Category: Germany

Regional Rail for Non-Work Trips

Good public transportation must be useful for all travel needs. This in particular includes trips that are not commutes to work, which are the most typical use case for suburban trains. This is a key difference between American and European public transportation: in some cases the modal split for work trips are similar, for example New York’s split is similar to that of the major German cities, but per capita ridership in the German cities is a lot higher than in New York, because off-peak service is better and people use it more for non-commute trips. In the linked post I went over this as a matter of better off-peak service; in this post I am going to go over the more fundamental question of, what kind of trips can regional public transport provide apart from work trips?

Some data from Germany

Germany periodically conducts surveys of transportation usage, called Mobilität in Deutschland, or MiD. The most recent was in 2017, and the one before it was in 2008. In Berlin, the data I have is from 2008, from the city’s transportation plan for 2030. On PDF-p. 30, it produces the following modal splits by trip type:

  • Work: 39% transit, 40% car
  • School: 31% transit, 31% car
  • Shopping: 19% transit, 30% car
  • Pleasure: 21% transit, 32% car
  • Going back home: 27% transit, 31% car
  • Other, including business: 25% transit, 67% car

Here is Hamburg, also as of 2008 and not 2017, on p. 7, with the city and suburbs listed separately:

  • Work: 33%/48% city, 16%/65% suburbs
  • School: 32%/13% city, 34%/30% suburbs
  • Shopping: 11%/41% city, 4%/65% suburbs
  • Errands: 21%/37% city, 4%/71% suburbs
  • Pleasure: 17%/40% city, 5%/55% suburbs

The Hamburg S-Bahn barely extends past city limits, even less so than the Berlin S-Bahn, so the low suburban modal splits cannot be viewed as a failure of S-Bahn service to be useful for non-work trips. But it’s worth pointing out that in both Berlin and Hamburg (city, not suburbs), work is the activity with the highest modal split for public transport, followed by school.

Long and short trips

In a few posts over the years, I talked about a dichotomy of long and short trips. Long trips include the primary commute but also extraordinary trips such as to the airport; short trips are routine errands, including shopping and short-distance leisure trips.

In most transit cities, short trips are not done on transit but on foot. I usually bring up Asian examples because they concentrate development near the train station, so one walks to the train station either to shop at the department store within the station or to get on an actual train to get to work in city center. But this is equally true of Germany, even with vastly lower extents of transit-oriented development. The intersection points of the Ringbahn with U- and S-Bahn lines are replete with shopping centers.

The upshot is that if people don’t take regional trains to go shopping, because if the system works, then they can walk to retail. This is true even when retail is at big box scale – those Ringbahn stations have Kaufland and Real hypermarkets.

Sporadic long trips

If regional rail is not for short trips, then what non-work trips is it for? The answer cannot be none, because ridership on S-Bahn trains in Berlin and Hamburg is too high compared with the work modal split. The answer can’t just be school either, because there aren’t vast numbers of school commuters.

Rather, it’s better to think in terms of sporadic and usual long trips. When I go play board games, it’s a long trip and not a short trip, because the community is citywide, and people come from Friedrichshain, from Charlottenburg, from far western suburbs, from Lichtenberg, from Pankow, from Schöneberg. The same is true of queer meetups – even when I lived in Neukölln and some of these meetups were walking distance to me, they were not walking distance to most attendees, who would take the U- or S-Bahn.

All of this falls under the rubric of sporadic long trips: long because they are not normally in-neighborhood, and sporadic because they are not one’s usual commute to work or school. But they often involve several roundtrips a week, producing healthy ridership at all hours of day.

Meetups are an example of using the train for socialization at a scale that’s expressly citywide or even regionwide. In that sense, a large city with a good regional transportation network is good for social connections, because it encourages communities to be more specialized to people’s interests. In a city the size of Berlin, even with Germany’s shocking lack of diversity, one can find enough queers for an English-language meetup. In a larger city like New York, without the same language load, one can even find ever more specialized communities – there is no one gaming community but many, and they intersect, for example one can look for queer gamers, or for a Harlem-based group with predominantly black demographics, and so on. This isn’t really any different from the economic advantages of large cities, which offer more division of labor.

The upshot is that even if the sort of travel one can do by regional rail that is not for work does not seem to exist in a city with poor off-peak public transportation service, this does not mean improving off-peak transit is pointless. On the contrary: over time, the existence of such service will let communities form at convenient locations based on the shape of the network. It will make the city bigger in a sense, and this is a good thing economically and socially.

Building Depth and Window Space

How much window space does an apartment need, relative to its area, and how does this affect building style? A fascinating post from about a year ago on Urban Kchoze makes the argument that modern North American buildings are too deep – Simon calls them obese. Simon contrasts the typical building style in major cities in Europe and Asia with modern North American imitators and argues that the North American versions have too much ratio of floor area to exterior window width, which only works with loft-style apartments, which are not fit for families.

Is Simon correct? Not really. There’s an important feature of the block style in Europe that he’s missing. And this leads to an interesting observation by itself about area-to-window-width ratios.

The issue of building depth

Simon shows a bunch of satellite photos of buildings in a style called the euroblock. Here’s one example from Stockholm, in Södermalm:

The block has a width that looks like 14.6 meters. Midblock buildings have front windows overlooking the street and back windows overlooking a central courtyard; corner buildings overlook two streets. Either way, the area-to-frontage ratio is 7.3 meters. In general, buildings in Central Stockholm, urban Berlin, and Paris in average a depth of 13-14 meters, so the above typology would generate a ratio of 6.5-7 meters.

Simon contrasts this with American buildings. The euroblock typology is very uncommon in the US – New York’s typology is much less neat and liberally uses windows that overlook very narrow spaces. But it does exist, generally in higher-end recent developments. For example, here’s the Avalon East Norwalk, a condo project wedged between I-95 and the Northeast Corridor.

It has essentially the same built form as the euroblock. Its development history is of course different: there are no streets on the exterior, only parking lots, and it is a single project surrounding a big plaza with a swimming pool rather than many small buildings that together enclose a courtyard that comprises several separate gardens. But in terms of how the building looks from space, it’s similar. The width is 20 meters, for an area-to-frontage ratio of 10 meters, well above 6.5-7 meters.


Euroblocks are complicated

The above Stockholm pic is a pretty simple building, conceptually: a linear building outlining the edge of a rectangle. This is not the typical euroblock; I had to look around Central Stockholm to find a fitting example. I could equally well use Hamburg or another such city of the same size class.

But in Paris, this form is almost unheard of, and in Berlin it is uncommon, I think mostly denoting postwar reconstruction. Paris and Berlin are larger cities, especially historically – in the Belle Epoque/Wilhelmine era, when this typology flourished, they were two of the largest few cities in the world, Berlin stagnating after World War Two and Paris growing exclusively in the suburbs. So they’d build up more of each lot and leave less unbuilt space between buildings. Instead, here is what a traditional Berlin block looks like, in this case in Neukölln:

These buildings enclose a central courtyard, as in Stockholm, but there the similarity ends. The courtyard is small, and there are several to a block. All these wings have internal corners with limited window space. Moreover, the wings that do not make it all the way to enclosing the courtyard, like the ones on the buildings north of Laubestrasse, have blank walls facing northeast, because they were built expecting the wing of another building to directly abut them. The wing of the building at the Laubestrasse/Elbestrasse eastern corner likewise has blank northeast-facing walls, and from space looks awkward, like a half-building. All of this was designed for more buildings, but some were never built or were knocked down.

If the euroblock has one big courtyard for the entire block as in the Stockholm and Norwalk examples, then the area-to-frontage ratio equals exactly half the building depth. But as soon as there are multiple courtyards, the ratio grows. The dimensions of the C-shaped building on Sonnenallee (one block south of Laubestrasse) just west of the corner building with which it shares the courtyard are 18 meters of street frontage by 38 of lot depth minus a half-courtyard of 11.5*12. This works out to 546 m^2/71 m, for a total ratio of 7.7 m, even though technically the building is never deeper than 13 m.

The blocks can get even more fractured. Here’s Prenzlauer Berg, in an area wedged between the former Wall and the Ringbahn:

The dimensions of the buildings fronting Korsörer Strasse on the north are pretty consistent. They all have an overall lot depth of about 32 meters, consisting of 14 meters of building, 11 meters of courtyard, and 7 meters of half-building with blank north-facing walls. The side wings are pretty consistently 7 meters deep each as half-buildings. Taking the pair of buildings flanking the second courtyard from the east as an example, they together are 35*32 minus 21*11, for 889 m^2/99 m = 9 m.

In Paris, building forms vary. But here is an example with wings, in the 17th:

The courtyards are smaller than in Berlin. Taking the second building from the west, we get 35*25 – 11*13, or 732 m^2/98 m = 7.5 m. When the courtyard is only about as wide as the building is deep, the above typology, similar to the image from Neukölln, generates a ratio equal to 5/8 the building depth, and not 1/2 as in the Stockholm example. The Prenzlauer Berg typology generates an even higher ratio, a full 2/3 of building depth if the courtyard is a square of side equal to the building depth.

And this matters. Buildings with simpler sides do get deeper in Paris. For example, this building in the 16th, wedged between two streets:

The depth of these buildings is 18 meters, so the area-to-frontage ratio is 9 m.

What does this mean?

My choice of the 16th and 17th in Paris for my examples is not random. Western Paris has been rich from the moment it urbanized – families of means choose to live this way. In general, within the family of euroblocks, the more desirable areas seem to have buildings with a slightly larger depth – the more working-class parts, such as Eastern Paris, have shallower buildings. Rich people would all else being equal prefer more window frontage space, but all else is not equal, and they prefer bigger apartments.

There is a definite limit on how deep buildings can be and how large the ratio of area to window frontage can be, but it is not as low as Simon posits. Ratios in the 8-9 region are not unheard of in old European buildings, and it stands to reason that euroblocks built in an environment of more prosperity, such as that of the early 21st century, could go slightly higher.

Moreover, the Norwalk example of a deeper building without wings is generally preferable to the traditional Berlin and Paris form of shallower buildings with wings. In Berlin, the apartments with street-facing windows are the most desirable. Historically, the wings were for the working class, which had to make do with narrow courtyards – sometimes narrower than today, the original statutory limit being less than 6 m wide due to 19th-century fire regulations. So the evolution of the euroblock is likely to be toward its American condo form.

More on Station Costs

Talking to Marco Chitti about the history of Italian construction always fills me with hope. He’s been gathering data about metro construction in Milan and Rome, and told Elif, Eric, and me about the issue of building through constrained areas. Historic city centers are constrained because tunneling can damage buildings – the first two lines in Milan, built in the 1950s and 60s at abnormally low costs, caused some damage to buildings, since they involved cut-and-cover under streets only 12-15 meters wide. The good news is that tunneling with a tunnel boring machine is fine now. Stations remain an enormous challenge – but the conversation did fill me with optimism about future construction in cities that were not global imperial capitals 2,000 years ago.

TBM technology

Tunnel-boring machines have advanced to the point of being archeology-safe. Italian heritage protection laws from the 2000s forbid any risk to historic buildings and historic sites, but TBM technology at this point allows preserving artifacts. It involves injecting a gel ahead of the cutting edge, which is not supposed to be a cost-raiser.

The result is that tunneling is cheap. This is not a matter of low wages – in fact, Marco cites higher wages for Italian skilled workers who staff TBMs, up to €4,500 a month net, which rises to about €9,000 gross with social contributions. These are based on a nationwide scale that only weakly varies with location, which helps explain why Naples costs are not low despite the region’s low incomes.

Station construction

Station construction costs vary immensely by location. In Rome, on the same project, stations in a suburban part of the city might be €60-70 million. This does not mean construction is trivially easy: Rome’s suburbs still often host historic sites, having been home to patrician villas in Antiquity, and in fact the word suburb dates to that era. However, it’s relatively safe, and I don’t think Line C ran into such sites.

Then in the most constrained parts of the city, things are different. The extension plans for Line C deeper into city center have station costs in the €400-600 million range. This is not what things cost everything within Rome, or even everywhere within the densely-built parts of the city. But the Line C extension passes through the most historic sites. An already-under construction segment will go to the Colosseum, and a planned extension deeper into city center is to go to Piazza Venezia, at the Wedding Cake, and it is that station that is projected to cost €600 million.

The reason for the high cost is that it is not possible to do archeology- and building-safe cut-and-cover. Piazza Venezia doesn’t quite have enough room for a cut-and-cover dig of a full-length station. It is fed by a wide street, the Via Fori Imperali, and I asked Marco why not build cut-and-cover there, but he pointed out that the street goes through the historic Forum. It is in fact elevated over the ruins; any cut-and-cover there would endanger the Forum, and is not acceptable.

Without cut-and-cover, the only alternative is to mine the stations. Rome investigated the option of large-diameter TBMs on the Barcelona L9 model and found it infeasible, since the tunnels are so big they might themselves cause some building damage. Once the stations are mined from a small shaft, their costs explode. Second Avenue Subway built stations using the same method, and had similar per-station construction costs.

The good news

Mined station construction is in practically all cases not necessary. New Yorkers talk about the city’s high built-up density as a reason why costs are high. But in terms of actual stuff in the way of a tunnel, there’s less in New York than in Rome or Istanbul, which has even lower construction costs.

In fact, there is a line in Rome that is rather similar in urban geography to Second Avenue Subway: the Line B1 branch. It runs under a 27 meter wide street flanked by modern buildings that are about 9 stories tall above ground but also have underground parking, Italy having such a car culture that the middle class expects to own cars even in Rome. The cost: €527 million for 3.9 km, in 2010-15.

Moreover, the hard rock in New York should make it easier to build stations while maintaining building safety. Manhattan’s schist is brittle and therefore requires concrete lining, unlike the more uniform gneiss of Stockholm, famously forming natural arches that are pretty to look at from within the tunnels. However, it is still better soil for construction than the sand of Berlin’s U5 extension, to be opened next month, or the alluvial soil of Amsterdam.

The explanation Marco gives concerning station construction is physical and not institutional. This means it should transplant well into another setting – which it does!

In Berlin, the city-center U5 extension, including U55, is in today’s money around €240 million/km. The stations look like cut-and-cover to me, and if they’re not then it comes from severe NIMBYism since the line goes under the very wide Unter den Linden, but one of the stations is basically under the river and another is under U6 and involves moving the U6 station, and the sandy soil is genuinely bad to tunnel through. Suburban extensions in Berlin, with easy cut-and-cover stations, are consistently in the €100-150 million/km range, which is barely higher than the non-Forum Italian range. So Berlin looks fine, and just needs to invest resources into U- and S-Bahn extensions and not into extending the A 100 motorway.

Can New York have what Italy has?

Almost certainly! Second Avenue is not an old or narrow street by Italian standards. Nor are any of the other streets slated for subway construction in New York, such as Nostrand, Utica, and even 125th. Importing construction techniques from Italy and Germany should be feasible. There may be problems with local politics – New Yorkers absolutely hate admitting that another city may be better than theirs in any way, and this makes learning harder. But it is not impossible, and so far there do not seem to be any physical or economic obstacles to doing so.

The German Way of Building Rapid Transit

Continuing my series on different traditions of building urban rapid transit, today it’s time for Germany and Austria, following the posts on the US, the Soviet bloc, Britain, and France. Germany had a small maritime empire by British and French standards and lost it all after World War 1, but has been tremendously influential on its immediate neighbors as a continental power. This is equally true of rapid transit: Germany and Austria’s rail traditions have evolved in a similar direction, influential also in Switzerland, Denmark, the Netherlands, and Belgium to varying extents.

S-Bahns and U-Bahns

Germany is one of the origins of urban regional rail, called S-Bahn here in contrast with the U-Bahn subway. The first frequent urban rail service in the world appeared in London in 1836, but trains ran every 20 minutes and the stop spacing was only borderline urban. Berlin in contrast innovated when it opened the east-west elevated Stadtbahn in 1882, running frequent steam trains with local spacing.

As elevated steam-powered urban rail, the Stadtbahn was not particularly innovative. New York had already been running such service on its own els going back to 1872. But the Stadtbahn differed in being integrated into the mainline rail system from the start. Berlin already had the Ringbahn circling the city’s then-built up area to permit freight trains to go around, but it still built the Stadtbahn with four tracks, two dedicated to local traffic and two to intercity traffic. Moreover, it was built to mainline rail standards, and was upgraded over time as these standards changed with the new national rail regulation of 1925. This more than anything was the origin of the concept of regional rail or S-Bahn today.

Vienna built such a system as well, inspired by many sources, including Berlin, opening in 1898. Hamburg further built a mainline urban rail connection between Hauptbahnhof and Altona, electrifying it in 1907 to become the first electrified S-Bahn in the world. Copenhagen, today not particularly German in its transportation system, built an S-Bahn in the 1930s, naming it S-tog after the German term.

However, German cities that built such S-Bahn systems would also build separate U-Bahn systems. U-Bahns in Germany have short stop spacing and tend to mostly serve inner areas: for example, on this map of Munich, the U-Bahn is in blue, and the trams are in red. Berlin has some farther-reaching U-Bahn lines, especially U7, a Cold War line built when the West got the U-Bahn and the East got the S-Bahn; had the city not been divided, it’s unlikely it would have been built at all.

Some of the early U-Bahns were even elevated, similarly to New York subway lines and a few Paris Métro lines. Hamburg’s operator is even called Hochbahn in recognition of the elevated characteristic of much of its system. Like Paris and unlike New York, those elevated segments are on concrete viaducts and not steel structures, and therefore the trains above are not very noisy, generally quieter than the cars at street level.

Light rail and Stadtbahns

The early els of Berlin and Vienna were called Stadtbahn when built in the 19th century, but since the 1960s, the term has been used to refer to mixed subway-surface systems.

Germany had long been a world leader in streetcar systems – the first electric streetcar in the world opened in Berlin in 1881. But after World War Two, streetcars began to be viewed as old-fashioned and just getting in the way of cars. West German cities generally tore out their streetcars in their centers, but unlike American or French cities, they replaced those streetcars with Stadtbahn tunnels and retained the historic streetcar alignments in outer neighborhoods feeding those tunnels.

The closure of the streetcars was not universal. Munich and Vienna retained the majority of their tram route-length, though they did close lines parallel to the fully grade-separated U-Bahn systems both cities built postwar. Many smaller cities retained their trams, like Augsburg and Salzburg, though this was generally more consistent in the Eastern Bloc, which built very little rapid transit (East Berlin) or severed itself from the German planning tradition and Sovietized (Prague, Budapest).

The Stadtbahn concept is also extensively used in Belgium, where it is called pre-metro; the Vienna U-Bahn and even the generally un-German Stockholm T-bana both have pre-metro history, only later transitioning to full grade separation. Mixed rapid transit-streetcar operations also exist in the Netherlands, but not in the consistent fashion of either the fast-in-the-center-slow-outside Stadtbahn or its fast-outside-slow-in-the-center inverse, the Karlsruhe model of the tram-train.

Network design

Rail network design in German-speaking cities is highly coordinated between modes but is not very systematic or coherent.

The coordination means that different lines work together, even across modes. In the post about France, I noted that the Paris Métro benefited from coordinated planning from the start, so that on the current network, there is only one place where two lines cross without a transfer. This is true, but there are unfortunately many places where a Métro line and an RER line cross without a transfer; the central RER B+D tunnel alone crosses three east-west Métro lines without a transfer. In Berlin, in contrast, there are no missed connections on the U-Bahn and the S-Bahn, and only one between the U-Bahn and S-Bahn, which S21 plans do aim to fix. Hamburg has two missed connections on the U-Bahn and one between the U- and S-Bahn. Munich has no missed connections at all.

But while the lines work well as a graph, they are not very coherent in the sense of having a clear design paradigm. Berlin is the most obvious example of this, having an U-Bahn that is neither radial like London or Moscow nor a grid like Paris. This is not even a Cold War artifact: U6 and U8 are parallel north-south lines, and have been since they opened in the 1920s and early 20s. Hamburg and Vienna are haphazard too. Munich is more coherent – its U-Bahn has three trunk lines meeting in a Soviet triangle – but its branching structure is weird, with two rush hour-only reverse-branches running as U7 and U8. The larger Stadtbahn networks, especially Cologne, are a hodgepodge of mergers and splits.


The German planning tradition has distinguishing characteristics that are rare in other traditions, particularly when it comes to fare payment – in many other respects, the Berlin U-Bahn looks similar to the Paris Métro, especially if one ignores regional rail.

Proof of payment: stations have no fare barriers, and the fare is enforced entirely with proof of payment inspections. This is common globally on light rail (itself partly a German import in North America) and on European commuter rail networks, but in Germany this system is used even on U-Bahns and on very busy S-Bahn trunks like Munich and Berlin’s; in Paris there’s POP on the RER but only in the suburbs, not in the city.

Unstaffed stations: because there are no fare barriers, stations do not require station agents, which reduces operating expenses. In Berlin, most U-Bahn stations have a consistent layout: an island platform with a stairway exit at each end. This is also common in the rest of the German-speaking world. Because there is no need for fare barriers, it is easy to make the stations barrier-free – only one elevator is needed per station, and thus Berlin is approaching fully wheelchair accessibility at low cost, even though it’s contemporary with New York (only 25% accessible) and Paris (only 3% accessible, the lowest among major world metros).

Fare integration: fares are mode-neutral, so riding an express regional train within the city costs the same as the U-Bahn or the bus, and transfers are free. This is such an important component of good transit that it’s spreading across Europe, but Germany is the origin, and this is really part of the coordination of planning between U- and S-Bahn service.

Zonal fares: fares are in zones, rather than depending more granularly on distance as is common in Asia. Zones can be concentric and highly non-granular as in Berlin, concentric and granular as in Munich, or non-concentric as in Zurich.

Monthly and annual discounts: there is a large discount for unlimited monthly tickets, in order to encourage people to prepay and not forget the fare when they ride the train. There are even annual tickets, with further discounts.

No smartcards: the German-speaking world has resisted the nearly global trend of smartcards. Passengers can use paper tickets, or pay by app. This feature, unlike many others, has not really been exported – proof-of-payment is common enough in much of Northern and Central Europe, but there is a smartcard and the fare inspectors have handheld card readers.

Verkehrsverbund: the Verkehrsverbund is an association of transport operators within a region, coordinating fares first of all, and often also timetables. This way, S-Bahn services operated by DB or a concessionaire and U-Bahn and bus services operated by a municipal corporation can share revenue. The first Verkehrsverbund was Hamburg’s, set up in 1965, and now nearly all of Germany is covered by Verkehrsverbünde. This concept has spread as a matter of fare integration and coordinated planning, and now Paris and Lyon have such bodies as well, as does Stockholm.

Germany has no head

The American, Soviet, British, and French traditions all rely on exports of ideas from one head megacity: New York, Moscow, London, Paris. This is not at all true of the German tradition. Berlin was the richest German city up until World War 2, and did influence planning elsewhere, inspiring the Vienna Stadtbahn and the re-electrification of the Hamburg S-Bahn with third rail in the late 1930s. But it was never dominant; Hamburg electrified its S-Bahn 20 years earlier, and the Rhine-Ruhr region was planning express regional service connecting its main cities as early as the 1920s.

Instead, German transportation knowledge has evolved in a more polycentric fashion. Hamburg invented the Verkehrsverbund. Munich invented the postwar S-Bahn, with innovations like scheduling a clockface timetable (“Takt”) around single-track branches. Cologne and Frankfurt opened the first German Stadtbahn tunnels (Boston had done so generations earlier, but this fell out of the American planning paradigm). Karlsruhe is so identified with the tram-train that this technology is called the Karlsruhe model. Nuremberg atypically built a fully segregated U-Bahn, and even more atypically was a pioneer of driverless operations, even beating Paris to be the first city in the world to automate a previously-manual subway, doing so in 2010 vs. 2012 for Paris.

There’s even significant learning from the periphery, or at least from the periphery that Germany deigns acknowledge, that is its immediate neighbors, but not anything non-European. Plans for the Deutschlandtakt are based on the success of intercity rail takt planning in Switzerland, Austria, and the Netherlands, and aim to build the same system at grander scale in a larger country.

The same polycentric, headless geography is also apparent in intercity rail. It’s not just Germany and Switzerland that build an everywhere-to-everywhere intercity rail system, in lieu of the French focus on connecting the capital with specific secondary cities. It’s Austria too, even though Vienna is a dominant capital. For that matter, the metropolitan area of Zurich too is around a fifth of the population of Switzerland, and yet the Swiss integrated timed transfer concept is polycentric.

Does this work?

On the most ridiculously wide definition of its metropolitan area, Vienna has 3.7 million people, consisting of the city proper and of Lower Austria. In 2012, it had 922 million rail trips (source, PDF-p. 44); the weighted average work trip modal split in these two states is 40% (source, PDF-p. 39). In reality, Vienna is smaller and its modal split is higher. Zurich, an even smaller and richer city, has a 30% modal split. Mode shares in Germany are somewhat lower – nationwide Austria’s is 20%, Germany’s is 16% – but still healthy for how small German cities are. Hamburg and Stuttgart both have metropolitan public transport modal splits of 26%, and neither is a very large city – their metro areas are about 3.1 and 2.6 million, respectively. Munich is within that range as well.

In fact, in the developed world, one doesn’t really find larger modal splits than these in the 2 million size class. Stockholm is very high as well, as are 1.5th-world Prague and Budapest, but one sees certain German influences in all three, even though for the most part Stockholm is its own thing and the other two are Soviet. Significantly higher rates of public transport usage exist in very large Asian cities and in Paris, and Germany does deserve demerits for its NIMBYism, but NIMBYism is not why Munich is a smaller city than Taipei.

To the extent there’s any criticism of the German rapid transit planning tradition, it’s that construction costs lately have been high by Continental European standards, stymieing plans for needed expansion. Märkisches Viertel has been waiting for an extension of U8 for 50 years and it might finally get it this decade.

The activist sphere in Germany is especially remarkable for not caring very much about U-Bahn expansion. One occasionally finds dedicated transport activists, like Zukunft Mobilität, but the main of green urbanist activism here is bike lanes and trams. People perceive U- and S-Bahn expansion as a center-right pro-car plot to remove public transit from the streets in order to make more room for cars.

The high construction costs in Germany and the slow, NIMBY-infused process are both big drags on Germany’s ability to provide better public transportation in the future. It’s plausible that YIMBYer countries will overtake it – that Korean and Taiwanese cities of the same size as Munich and Hamburg will have higher modal splits than Munich and Hamburg thanks to better transit-oriented development. But in the present, the systems in Munich and Zurich are more or less at the technological frontier of urban public transportation for cities of their size class, and not for nothing, much of Europe is slowly Germanizing its public transport planning paradigm.


I recently covered the Stadtbahn, a mode of rail transportation running as rapid transit (almost always a subway) in city center and as a tramway farther out. The tram-train is the opposite kind of system: it runs as a tramway within the city, but as rapid transit farther out. There’s a Human Transit blog post about this from 2009, describing how it works in Karlsruhe, which invented this kind of service pattern. Jarrett is bearish on the tram-train in most contexts, giving a list of required patterns that he says is uncommon elsewhere. It’s worth revising this question, because while the tram-train is not very useful in an American context, it is in countries with discontinuous built-up areas, including Germany and the Netherlands but also Israel. Israeli readers may be especially interested in how this technology fits the rail network away from the Tel Aviv region.

What is a tram-train?

Let’s dredge the 2*2 table from the Stadtbahn post:

Slow in centerFast in center
Slow in outlying areasTramwayStadtbahn
Fast in outlying areasTram-trainRapid transit

The terms fast and slow are again relative to general traffic. The Paris Métro averages 25 km/h, less than some mixed-traffic buses in small cities, but it still counts as fast because the speed in destinations accessed per hour is very high.

Be aware that I am using the terms Stadtbahn and tram-train to denote two different things, but in Karlsruhe the system is locally called Stadtbahn. German cities use the term Stadtbahn to mean “a tramway that doesn’t suck,” much as American cities call a dazzling variety of distinct things light rail, including lines in all four cells of the above table. Nonetheless, in this post I am keeping my terminology distinct, using the advantage of switching between different languages and dialects.

Tram-trains and regional rail

The Karlsruhe model involves trains running on mainline track alongside mainline trains, diverging to dedicated tramway tracks in the city, to connect Karlsruhe Hauptbahnhof with city center around Marktplatz. This also includes lines that do not touch the mainline, like S2, but still run with higher-quality right-of-way separation outside city center; but most lines run on mainline rail part of the way.

North American light rail lines, with the exception of the Boston, Philadelphia, and San Francisco Stadtbahn systems, tend to run as tram-trains, but never have this regional rail tie-in. They run on entirely dedicated tracks, which has two important effects, both negative. First, it increases construction costs. And second, it means that the shape of the network is much more a skeletal tramway map than the more complicated combination of an S-Bahn and a tramway that one sees in Karlsruhe. San Diego has a short segment sharing tracks with freight with time separation, but the shape of the network isn’t any different from that of other American post-1970s light rail systems, and there’s an ongoing extension parallel to a mainline railroad that nonetheless constructs a new right-of-way.

In this sense, the Karlsruhe model can be likened to a cheaper S-Bahn. S-Bahn systems carve new right-of-way under city center to provide through-service whenever the historic city station is a terminus, such as in Frankfurt, Stuttgart, Munich, or German-inspired Philadelphia. They can also build new lines for more expansive service, higher capacity, or a better connection to city center, like the second S-Bahn trunk in Hamburg; Karlsruhe itself is building a combined road and rail tunnel, the Kombilösung, after a generation of at-grade operation. The tram-train is then a way to achieve some of the same desirable attributes but without spending money on a tunnel.

It follows that the tram-train is best when it can run on actual regional rail tracks, with good integration with the mainline system. It is a lower-speed, lower-cost version of a regional rail tunnel, whereas the North American version running on dedicated tracks is a lower-cost version of a subway. Note also that regional rail can be run at different scales, the shorter and higher-frequency end deserving the moniker S-Bahn; the Karlsruhe version is long-range, with S1 and S11 reaching 30 km south of city center and S5 reaching 70 km east.

Where is a tram-train appropriate?

Jarrett’s 2009 post lays down three criteria for when tram-trains work:

  • The travel market must be small enough that an S-Bahn tunnel is not justified.
  • The destination to be served isn’t right next to the rail mainline.
  • The destination to be served away from the mainline is so dominant that it’s worthwhile running at tramway speeds just to get there and there aren’t too many people riding the line beyond it.

The center of Karlsruhe satisfies the second and third criteria. It is borderline for the first – the region has maybe a million people, depending on definitions, and the city proper has 312,000 people; the Kombilösung is only under-construction now and was not built generations ago, unlike S-Bahn tunnels in larger cities like Munich.

Jarrett points out that in the urban world he’s most familiar with, consisting of the United States, Canada, Australia, and New Zealand, it is not common for cities to satisfy these criteria. He does list exceptions, for example Long Beach, where the Blue Line runs in tramway mode before heading into Los Angeles on a mostly grade-separated right-of-way, whereupon it goes back into the surface in Downtown LA before heading into an under-construction tunnel. But overall, this is not common. City centers tend to be near the train station, and in the United States there’s such job sprawl that just serving one downtown destination is not good enough.

That said, the Long Beach example is instructive, because it is not the primary city in its region – Los Angeles is. I went over the issue of outlying S-Bahn tunnels a year ago, specifying some places where they are appropriate in Israel. The tram-train must be a key tool in the planner’s box as a cheaper, lower-capacity, lower-speed version of the same concept, diverging from the mainline in tramway mode in order to serve a secondary center. Karlsruhe itself is a primary urban center – the only time it’s the secondary node is when it connects to Mannheim, and that train doesn’t use the tramway tracks – but a secondary tram-train connection is being built in outlying areas there, namely Heilbronn.

Different models of urban geography

In the American model of urban geography, cities are contiguous blobs. Stare at, for example, Chicago – you’ll see an enormous blob of gray stretching in all directions. Parkland is mostly patches of green in between the gray, or sometimes wedges of green alternating with wedges of gray, the gray following commuter railroads and the green lying in between. Boundaries between municipalities look completely arbitrary on a satellite map.

In the German model of urban geography, it’s different. Look at Cologne, Frankfurt, Mannheim, or Stuttgart – the built-up area is surrounded by green, and then there are various suburban towns with parkland or farmland in between. This goes even beyond the greenbelt around London – there’s real effort at keeping all these municipalities distinct.

I don’t want to give the impression that the United States is the weird one. The contiguous model in the United States is also common in France – Ile-de-France is one contiguous built-up area. That’s how despite being clearly a smaller metropolitan region than London, Paris has the larger contiguous population – see here, WUP 2007, and see also how small the German and Dutch urban areas look on that table. Urban agglomeration in democratic East Asia is contiguous as in the US and France. Canada looks rather American to me too, especially Vancouver, the city both Jarrett and I are the most familiar with, while Toronto has a greenbelt.

This distinction moreover has to be viewed as a spectrum rather than as absolutes. Boston, for example, has some of the German model in it – there’s continuous urbanization with inner suburbs like Cambridge and Newton, but beyond Route 128, there are many small secondary cities with low density between them and the primary center. Conversely, Berlin is mostly American or French; the few suburbs it has outside city limits are mostly contiguous with the city’s built-up area, with the major exception of Potsdam.

The relevance of this distinction is that in the German or Dutch model of urban geography, it’s likely that a railway will pass through a small city rather far from its center, fulfilling the second criterion in Jarrett’s post. Moreover, this model of independent podlike cities means that there is likely to be a significant core, which fulfills the third criterion. The first criterion is fulfilled whenever this is not the center of a large metropolitan area.

It’s not surprising, then, that the Karlsruhe model has spread to the Netherlands. This is not a matter of similarity in transport models: the Netherlands differs from the German-speaking world, for examples it does not have monocentric S-Bahns or S-Bahn tunnels and it builds train stations with bike parking where Germany lets people bring bikes on trains. Nonetheless, the shared model of distinct municipalities makes tram-train technology attractive in South Holland.

Israel and tram-trains

In Israel, there are very few historic railways. A large share of construction is new, and therefore has to either swerve around cities or tunnel to enter them, or in a handful of cases run on elevated alignments. Israel Railways and local NIMBYs have generally preferred swerving.

Moreover, the urban layout in Israel is very podlike. There do exist contiguous areas of adjacent cities; Tel Aviv in particular forms a single blob of gray with Ramat Gan, Givatayim, Bni Brak, Petah Tikva, Bat Yam, and Holon, with a total population of 1.5 million. But for the most part, adjacent cities are buffered with undeveloped areas, and the cities jealously fight to stay this way despite extensive developer pressure.

The final important piece in Israel’s situation is that despite considerable population growth, there is very little rail-adjacent transit-oriented development. The railway was an afterthought until the Ayalon Railway opened in 1993, and even then it took until last decade for mainline rail to be a significant regional mode of transport. The state aggressively builds new pod-towns without any attempt to expand existing towns toward the railway.

The upshot is that all three of Jarrett’s criteria for tram-trains are satisfied in Israel, everywhere except in and around Tel Aviv. Tel Aviv is large enough for a fully grade-separated route, i.e. the already-existing Ayalon Railway. Moreover, because Tel Aviv needs full-size trains, anything that is planned to run through to Tel Aviv, even as far as Netanya and Ashdod, has to be rapid transit, using short tunnels and els to reach city centers where needed. A tram-train through Ashdod may look like a prudent investment, but if the result is that it feeds a 45 meter long light rail vehicle through the Ayalon Railway then it’s a waste of precious capacity.

But Outside Tel Aviv, the case for tram-trains is strong. One of my mutuals on Twitter brings up the Beer Sheva region as an example. The mainline going north has a station called Lehavim-Rahat, vaguely tangent to Lehavim, a ways away from Rahat. It could get two tramway branches, one diverging to the built-up area of Lehavim, a small suburb that is one of Israel’s richest municipalities, and the other to Rahat, one of Israel’s poorest. There are also interesting options of divergence going south and east, but they suffer from being so far from the mainline the network would look scarcely different from an ordinary tramway.

Beer Sheva itself would benefit from tramways with train through-service as well. The commercial center of the city is close to the train station, but the university and the hospital aren’t, and are not even that close to the subsidiary Beer Sheva North station. The station is also awkwardly off-center, lying southeast of the city’s geographic center, which means that feeding buses into it with timed transfers screws internal connections. So tramway tracks on Rager Boulevard, cutting off Beer Sheva North for regional trains, would do a lot to improve regional connectivity in Beer Sheva; intercity trains should naturally keep using the existing line.

In the North, there are similar examples. Haifa is not going to need the capacity of full-size trains anytime soon, which makes the case for various branches diverging into smaller cities to provide closer service in tramway mode strong. Unlike in Beer Sheva, the case for doing so in the primary center is weak. Haifa’s topography is the stuff of nightmares, up a steep hill with switchback streets. The mainline already serves the Lower City well, and climbing the hill is not possible.

This creates an interesting situation, in which the technology of the tram-train in the North can be used to serve secondary cities like Kiryat Ata and Tirat Carmel and maybe enter the Old City of Acre, but the operational pattern is really that of a Stadtbahn – fast through Haifa and up most of the Krayot, slow through smaller suburbs.

Stadtbahn Systems

I made an off-hand remark about subway-surface systems, called Stadtbahn in German (as is, confusingly, the fully grade-separated east-west Berlin S-Bahn line), regarding a small three-line single-tail network that Brooklyn could build. I also talked about it in a little more detail last year. I want to go more deeply into this now. It’s a public transportation typology that’s almost nonexistent outside Germany and Belgium; Tel Aviv is building one line, and the US has three but two of those are from more than 100 years ago. But there are interesting examples of good places to use this technology elsewhere, especially elsewhere in Europe.

What is the Stadtbahn?

The Stadtbahn (“city rail”), or the subway-surface line in US usage, is an urban line running light rail vehicles, with grade separation in city center and street running outside city center. All examples I know of are in fact underground in city center, but elevated lines or lines running in private rights-of-way could qualify too, and in Cologne, there’s a semi-example over a bridge dropping to the surface at both ends.

It’s best illustrated as a 2*2 grid:

 Slow in centerFast in center
Slow in outlying areasTramwayStadtbahn
Fast in outlying areasTram-trainRapid transit

The terms fast and slow are relative to general traffic, so a mixed-traffic bus in a low-density city that averages 30 km/h is slow whereas the Paris Métro, which averages 25 km/h, is fast; the speed in km/h may be higher on the bus, but the speed in destinations accessed per hour is incomparably higher on the Métro.

The tram-train is confusingly also called Stadtbahn in Germany, for example in Karlsruhe; this is nearly every light rail built in North America. It is not the topic of this post.

What is the purpose of the Stadtbahn?

Historically, Stadtbahn systems evolved out of pure surface tramways. City center congestion made the streetcars too slow, so transit agencies put the most congested segments underground. This goes back to Boston in 1897 with the Tremont Street Subway and Philadelphia in 1906 with the Subway-Surface Lines. The contrast both in that era and in the era of Stadtbahn construction in Germany from the 1960s to the 80s is with pure subways, which are faster but cost more because the entire route must be underground.

Stadtbahns always employ surface branching. This is for two reasons. First, there’s more capacity underground than on the surface, so the higher-capacity rapid transit segment branches to multiple lower-capacity tramways to permit high throughput. And second, there’s generally less demand on the outer segments than in the center – lines with very strong demand all the way tend to turn into full subways.

This is therefore especially useful for cities that are not huge. In a city the size of Cologne or Stuttgart or Hanover, there isn’t and will never be demand for a rapid transit system with good citywide coverage. Instead, there is something like a sector principle. For example, in Cologne, the Deutz side of the city, on the right bank of the Rhine, has service to city center on the S-Bahn, on tramway lines over the Deutzer Bridge branching on the surface, and on tramway lines over the Mülheimer and Severin Bridges feeding into the north-south ring Stadtbahn. Smaller cities have simpler systems – Hanover for has three underground trunk lines meeting at one central station, and Dortmund has three meeting in a Soviet triangle. This maintains good coverage even without the budget for many rapid transit lines.

Where are Stadtbahns appropriate?

Cities should consider this technology in the following cases:

  • The city should not be too big. Tel Aviv is too big for this, and people in Israel are starting to recognize this fact and, in addition to the under-construction three-line Stadtbahn system are proposing a larger-scale three-line fully grade-separated metro system. If the city is big enough, then a full metro system is justified.
  • There should be a definitive city center for substantial traffic to funnel to. The purpose of the Stadtbahn is to have comparable throughput to that of a metro, albeit with shorter trains.
  • There should be wide swaths of sectors of the city where having multiple parallel lines is valuable. This, for example, is the case in cities that are not exceptionally dense and cannot expect transit-oriented development to completely saturate one metro corridor.
  • The street network should not be too gridded, because then the sector-based branching is more awkward, and the combination of rapid transit to city center and a surface transit grid can be powerful, as in Toronto.
  • There should be too much city center congestion for a pure surface system to work, for example if most streets are very narrow and traffic funnels to the few streets that can use

These circumstances are all common to German urbanism: city centers here are strong, but residential density peaks at 15,000/km^2 or thereabouts in near-center neighborhoods and drops to 3,000-6,000/km^2 farther out. Moreover, Germany lacks huge cities, and of the largest four urban cores – Berlin, Hamburg, Munich, Frankfurt – three have full rapid transit systems. Finally, grids are absent here except at very small scale, as in Mannheim.

However, these are not unique features to Germany. They’re common around Europe. European cities are not very big, and the only ones that can genuinely fill any subway line with transit-oriented development are a handful of very big, very rich ones like London and Paris. Even Stockholm and Munich have to be parsimonious; they have have full metro systems with branching.

The French way of building rapid transit does not employ the Stadtbahn, and perhaps it should. In a city the size of Bordeaux or Nice, putting a tramway underground in city center and then constructing new branches to expand access would improve coverage a lot.

This is likely also the case in Italian cities below the size class of Milan or Rome. Many of these cities are centered around Renaissance cores with very narrow streets, which are nonetheless auto-centric with impossibly narrow sidewalks, Italy having nearly the highest car ownership in Europe. Finding one to three good corridors for a subway and then constructing tramways funneling into them would do a lot to speed up public transit in those cities. Bologna, for example, is planning a pure surface tramway, but grade-separated construction in the historic center would permit trams to have decent coverage there without having to slow down to walking speed.

Are there good examples outside Europe?

Yes! From my original post from 2016, here is one proposal for New York:

The B41 could be a tramway going between City Hall and Kings Plaza, using two dedicated lanes of the Brooklyn Bridge. In that case, the line would effectively act as subway-surface, or more accurately elevated-surface: a surface segment in Brooklyn, a grade-separated segment between Manhattan and Brooklyn. Subway-surface lines should branch, as all current examples do (e.g. Boston Green Line, Muni Metro, Frankfurt U-Bahn), because the subway component has much higher capacity than the surface components. This suggests one or two additional routes in Brooklyn, which do not have strong buses, but may turn into strong tramways because of the fast connection across the river to Manhattan. The first is toward Red Hook, which is not served by the subway and cut off from the rest of the city by the Gowanus Expressway. Unfortunately, there is no really strong corridor for it – the streets are not very wide, and the best for intermediate ridership in Cobble Hill and Carroll Gardens require additional twists to get into the core of Red Hook. Court Street might be the best compromise, but is annoyingly a block away from the F/G trains, almost but not quite meeting for a transfer. The second possible route is along Flushing Avenue toward the Navy Yard; it’s not a strong bus by itself, but the possibility of direct service to Manhattan, if a Flatbush tramway preexists, may justify it.

Note that this proposal is opportunistic: Brooklyn Bridge just happens to be there and point in the right direction for at least one strong surface route in Brooklyn, and conversely would connect too awkwardly to the subway. In a city the size of New York, Stadtbahn lines must be opportunistic – if the region intentionally builds new river crossings then they must carry the highest-capacity mode of transportation, which is rapid transit, not a light rail variant.

American cities smaller than New York are often very big by European standards, but also very decentralized. This hurts the Stadtbahn as a mode – it really only works for a monocentric city, because if there are multiple centers, then all but the primary one get slow transit. The Rhine-Ruhr notably uses the S-Bahn, which is rapid transit, to connect its various cities, and only run Stadtbahn service internally to each center, like Cologne or Dortmund.

There are a number of places in the United States where burying a light rail line in city center is advisable, but this is for the most part conversion of a tram-train to rapid transit, for examples in Portland and Dallas. The only example that come to mind of a decent Stadtbahn in the US that doesn’t already exist is Pittsburgh, converting the BRT system to rail.

Outside the United States, I get less certain. Canada is bad geography for a Stadtbahn because of its use of grid networks; Ottawa may be good for a Stadtbahn using the Confederation Line tunnel, but that’s probably it. Australia may be better, combining decently strong city centers with very low residential density; transit-oriented development potential there is very high, but it could plausibly come around multiple distinct corridors as well as regional rail stations. Melbourne’s tramways thus may be a candidate for Stadtbahn conversion.

In both East Asia and in the developing world, it’s likely best to just build full metros. East Asian cities are big and have high rates of housing construction (except Hong Kong). I can see a Stadtbahn succeed in Taichung, extending the under-construction Green Line on the surface and building intersecting lines, but that’s probably it. Kaohsiung already has a (very underused) subway, what I think is Daejeon’s best next corridor on top of Line 1 and the planned Line 2 is unusually bad for a Stadtbahn because the streets are too gridded west of the center, Daegu is too gridded as well.

A similar set of drawbacks is also true for the developing world. The urban population of the developing world tends to cluster in huge cities. Moreover, these cities tend to have high residential density but low city center job concentration; the Addis Ababa light rail is bad at serving people’s work trips because so few people work in the center. Finally, the developing world has high rates of increase in urbanization, which make future-proofing systems with higher capacity more valuable.

Corona and Europe’s Idiocy

550 new coronavirus cases in Berlin yesterday. 7,000 in Germany. 110,000 in the European Union, which at 240 per million people is even higher than the US, which is at 200/million. French hospitals are flooded with corona patients, and the state expresses its grave concerns but will still not set up quarantine hotels or universalize the use of surgical masks or do anything else that Taiwan did in less time. This is the second wave, and seven months after Taiwan showed the way how to deal with this and ended up being the only country this year to have positive economic growth to boot, Europe (and the US) still stays in its comfort zone of mass death.

It’s worth discussing the excuses, because so many of them port well to the realm of public transportation, where Europe is not so bad (there are even things East Asia can learn from us); Europe’s real disaster compared with rich Asia is in urbanism and its resistance to tall buildings. But the United States is horrific on all matters of transportation and urban redevelopment and the excusemaking there is ensuring no infrastructure can be built.

Excuse #1: the restricted comparison

The Max Planck Society (MPG) put out a statement three weeks ago, with some interesting insights about the need for a multi-pronged strategy, including contact tracing, hygiene, and social distancing. But it kept engaging in these silly intra-European comparisons, praising Germany in contrast with Britain. At no point was there any engagement with East Asia, even though we know that Taiwan has not had community spread since April, and that in Korea and Japan the current rates are about 2 and 4 daily cases per million people respectively.

Excuse #2: bullshit about culture

I’m told that there is general understanding within Germany that Taiwan and South Korea are doing far better. However, people keep making up cultural reasons why Europe can’t have what East and Southeast Asia have. This excuse unfortunately is not restricted to people who are totally unaware: a few months ago, Michel Bauwens, a Belgian degrowth advocate who lives in Thailand, talked up Thailand’s corona suppression, but attributed it to a communitarian, collectivist culture. The Thais are mass-protesting their autocratic government’s state of emergency (while wearing masks, unlike Western anti-regime protesters); what collectivism? The actual policy differences – mandatory centralized quarantine for people who test positive, mask wearing mandates – were not mentioned.

When I bring up the necessity of centralized quarantine, and even the fact that Israel used corona hotels to nearly eradicate the virus in the first wave (the second wave came from mass abandonment of social distancing – MPG is right about multi-pronged strategies), Europeans and Americans keep making a “but freedom” line. It’s strange. Yes, Thailand is autocratic. But Taiwan and South Korea are not – and they had authoritarian governments within living memory, and both are currently run by political parties that emerged out of democratic opposition to autocracy in the 1980s and 90s, and that far from becoming autocrats themselves, ceded power peacefully when they lost reelection in the past.

Excuse #3: the fake tradeoff

Many aspects of policy involve genuine tradeoffs. But many others don’t, and corona protection is one. Taiwan is the only developed country that is projecting positive economic growth in 2020. South Korea is projecting 1% contraction, the smallest contraction in the OECD, of which Taiwan is not a member. There is no economy-death tradeoff. Plowing through with reopening before the virus has been suppressed just means mass closures later and a weaker economy. The only major suppression country that is seeing economic contraction is Thailand, whose economy is based heavily on tourism and therefore more sensitive to crises outside its borders than are the industrial export-based economies of Taiwan and Korea.

Excuse #4: learned helplessness

I write occasionally about the importance of state capacity, but centralized quarantine is not some specialized technique only available to the most advanced states. It was routine in developed countries until the 1960s, when the incidence of infectious disease had fallen to a point that it was no longer necessary. The same is true of social distancing – Nigeria for example has used it and appears to be successful, with semi-decent test positivity rates and lower per capita confirmed infections than Korea.

However, various leaders keep saying “we can’t.” This is not about technical matters. Rather, it’s about political ones: we can’t established corona hotels, we can’t ban indoor dining and drinking, we can’t scale up surgical mask production like Taiwan did 8 months ago and require people to wear surgical masks in public. The only thing Europe seems capable of doing is prohibiting travel from countries that at this point often have less corona than we do.

This is learned helplessness. Risk-averse politicians who know on some level what needs to be done are still too spineless to do it, even knowing very well that successfully suppressing corona is an amazing crowd booster.

The connection with infrastructure

All of the above problems also lead to disastrous infrastructure projects. This is to some extent a problem in Germany, where “we can’t” is a common excuse for surrender to NIMBY opposition; this is why certain key high-speed rail segments have yet to be built. But it’s a truly massive drag on the English-speaking world, especially the United States. I have seen advocates engage in internal-only comparisons within the last 24 hours; the other excuses, I saw earlier this week, and many times in the last few months, with so many different American transit managers incanting “it’s not apples-to-apples” whenever Eric and I ask them about costs. One literally said “we can’t” and “it’s not possible” and is regionally viewed as progressive and forward-thinking.

In the same manner Europeans discount any knowledge produced outside of Europe and the United States, Americans discount everything produced outside their country. Occasionally they’ll glance at Canada and Britain to affirm prior prejudices. They treat foreign language fluency as either dilettantism or immigrant poverty and not as a critical skill in the modern world right next to literacy and numeracy. They’ll flail about as they die of corona and blame one another when, just as the EU flag today is twelve yellow coronaviruses on a field of blue, the US flag is fifty white viruses on a field of blue with red and white stripes.

High-Speed Rail and Cities

When preparing various maps proposing high-speed rail in Germany, I was told that it looks nice but it overfocuses on the largest cities and not about connecting the entirety of the country. I’ve seen such criticism elsewhere, asserting that high-speed rail is a tradeoff in which the thickest connections get fast trains but the long tail suffers, whereas the medium-speed system of Germany or Switzerland or Austria serves everyone. So with that in mind, let’s look at the actual population served by a Germany-wide high-speed rail program.

I made a proposal last year, but then made some additional tweaks, posted as part of a Europe-wide map. The most important tweak: the main east-west trunk line was extended to Dortmund, which trades off some additional tunneling in the Ruhr for both higher frequency on Berlin-Dortmund and fast, frequent Dortmund-Cologne and Dortmund-Düsseldorf service. To my later map I’ll add one proposal: moving the Hanover-Dortmund tracks so that trains can stop in Bielefeld. Otherwise, take the maps as given.

The question is, what population is served by those maps? The answer of course depends on what this exactly means. The sum total of the populations of the cities served – Berlin, Hamburg, Hanover, Dortmund, Würzburg, Erfurt, Mannheim, etc. – is 18.2 million, or 21% of Germany’s population. But is that the full story? This just includes central cities, where people in many nearby suburbs and satellite cities would travel to the rest of the country via the primary city center anyway.

For example, let’s go down this list of German cities. The largest city without a stop on my proposed network is Bonn. But Bonn is very close to Cologne and there are Stadtbahn subways connecting the two cities, in addition to regional rail lines; Bonn also has a shorter-range Stadtbahn to a suburban station at which some high-speed trains on the Cologne-Frankfurt line call. Is it really correct to say Bonn is unserved? Not really. So its population should be added to the 18.3 million.

Going down the list, the same can be said of Wiesbaden (near Frankfurt), Mönchengladbach (Düsseldorf) and likewise many Rhine-Ruhr cities, Halle (near Leipzig and potentially on some slower Berlin-Erfurt trains like today), Potsdam (near Berlin), Ludwigshafen (near Mannheim), and many others. Some cities remain unserved – the largest is Münster, like a few other northwestern cities not really near anything bigger or on any line – but overall this adds another 5.3 million. So we get 23.6 million, around 30% of Germany’s population.

But that list is just cities of 100,000 people or more, and there are smaller suburbs than that. These form counties (“Kreise”), which should be added as well when feasible, e.g. when they lie on S-Bahn systems of large cities or when they are right across from cities with stations, such as Neu-Ulm to Ulm. For example, the Kreise served by the Munich S-Bahn, excluding the city proper, have a total of 1.3 million people, and people in those suburbs would be connecting to the rest of Germany by train at Munich Hauptbahnhof anyway – a lower-intensity, higher-coverage network would do nothing for them.

Overall, these suburbs add another 18.7 million people. In Berlin I used this list of suburbs; elsewhere, I went by S-Bahn reach, or in a few cases used an entire region where available (Hanover, Göttingen, Fulda). There are a few quibbles on the margin in the gaps between the Frankfurt and Rhine-Neckar and in places that probably should count but aren’t on any big city S-Bahn like Frankfurt an der Oder, but it doesn’t change the big picture: a dedicated high-speed rail network would serve around half of Germany’s population pretty directly.

Very little of the remaining half would be genuinely bypassed the way Magdeburg and Brunswick were when Germany built the Berlin-Hanover line. Regensburg, for example, is and will remain peripheral under any rail plan, with regional connections to Ingolstadt and Nuremberg; high-speed rail serving those cities is the best way to connect it to destinations beyond Bavaria. Kiel, at the other end of the country, is and will always remain connected to Hamburg by regional rail. Münster, genuinely unserved, is not really bypassed, not with how close it is to Dortmund. And so on.

Such a plan cannot serve the entire country, but it can definitely then serve a majority of it. It mostly serves the largest metropolitan areas, but that’s fine – Germany is an urban country, around 40% of the country lives in metro areas of at least 1 million people (defined again mostly by S-Bahn reach, which is a conservative definition by American MSA or French aire urbaine or Japanese MMA standards) and much of the rest is either in metro areas somewhat below the cutoff or in exurbs served by regional trains but not the S-Bahn.

Low- and Medium-Cost Countries

I was asked a very good and very difficult question in comments yesterday:

What, specifically, are the best practices we all should be learning from the lower cost countries? I’m reading a lot of what not to do, but not on what do to.

I’ve gone a lot over bad industry practices leading to high costs in the Anglosphere, especially the United States, especially New York, and to some extent also on bad practices in developing countries like India. These I am contrasting with a set of good practices from a host of low-cost countries like Spain and Italy as well as medium-cost ones like Germany and France.

However, the question remains, what distinguishes low- and medium-cost countries? The differences between them are not small – underground rail extensions in German cities are averaging around 250 million euros per kilometer, and ones in French cities are around 200 million or just less than that, whereas Milan and Turin average around 100 million, and Spanish cities average even less. Germany is a higher-cost and higher-wage country than Italy and Spain, but Berlin wages are not higher than Madrid and Milan wages, and within these countries, richer cities don’t really have higher costs (Milan is cheaper to tunnel in than Naples, Madrid has lower costs than Barcelona and similar costs to the rest of Spain, the cheapest German tunneling seems to be in Hamburg of all places). No: this is almost certainly a real difference in institutions that enables Southern Europe, Scandinavia, South Korea, and Turkey to dig tunnels at one third to one half the cost of Germany.

This argues in favor of doing a deep dive case on a medium-cost example like Paris or Berlin, in addition to the work we’re doing on low-cost Milan and Istanbul. The problem is that it’s not clear, so far, what to even look at. I have a decent idea of what the difference between the high-cost world and the rest of the world is – but applying it to the low- and medium-cost world is dicey.

In-house engineering capacity

So much of the problem in the Anglosphere seems to come from the loss of in-house engineering capacity, and its replacement with private consultants. The latest iteration of this is the penchant for design-build contracts, in which the state contracts with one company to handle the entire process and doesn’t have much if any public-sector oversight. Design-build doesn’t exist in any of the countries in Continental Europe I have any familiarity with; France is looking into it as a reform in the future, but only under the aegis of a large public-sector planning team coordinating the private-sector design and construction. Moreover, Canada’s recent adoption of design-build, coming from an ideology imported from Britain and then falsely claimed to come from Madrid, preceded an explosion in costs.

However, this does not really explain the difference between France or Germany and Scandinavia or Southern Europe. Norway and Spain have separation of design and construction; so does France. Italy and Spain have in-house engineering teams responsible for a great deal of the design, but to some extent France does too, with a large in-house planning team overseeing the private-sector designs.

Procurement issues can’t really distinguish the low- from medium-cost world either. Madrid does not hand out lowest-bid contracts – at least in its big wave of expansion in the 1990s and 2000s, contracts were given 50% on the basis of a technical score marked by the in-house engineering team, 30% on that of cost, and 20% on that of how fast they could finish the project. Paris doesn’t have a 50-30-20 split but a 60-40 one; that may be significant, but I doubt it. Both systems contrast with the American system of lowest bid, or sometimes 30-70 in California. Moreover, Turkey is lowest-bid, but it’s a repeated game due to the country’s fast growth and construction – contractors who screw up do get penalized in future projects.

Citizen voice and NIMBYism

Germany has a huge problem with NIMBYism. Key segments of the national passenger rail network, for example Hamburg-Hanover, remain slow because local NIMBYs who don’t like fast trains have litigated high-speed rail to death. France has had anti-LGV NIMBYism in Provence as well, which NIMBYism is often extralegal (that is, aggrieved drivers blocking roads); this forced the state to change its plans for a high-speed railway to Nice from a mostly above-ground inland route to a tunnel-heavy coastal route through the Maritime Alps and, as the cost was prohibitive, eventually downgrade into a mixture of high- and low-speed rail line.

As I understand it, this is less of an issue in Southern Europe. I do not know to what extent it’s a problem in Scandinavia and Switzerland; Switzerland does have a lot of bucolic NIMBYism, where “bucolic” means “the city as it looked in 1957,” but I don’t think it’s had any that successfully scuttled infrastructure, and overall the political imperative there seems to reduce costs more than anything.

The NIMBY issue is also important in the US and UK. In the US, NIMBYs are not legally strong, but politicians prefer to avoid the appearance of controversy and therefore give local actors whatever they ask for, no matter the cost; many sources told Eric and me versions of this story regarding the high cost of stations on the Green Line Extension (which are, to be clear, maybe 20% of the cost of the whole project). Brooks-Liscow favor this explanation for the internal increase in the cost of highways in the US from the 1970s onward.

I do not know to what extent there’s an institutional explanation here. I do not even know if this is a real difference between on the one hand France, Germany, Austria, the Netherlands, most of the 2004-7 EU accession countries, and Japan, and on the other hand Southern Europe, Bulgaria, Turkey, and South Korea. It’s possible that this is a bigger problem in Northern Italy than I realize.

The most worrying possibility is that this is a real difference, and it comes not from something about institutions, but from surplus extraction. The European core and Japan are rich, and at $150 million/km, subways there would create immense social surplus and decent financial surplus. (The Japanese state is refusing to build at $500 million/km because it wants a 30-year financial payback). Southern Europe is less rich, so there is less social surplus to extract by local actors wanting to dip their beaks in state money; Switzerland and the Nordic countries are rich, but their cities are smaller and farther-apart, so there is less surplus there too.

There are a lot of objections that can be raised to the surplus extraction hypothesis: there is plenty of surplus in Seoul and not much in Vienna or Prague or Bucharest or Warsaw or Tel Aviv, Japan already reached $250 million/km in the 1970s when it was a lot poorer than Korea is today, the surplus hypothesis predicts that there should be higher costs in richer cities within the same country and yet this is not observed, local interference with Métro expansion in Paris unlike with LGVs doesn’t seem very significant.


There’s no good answer to what distinguishes low- from medium-cost countries. I wish more people here and in France were interested in this question – the activist sphere in Berlin seems far more interested in trams and bike lanes than in rapid transit. Nor do I imagine Germans and French are ready to hear that there’s something the Italians and Spaniards and Turks do better than they do. But it’s something Germany is going to need to learn to deal with if it wants better infrastructure; on the same budget, it can get 2-3 times as much as it’s getting now.

The Limit of Circles in the Suburbs

In dense urban cores, it’s valuable to run circular rail lines. They connect dense near-center neighborhoods to one another without going through the more congested center, and help make transferring between parallel lines more efficient, again through avoiding central business district congestion. Some of the largest cities in the world even support multiple circles, line Lines 2 and 10 in Beijing, or the various overlapping circles of Moscow, Tokyo, and soon Paris. However, this system of radial lines through the center and circular lines around the center cannot go on forever. There is a limit to how far out one can build circles, which is much sharper than the limit of how far radial lines can go. Lower-density suburbs can have radial lines connecting them to city center or to near-center nodes of activity, but circumferential lines are likely to be weak.

For a concrete example, take Berlin. It has the Ring through fairly dense neighborhoods, supporting 5-minute frequency on the S-Bahn during most of the day. But it also has the Outer Ring, built in the 1950s through East Berlin and the Brandenburg suburbs to surround West Berlin and permit the construction of the Wall; today it runs regional trains, and one segment through East Berlin runs the S75 every 10 minutes, but there is no train making the entire orbit, just trains using short segments to position themselves to a better radial entry into the center of Berlin. It looks frustrating – there is circular infrastructure, why not use it? But there’s a solid reason not to run it as a true circle.

See map below:

A schematic of service patterns can be seen here.

The line’s origin as a bypass means it doesn’t serve any of the nodes near its radius, like Potsdam (too built-up), Spandau (in West Berlin), or Märkisches Viertel (also in West Berlin). The only node it does pass through is the soon-to-close Schönefeld airport, which only became important well into the Cold War; moreover, a branch parallel to the line to the southeast serves the soon-to-open Berlin-Brandenburg Airport, with plans to run many different kinds of regional services entering Berlin from both the Stadtbahn and the North-South Main Line. So a circular service would, by itself, just connect various outlying areas like Marzahn, Hennigsdorf, and Falkensee to the airport. By itself, this doesn’t support very high frequency.

Now, what the line could do is work as a network together with radial lines, connecting to them to facilitate travel not passing through the center of Berlin. However, there is not much point in transfers unless they are either high-frequency or timed. High-frequency transfers are out – the radial lines that penetrate the Outer Circle run 2-3 trains per hour. This forces the transfers to be timed.

Timed connections on lines that intersect crosswise rather than parallel with cross-platform transfers are completely possible. The trains can’t be too long, but that’s fine, a 4-car train with stair and elevator connections could have 2-3 minute transfer windows and still exchange passengers in all directions. It’s worth establishing at sufficiently important stations where a cross-platform transfer is not possible; as a four-way transfer, it’s not even that much more involved than a cross-platform transfer with timed wrong-direction transfers like Wittenbergplatz between U2 and U1/3. However, this is for one station.

All of this goes out the window when a circle intersects 12 different radial lines. Such a scheme can only work if all of the transfers are timed, or at least a large majority of them. Otherwise, people might as well take the train through the center and connect at Berlin Hauptbahnhof, or even stay on the same train if it runs through like RE 1 or RE 3.

In theory, you can time a short succession of transfers on the same line. All it really takes is to make sure that the circular line takes a half-integer multiple of the takt interval between every pair of transfer points, allowing both-direction transfers everywhere. On a few stretches of the line, it’s even plausible, with a 20-minute takt – the line would be fast because it’s so far out and has to few stops, so 7-10 km in 8 minutes (10 minus 2 for the transfer window) is not outside the realm of possibility.

Except that some segments between transfer points are still bad, like between the two just west of Spandau, or on both sides of the crossing with S5 and RE 1 in Lichtenberg. And even if they weren’t, this runs into the problem that trains are not infinitely punctual. Having 12 knots between a circular line and radials around Berlin, or even just 10 if weak ones are dropped, means that suburban Berlin would have more knots every 20 minutes than Switzerland has today every half hour (8), and not too many fewer than Switzerland is planned to have every half hour in the 2030s. The required schedule discipline is intense, especially in a big city defined by crowded rush hour trains.

This has implications elsewhere. Paris has its Grande Ceinture, which is tempting for a regional rail ring, but the frequency at which it can support a full RER line is not high; instead, the region is breaking the line into segments, to be turned over into tram-trains, with some segments diverging from the mainline to serve nodes near but not on the line.

In general, what this means is that if you’re not connecting to a major city center, there’s only so much service you can run. If you’re within the densely built-up area, as the Ring is or as the various orbitals Paris has (M2/M6, T3) or plans (M15), then it’s fine – untimed transfers are fine when trains come every 5 minutes, and overlapping one-seat rides like Prenzlauer Berg-Neukölln and Ostkreuz-Tempelhof and so on can help fill the train as well. But once frequency drops below about a train every 10 minutes, untimed transfers no longer work, which means that services that rely on connections only work if the connections are at a handful of key points, not at 12 different radii around the city.