Category: Urban Design

Tram-Trains

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.

Pedestrianizing Streets in New York

I was asked a few months ago about priorities for street pedestrianization in New York. This issue grew in importance during the peak of the corona lockdown, when New Yorkers believed the incorrect theory of subway contagion and asked for more bike and pedestrian support on the street. But it’s now flared again as Mayor de Blasio announced the cancellation of Summer Streets, a program that cordons off a few streets, such a the roads around Grand Central, for pedestrian and bike traffic. Even though the routes are outdoors, the city is canceling them, citing the virus as the reason even though there is very little outdoor infection.

But more broadly, the question of pedestrianization is not about Summer Streets, which is an annual event that happens once and then for the rest of the year the streets revert to car usage. It’s about something bigger, like the permanent Times Square and Herald Square pedestrianization.

In general, pedestrianization of city centers is a good thing. This can be done light, as when cities take lanes off of roadways to expand bike lanes and sidewalks, or heavy, as when an entire street loses car access and becomes exclusive to pedestrians and bikes. The light approach should ideally be done everywhere, to reduce car traffic and make it viable to bike; cycling in New York is more dangerous than in Paris and Berlin (let alone Amsterdam and Copenhagen) since there are too few separated bike lanes and they are not contiguous and since there is heavy car traffic.

The heavy approach should be used when feasible, but short of banning cars cannot be done everywhere. The main obstacle is that in some places a critical mass of consumers access retail by car, so that pedestrianization means drivers will go elsewhere and the region will suffer; this happened with 1970s-era efforts in smaller American cities like Buffalo, and led to skepticism about the Bloomberg-era Times Square pedestrianization until it was completed and showcased success. Of course, Midtown Manhattan is rich in people who access retail by non-auto modes, but it’s not the only such place.

Another potential problem is delivery access. This is in flux, because drone delivery and automation stand to simplify local deliveries, using sidewalk robots at pedestrian scale. If delivery is automated then large trucks no longer offer much benefit (they’re not any faster than a bicycle in a congested city). But under current technology, some delivery access is needed. In cities with alleys the main street can be pedestrianized with bollards while the alleys can be preserved for vehicular access, but New York has about three alleys, which are used in film production more than anything because they connote urban grit.

Taking all of this together, the best places for pedestrianization are,

  1. City centers and near-center areas. In New York, this is the entirety of Manhattan south of Central Park plus Downtown Brooklyn and Long Island City. There, the car mode share is so low that there is no risk of mass abandonment of destinations that are too hard to reach by car.
  2. Non-residential areas. The reason is that it’s easier to permit truck deliveries at night if there are no neighbors who would object to the noise.
  3. Narrow streets with plenty of commerce. They’re not very useful for drivers anyway, because they get congested easily. If there are deliveries, they can be done in off-hours. Of note, traffic calming on wider streets is still useful for reducing pollution and other ills of mass automobile use, but it’s usually better to use light rather than heavy traffic reduction, that is road diets rather than full pedestrianization.
  4. Streets with easy alternatives for cars, for example if the street spacing is dense. In Manhattan, this means it’s better to pedestrianize streets than avenues.
  5. Streets that are not useful for buses. Pedestrianized city center streets in Europe are almost never transit malls, and the ones I’m familiar with have trams and not buses, e.g. in Nice.

Taking this all together, some useful examples of where to pedestrianize in New York would be,

  1. Most of Lower Manhattan. There are no residents, there is heavy commerce, there is very heavy foot traffic at rush hour, and there are enough alternatives that 24/7 pedestrianization is plausible on many streets and nighttime deliveries are on the rest.
  2. Some of the side streets of Downtown Brooklyn and Long Island City. This is dicier than Manhattan – the mode share in those areas as job centers is far below Manhattan’s. A mid-2000s report I can no longer find claimed 50% for Downtown Brooklyn and 30% for LIC, but I suspect both numbers are up, especially LIC’s; Manhattan’s is 67%, with only 15% car. So there’s some risk, and it’s important to pick streets with easy alternatives. Fulton Mall seems like a success, so presumably expansions can start there and look at good connections.
  3. St. Mark’s. It’s useless for any through-driving; there’s a bus but its ridership is 1,616 per weekday as of 2018, i.e. a rounding error and a prime candidate for elimination in a bus redesign. There’s so much commerce most buildings have two floors of retail, and the sidewalk gets crowded.
  4. Certain Midtown side streets with a lot of commerce (that’s most of them) and no buses or buses with trivial ridership (also most of them). One-way streets that have subway stations, like 50th and 53rd, are especially attractive for pedestrianization. Two-way streets, again, are valuable targets for road diets or even transit malls (though probably not in Midtown – the only east-west Manhattan-south-of-59th-Street bus route that screams “turn me into a transit mall” is 14th Street).

School Transit-Oriented Development

Transit-oriented development, or TOD, means building more stuff in places with good access to public transportation, typically the immediate vicinity of a train station. This way people have more convenient access to transit and are encouraged to take it because they live or work near the train, or ideally both. In practice, American implementations heavily focus on residential TOD, and secondarily on commercial TOD, the latter focusing more on office than retail. I covered some retail issues here; in this post, I’m going to look at a completely different form of TOD, namely public-sector institutions that government at various levels can choose the location of by fiat. These includes schools, government offices, and cultural institutions like museums. Of these, the most important are schools, since a huge share of the population consists of schoolchildren, who need convenient transportation to class.

This principle here is that the state or the city can site public schools where it wants, whether it’s by diktat or by inducements through funding for school construction. This occurs even in situations with a great deal of autonomy: American suburban schools are autocephalous, but still receive state funding for school construction, and if anything that incentivizes moving to new suburban campuses inaccessible by public transit. Other cultural institutes are usually less autonomous and more strapped for cash, and getting them to move to where it’s easier for people to access them without a car should be easier.

School siting: central cities

Urban schools tend to spread all over the city. There are more schools in denser and younger neighborhoods; there also are more high-end schools (Gymnasiums, etc.) in richer neighborhoods. But overall, there isn’t much clustering. For example, here is what I get when Googling both Gymnasiums in Berlin:

There are many Gymnasiums in rich areas like Wilmersdorf and few in poor areas (the map shows one in Neukölln and none in Gesundbrunnen and Wedding, although a few that aren’t shown at this zoom level do exist). But overall, the school locations are not especially rail-oriented. They’re strewn all over the middle-class parts of the city, even though most students do not live close enough to walk. Only the most specialized of the elite schools is in city center, the French school.

The situation in New York is similar to that of Berlin – the schools in the city are all over. This is despite the fact that there’s extensive school choice at the high school level, so that students typically take the subway and bus network over long distances. New York’s school stratification is not the same as Berlin’s – its Specialized High Schools serve the top 3% of city population, Germany’s Gymnasiums serve maybe 30% – but there, too, schools that explicitly aim to draw from all over the city are located all over the city. Only the most elite of New York’s schools, Stuyvesant, is in the central business district, namely in Lower Manhattan; the second and third most elite, Bronx Science and Brooklyn Tech, are just outside Downtown Brooklyn and in the North Bronx, respectively. A huge fraction of Bronx Science’s student population commutes from feeder neighborhoods like Flushing, Sunset Park, Chinatown, Jackson Heights, and the Upper West Side, and has to wake up early in the morning for an hour-long commute.

If schools are not just for very local neighborhood children, then they should not be isotropic, or even middle-class-isotropic as in Berlin. They should be in areas that are easily accessible by the city’s rapid transit network, on the theory that the time of children, too, is valuable, and replacing an hour-long commute with a half-hour one has noticeable benefits to child welfare and educational outcomes.

Urban school nodes

So to improve transit access to school in transit cities, it’s useful to get schools to move to be closer to key nodes on the rail network. City center may be too expensive – the highest and best use of land around Times Square or Pariser Platz is not a school. But there are other useful nodes.

The first class of good locations is central and near-center areas that don’t have huge business demand. In New York, Lower Manhattan and Downtown Brooklyn both qualify – business prefers Midtown. In Berlin, there are a lot of areas in Mitte that don’t have the development intensity of Potsdamer Platz, and to some extent the French school picked such an area, on the margin of Mitte.

The second is key connection points on the rail network that are not in the center. Berlin is rich in such connections thanks to the Ring. To some extent there are a bunch of schools close to Ringbahn stations, but this isn’t perfect, and for example the Europasportspark shown on the map is between two Ringbahn stations, at one of the few arterial roads through the Ring that doesn’t have an S-Bahn station. In New York, there is no ring, so connections are more sporadic; desirable nodes may include Queensborough Plaza, Metropolitan/Lorimer in Williamsburg, and East New York.

East New York supplies an example of the third class: an area that is rich in transit connections but is commercially undesirable because the population is poor. (The Berlin equivalent is Gesundbrunnen – non-German readers would be astounded by the bile Germans I know, even leftists who vote for anti-racist politicians, heap on U8 and on Gesundbrunnen and Neukölln.) Since everyone goes to school, even working-class children, it is valuable to site schools and other cultural amenities in such areas for easy accessibility.

One important caveat is that freeways, which make office and retail more attractive, have the opposite effect on schools. Air pollution makes learning more difficult, and children do not own cars and thus do not benefit from the convenience offered by the car. If rail lines are near freeways, then schools should be set somewhat away, on the principle that the extra 5-minute walk is worth the gain in health from not sitting hours in a polluted environment.

The suburbs

Outside the cities, the place for schools is the same as that for local retail and offices: the town center, with a regional rail station offering frequent access by train and timed connections by bus. Even when the student population is local, as it is in American suburbs, the density is too low for people to walk, forcing some kind of mechanized transportation. For this, the school bus is a poor option – it is capital-intensive, requiring what is in effect a second bus system, one that is as useless for non-students as the regular buses are for students if the school is far away from the local transit network.

Instead, a central school location means that the suburban bus network, oriented around city center, is useful for students. It increases transportation efficiency rather than decreasing it – there is no duplication of service, and the school peaks don’t usually coincide with other travel peaks, like the office worker peak and the retail worker peak. The bus network, designed around a 15- or 30-minute clockface schedule, also means that students can stay in longer, if they have on-campus club activity or if they have things to do in the town center, such as going shopping.

In some distant suburbs the school peak, arriving around 8 in the morning, may be the same as the peak for office workers who take the bus to the train to go to the central city. This isn’t necessarily a bad thing – for parents who insist on driving, this makes it easier to drop off children on the way to work. If this turns out to create real congestion on the bus, then the solution is to move school start time later, to 9 or so.

It’s crucial to use state power to effect this change when possible. For example, Massachusetts funds school construction through state funds but not renovation, which has encouraged schools to move to new campuses, generally in harder-to-reach areas. Fitchburg’s high school used to be in city center but recently moved to a suburban location close to nothing. Even in environments with a lot of local autonomy, the state should fund school construction in more central areas.

Density and Subway Stop Spacing

Normally, the best interstation distance between subway or bus stops does not depend on population density. To resurrect past models, higher overall density means that there are more people near a potential transit stop, but also that there are more people on the train going through it, so overall it doesn’t influence the decision of whether the stop should be included or deleted. Relative density matters, i.e. there should be more stops in areas that along a line have higher density, for example city centers with high commercial density, but absolute density does not. However, there is one exception to the rule that absolute density does not matter, coming from line spacing and transfer placement. This can potentially help explain why Paris has such tight stop spacing on the Métro and why New York has such tight stop spacing on the local subway lines.

Stop spacing and line spacing

The spacing between transit stops interacts with that between transit lines. The reason is that public transportation works as a combined network, which requires every intersection between two lines to have a transfer. This isn’t always achieved in practice, though Paris has just one missed connection on the Métro (not the RER), M5/M14 near Bastille; New York has dozens, possibly as many as all other cities combined, but the lines built before 1930 only have one or two, the 3/L in East New York and maybe the 1/4-5 around South Ferry.

The upshot is that the optimal stop spacing depends on the line spacing. If the line spacing is tight – say this is Midtown Manhattan and there is a subway line underneath Lex/Park, Broadway, 6th, 7th, and 8th – then crossing lines have to have tight stop spacing in order to connect to all of these parallel lines. In the other direction, there were important streetcars on so many important cross-streets that it was desirable to intersect most or ideally all of them with transfers. With so many streetcar lines extending well past Midtown, it is not too surprising that there had to be frequent subway stops.

So why would denser cities have tighter line spacing?

Line spacing and density

The intuitive relationship between line spacing and density is that denser cities need more capacity, which requires them to build more rail lines.

To see this a bit more formally, think of an idealized city on a grid. Let’s say blocks are 100*100 meters, and the planners can figure out the target density in advance when designing the subway network. If the city is very compact, then the subway could even be a grid, at least locally. But now if we expect a low-density city, say 16 houses per block, then the subway grid spacing should be wide, since there isn’t going to be much traffic justifying many lines. As the city densifies, more subway is justifiable: go up to missing middle, which is around 30-40 apartments per block; then to the Old North of Tel Aviv, which would be around 80; then to a mid-rise euroblock, which is maybe 30-40 per floor and 150-200 per block; then finally a high-rise with maybe 500-1,000 apartments.

Each time we go up the density scale, we justify more subway. This isn’t linear – an area that fills 500 apartments per block, which is maybe 100,000 people per km^2, does not get 20 times the investment of an area on the dense side of single-family with 16 houses per block and 5,000 people per km^2. Higher density justifies intensification of service, with bigger and more frequent trains, as well as more crowding. With more subway lines, there are more opportunities for lines to intersect, leading to more frequent stop spacing.

Even if the first subway lines are not planned with big systems in mind, which New York’s wasn’t, the idea of connections to streetcar lines was historically important. A stop every 10 blocks, or 800 meters, was not considered on the local lines in New York early on; however, stops could be every 5 blocks or every 7, depending on the spacing of the major crosstown streets.

Dense blobs and linear density

Line spacing is important to stop spacing not on parallel lines, but crossing lines. If a bunch of lines go north-south close to one another, this by itself says little about the optimal spacing on north-south lines, but enforces tight spacing on east-west lines.

This means that high density encourages tight stop spacing when it is continuous in a two-dimensional area and not just a line. If large tracts of the city are very dense, then this provides justification for building a grid of subway, since the crosstown direction is likely to fill as well; in New York, 125th Street is a good candidate for continuing Second Avenue Subway Phase 2 as a crosstown line for this reason.

In contrast, if dense development follows a linear corridor, then there isn’t much justification for intense crosstown service. If there’s just one radial line, then the issue of line spacing is moot. Even if there are two closely parallel radial lines in the same area, a relatively linear development pattern means there’s no need for crosstown subways, since the two lines are within walking distance of each other. The radial urban and suburban rail networks of Tokyo and Seoul do not have narrow interstations, nor do they have much crosstown suburb-to-suburb service: density is high but follows linear corridors along rapid transit. Dense development in a finger plan does not justify much crosstown service, because there are big low-density gaps, and suburb-to-suburb traffic is usually served efficiently by trips on radial lines with a transfer in city center.

YIMBY and Production Theory

Two years ago, at a Breakthrough Institute conference, I met Tory Gattis in real life for the first time, having known him on the Internet for maybe ten years. He was doing a debate with Kim-Mai Cutler, except they mostly agreed, and I think the reason for the agreement is their conception of production theory.

Tory’s opening was the most illuminating part, and only then, in 2018, did I understand why in 2008-9 I was so interested in reading him even though he was always pro-car, an unabashed Houston booster, and a fan of Joel Kotkin. He opened by defining himself in opposition to three ideas from the 2000s: smart growth, New Urbanism, and Richard Florida’s conception of the creative class. And there is clicked: these three ideas are all about cities as loci of consumption. Before YIMBYism, when Market Urbanism was an obscure libertarian blog, there wasn’t a lot in there for people who think in terms of urban job and residential growth, who think that consumption follows production and not the reverse.

New Urbanism and Richard Florida’s theory both hold, in different ways, that if cities make themselves nice to specific (different) classes of people, they will attract people who are morally and economically better to have as residents, stimulating further growth. In New Urbanism, this is about designing cities based on principles that are held to be objectively nicer for residents; this quickly boils down to the “when we’re expensive this proves we’re desirable, when you’re expensive this proves you’re unaffordable” principle. Ironically, the blog Old Urbanist holds something similar, it just posits a different (generally better) set of design principles. Richard Florida is less about physical design and more about community amenities for groups that in the 2000s he held were more creative, like gay people, for whom he prescribed more gay bars.

The irony is that even as he has increasingly repudiated the creative class theory, Florida maintains his attachment to consumption theory of cities. The difference is that 18 years ago he thought that building New Left-coded amenities like bike lanes and gay bars would attract creatives and increase social and economic outcomes and now he believes the same except that the final outcome is to raise rents. Tory was critiquing the idea already in the late 2000s, pointing out the anemic outcomes of cities whose development policy was consumption-based – it’s not that they were creating jobs but their rents was rising, but rather that they kept having low job growth and net emigration.

Smart growth is somewhat different, in that it is not explicitly an endorsement of consumption theory. However, in practice its effect is always to make development harder, not easier. The contrast is with transit-oriented development, which in theory means the same thing but in practice counts dwellings build near train stations and not dwellings prevented from being built far from train stations. California celebrates smart growth and smart growth celebrates California, and in practice the effect of California’s housing policy for the last 50 or so years has been to make all housing hard to build, creating a supply shortage.

In comes YIMBY. The central policy proposal of YIMBYism is to build more housing in rich, expensive cities. But the central tenet of YIMBYism is that people’s decisions about where to move to are driven by production rather than by consumption – that is, that people move for work rather than for the sort of consumption amenities that urban policymakers focus on.

This does not mean consumption amenities do not exist. They clearly do, but they operate at different levels from that of neighborhood activism. Albouy-Ehrlich-Liu find extensive consumption effects on urban desirability, but these are almost all geographic, like mild weather and proximity to the coast; only one is affected by policy, air quality, and that is a regional rather than local variable. Other policy-relevant consumption variables may be crime and education, neither of which is that responsive to local-level policy, especially when it pertains to development. People like New York and London and Paris, and maybe they’ll like them more if they provide public services like clean air better, but they’ll certainly not like them less if they replace 150-year-old 4-story buildings with 50-story ones. What people like about New York and London and Paris is not the architecture or the size of the buildings, but the dense job networks.

The Politics of Taking Out the Garbage

There’s a quote bouncing around urbanist media, attributed to Fiorello LaGuardia, that there is no Republican or Democratic way of taking out the garbage; see for examples CityLab and Governing. The idea of this quote is, there is no ideology in urban governance, only pragmatism. In this framework, important questions about how to govern a city are assumed away, as is any conflict between different class-based, ethnic, or industry-based interests.

The object-level political questions

There are key political questions about how to provide city services as delegated to the local government by the state. Berlin is a city as well as a state of Germany and thus has especially high levels of autonomy, with lively political debate about housing, education, and transportation. But even cities with less autonomy, like Paris, still have debates regarding land use, public housing, and street usage. These can be any of the following:

  • Is this service worth spending more money on, or should the city prioritize other services?
  • Should this service be provided directly by the city government, or by the private sector? If the latter, what kind of regulations are appropriate, if any?
  • Where should the city prioritize service? For example, in education, should the city prioritize class integration or build segregated schools (“Gymnasien”)? In garbage, which neighborhoods should the city make sure to prioritize in collection?
  • Should the workers be unionized? Should the city side more with the unions or with management in industrial disputes?
  • How should the service be run? For example, in education, what should the curriculum focus on, how should assessment work, what is the priority for investment, and how big should schools be? In policing, which crimes should get the most resources, should the city side with the police more or with civil rights activists, and which theories of policing should be implemented (broken windows, community policing, etc.)?

The earlier questions on the above list tend to be the same regardless of service, and generally people who like privatizing one service also like privatizing others. But shouldn’t this be an open ideological debate? A multiparty governing coalition might compromise on which services should be municipal and which private, and political parties would have to put their ideas to the test by either crafting a workable privatization contract or competently running service publicly.

The later questions on the list depend more on the service in question, and usually the biggest ideological load is on bigger issues than sanitation, like education or policing, the former of which especially animates the New Right in Germany and white flighters in the United States. However, even with sanitation, there are questions of priorities like what frequency to collect, how much to prioritize low-income neighborhoods, and how much space to make for dumpsters on the streets. New York infamously has open trash on the sidewalks because dumpsters would have to take up space that is currently devoted to street parking, which the most powerful mass groups of voters in the city consider sacrosanct.

The meta questions

Beyond questions of how to run various services, there are even broader questions about what is appropriate to be decided at what level. For examples:

  • How big should the city be? That is, should it annex its suburbs for a greater regional government, as in London, Berlin, and Toronto, or remain more local, as in Paris and most American cities? Should local governments outside the city be very fractionalized as in France and the Northeastern United States, or should there be amalgamations of regional municipalities as in most of non-France Europe?
  • Which issues are appropriate to be decided at what level? Should local governments have taxing power at all, or should they only have to make do with the budgets given to them by state taxes? Should education, policing, sanitation, transport, parks, electricity, and water be responsibilities of the state, a regional government, or the city?
  • What role, if any, should referendums have in budgetary and other political questions?
  • Regardless of what services are provided at what level, how should the bodies providing them be overseen? Should there be an elected board, a ministerial appointment, a civil service, or any combination of those three?

These questions sometimes do and sometimes don’t carry ideological load, but even when they don’t, they deserve to be debated and voted on in the open. In France, Sweden, and Japan, questions regarding zoning and housing production are decided at the national level, so in the 2014 election campaign, political parties in Sweden had posters all over Stockholm promising to build more housing to alleviate the country’s severe shortage. In the United States and in Germany these decisions are more local, but it’s completely legitimate for a political movement to demand that decisions be transferred upward to the state level, and to a large extent the YIMBY movement in California argues openly for state-level mandates and against local control.

This is especially important when there is consistent ideological load. Questions of annexation and boundaries between local or regional governments frequently intersect with inequality. In Israel, there are revenue-generating industrial zones in non-urban regional councils adjacent to low-income cities, where local interests agitate for the right to annex these zones to enhance those cities’ tax bases; conversely, the kibbutzes within those regional councils agitate for keeping borders as they are, and have so far succeeded in forestalling any change.

Interaction between different questions

The various object-level and meta questions about how to run city government – or whether to even have much local empowerment in the first place – interact in ways that make the answers to some questions depend on others.

The issue of pragmatism and apolitical government is especially instructive, because if the idea is to reduce the role of ideology in answering object-level questions, then certain meta elements follow. Specifically, if there is no ideological conflict, then there is no need for elected government. Consensus can be formed entirely at the elite civil service level, and in particular the number of political appointments should be kept to a minimum, ideally zero except for the minister.

The analog here is the military, which is depoliticized in every democracy, to the point that a politicized military generally means a country is not fully democratic. The military appoints its own officers, and even when the elected government must sign off on officer commissions, it is a pure rubber stamp, as the decisions are made internally. Only at the highest levels do politicians decide on appointment to provide civilian oversight, such as the IDF chief of staff. The role of the political system is to make decisions on war and peace and allocate the budget, and even then the military gets considerable latitude in internal allocation of funding. What is more, this arrangement is not a cloak-and-dagger affair – the public fully knows what is going on and is supportive, because the public has high levels of trust in the military as an institution, even in times and places with low public support for war.

Pragmatism and excuses

In practice, self-identified pragmatism in politics tends to mean treating certain positions as so obvious that they do not require any further defense. But then the question of what is obvious depends on time and place; for example, in the late 20th century through today, English-speaking governments have assumed that public-private partnerships with multi-decade contracts are obviously the superior way to provide services, whereas the Nordic countries prefer regionwide governance with more ubiquitous but shorter-term contracting and France and Germany keep most services in the public sector.

Most people do not stop to ask whether a foreign way works better. This has nothing to do with pragmatism – people who identify differently do it just as much. However, the lack of political pluralism means that it is not possible for an opposition movement to point out that other places do things differently and use this to come up with concrete proposals for change. This problem occurs often where there is no regular change in government; multiparty elections can ameliorate it by giving people the option of voting for a different coalition members, for example voting Green in Berlin within the dominant red-red-green coalition to express a wish to stop building highways, but even that works less well than the threat of the opposition actually taking over. In cities with no real ideological choice, it becomes completely impossible to adopt new practices, and this should be viewed as a primary reason why local governance in the United States is so bad by European standards.

Democratic consensus as mediation

In contrast with the idea of a leader who stands about mere politics, democratic consensus governance permits debate on different urban questions, including meta-discussions of which questions are most important. The key here is multiparty elections that force coalition governments. This has three benefits.

  • It reduces the ability of an executive to engage in an authoritarian takeover, since junior coalition members in nearly all cases have an incentive to defect – if the opposition is destroyed, they are next on the chopping block.
  • It widens the space of permissible ideas, since niche groups can take over smaller parties; environmentalism made the jump from street protests to serious politics through green parties in multiparty states. In cases of extremism it’s still possible to form a cordon sanitaire against unwanted parties like AfD, and this puts pressure on parties to behave in socially acceptable ways to avoid being treated as illegitimate.
  • It allows junior members to advocate on a specific issue and get the relevant ministerial portfolio to make changes that can succeed or fail in the real world.

This is a set of answers to meta-questions, much more so than to object-level questions. As always, there is interaction between answers: if political parties are the vessel that mediates between individual voters and the state, then the polity size must be large enough to maintain ideological vote and ideological diversity, which argues in favor of more extensive annexation and against very small, homogeneous municipalities like Eastern and Midwestern American suburbs.

There is extensive room for pragmatism here, since this is a governance method that lives on political compromise, denying any single faction a majority. But it’s a pragmatism layered on ideological questions, because different parties will have different ideas about how to run the police, provide sanitation, allocate street space, etc., and this is fine. Different parties will have different ideas about whether to side with workers or management more, and this too is fine. And different parties will have different ideas about how to prioritize the budget and which services to provide in the first place, and that, like the previous points of contention, is also fine.

Coronavirus and Cities

There’s a meme going around the American discourse saying that the Covid-19 outbreak is proving that dense cities are bad. Most of this is bullshit from politicians, like Andrew Cuomo. But now there’s serious research on the subject, by a team at Marron led by the excellent Solly Angel. Solly’s paper looks at confirmed infection rates in American metropolitan areas as of late March and finds a significant correlation with density, but no significant correlation between deaths and density. In this post, I’m going to look at Germany. Here, big or dense cities are not disproportionately affected by the virus.

Why Germany?

Germany has pretty reliable data on infections because testing is fairly widespread, so far covering 1.6% of the population. Moreover, testing is this high throughout the country, whereas in the US, there are vast differences in testing as well as in other aspects of response by state, e.g. New York has tested 2% of state population, Louisiana 1.9%, Florida 0.8%, California and Texas 0.4%.

I also have granular data on infection rates in Germany, thanks to Zeit. The data I’m using is synchronic rather than diachronic, i.e. I’m looking at current infection rates rather than growth. Growth rates aren’t the same everywhere – in particular, they’re lower in North Rhine-Westphalia, which was the epicenter of the German outbreak weeks ago, than in southern Germany – but they’re low enough that I don’t think the situation will change in short order.

Size and density

Within Germany, there aren’t huge gradients in density between cities. More central neighborhoods have taller buildings than less central ones and higher ratios of building to courtyard, but there are no huge differences in residential built form the way there are between American cities.

For example, look at densities by neighborhood in Berlin, Hamburg, Munich, Frankfurt, Cologne, Stuttgart. There aren’t big differences in the pattern: the densest inner neighborhoods have about 15,000 people per square kilometer, and density falls to 3,000-5,000 in outer neighborhoods. Hamburg has a few areas with no residents, since they include the city’s immense port. Stuttgart’s densest districts are in the 5,000-6,000/km^2 range, but that’s because the districts are not very granular and the dense ring of inner-city neighborhoods just outside the commercial center is not congruent to district boundaries.

The upshot is that the big question about density and the risk of epidemics cannot be answered by comparing German cities to one another, but only to the surrounding rural areas. So the real question should be, are the major German cities more afflicted by the virus than the rest of the country?

Infection rates by city

As of the end of 2020-04-09, Zeit reports 118,215 confirmed coronavirus cases, which is 14.2 per 10,000 people. The six states of former East Germany, counting the entirety of Berlin and not just East Berlin, total only 12,873 cases, or 7.9 per 10,000. The Robert Koch Institute’s definitive numbers are slightly lower, but are also slightly outdated, as states sometimes take 1-2 days to report new cases. Going by Zeit data, we have the following infection rates by major city:

City Population Cases Cases/10,000
Berlin 3,644,826 4,357 12
Hamburg 1,841,179 3,518 19.1
Munich 1,471,508 4,123 28
Hanover* 1,157,624 1,389 12
Cologne 1,085,664 1,947 17.9
Frankfurt 753,056 730 9.7
Stuttgart 634,830 1,056 16.6
Dusseldorf 619,294 737 11.9
Leipzig 587,857 451 7.7
Dortmund 587,010 507 8.6
Essen 583,109 578 9.9
Bremen 569,352 425 7.5
Dresden 554,649 476 8.6
Nuremberg 518,365 733 14.1
Duisburg 498,590 525 10.5

*Zeit reports Hanover data for the entire region; the city itself only has 538,000 people

The sum total of the fifteen largest cities in Germany, with 15.1 million people, is 21,552 cases, which is 14.3 cases per 10,000 people. This is the same as in the rest of the country to within measurement error of total population, let alone to within measurement error of Covid-19 cases.

State patterns

Bavaria and Baden-Württemberg both have high confirmed case counts, averaging 23.6 and 21.7 per 10,000 people respectively. Munich’s rate is somewhat higher than the Bavarian average, but its suburbs are on a par with the city, as are some entirely rural areas all over the state. Oddly, the second and third largest cities in the state, Nuremberg and Augsburg, have lower rates – though both Fürth and the rural areas around Nuremberg and Fürth have very high rates as well.

The pattern around Stuttgart is perhaps similar to that around Nuremberg. The city’s infection rate is not much higher than the national average, but the infection rates in counties and cities around it are: Esslingen (24.8/10,000), Reutlingen (29.3), Tübingen (47.9), Böblingen (28.4), Ludwigsburg (22.9).

NRW’s rate is 13.9/10,000, i.e. essentially the same as the national average. The worst is in areas right on the Belgian border, like Heinsberg. Cologne has a noticeably higher rate, but Dusseldorf has a lower rate, and the cities of the Ruhr area a yet lower one. Don’t let the fact that these cities only have around 600,000 people each fool you – they’re major city centers, with the density and transportation network to boot. Dortmund alone has three independent subway-surface trunks, meeting in a Soviet triangle; total public transportation ridership in Dortmund across all modes is 130 million per year. Essen has two subway-surface trunks, one technically light rail and one technically a streetcar tunnel; total ridership there and in Mülheim, population 170,000, is 140 million per year.

What’s going on in Frankfurt?

There is some correlation between wealth and a high infection rate, since Bavaria and Baden-Württemberg have high rates of confirmed cases and the East German states have low ones. However, Frankfurt’s rate is fairly low as well, as are the rates of surrounding suburbs like Offenbach and Darmstadt. Frankfurt is not as rich as Munich, but like Hamburg and Stuttgart, it is fairly close, all three metro regions surpassing Ile-de-France and roughly matching London per Eurostat’s per capita market income net of rent and interest table.

In particular, it is unlikely that the greater international connections of rich cities like Munich explain why they have higher rates. Frankfurt Airport is the primary international hub in Germany, with many passengers standing in line at the terminal and coughing on other people. It would have been the easiest for imported infections to arise there rather than in the Rhineland, and yet it doesn’t have a major cluster.

Frankfurt also has extensive O&D business travel; Wikipedia puts it third after Berlin and Munich, but Frankfurt’s visitors are most likely disproportionately business travelers rather than tourists. This is important, since February and March are low season for tourism, whereas business travelers are if anything more likely to be going to Frankfurt during low season because during the summer high season they go on vacation in more interesting places.

So, is urban density more vulnerable to infectious diseases?

Probably not. Rural Germany has some areas with Korean levels of confirmed cases per capita, and some where 1% of the population and counting has tested positive. Overall, there isn’t much of an urban-rural difference – the 15 largest cities in Germany collectively have the same rate as the rest of the country, and moreover, where there are notable state-level patterns, they also hold for the states’ big cities. If Munich’s high infection rate is caused by its high rate of U- and S-Bahn usage, then the suburbs should have lower infection rates (they’re more auto-oriented) and the rest of Bavaria should be much lower; in reality, nearly the entirety of Bavaria has high rates.

The highest density in the developed world does not exist in Germany. German neighborhoods top at 15,000/km^2, with individual sections scratching 20,000; Paris tops at 40,000 in the 11th Arrondissement, New York scratches 50,000 on the Upper East Side, and Hong Kong has entire districts in the 50s. So the “density doesn’t matter” null hypothesis, while amply supported on German data, requires some extrapolation for the handful of world cities with the highest density.

Nonetheless, these are not huge caveats. German data is pretty reliable in the density range for which it exists; if cities today had the infection rates they did before modern plumbing, when a noticeable fraction of a city’s population might die in a single epidemic, it would be noticeable today. But there is no mass death, nor are urban hospitals here collapsing under the strain. On both the level of a basic sanity check and that of looking at the data, cities do not appear to be vulnerable to disease.

What does this mean?

There is no need to redesign the world to be less urban or dense in the wake of the coronavirus. Nor is there any need to let go of collective public transportation. The Rhine-Ruhr and Frankfurt are not Tokyo or Hong Kong in their public transportation usage, or even Paris or Berlin, but they have extensive urban and regional connections by train. And yet, the Heinsberg disaster zone and the high infection rate of Cologne have not been exported to the Ruhr, nor is southern Hesse particularly affected by German standards.

The virus has exposed serious issues with cleanliness. But even given Germany’s current levels of urban cleanliness, those issues are not enough to turn Berlin, Frankfurt, Hanover, or the Ruhr cities into hotspots. There is no danger to public health coming from urbanization, density, development, or public transportation. Cities should keep investing in all four in order to reduce the costs of transportation and environmental damage, even if the occasional failed politician blames the virus on density to deflect attention from his own incompetence.

What Does Private Affluence, Public Squalor Mean?

I’d like to compare three cities: Paris, New York, Boston. They’re about equally wealthy, and I’ve lived years in two and spent a lot of time in the third. Americans dismiss New York and Boston too often as Not Real America, but they’re both excellent examples of how the US differs from Europe.

Private affluence and squalor at home

Visit the home of a middle-class person in the city. (I mean “middle-class” in the European sense of “reasonably educated professional,” not the American one of “not homeless.”) If you’re used to a certain suburban American standard of normality then the New York apartment will look small to you, but the one in Boston will not, and a few years seeing how Europeans live will disabuse you of any notion that New York apartments are small.

Parisian apartments are tiny. I had 40 square meters near Nation, but the citywide average is 31 per person; in New York, it’s 50 if I understand the Census Factfinder correctly. There are studios in Paris well below 20 m^2 – even Stockholm tends to stick to micro-units in the 20-25 m^2 area. There is something called studettes going down to 9 m^2 in the most extreme cases, many inherited from servant attic units built in the Second Empire and Belle Epoque. In New York it’s more or less prohibited by regulation, with the attendant high rents, but the regulations are about bedrooms, not unit size, hence the common experience of living 3 or 4 people to a large apartment, one that in Continental Europe is largely restricted to lower-income cities like Lisbon or Berlin.

In the 1950s, when John Galbraith coined the expression private affluence and public squalor, the American home had amenities unheard of in Europe, like universal ownership of appliances. This is not as stark a distinction today. Europeans have televisions and fast Internet connections for cheaper prices than in the US. But Europeans don’t have driers or air conditioning and don’t have dishwashers as commonly as Americans. I don’t want to exaggerate the difference in housing quality – for one, insulation is a lot better in Paris (and Berlin) than in New York and Boston, so the experience of living on the 3rd floor facing a city street is a lot noisier west of the Pond than east of it. For another difference, American air conditioning is window units in all but the highest-end apartments, which would have central air in Europe too. But the difference exists, and is noticeable.

Public affluence and squalor on the street

Let’s leave the inside of our houses now. How does the public sphere look?

The recent reporting of New York as trash city can make people think that this is literally about the street. To some extent, this is – but it’s not just about trash. For one, the street lighting is better in Paris, and better in Manhattan than in Cambridge, in what I think is an artifact of high density and not just wealth. For two, I don’t remember having to dodge puddles in the rain in Paris; in New York and Boston it’s a common occurrence whenever there’s heavier rain than a drizzle. For three, in the snow, Cambridge becomes mostly impassable to pedestrians, and while Paris does not get serious enough snow for shoveling to ever be a big issue, Stockholm does and the sidewalks in Central Stockholm are shoveled just fine.

The importance of Paris’s wealth and density is that Berlin is not this nice. The street lighting in Berlin is not great by Parisian standards (or, as I recall, by Stockholm ones?). Walking around Bernauer Strasse (let alone Neukölln, one of inner Berlin’s poorest neighborhoods), one never gets the feeling the area is as well-off as Nation, which is itself lower middle-class by Parisian standards. I’m saying this knowing the comparative income levels of Berlin and Paris, and perhaps it’s unfair, but from what I’ve seen, it’s fairly easy to compare France and Germany, their relative levels of public and private affluence are similar.

Public services

Most Americans know, on some level, that various public services are better in Western Europe. Life expectancy in France is higher than in the US by 3-4.5 years depending on source, and life expectancy in Germany is higher by 2-3 years. New York and Massachusetts are wealthy states and outlive the rest of the country by a margin, but they’re still not French, let alone Parisian.

Public health is there in various statistics, but the same is true of transportation. This is not even just public transportation – my recollection of the handful of times I’ve found myself in a taxi in Paris is that it’s a much more pleasant experience than the potholed American streets I’ve taken taxis or ridden with other people on. But it’s much more glaring in public transit than on roads, because public transit inherently requires more public competence. Parisians do not think the RER is particularly good, but it’s a marvel compared with any American commuter rail network, and involves a level of interagency coordination in fares, schedules, and services that is unheard of in the United States.

Worse, public transit in the United States has the reputation of a social service. In metro New York the incomes of transit and car commuters are very close, and in metro Boston transit commuters slightly outearn car commuters, but in both areas, anything that is not a segregated suburban middle-class commuter line is treated as a social service, run by managers who do not use their own system and do not consider use cases beyond their own 9-to-5 work travel.

Squalor and incompetence

Squalor and incompetence feed each other. This does not mean poverty is a moral failing or a result of weakness or stupidity. But it does mean that someone who is denied access to good work will, over a lifetime, learn to do lower-value things and, even if the job denial at 18 was entirely random or a matter of discrimination, be worse at high-value jobs by 50. I don’t think it’s a coincidence that countries with more income mobility and less persistent poverty – for examples, Canada, Australia, and the Nordic countries – do not determine people’s careers by how they did at 18 at the university admissions the way the US, UK, and France do. Talented Canadians who get worse grades in high school because of obstructive teachers will have opportunities to shine at 23 that their French or American counterparts, denied the ability to go to the most prestigious universities, will simply not get.

I bring this up because the US has a cycle of public squalor. Public-sector wages are uncompetitive, so workers are either nerds with particular personal or social interest in the field (sanitation, public transit, etc.), or people who couldn’t get better private-sector work – and this is particularly acute at the management level, especially senior management, since the best managers can leak to the private sector and get better pay there. Weak civil service in turns reduces the political will to pay civil servants high salaries, especially among politicians, who encounter senior managers much more often than they do hard-working train drivers, sanitation workers, and individual teachers.

There’s perhaps an analog of private affluence and public squalor, in which Americans are individually diligent and collectively lazy. Some of this has to be political: ambitious politicians get ahead by doing nothing and packaging it as bravery. I can name multiple national Republicans who became nationally famous by saying no to spending, and not a single Democrat who became nationally famous by successfully pushing through a major government program, such statewide universal health care or a green transition. But it’s not just politicians and their political appointees – there’s punch-clock behavior and agency turf battles below that level.

Is there a solution?

Unambiguously, yes. It’s not evident from just reading about the history of the Anglosphere, since Britain took forever to develop its civil service and thus assumes the process would be equally long in South Korea or Finland (“first 500 years are hardest“). It requires political will, and often a good model – I suspect Finland was able to develop good government so quickly because it consciously imitated Swedish governance. It doesn’t even require setting everything on fire first – South Korea and Taiwan engaged in land reform but did not kill the entire middle class the way some communist countries did.

The good news is that most public-sector workers in the US are not incompetent political appointees. The people I talk to in New York and Boston are sharp and informed and often difficult to keep up with because of how much they understand that I don’t, and for the most part I get the impression that they don’t think their colleagues are morons. The competence level on average decreases as one goes upward, partly because of negative selection of management, but it’s possible and desirable to internally promote people and raise wages to retain talent.

Fundamentally, the US needs to let go of the idea that the public is inferior to the private. But this isn’t just about what’s in Americans’ heads. They need to treat the public commons well, and I don’t just mean building monuments that look nice now and will rust in 10 years. I mean investing in public services, and paying the people who provide them competitively. Public squalor is a choice the US makes every day that it can stop making.

Urban Freeways and Rapid Transit

A ride-hailing trip today reminded me of something about freeway travel in cities – namely, it is untethered from the surface street network. Oddly enough, for a different reason this is equally true of rapid transit. The commonality to these two ways of travel is that they change the geography of the city, rather than just extending the range of walking along the usual paths as surface arterial streets and surface transit do.

Rapid transit compression

Rapid transit networks compress distances along the lines, and by the same token magnify distances in orthogonal directions. Manhattan is a good example of how this works: north of Midtown the subway only runs north-south, not east-west, so there are separate East Side and West Side cultures. Moreover, as middle-class gentrifiers are displaced by rising rents coming from even richer gentrifiers, they tend to move along subway lines, and thus people from the Upper West Side and Columbia end up in Washington Heights and Inwood.

The contrast here is with surface transit. Bus networks are far too dense to have the same effect. A citywide bus grid would offer 15 km/h transit in all directions in New York, and a tramway grid like what parts of Berlin have (and what big Eastern European cities like Prague and Budapest have) offers 15-20 km/h transit in all directions. It extends walking, in the sense that the most important throughfares probably get their own routes, or if they don’t they are closely parallel with roads with surface transit.

This is not how rapid transit works. A handful of very strong orthogonal routes can and should get rapid transit, hence the Ringbahn, M2/M6 in Paris, and the under-construction M15 – and by the same token, 125th Street in New York should get a subway extension off of Second Avenue. But that still leaves the city with a wealth of major routes that have no reason to get rapid transit, ever. Most of these are crosstown routes, for example the east-west streets of Manhattan, but in less gridded cities they can just be major streets that don’t quite fit into a regionwide radial metro network.

Rapid transit spikiness

I get a lot of pushback when I talk about this, but rapid transit encourages spiky density. This does not mean that every transit city is spiky and every spiky city is a transit city. Density in Paris within the city is fairly uniform, aided by zoning rules that prohibit high-rises even though many could succeed commercially on top of Métro transfer points or RER stations. In the other direction, some American auto-oriented cities have spiky density near transit, like San Diego’s Mission Valley or Atlanta’s Buckhead, but it’s not big enough a development to permit people to comfortably walk and take transit to all destinations.

Nonetheless, for the most part, rapid transit tends to be associated with spiky development forms, especially if it’s been built more recently and if the interstation is long (as in Vancouver, Singapore, Hong Kong, or Stockholm). This isn’t really how a pedestrian city works: pedestrians have no need for spikiness because they don’t have particular distinguished stations – at most, the corner nodes are distinguished, but that includes all corners, which are placed at far shorter intervals than subway stops.

Freeways as street bypasses

Surface transit promotes urban forms that look like an extended pedestrian city. This is equally true of surface roads designed around car access. The car was originally not supposed to take over the entire city, but merely provide convenient intra-urban transportation at a faster speed than walking. It was originally just a faster, more private, more segregated streetcar. The effect on urbanism was to reduce overall density (as did the streetcars and rapid transit in New York, which used to have inhuman overcrowding levels on the Lower East Side), but not to change the urban form beyond that.

Freeways, like rapid transit, are completely different. This does not mean that they change the city in the same way as rapid transit, just that both operate independently of the usual street grid. Freeways, like rapid transit, compress travel distances along the freeway, and simultaneously lengthen them in all other directions because of the effect of traffic congestion.

Moreover, freeways are different from rapid transit in typical alignments. They are far more land-intensive, which is why they tend to be placed in formerly marginal parts of the city. This can include the waterfront if it is originally industrial and low-value, as it was in midcentury America, rather than a place of high-end residential consumption because of the views.

Interface with the street

How does a surface street transit network interface with either rapid transit or freeways?

With rapid transit, the answer is that surface transit is slow, so it should feed rapid transit using transfers, which may be timed if the trains are not so frequent (say, 15 minutes or worse, as is common on suburban rail branches). Rapid transit should then be constructed to connect with surface transit this way, that is the stations should be at intersections with arterial corridors for bus connections.

With freeways, the answer is that often interface is impossible. San Diego provides a convenient example: there is an arterial road that’s great for buses running northward from city center toward the beachfront neighborhood of Pacific Beach. But there’s also a parallel freeway inland, so drivers mostly use the freeway, and commerce on the north-south arterial is neglected. In contrast, the main east-west arterials feeding the freeway are bustling, and one of them has of the city’s strongest buses. Buses can make stops on these arterials and then express to city center on the freeway, but on the freeway itself the buses are not very efficient since there’s minimal turnover, and chaining a few neighborhoods together on one frequent route is usually not possible.

New York City Zoning and Subway Capacity

I got a bunch of accolades and a bunch of flaming replies over a tweetstorm imagining a bigger, better New York. Some people complained about my claim that subway trains in Brooklyn are underfull; I urge everyone to read my analysis of data from 2016 – it’s still relevant today, as the only big change is that Second Avenue Subway has reduced Upper East Side crowding. The point of this post is to demonstrate where zoning should definitely focus on adding more apartments, to fill trains that are not yet full.

The map

Instead of using the current subway map, let us start with a deinterlined map:

The reason for using this map is that it’s cleaner than the real map, since there is no track-sharing between routes of different colors, and not much route-sharing (one color local, one express). Getting from here to this map is cheap but not free, as it requires certain junction rebuilds, especially on the 2/3. I ask that my commenters resist the temptation to argue over the details of this map, since the point about zoned capacity does not really depend on questions like whether the E runs local in Queens and the F runs express or the reverse.

Where there is capacity

In 2016, three directions on the subway were truly at capacity, surpassing 4 standees per square meter: the 2/3 and 4/5 coming into Midtown from Uptown, and the L. The analysis looks at crowding on trains entering the Manhattan core, so it lumps lines from Queens based on which tunnel they enter from, which underestimates crowding on the E, since it shares tracks with the under-capacity M. Counted properly, the express Queens Boulevard trains should be viewed as near or at capacity as well, the F having 3.33 standees per square meter and the E having somewhat more.

Additional lines with capacity crunches, with about 3 standees per square meter or more, include the A/D coming in from Uptown, the 6, and the Astoria Line (then the N/Q, now the N/W). The 1 and 7 trains have capacity crunches as well in outlying areas: the 7 is overcrowded until it hits the transfer points to the E/F and N/W but has plenty of space in Long Island City, and the 1 is fairly crowded north of the junction with the express trains and then unloads passengers onto the overcrowded 2/3. These areas should not be deemed to have much spare capacity until such time as operations on the subway improve, permitting higher frequency and eventually more lines.

In contrast, the remaining lines have space, often plenty of space. Everything in Brooklyn except the L and to some extent the J/M/Z is underfull: these trains have high frequency as determined by crowding guidelines at the Uptown or Queens end, but in Brooklyn there are fewer people today so the ridership is weaker. The local lines on the Upper West Side both have plenty of space on the trains as well as space on the tracks for more trains if need be. The 7 downstream of Queensboro Plaza has plenty of space, and the local Queens Boulevard trains downstream of Jackson Heights have nowhere for passengers to transfer to an overcrowded express service.

Since I’m relying on data from 2016, there’s no accounting for Second Avenue Subway. Even then, the 4/5 was only the third most overcrowded trunk line entering the Manhattan core, and it’s likely that there’s additional capacity coming from the new line. There’s certainly space on the tracks for more trains on Second Avenue, and one of the goals of deinterlining specifically is to make it feasible to run more service on this line, which currently only runs a train every 6-8 minutes at rush hour.

The map of where New York could add housing

The map excludes parts of Lower and Midtown Manhattan where the highest and best use is commercial rather than residential. But the boundaries there are deliberately crude: Downtown Brooklyn, NYU, and the Meatpacking District are drawn, to avoid excessive fragmentation of the drawn area, while Chelsea and Hell’s Kitchen are excluded as too close to Midtown.

The map also does not look at considerations other than capacity. Some of the highlit areas on the Upper East and West Sides and Lower East Side are already built to very high density, at least on the avenues and major streets; these areas should be the template of how the rest of the city should look. At the other end, East New York has too weak demand for massive construction, especially if everything to its west is upzoned.

However, large swaths of desirable, close-in areas with relatively short buildings are highlit. Rich inner Brooklyn neighborhoods like Park Slope and South Brooklyn are currently built to missing middle density, with a floor area ratio of about 1.5 away from corner lots. A more appropriate floor area ratio in these neighborhoods is 12, corresponding to tapering buildings in the 20-30 story range, as on the avenues on the Upper East and West Sides. Park Slope is half an hour from Midtown by subway, and less than that from Lower Manhattan. The population of these neighborhoods is perhaps 150,000, and should be more than a million given their proximity to job centers.

Subway deserts and future additions

The map is designed to work with more or less the same service as today, maybe with slightly more frequency on lines that could handle it easily (that is, Second Avenue Subway). But what about future service? The L train is overcrowded, but only runs 19 trains per hour at the peak due to electrical limitations, and could go up to 26 with better electrical capacity, or for that matter lighter trains drawing less power during acceleration. Further extensions of Second Avenue Subway could more effectively relieve pressure off the 4/5, to the point of creating more capacity in the Bronx, which remains well below peak population. Commuter rail modernization opens up large swaths of Queens. Decades in the making extensions on Nostrand and Utica fill in the transit desert in southeast Brooklyn, currently served by buses that nominally come every 2 minutes and in practice comes in platoons of 4 every 8 minutes.

As with the map above, a hypothetical map of development sites assuming reasonable subway expansion includes areas that would be unlikely to actually see new development. Williamsburg and Greenpoint may turn into forests of towers given the opportunity, but in neighborhoods like Sheepshead Bay and East Flatbush developers might well stick to the occasional 6-to-10-story mid-rise building that would not look out of place in Paris. In Eastern Queens, the desired density is probably spiky, with clusters of tall buildings around LIRR stations surrounded by single-family houses and missing middle, much like the structure of density in Toronto and Vancouver.