 north of Boston, some of the edge cities of New York are based on historic cores. Those include White Plains and Stamford, which have had booms in high-end jobs in the last 50 years due to job sprawl, but also Mineola, Tarrytown, and even New Brunswick and Morristown.

The upshot is that it’s much easier to connect these edge cities to public transportation than is typical. In Boston, I’ve spent a lot of time trying to figure out good last mile connections from commuter rail stations. Getting buses to connect outlying residential areas and shopping centers to town center stations is not too hard, but then Route 128 is completely unviable without some major redesign of its road network: the office parks front the freeway in a way that makes it impossible to run buses except dedicated shuttles from one office park to the station, which could never be frequent enough for all-day service. Tysons is investing enormous effort in sprawl repair, which only works because the Washington Metro could be extended there with multiple stations. Far and away, these edge cities are the most difficult case for transit revival for major employment centers.

And in New York, because so much edge city activity is close to historic cores, this is far easier. Stamford and White Plains already have nontrivial if very small transit usage among their workers, usually reverse-commuters who live in New York and take Metro-North. Mineola could too if the LIRR ran reverse-peak service, but it’s about to start doing so. Tarrytown and Sleepy Hollow could be transit-accessible. The New Jersey edge cities are harder – Edison and Woodbridge have lower job density than Downtown Stamford and Downtown White Plains – but there are some office parks that could be made walkable from the train stations.

I don’t know what the history of this peculiar feature is. White Plains and Mineola are both county seats and accreted jobs based on their status as early urban centers in regions that boomed with suburban sprawl in the middle of the 20th century. Tarrytown happened to be the landfall of the Tappan Zee Bridge. Perhaps this is what let them develop into edge cities even while having a much older urban history than Tysons (a decidedly non-urban crossroads until the Beltway was built), Route 128, or Silicon Valley (where San Jose was a latecomer to the tech industry).

What’s true is that all of these edge cities, while fairly close to train stations, are auto-oriented. They’re transit-adjacent but not transit-oriented, in the following ways:

  • The high-rise office buildings are within walking distance to the train station, but not with a neat density gradient in which the highest development intensity is nearest the station.
  • The land use at the stations is parking garages for the use of commuters who drive to the station and use the train as a shuttle from a parking lot to Manhattan, rather than as public transportation the way subway riders do.
  • The streets are fairly hostile to pedestrians, featuring fast car traffic and difficult crossing, without any of the walkability features that city centers have developed in the last 50 years.

The street changes required are fairly subtle. Let us compare White Plains with Metrotown, both image grabs taken from the same altitude:

These are both edge cities featuring a train station, big buildings, and wide roads. But in Metrotown, the big buildings are next to the train station, and the flat-looking building to its north is the third-largest shopping mall in Canada. The parking goes behind the buildings, with some lots adjoining Kingsway, which has a frequent trolleybus (line 19) but is secondary as a transportation artery to SkyTrain. Farther away, the residential density remains high, with many high-rises in the typical thin-and-tall style of Vancouver. In contrast, in White Plains, one side of the station is a freeway with low-density residential development behind it, and the other is parking garages with office buildings behind them instead of the reverse.

The work required to fix this situation is not extensive. Parking must be removed and replaced with tall buildings, which can be commercial or residential depending on demand. This can be done as part of a transit-first strategy at the municipal level, but can also be compelled top-down if the city objects, since the MTA (and other Northeastern state agencies) has preemption power over local zoning on land it owns, including parking lots and garages.

On the transit side, the usual reforms for improvements in suburban trains and buses would automatically make this viable: high local frequency, integrated bus-rail timetables (to replace the lost parking), integrated fares, etc. The primary target for such reforms is completely different – it’s urban and inner-suburban rail riders – but the beauty of the S-Bahn or RER concept is that it scales well for extending the same high quality of service to the suburbs.

TransitCenter’s Commuter Rail Proposal

Last week, TransitCenter released a proposal for how to use commuter rail more effectively within New York. The centerpiece of the proposal is to modify service so that the LIRR and Metro-North can run more frequently to stations within the city, where today they serve the suburbs almost exclusively; at the few places near the outer end of the city where they run near the subway, they have far less ridership, often by a full order of magnitude, which pattern repeats itself around North America. There is much to like about what the proposal centers; unfortunately, it falls short by proposing half-hourly frequencies, which, while better than current off-peak service, are far short of what is needed within the city.

Commuter rail and urban ridership

TransitCenter’s proposal centers urban riders. This is a welcome addition to city discourse on commuter rail improvement. The highest-ridership, highest-traffic form of mainline rail is the fundamentally urban S-Bahn or RER concept. Truly regional trains, connecting distinct centers, coexist with them but always get a fraction of the traffic, because public transit ridership is driven by riders in dense urban and inner-suburban neighborhoods.

A lot of transit and environmental activists are uncomfortable with the idea of urban service. I can’t tell why, but too many proposals by people who should know better keep centering the suburbs. But in reality, any improvement in commuter rail service that does not explicitly forgo good practices in order to discourage urban ridership creates new urban ridership more than anything else. There just aren’t enough people in the suburbs who work in the city (even in the entire city, not just city center) for it to be any other way.

TransitCenter gets it. The proposal doesn’t even talk about inner-suburban anchors of local lines just outside the city, like Yonkers, New Rochelle, and Hempstead (and a future update of this program perhaps should). No: it focuses on the people near LIRR and Metro-North stations within the city, highlighting how they face the choice between paying extra for infrequent but fast trains to Midtown and riding very slow buses to the edge of the subway system. As these neighborhoods are for the most part on the spectrum from poor to lower middle-class, nearly everyone chooses the slow option, and ridership at the city stations is weak, except in higher-income Northeast Queens near the Port Washington Branch (see 2012-4 data here, PDF-pp. 183-207), and even there, Flushing has very little ridership since the subway is available as an alternative.

To that effect, TransitCenter proposes gradually integrating the fares between commuter rail and urban transit. This includes fare equalization and free transfers: if a bus-subway-bus trip between the Bronx and Southern Brooklyn is covered by the $127 monthly pass then so should a shorter bus-commuter rail trip between Eastern Queens or the North Bronx and Manhattan.

Interestingly, the report also shows that regionwide, poorer people have better job access by transit than richer people, even when a fare budget is imposed that excludes commuter rail. The reason is that in New York, suburbanization is a largely middle-class phenomenon, and in the suburbs, the only jobs accessible by mass transit within an hour are in Midtown Manhattan, whereas city residents have access to a greater variety of jobs by the bus and subway system. But this does not mean that the present system is equitable – rich suburbanites have cars and can use them to get to edge city jobs such as those of White Plains and Stamford, and can access the entire transit network without the fare budget whereas poorer people do have a fare budget.

The issue of frequency

Unfortunately, TransitCenter’s proposal on frequency leaves a lot to be desired. Perhaps it’s out of incrementalism, of the same kind that shows up in its intermediate steps toward fare integration. The report suggests to increase frequency to the urban stations to a train every half an hour, which it phrases in the traditional commuter rail way of trains per day: 12 roundtrips in a six-hour midday period.

And this is where the otherwise great study loses me. Forest Hills, Kew Gardens, and Flushing are all right next to subway stations. The LIRR charges higher fares there, but these are fairly middle-class areas – richer than Rosedale in Southeast Queens on the Far Rockaway Branch, which still gets more ridership than all three. No: the problem in these inner areas is frequency, and a train every half hour just doesn’t cut it when the subway is right there and comes every 2-3 minutes at rush hour and every 4-6 off-peak.

In this case, incremental increases from hourly to half-hourly frequency don’t cut it. The in-vehicle trip is so short that a train every half hour might as well not exist, just as nobody runs subway trains every half hour (even late at night, New York runs the subway every 20 minutes). At outer-urban locations like Bayside, Wakefield, and Rosedale, the absolute worst that should be considered is a train every 15 minutes, and even that is suspect and 10 minutes is more secure. Next to the subway, the absolute minimum is a train every 10 minutes.

All three mainlines currently radiating out of Manhattan in regular service – the Harlem Line, the LIRR Main Line, and the Port Washington Branch – closely parallel very busy subway trunk lines. One of the purposes of commuter rail modernization in New York must be decongestion of the subway, moving passengers from overcrowded 4, 5, 7, E, and F trains to underfull commuter trains. The LIRR and Metro-North are considered at capacity when passengers start having to use the middle seats, corresponding to 80% of seated capacity; the subway is considered at capacity when there are so many standees they don’t meet the standard of 3 square feet per person (3.59 people/m^2).

To do this, it’s necessary to not just compete with buses, but also directly compete with the subway. This is fine: Metro-North and the LIRR can act as additional express capacity, filling trains every 5 minutes using a combination of urban ridership and additional ridership at inner suburbs. TransitCenter has an excellent proposal for how to improve service quality at the urban stations but then inexplicably doesn’t go all the way and proposes a frequency that’s too low.

I Gave a Talk About Through-Running

The ReThink NYC online panel earlier today was strange in a lot of ways: in delivery, in tone, in emphasis. Perhaps the full slide deck will be uploaded and I will be able to more easily point this out. For now, look at my slides; they’re a very condensed version of this post, criticizing the Empire State Development report saying that through-running at Penn Station is impossible.

The technical issue is that as you can see, my slides are a Beamer PDF. The version that I delivered was line-by-line, as is the norm for math presentations; you can click through to see what it means and why every presentation I upload on this blog is modified to be slide-by-slide and therefore has “2” in the file name. Everyone else was on PowerPoint or Google Slides, with centralized control; I took control for my portion, which was not designed around having an assistant who I tell “next slide please” periodically, and the system wasn’t as responsive to my clicks as I’d hoped.

The tone issue is that somehow I was the least offensive person on the panel. Moderator Sam Turvey was complaining that the MTA called the panel a private event as a reason not to send anyone to attend; I just stuck to some technical critiques, even with my background of calling for people to be fired here and on Twitter. I’m not sure how that came to be. But I somehow was the most polite person to the decision makers, I think, and that’s always jarring, when within the Transit Costs Project team I’m the least polite and least charitable (why should I be charitable to $2 billion/km subway builders?).

And then there’s the emphasis issue. I was trying to give a 10-minute technical primer about the value of through-running and suggest one way of doing so (in practice, more like 15 minutes – everyone ran over). There are some differences between my concept and ReThink’s that I think are worth going over:

  • On the level of crayon, I think through-running at Penn Station should connect to Grand Central (similar to the old Alternative G from the early 2000s). ReThink prefers pure East River through-running, I can’t tell whether via the existing tunnels or via a new two-track tunnel (called Alternative S in the 2000s, S standing for Sunnyside), which you can see one version of on Tri-State’s generally excellent report on the subject.
  • My conception of commuter rail is a predominantly urban service, using infrastructure that can then also be used for secondarily important suburban service. I wrote the linked blog post after seeing some discussion on Twitter, without realizing what ReThink was planning; next day, they told me about their conception of commuter rail as a system for decentralizing employment to suburban centers.
  • I think much more about non-crayon issues like junctions, high platforms, electrification of tails than do other advocacy organizations. That’s what I mean by electronics before concrete: fix the surface issues before or during construction of tunneled megaprojects.
  • I’m pretty rigidly against expansion of the footprint of Penn Station. It’s unnecessary (see for example this post), and so expensive it should only be done if absolutely critical; it’s fine to make compromises on platform amenities to avoid such expense. ReThink is against the full demolition of the block south of Penn Station but is open to moderate expansion of the footprint, as is Tri-State.
  • I’m openly YIMBY. I think Penn Station is the best place in the United States to put new commercial skyscrapers – the area is very well-served by mass transit, and the commuter trains are underfull by the crowding standards used to determine subway service. I see fully recovered rail ridership where I live and where I last lived and slower but noticeable corona recovery in New York. ReThink… all I’ll say is that they’re not YIMBY.

And none of this was really discussed. I can’t tell if it’s because everyone ran over, or because audience questions had a different focus, or because some of the other panelists were more critical of the plans to redevelop the area around Penn Station than of the technical merits of different paradigms of rail service. In a way, that kind of advocacy space is the wrong space to decide technical matters like Grand Central vs. no Grand Central through-running, but it might be useful to introduce the options and go over some pros and cons.

S-Bahn Frequency and Job Centralization

Commuter rail systems with high bidirectional frequency succeed in monocentric cities. This can look weird from the perspective of rail advocacy: American rail advocates who call for better off- and reverse-peak frequency argue that it is necessary for reverse-commuters. The present-day American commuter rail model, which centers suburban commuters who work in city center between 9 am and 5 pm, doesn’t work for other workers and for non-work trips, and so advocates for modernization bring up these other trips. And yet, the best examples of modern commuter rail networks with high frequency are in cities with much job centralization within the inner areas and relatively little suburbanization of jobs. What gives?

The ultimate issue here is that S-Bahn-style operations are not exactly about the suburbs or about reverse-commutes. They’re about the following kinds of trips, in roughly descending order of importance:

  • Urban commuter trips to city center
  • Commuter trips to a near-center destination, which may not be right at the one train station of traditional operations
  • Urban non-work trips, of the same kind as subway ridership
  • Middle-class suburban commutes to city center at traditional midcentury work hours, the only market the American commuter rail model serves today
  • Working-class reverse-commutes, not to any visible office site (which would tilt middle-class) but to diffuse retail, care, and service work
  • Suburban work and non-work trips to city center that are not at traditional midcentury hours
  • Middle-class reverse-commutes and cross-city commutes

The best example of a frequent S-Bahn in a monocentric city is Munich. The suburbs of Munich have a strong anti-city political identity, rooted in the pattern in which the suburbs vote CSU and the city votes SPD and Green and, increasingly, in white flight from the diverse city. But the jobs are in the city, so the suburbanites ride the commuter trains there, just as their counterparts in American cities like New York do. The difference is that the same trains are also useful for urban trips.

I don’t know the ridership by segment in Munich, but I do know it in Berlin, as of 2016 (source, p. 6):

Daily ridership on the Berlin U- and S-Bahn by interstation, in thousands; the Ring encircles city center, meeting the radials at Ostkreuz, Gesundbrunnen (north), Westkreuz, Schöneberg (south), and Südkreuz (also south, one stop east of Schöneberg)

Between Ostkreuz and Hauptbahnhof, just west of the meeting point with the North-South Tunnel, the east-west Stadtbahn has 160,000 daily riders. The proper suburbs are mostly less than 10,000 each, and even the more suburban neighborhoods of the city, like Wannsee, don’t contribute much. Overall, the majority of S-Bahn traffic is urban, consisting of trips taken either within the Ring or in the more urban outside-the-Ring areas, like Pankow, Steglitz, and especially Lichtenberg.

The high-frequency model of the S-Bahn works not because there is a mass of people who work in these outer areas. I don’t know the proportion of jobs in the Berlin region that are within the Ring, but I doubt it’s low. For reference, about 35% of Ile-de-France jobs are in a 100 km^2 blob (about the same area enclosed by the Ring) consisting of Paris, La Défense, and the suburbs in between. New York likewise has about 35% of metro area jobs in a 100 km^2 blob chosen to include Manhattan and the major non-Manhattan job centers like Downtown Brooklyn, Long Island City, and the Jersey City waterfront. I imagine Berlin should be the same or even somewhat higher (this proportion is inversely correlated with city population all else being equal) – Berlin is polycentric but all of its centers are on or within the Ring.

Rather, the reason the high-frequency model works is that there is a lot more ridership in urban areas than in low-density suburbs generating strictly unidirectional trips. The main users of the S-Bahn are city residents, or maybe residents of dense inner suburbs in regions with unusually tightly drawn city limits like Paris. If the highest demand is by people whose trip is 20 minutes and not 90 minutes, then the trains must run very frequently, or else they won’t ride. And if the highest demand is by people who are traveling all over the urban core, even if they travel to the central business district more than to other inner neighborhoods, then the trains must have good connections to the subway and buses and many urban stops.

In this schema, the suburbs still get good service because the S-Bahn model, unlike the traditional metro model (but like the newer but more expensive suburban metro), is designed to be fast enough that suburb-to-city trips are still viable. This way, middle-class suburbanites benefit from service whose core constituency is urban, and can enjoy relatively fast, frequent trips to the city and other suburbs all day.

I emphasize middle-class because lower-income jobs are noticeably less centralized. I don’t have any European data on this, but I do have American data. In New York, as of 2015, 57% of $40,000-a-year-and-up workers worked in Manhattan south of 60th Street, but only 37% of under-$40,000-a-year workers did. Moreover, income is probably a better way of conceptualizing this than the sociological concept of class – the better-off blue-collar workers tend to be centralized at industrial sites or they’re owner-operators with their own vans and tools and in either case they have very low mass transit ridership. The sort of non-middle-class workers who high-frequency suburban transit appeals to are more often pink-collar workers cleaning the houses of the middle class, or sometimes blue-collar workers with unpredictable work assignments, who might need cross-city transit.

In contrast, the sort of middle-class ridership that is sociologically the same as the remnants of the midcentury 9-to-5 suburban commuters but reverse-commutes to the suburbs is small. American commuter rail does take it into account: Metro-North has some reverse-peak trains for city-to-White Plains and city-to-Stamford commuters, and Caltrain runs symmetric peak service for the benefit of city-to-Silicon Valley commuters. And yet, even on Caltrain ridership is much more traditional- than reverse-peak; on Metro-North, the traditional peak remains dominant. There just isn’t enough transit-serviceable ridership in a place like Stamford the way it looks today.

So the upshot of commuter rail modernization is that it completely decenters the suburban middle class with its midcentury aspirations of living apart from the city. It does serve this class, because the S-Bahn model is good at serving many kinds of trips at once. But the primary users are urban and inner-suburban. I would even venture and presume that if, on the LIRR, the only options were business-as-usual and ceasing all service to Long Island while providing modern S-Bahn service within city limits, Long Island should be cut off and ridership would increase while operating expenses would plummet. The S-Bahn model does not force such a choice – it can serve the suburbs too, on local trains making some additional city stops at frequencies and fares that are relevant to city residents – but the primacy of city ridership means that the system must be planned from the inside out and not from the outside in.

One- and Two-Seat Rides

All large urban rail networks rely on transfers – there are too many lines for direct service between any pair of stations. However, transfers are still usually undesirable; there is a transfer penalty, which can be mitigated but not eliminated. This forces the planners who design urban and suburban rail systems to optimize: too many transfers and the trips are too inconvenient, too few and the compromises required to avoid transfers are also too inconvenient. How do they do it? And why?

Of note, the strategies detailed below are valid for both urban rail and suburban commuter rail systems. Multi-line commuter rail networks like the RER and the Berlin S-Bahn tend to resemble urban rail in their core and work in conjunction with the rest of the urban rail network, and therefore strategies for reducing the onerousness of transferring work in much the same way for both kinds of systems. Suburban strategies such as timing half-hourly trains to meet connecting buses are distinct and outside the scope of this post.

Transfer penalties

Passengers universally prefer to avoid transfers between vehicles, keeping everything else constant. The transportation studies literature has enough studies on this pattern that it has a name: transfer penalty. The transfer penalty consists of three elements:

  • Walking time between platforms or bus curbs
  • Waiting time for the connecting train or bus
  • An independent inconvenience factor in addition to the extra time

One meta-study of this topic is by Iseki-Taylor-Miller of the Institute for Transportation Studies. There’s a bewildering array of different assumptions and even in the same city the estimates may differ. The usual way this is planned in elasticity estimates is to bundle the inconvenience factor into walking and waiting times; passengers perceive these to be more onerous than in-vehicle time, by a factor that depends on the study. Iseki-Taylor-Miller quote a factor as low as 1.4-1.7 and Lago-Mayworm-McEnroe’s classic paper, sourced to a Swedish study, go up to 3; Teulings-Ossokina-de Groot suggest it is 2, which is the figure I usually use, because of the convenience of assuming worst-case scenario for waiting time (on average, the wait is half the headway).

The penalty differs based on the quality of station facilities, and Fan-Guthrie-Levinson investigate this for bus shelter. However, urban rail estimates including those in the above meta-studies are less dependent on station facilities, which are good in all cases.

Mitigating the transfer penalty

Reducing the transfer penalty for riders can be done in three ways, if one believes the model with a constant penalty factor (say 2):

  • Reducing the number of transfers
  • Reducing walking time between platforms
  • Reducing waiting time for trains

All three are useful strategies for good urban rail network planning, and yet all three are useful only up to a point, beyond which they create more problems than they solve.

Reducing transfers

The most coherent network planning principle for reducing passengers’ need to transfer is to build radial rail networks. Such networks ideally ensure each pair of lines intersects once in or near city center, with a transfer, and thus there is at most one transfer between any pair of stations. A circumferential line may be added, creating some situations in which a three-legged trip is superior in case it saves a lot of time compared with the two-legged option; in Moscow, the explicit purpose of the Circle Line is to take pressure off the congested passageway of the central transfer connecting the first three lines.

In general, the most coherent radial networks are those inherited from the Soviet tradition of metro building; the London Underground, which influenced this tradition in the 1920s, is fairly radial itself, but has some seams. It’s important in all cases to plan forward and ensure that every pair of lines that meets has a transfer. New York has tens of missed connections on the subway, and Tokyo has many as well, some due to haphazard planning, some due to an explicit desire to build the newer lines as express relief lines to the oversubscribed older lines.

On a regional rail network, the planning is more constrained by the need to build short tunnels connecting existing lines. In that case, it’s best to produce something as close to a coherent radial network with transfers at all junctions as possible. Through-running is valuable here, even if most pairs of origins and destinations on a branched commuter line trunk still require a transfer, for two reasons. First, if there is through-running, then passengers can transfer at multiple points along the line, and not just at the congested city center terminus. And second, while through-running doesn’t always cut the transfer for suburb-to-suburb trips, it does reliably cut the transfer for neighborhood-to-suburb trips involving a connection to the metro: a diameter can be guaranteed to connect with all radial metro lines, whereas a radius (terminating at city center) will necessarily miss some of them, forcing an extra transfer on many riders.

Reducing walking time

The ideal transfer is cross-platform, without any walking time save that necessary to cross a platform no more than 10-15 meters wide. Some metro building traditions aim for this from the outset: London has spent considerable effort on ensuring the key Victoria line transfers are cross-platform and this has influenced Singapore and Hong Kong, and Berlin has accreted several such transfers, including between the U- and S-Bahn at Wuhletal.

However, this is not always viable. The place where transfers are most valuable – city center – is also where construction is the most constrained. If two lines running under wide streets cross, it’s usually too costly to tilt them in such a way that the platforms are parallel and a cross-platform transfer is possible. But even in that case, it’s best to make the passageways between the platforms as short as possible. A cruciform configuration with stairs and an elevator in the middle is the optimum; the labyrinthine passageways of Parisian Métro stations are to be avoided.

Reducing waiting time

The simplest way to reduce waiting time is to run frequently. Passengers’ willingness to make untimed transfers is the highest when frequency is the highest, because the 2-minute wait found on such systems barely lengthens one’s trip even in the worst case, when one has frustratingly just missed the train.

Radial metro networks based on two- rather than one-seat rides pair well with high frequency. Blog supporter and frequent commenter Threestationsquare went viral last month when he visited Kyiv, a Soviet-style three-line radial system, and noted that due to wartime cuts the trains only run every 6-7 minutes off-peak; Americans amplified this and laughed at the idea that base frequency could be so high that a train every 7 minutes takes the appellation “only.”

When frequency is lower, for example on a branch or at night, cross-platform transfers can be timed, as is the case in Berlin. But these are usually accidental transfers, since the core city center transfers are on frequent trunks, and thus the system is only valuable at night. Moreover, timed transfers almost never work outside cross-platform transfers, which as noted above are not always possible; the only example I’m aware of is in Vienna, where a four-way transfer with stacked parallel platforms is timed.

This is naturally harder on a branched commuter rail system. In that case, it’s possible to set up the timetable to make the likeliest origin-destination pairs have short transfer windows, or even one-seat rides. However, in general transfers may require a wait as long as the system’s base clockface intervals, which is unlikely to be better than 20 minutes except on the busiest trunks in the largest cities; even Paris mixes 10-, 15-, and occasionally 20- and 30-minute intervals on RER branches.

The Nine-Euro Ticket

A three-month experiment has just ended: the 9€ monthly, valid on all local and regional public transport in Germany. The results are sufficiently inconclusive that nobody is certain whether they want it extended or not. September monthlies are reverting to normal fares, but some states (including Berlin and Brandenburg) are talking about restoring something like it starting October, and Finance and Transport Ministers Christian Lindner and Volker Wissing (both FDP) are discussing a higher-price version on the same principle of one monthly valid nationwide.

The intent of the nine-euro ticket

The 9€ ticket was a public subsidy designed to reduce the burden of high fuel prices – along with a large three-month cut in the fuel tax, which is replaced by a more permanent cut in the VAT on fuel from 19% to 7%. Germany has 2.9% unemployment as of July and 7.9% inflation as of August, with core inflation (excluding energy and food) at 3.4%, lower but still well above the long-term target. It does not need to stimulate demand.

Moreover, with Russia living off of energy exports, Germany does not need to be subsidizing energy consumption. It needs to suppress consumption, and a few places like Hanover are already restricting heating this winter to 19 degrees and no higher. The 9€ ticket has had multiple effects: higher use of rail, more domestic tourism, and mode shift – but because Germany does not need fiscal stimulus right now and does need to suppress fuel consumption, the policy needs to be evaluated purely on the basis of mode shift. Has it done so?

The impact of the nine-euro ticket on modal split

The excellent transport blog Zukunft Mobilität aggregated some studies in late July. Not all reported results of changes in behavior. One that did comes from Munich, where, during the June-early July period, car traffic fell 3%. This is not the effect of the 9€ ticket net of the reduction in fuel taxes – market prices for fuel rose through this period, so the reduction in fuel taxes was little felt by the consumer. This is just the effect of more-or-less free mass transit. Is it worth it?

Farebox recovery and some elasticities

In 2017 and 2018, public transport in Germany had a combined annual expenditure of about 14 billion €, of which a little more than half came from fare revenue (source, table 45 on p. 36). In the long run, maintaining the 9€ ticket would thus involve spending around 7 billion € in additional annual subsidy, rising over time as ridership grows due to induced demand and not just modal shift. The question is what the alternative is – that is, what else the federal government and the Länder can spent 7 billion € on when it comes to better public transport operations.

Well, one thing they can do is increase service. That requires us to figure out how much service growth can be had for a given increase in subsidy, and what it would do to the system. This in turn requires looking at service elasticity estimates. As a note of caution, the apparent increase in public transport ridership over the three months of more or less free service has been a lot less than what one would predict from past elasticity estimates, which suggests that at least fare elasticity is capped – demand is not actually infinite at zero fares. Service elasticities are uncertain for another reason: they mostly measure frequency, and frequency too has a capped impact – ridership is not infinite if service arrives every zero minutes. Best we can do is look at different elasticity estimates for different regimes of preexisting frequency; in the highest-frequency bucket (every 10 minutes or better), which category includes most urban rail in Germany, it is around 0.4 per the review of Totten-Levinson and their own work in Minneapolis. If it’s purely proportional, then doubling the subsidy means increasing service by 60% and ridership by 20%.

The situation is more complicated than a purely proportional story, though, and this can work in favor of expanding service. Just increasing service does not mean doubling Berlin U-Bahn frequency from every 5 to every 2.5 minutes; that would achieve very little. Instead, it would bump up midday service on the few German rail services with less midday than peak frequency, upgrade hourly regional lines to half-hourly (in which case the elasticity is not 0.4 but about 1), add minor capital work to improve speed and reliability, and add minor capital work to save long-term operating costs (for example, by replacing busy buses with streetcars and automating U-Bahns).

The other issue is that short- and long-term elasticities differ – and long-term elasticities are higher for both fares (more negative) and service (more positive). In general, ridership grows more from service increase than from fare cutting in the short and long run, but it grows more in the long run in both cases.

The issue of investment

The bigger reason to end the 9€ ticket experiment and instead improve service is the interaction with investment. Higher investment levels call for more service – there’s no point in building new S-Bahn tunnels if there’s no service through them. The same effect with fares is more muted. All urban public transport agencies project ridership growth, and population growth is largely urban and transit-oriented suburban.

An extra 7 billion € a year in investment would go a long way, even if divided out with direct operating costs for service increase. It’s around 250 km of tramway, or 50 km of U-Bahn – and at least the Berlin U-Bahn (I think also the others) operationally breaks even so once built it’s free money. In Berlin a pro-rated share – 300 million €/year – would be a noticeable addition to the city’s 2035 rail plan. Investment also has the habit to stick in the long term once built, which is especially good if the point is not to suppress short-term car traffic or to provide short-term fiscal stimulus to a 3% unemployment economy but to engage in long-term economic investment.

Penn Station Expansion is Based on Fraud

New York is asking for $20 billion for reconstruction ($7 billion) and physical expansion ($13 billion) of Penn Station. The state is treating it as a foregone conclusion that it will happen and it will get other people’s money for it; the state oversight board just voted for it despite the uncertain funding. Facing criticism from technical advocates who have proposed alternatives that can use Penn Station’s existing infrastructure, lead agency Empire State Development (ESD) has pushed back. The document I’ve been looking at lately is not new – it’s a presentation from May 2021 – but the discussion I’ve seen of it is. The bad news is that the presentation makes fraudulent claims about the capabilities of railroads in defense of its intention to waste $20 billion, to the point that people should lose their jobs and until they do federal funding for New York projects should be stingier. The good news is that this means that there are no significant technical barriers to commuter rail modernization in New York – the obstacles cited in the presentation are completely trivial, and thus, if billions of dollars are available for rail capital expansion in New York, they can go to more useful priorities like IBX.

What’s the issue with Penn Station expansion?

Penn Station is a mess at both the concourse and track levels. The worst capacity bottleneck is the western approach across the river, the two-track North River Tunnels, which on the eve of corona ran about 20 overfull commuter trains and four intercity trains into New York at the peak hour; the canceled ARC project and the ongoing Gateway project both intend to address this by adding two more tracks to Penn Station.

Unfortunately, there is a widespread belief that Penn Station’s 21 existing tracks cannot accommodate all traffic from both east (with four existing East River Tunnel tracks) and west if new Hudson tunnels are built. This belief goes back at least to the original ARC plans from 20 years ago: all plans involved some further expansion, including Alt G (onward connection to Grand Central), Alt S (onward connection to Sunnyside via two new East River tunnel tracks), and Alt P (deep cavern under Penn Station with more tracks). Gateway has always assumed the same, calling for a near-surface variation of Alt P: instead of a deep cavern, the block south of Penn Station, so-called Block 780, is to be demolished and dug up for additional tracks.

The impetus for rebuilding Penn Station is a combination of a false belief that it is a capacity bottleneck (it isn’t, only the Hudson tunnels are) and a historical grudge over the demolition of the old Beaux-Arts station with a labyrinthine, low-ceiling structure that nobody likes. The result is that much of the discourse about the need to rebuild the station is looking for technical justification for an aesthetic decision; unfortunately, nobody I have talked to or read in New York seems especially interested in the wayfinding aspects of the poor design of the existing station, which are real and do act as a drag on casual travel.

I highlight the history of Penn Station and the lead agency – ESD rather than the MTA, Port Authority, or Amtrak – because it showcases how this is not really a transit project. It’s not even a bad transit project the way ARC Alt P was or the way Gateway with Block 780 demolition is. It’s an urban renewal project, run by people who judge train stations by which starchitect built them and how they look in renderings rather than by how useful they are for passengers. Expansion in this context is about creating the maximum footprint for renderings, and not about solving a transportation problem.

Why is it believed that Penn Station needs more tracks?

Penn Station tracks are used inefficiently. The ESD pushback even hints at why, it just treats bad practices as immutable. Trains have very long dwell times: per p. 22 of the presentation, the LIRR can get in and out in a quick 6 minutes, but New Jersey Transit averages 12 and Amtrak averages 22. The reasons given for Amtrak’s long dwell are “baggage” (there is no checked baggage on most trains), “commissary” (the cafe car is restocked there, hardly the best use of space), and “boarding from one escalator” (this is unnecessary and in fact seasoned travelers know to go to a different concourse and board there). A more reasonable dwell time at a station as busy as Penn Station on trains designed for fast access and egress is 1-2 minutes, which happens hundreds of times a day at Shin-Osaka; on the worse-designed Amtrak rolling stock, with its narrower doors, 5 minutes should suffice.

New Jersey Transit can likewise deboard fast, although it might need to throw away the bilevels and replace them with longer single-deck trains. This reduces on-board capacity somewhat, but this entire discussion assumes the Gateway tunnel has been built, otherwise even present operations do not exhaust the station’s capacity. Moreover, trains can be procured for comfortable standing; subway riders sometimes have to stand for 20-30 minutes and commuter rail riders should have similar levels of comfort – the problem today is standees on New Jersey Transit trains designed without any comfortable standing space.

But by far the biggest single efficiency improvement that can be done at Penn Station is through-running. If trains don’t have to turn back or even continue to a yard out of service, but instead run onward to suburbs on the other side of Manhattan, then the dwell time can be far less than 6 minutes and then there is much more space at the station than it would ever need. The station’s 21 tracks would be a large surplus; some could be removed to widen the platform, and the ESD presentation does look at one way to do this, which isn’t necessarily the optimal way (it considers paving over every other track to widen the platforms and permit trains to open doors on both sides rather than paving over every other track pair to widen the platforms much more but without the both-side doors). But then the presentation defrauds the public on the opportunity to do so.

Fraudulent claim #1: 8 minute dwells

On p. 44, the presentation compares the capacity with and without through-running, assuming half the tracks are paved over to widen the platforms. The explicit assumption is that through-running commuter rail requires trains to dwell 8 minutes at Penn Station to fully unload and load passengers. There are three options: the people who wrote this may have lied, or they may be incompetent, or they be both liars and incompetent.

In reality, even very busy stations unload and load passengers in 30-60 seconds at rush hour. Limiting cases reaching up to 90-120 seconds exist but are rare; the RER A, which runs bilevels, is the only one I know of at 105.

On pp. 52-53, the presentation even shows a map of the central sections of the RER, with the central stations (Gare du Nord, Les Halles, and Auber/Saint-Lazare) circled. There is no text, but I presume that this is intended to mean that there are two CBD stations on each line rather than just one, which helps distribute the passenger load better; in contrast, New York would only have one Manhattan station on through-trains on the Northeast Corridor, which requires a longer dwell time. I’ve heard this criticism over the years from official and advocate sources, and I’m sympathetic.

What I’m not sympathetic to is the claim that the dwell time required at Penn Station is more than the dwell time required at multiple city center stations, all combined. On the single-deck RER B, the combined rush hour dwell time at Gare du Nord and Les Halles is around 2 minutes normally (and the next station over, Saint-Michel, has 40-60 second rush hour dwells and is not in the CBD unless you’re an academic or a tourist); in unusual circumstances it might go as high as 4 minutes. The RER A’s combined dwell is within the same range. In Munich, there are six stations on the S-Bahn trunk between Hauptbahnhof and Ostbahnhof – but at the intermediate stations (with both-sides door opening) the dwell times are 30 seconds each and sometimes the doors only stay open 20 seconds; Hauptbahnhof and Ostbahnhof have longer dwell times but are not busier, they just are used as control points for scheduling.

The RER A’s ridership in 2011 was 1.14 million trips per weekday (source, p. 22) and traffic was 30 peak trains per hour and 24 reverse-peak trains; at the time, dwell times at Les Halles and Auber were lower than today, and it took several more years of ridership growth for dwell times to rise to 105 seconds, reducing peak traffic to 27 and then 24 tph. The RER B’s ridership was 983,000 per workday in 2019, with 20 tph per direction. Munich is a smaller city, small enough New Yorkers may look down on it, but its single-line S-Bahn had 950,000 trips per workday in 2019, on 30 peak tph in each direction. In contrast, pre-corona weekday ridership was 290,000 on the LIRR, 260,000 on Metro-North, and around 270,000 on New Jersey Transit – and the LIRR has a four-track tunnel into Manhattan, driving up traffic to 37 tph in addition to New Jersey’s 21. It’s absurd that the assumption on dwell time at one station is that it must be twice the combined dwell times at all city center stations on commuter lines that are more than twice as busy per train as the two commuter railroads serving Penn Station.

Using a more reasonable figure of 2 minutes in dwell time per train, the capacity of through-running rises to a multiple of what ESD claims, and through-running is a strong alternative to current plans.

Fraudulent claim #2: no 2.5% grades allowed

On pp. 38-39, the presentation claims that tracks 1-4 of Penn Station, which are currently stub-end tracks, cannot support through-running. In describing present-day operations, it’s correct that through-running must use the tracks 5-16, with access to the southern East River Tunnel pair. But it’s a dangerously false assumption for future infrastructure construction, with implications for the future of Gateway.

The rub is that the ARC alternatives that would have continued past Penn Station – Alts P and G – both were to extend the tunnel east from tracks 1-4, beneath 31st Street (the existing East River Tunnels feed 32nd and 33rd). Early Gateway plans by Amtrak called for an Alt G-style extension to Grand Central, with intercity trains calling at both stations. There was always a question about how such a tunnel would weave between subway tunnels, and those were informally said to doom Alt G. The presentation unambiguously answers this question – but the answer it gives is the exact opposite of what its supporting material says.

The graphic on p. 39 shows that to clear the subway’s Sixth Avenue Line, the trains must descend a 2.45% grade. This accords with what I was told by Foster Nichols, currently a senior WSP consultant but previously the planner who expanded Penn Station’s lower concourse in the 1990s to add platform access points and improve LIRR circulation, thereby shortening LIRR dwell times. Nichols did not give the precise figure of 2.45%, but did say that in the 1900s the station had been built with a proviso for tracks under 31st, but then the subway under Sixth Avenue partly obstructed them, and extension would require using a grade greater than 2%.

The rub is that modern urban and suburban trains climb 4% grades with no difficulty. The subway’s steepest grade, climbing out of the Steinway Tunnel, is 4.5%, and 3-3.5% grades are routine. The tractive effort required can be translated to units of acceleration: up a 4% grade, fighting gravity corresponds to 0.4 m/s^2 acceleration, whereas modern trains do 1-1.3 m/s^2. But it’s actually easier than this – the gradient slopes down when heading out of the station, and this makes the grade desirable: in fact, the subway was built with stations at the top of 2.5-3% grades (for example, see figure 7 here) so that gravity would assist acceleration and deceleration.

The reason the railroaders don’t like grades steeper than 2% is that they like the possibility of using obsolete trains, pulled by electric locomotives with only enough tractive effort to accelerate at about 0.4 m/s^2. With such anemic power, steeper grades may cause the train to stall in the tunnel. The solution is to cease using such outdated technology. Instead, all trains should be self-propelled electric multiple units (EMUs), like the vast majority of LIRR and Metro-North rolling stock and every subway train in the world. Japan no longer uses electric locomotives at all on its day trains, and among the workhorse European S-Bahn systems, all use EMUs exclusively, with the exception of Zurich, which still has some locomotive-pulled trains but is transitioning to EMUs.

It costs money to replace locomotive-hauled trains with EMUs. But it doesn’t cost a lot of money. Gateway won’t be completed tomorrow; any replacement of locomotives with EMUs on the normal replacement cycle saves capital costs rather than increasing them, and the same is true of changing future orders to accommodate peak service expansion for Gateway. Prematurely retiring locomotives does cost money, but New Jersey Transit only has 100 electric locomotives and 29 of them are 20 years old at this point; the total cost of such an early retirement program would be, to first order, about $1 billion. $1 billion is money, but it has independent transportation benefits including faster acceleration and higher reliability, whereas the $13 billion for Penn Station expansion have no transportation benefits whatsoever. Switzerland may be a laggard in replacing the S-Bahn’s locomotives with EMUs, but it’s a leader in the planning maxim electronics before concrete, and when the choice is between building a through-running tunnel for EMUs and building a massive underground station to store electric locomotives, the correct choice is to go with the EMUs.

How do they get away with this?

ESD is defrauding the public. The people who signed their names to the presentation should most likely not work for the state or any of its contractors; the state needs honest, competent people with experience building effective mass transit projects.

Those people walk around with their senior manager titles and decades of experience building infrastructure at outrageous cost and think they are experts. And why wouldn’t they? They do not respect any knowledge generated outside the New York (occasionally rest-of-US) bubble. They think of Spain as a place to vacation, not as a place that built 150 kilometers of subway 20 years ago for the same approximate cost as Second Avenue Subway phases 1 and 2. They think of smaller cities like Milan as beneath their dignity to learn about.

And what’s more, they’ve internalized a culture of revealing as little as possible. That closed attitude has always been there; it’s by accident that they committed two glaring acts of fraud to paper with this presentation. Usually they speak in generalities: the number of people who use the expression “apples-to-apples” and provide no further detail is staggering. They’ve learned to be opaque – to say little and do little. Most likely, they’re under political pressure to make the Penn Station reconstruction and expansion look good in order to generate what the governor thinks are good headlines, and they’ve internalized the idea that they should make up numbers to justify a political project (and in both the Transit Costs Project and previous reporting I’d talked to people in consulting who said they were under such formal or informal pressure for other US projects).

The way forward

With too much political support for wasting $20 billion at the state level, the federal government should step in and put an end to this. The Bipartisan Infrastructure Law (BIL) has $66 billion for mainline rail; none of this money should go to Penn Station expansion, and the only way any money should go to renovation is if it’s part of a program for concrete improvement in passenger rail function. If New York wishes to completely remodel the platform level, and not just pave over every other track or every other track pair, then federal support should be forthcoming, albeit not for $7 billion or even half that. But it’s not a federal infrastructure priority to restore some kind of social memory of the old Penn Station. Form follows function; beautiful, airy train stations that people like to travel through have been built under this maxim, for example Berlin Hauptbahnhof.

To support good rail construction, it’s obligatory that experts be put in charge – and there aren’t any among the usual suspects in New York (or elsewhere in the US). Americans respect Germany more than they do Spain but still less than they should either; unless they have worked in Europe for years, their experience at Berlin Hbf and other modern stations is purely as tourists. The most celebrated New York public transportation appointment in recent memory, Andy Byford, is an expert (on operations) hired from abroad; as I implored the state last year, it should hire people like him to head major efforts like this and back them up when they suggest counterintuitive things.

Mainline rail is especially backward in New York – in contrast, the subway planners that I’ve had the fortune to interact with over the years are insightful and aware of good practices. Managers don’t need much political pressure to say absurd things about gradients and dwell times, in effect saying things are impossible that happen thousands of times a day on this side of the Pond. The political pressure turns people who like pure status quo into people who like pure status quo but with $20 billion in extra funding for a shinier train hall. But both the political appointees and the obstructive senior managers need to go, and managers below them need to understand that do-nothing behavior doesn’t get them rewarded and (as they accumulate seniority) promoted but replaced. And this needs to start with a federal line in the sand: BIL money goes to useful improvements to speed, reliability, capacity, convenience, and clarity – but not to a $20 billion Penn Station reconstruction and expansion that do nothing to address any of these concerns.

In-Motion Charging is not for Trains

Streetsblog Massachusetts editor Christian MilNeil has just asked a very delicate question on Twitter about battery power for public transportation. In-motion charging (IMC) is a positive technological development for buses, wiring part of a route in order to provide electric coverage to a much broader area. So why not use it for trains? The context is that the government of Massachusetts is doing everything in its power to avoid wiring commuter rail; its latest excuse is that a partly-wired system with battery-electric trains is cheaper. So how come IMC works for buses but not trains?

The answer is that trains and buses differ in ways that make fully wiring a train much more advantageous for equipment cost while costing less compared with IMC-style partial wiring – and the size of trains makes the equipment cost much more prominent.

Equipment cost

The cost of a single-deck electric multiple unit (EMU) other than high-speed rail is about $100,000 per linear meter of length, and appears to have changed little over the last 10-20 years. I have a list of recent tramways built in Europe for that cost, a shorter one of subways (including more outliers due to procurement problems or bespoke designs), and some standard citations for commuter rail EMUs. For the latter, here is a recent example of a Coradia Continental order in Germany: 200M€ for 32 trainsets, 20 with five 18-meter cars and 12 with four, or 75,000€ per linear meter.

In contrast, battery-EMUs (BEMUs) are far more expensive. Comparing like with like, here is a recent Coradia Continental BEMU order for Leipzig-Chemnitz, which line should have long been wired: 100M€ for 11 three-car, 56-meter long trainsets, or 160,000€ per linear meter.

Buses do not display such a premium. Trolleybus advocate Martin Wright writes a comparison of battery-electric and trolleybuses for Vancouver, and suggests that equipment costs are largely the same in the North American market (which is expensive by European standards). TU Berlin’s Dominic Jefferies and Dietmar Göhlich find that the base cost of an electric 12-meter bus is 450,000€, rising to 600,000€ with battery (p. 25); this is a premium, but it’s small, almost an order of magnitude less than that for trains per unit of length. Kiepe says that the cost of rebuilding 16 12-meter trolleybuses with IMC for Solingen is in the single-digit millions.

Why?

How come trains display such a large premium for batteries over electric traction supplied by trackside distribution (catenary wire or third rail) and buses don’t? This is not about the cost of the batteries: Jeffries-Göhlich cite a cost of 500-800€/kWh for a battery pack on a bus, and while Alstom hasn’t said what the battery capacity of the Coradia is in kWh, based on the range (120 km) and this slide deck about BEMUs (or PDF-p. 22 of a VDE study about EMUs and BEMUs), the capacity is likely around 700 kWh for the entire three-car train, with a cost about an order of magnitude less than the observed cost premium over EMUs.

Rather, the issue is likely about fitting the batteries on the train. Railvolution reports that to fit the batteries, Alstom had to demotorize one of the three powered bogies, reducing the maximum power drawn from 2.16 MW to 1.44. As a byproduct, this also somewhat hurts performance, increasing the stop penalty from the train’s maximum speed of 160 km/h by 15-20 seconds (46 empty or 51 full for an EMU, 60 and 71 respectively for a BEMU).

The cost of wiring

The cost of trolleybus wiring, at least judging by industry brochures such as that of UITP, is linear in route-km. This makes IMC attractive in that it cuts said cost by a factor of 2 to 3 on a single route, or even more on a route that branches out of a common trunk. For this reason, IMC is ideally suited for branched bus networks such as that of Boston, and is less valuable on grids where it’s uncommon for multiple bus routes to run together for a significant portion, such as the systems in Chicago, Toronto, and Vancouver.

But rail electrification does not quite work this way. Overall, the cost of wiring is mostly proportional to route-length, but the cost appears to be split evenly between the wire and the substations. A full-size commuter train in a major metropolitan area like Boston would be drawing around 7 MW while accelerating; a Citaro bus has a 220 kW diesel engine, or 125 in the electric version. Even taking into account that buses are slower and more frequent than trains and thus run at much higher frequency per route-km, there’s nearly a full order of magnitude between the substation costs per km for the two modes.

The upshot is that while IMC saves the cost of installing wire, it does not save a single penny on the cost of installing substations. The substations still need to fully charge a train in motion – and derating the train’s power as Alstom did does not even help much, it just means that the same amount of energy is applied over a longer period while accelerating but then still needs to be recharged on the wire.

How benefits of electrification scale

Electrification has a number of benefits over diesel power:

  • No local air pollution
  • Much less noise, and none while idling
  • Higher reliability
  • Higher performance
  • Much lower lifecycle costs

The first three are shared between externally-supplied electric and battery-electric power, at least when there’s IMC (pure battery power is unreliable in cold weather). The fourth is a mix: BEMUs have better performance than DMUs but worse than EMUs – whereas with buses this flips, as trolleybuses have performance constraints at trolleywire junctions. The fifth is entirely an EMU benefit, because of the high cost of BEMU acquisition.

The first two benefits are also much more prominent for buses than for trains. Buses run on streets; the pollution affects nearby pedestrians and residents as well as waiting riders, and the idling noise is a nuisance at every intersection and whenever there’s car traffic. Bus depots are an air quality hazard, leading to much environmental justice activism about why they’re located where they are. Trains are more separated from the public except when people wait for them.

In contrast, the last benefit, concerning lifecycle costs, is more prominent on trains. The benefits of electrification scale with the extent of service; that the acquisition cost of EMUs is around half that of BEMUs, and the lifecycle cost is around half that of DMUs, means that the return on investment on electrification can be modeled as a linear function of the fleet size in maximum service.

A US-standard 25 meter railcar costs $2.5 million at global EMU prices (which the US was recently able to achieve, though not anymore), and twice that at BEMU prices. 40-year depreciation and 4% interest are $162,500/year; a single train per hour, per car, is around $3,000/km (this assumes 50-60 km/h average speed counting turnaround time), or $6,000 counting both directions, and lifecycle maintenance costs appear to be similar to initial acquisition cost, for a total of around $12,000/km. At $2.5 million/km, this means electrification has an ROI of 0.5% per peak car per hour; a single 8-car train per hour is already enough for 4% ROI.

The numbers don’t work out this way for buses. Workhorse city buses run every 5 minutes at rush hour, and may occasionally run articulated buses, but the capacity is still only equivalent to a single hourly train; in the absence of IMC, electrification of buses is therefore hard to justify without the additional environmental benefits. But those environmental benefits can be provided at much lower cost with IMC.

Why electrify?

The upshot of the above discussion is that the reasons to electrify buses and trains are not the same. Bus electrification benefits center environmental and environmental justice: diesel buses are noisy and polluting and have poor ride quality. The only reason to wire buses at all rather than go for unwired battery-electric buses (BEBs) is that BEBs are not reliable in freezing temperatures and cost far more than diesels due to their downtime for charging.

But rail electrification is different. The environmental benefits are real, but less important. Train depots have not been major sources of air pollution since the steam era, unlike bus depots. The primary reasons are technical: equipment acquisition costs, maintenance costs, performance, reliability. And those overall advantage EMUs over BEMUs with IMC.

Suburban Metros and S-Bahns

Liam O’Connell just wrote a deep dive into the history of PATH in the 1970s. I recommend people read it; as the unprofitable Hudson and Manhattan (H&M) system was transferred to Port Authority’s control, to be subsidized via the toll revenue from the Hudson bridges that had killed ridership starting in the 1930s, there were plans for expansion deep into suburbia, as far out as Plainfield. The expansion was a twofer: the H&M was unprofitable and needed change, and the same was true of mainline rail in the Northeast. Liam goes over the history of the proposal to expand service to Plainfield, and calls it an S-Bahn, comparing it to existing American examples of suburban metro like BART as well as to actual S-Bahn-type systems like the German ones bearing the name but also the Paris RER and the Tokyo subway.

In reality, there is a distinction between suburban metro service and S-Bahn service. Liam gets at one of the issues that derailed the Plainfield extension (it attempted to use high-cost capital expansion to paper over operational problems). But the distinction goes far deeper than that, and applies even to suburban metro services with a fraction of the operating costs of PATH, like BART. These are not S-Bahns, and understanding how they differ is critical.

The basic difference is that S-Bahns run on mainline rail tracks; suburban metros do not. This distinction has implications for capital planning, urban network shape, and urban growth planning. In reality it’s more complicated than that, but instead of drawing a sharp boundary, it’s better to begin by going over the core features of each of the two service types (in linguistics this is called prototypes).

S-Bahn

The core feature of an S-Bahn is that it runs on mainline track and combines urban and suburban rail service. Every S-Bahn service I know of that bears that name or is otherwise associated with the core of the model shares track with other mainline services, but the busier ones (Berlin, Paris, Tokyo) do it only peripherally, because core lines are limited by track capacity.

The reason to use mainline track is that it’s already there, cutting construction costs. In most cases it also fits into a growth plan around existing town centers, such as the Finger Plan. Cities that build S-Bahn systems often have a surplus of industrial track serving declining manufacturing uses that can be redeveloped, for example the goods yards of historic rail terminals in European cities.

With a surplus of mainline track to use, S-Bahn systems employ extensive branching. There are more branches in the suburbs than urban trunk lines to feed them, so the system maximizes use of existing track this way. Conversely, the urban trunk lines need very high frequency to be usable as urban rail whereas the suburban branches can make do with a train every 10-20 minutes, so the branching structure generally matches frequency to both demand and passenger convenience.

Suburban metro

It is sometimes desirable to extend a metro system isolated from the mainline rail network into the suburbs. This is most commonly done when there are too few mainlines for adequate suburban service; China makes extensive use of suburban metro lines, and the commuter lines it does have are not run to S-Bahn standards (for example, the Beijing Suburban Railway is infrequent). Seoul, whose first subway line is an S-Bahn, employs greenfield suburban metros extensively as well, for example the Shin-Bundang Line.

Without an extensive system of existing lines to tap into, suburban metros necessarily cost more than S-Bahns. This means that there are fewer lines, so each line or branch has to be shorter, more frequent, and more intensively developed. Stockholm provides a ready-made example: it did not build an urban S-Bahn like the Copenhagen S-Tog, and instead built the three-line T-bana to a range of 10-20 km out of city center, with Million Program projects centered on T-bana stations.

In reality, it’s common for S-Bahn systems to also build greenfield suburban lines. For example, the RER A’s Marne-la-Vallée branch is greenfield, and does not look too different from the lines inherited from mainline rail; but it’s embedded in a mainline-compatible system, running through to legacy track on the other side of the city.

American postwar suburban rapid transit

American cities extending their urban rail networks into the suburbs ended up building suburban metros: they were never integrated with mainline rail. BART even runs on a different track gauge from the mainline network. Many of the other systems run alongside legacy lines instead of on them, at high cost. The high costs meant that there were fewer lines – the Washington Metro has complex interlining for a three-line metro, but by S-Bahn standards, it’s poor in branches.

Some of these systems had older metros to integrate with, including the Rockaways extension of the A in New York and the Green Line D Branch and the Red Line to Braintree in Boston; all three were taken over from disused commuter rail. The Braintree extension is notable in that the Old Colony Lines go much further than Braintree, but the conversion costs meant there would be no subway extension into suburbia past Braintree, and more recently the region awkwardly reopened the Old Colony Lines as low-frequency diesel commuter rail, with parts of the right-of-way encroached by the subway.

The PATH extension was to cost $402 million in 1975, or $2.2 billion today, about $80 million/km for an above-ground system that could run entirely on existing track. Newark-Elizabeth, on the Northeast Corridor, had plenty of spare capacity then and still does now – only after Gateway opens does the section need additional tracks, and parts of it are already six-track. Relative to what was required, the construction cost was extremely high. The projected two-way ridership was 28,200/day, or $78,000/rider, in an economy with less than half the average income of today.

The failure of postwar American rapid transit

Liam’s post mentions BART in the same sentence as the RER or the Tokyo subway system. This is a provocation, and Liam knows this. BART’s annual ridership before corona was not much higher than just the total number of boardings and alightings at Gare du Nord. The Bay Area’s modal split is comparable to that of provincial French metro areas like Marseille and Toulouse, with an urban light metro or light rail system and thoroughly auto-oriented character outside the historic core. So what gives?

This isn’t quite a shortcoming of the suburban metro model. Stockholm uses it, and so does all of China. Rather, it’s a combination of several problems.

  1. The suburban metro model requires extensive transit-oriented development to compensate for the narrower reach of the system. Stockholm built Vällingby and countless other suburbs on top of the T-bana. Washington built a handful of TOD centers like Arlington and Bethesda, and the other American examples built nothing, preferring parking lots and garages at stations.
  2. American construction costs were too high even then. The cost of the proposed PATH extension was $2.2 billion for 27 km on existing above-ground right-of-way. The actually-built Washington Metro cost $9.3 billion in current dollars by 2001, around $25 billion in today’s money, for a 166 km system of which 72 are underground. In contrast, the T-bana cost, in today’s PPP money, around $3.6 billion for 104 km of which 57 are underground, around one fifth the per-km cost of WMATA. As a result, not much was built, and in many cases what has been built follows freeway medians to economize, leading to further ridership shortfalls.
  3. BART specifically suffers from poor urban service. As pointed out more than 15 years ago by Christof Spieler, it has very little service in San Francisco outside city center; Oakland service is awkward too, with most residential areas on a separate branch from Downtown Oakland. The Washington Metro has done this better.
  4. The A train in New York has the opposite problem as BART: the Rockaways tail was tacked on so awkwardly, at the end of a line that runs express but is still not fast enough – Far Rockaway-Times Square takes 1:08-1:10 for a distance of 37 km. The Green Line D Branch takes 46 minutes peak, 40 off-peak to traverse 19 km from Riverside to Government Center. PATH to Plainfield would likely have had the same problem; the core system is not fast, and with no through-service beyond its Manhattan terminals, it would have had cumbersome transfers for onward travel.

Conclusion

There are two models for how to extend rapid transit into the suburbs: the commuter rail model of the S-Bahn systems, Tokyo, and the RER, and the suburban metro model of Stockholm and China; Seoul uses the S-Bahn model where legacy lines exist and the suburban metro model otherwise. The segregation of mainline rail from all other forms of mass transit forced postwar America to select the latter model.

But implementation fell short. Construction costs were far too high even in the 1970s. Transit-oriented development ranged from mediocre in Washington to nonexistent elsewhere; the systems were built to interact with cars, not buses or streetcars or subways or commuter rail. And most of the lines failed at the basic feature of providing good urban and suburban service on the same system – they either were too slow through the city or didn’t make enough city stops.

Moreover, much of this failure has to be viewed in light of the distinction between S-Bahns and suburban metro systems. S-Bahns had better turn their outlying stations into nodes with bus service (timed with the train unless frequency is very high) and local retail, but Berlin is full of park-and-rides and underdeveloped stations and suburban Zurich is low-density. In contrast, suburban metros have to have the TOD intensity of Stockholm or suburban Seoul – their construction costs are higher, so they must be designed around higher ridership to compensate. This should have been especially paramount in the high-cost American context. But it wasn’t, so ridership is low relative to cost, and expansion is slow.