Last post, I brought up the point that the neighborhoods along the Interborough Express corridor in New York are residential. An alert commenter, Teban54transit, pointed out that this should weaken the line, since subway lines should connect residential neighborhoods with destinations and not just with other residential neighborhoods. To explain why this is not a major problem in this case, I’d like to go over what exactly is a residential neighborhood and what exactly is a destination. In short, a predominantly residential neighborhood may still have other functional uses, turning it into a destination. It’s imperfect in the case of IBX, but the relative ease of using the right-of-way makes the line still viable.

Residential-but-mixed neighborhoods

Residential neighborhoods always have nonresidential uses, serving the local population: supermarkets, schools, doctors’ offices, restaurants, pharmacies, clothing stores. These induce very few trips from out of the neighborhood, normally. But things are not always normal, and some residential areas end up getting a cluster of destinations.

In New York, the most common way such a cluster can form is as an ethnic center, including Harlem and several Chinatowns. People in and around New York travel to Harlem for specifically black cultural events, for example the shows at the Apollo Theater; they travel to Chinatown and Flushing for Chinese restaurants and supermarkets. Usually the people who so travel are members of the same ethnic community who live elsewhere; this way, in Washington Metro origin-and-destination travel data, one can see a few hundred extra trips a day between black neighborhoods east of the Anacostia River and Columbia Heights, whereas no noticeable bump is seen in work trips between those two areas on OnTheMap.

On the IBX route, this is Jackson Heights. It’s on net a bedroom community, whereas Flushing has within 1 km of Main and Roosevelt 43,000 jobs and 29,000 employed residents, but such ethnic cultural centers over time grow into destinations. People travel to the neighborhood for Indian restaurants, groceries, and cultural events, and it’s likely that over time the area will also get more professional services that cater to the community, creating more non-work and work destinations. The growth of Flushing as a job center is recent and has to be understood as part of this process: in 2007, on the eve of the Global Financial Crisis, there were only 17,000 jobs within 1 km of Main and Roosevelt. Jackson Heights, too, has seen growth in jobs from 2007 to 2019, though much less, by 27%, or 50% excluding Elmhurst Hospital, which over this period saw a small decrease in jobs.

Not only ethnic neighborhoods have this pattern. A neighborhood can grow to become mixed out of proximity to a business district, for example the Village, or out of a particular destination, for example anything near a university. On IBX, there’s nothing like the Village or Long Island City, but Brooklyn College is a destination in and of itself.

Building neighborhood-scale destinations

New public transit lines can help build neighborhoods into destinations. At the centers of cities, central business districts and rapid transit systems tend to co-evolve with each other: a high degree of centralization creates demand for more lines as the only way to truly serve all of those jobs, while a larger rapid transit system in turn can encourage the growth of city center as the place best served by the network. The same is true for secondary centers and junctions of other lines.

This, to be clear, is not a guarantee. Broadway Junction is very easily accessible by public transportation from a large fraction of New York. It’s also more or less the poorest area of the city, where working-class Bangladeshi immigrants living several to a room to save money on rent are considered a sign of gentrification and growth in rent. Adding IBX there is unlikely to change this situation.

But in Jackson Heights and around Brooklyn College, a change is more likely. Jackson Heights already has large numbers of residents using the radial subway lines to get to Manhattan for work, and a growing number of nonresidents who use its specialized businesses and cultural events. The latter group is the greatest beneficiary from circumferential transit, if it connects to the radial lines well; strong radial transit is a prerequisite, but in Jackson Heights, there already is such transit. Brooklyn College is already a destination, in a neighborhood that’s much better off than East New York and already draws widely because of the university trips; I expect that rapid transit service in three directions, up from the one direction available today (toward Manhattan), would encourage the growth of university-facing amenities, which generate their own trips.

Where to build circumferential rail

The best alignment for circumferential rail remains one that connects strong secondary destinations. However, that is strictly in theory, because usually such destinations don’t form a neat circle around city center, especially not in a city so divided by water like New York. If we were to draw the strongest secondary destinations in the city outside the Manhattan core excluding Downtown Brooklyn and Long Island City on the G, we’d get Morningside Heights for Columbia (centered on 116th), maybe 125th Street, the Bronx Hub, LaGuardia, Flushing, Jamaica, and Kings County Hospital/SUNY Downstate. These barely even form a coherent line if dug entirely underground by tunnel boring machine, diagonally under private blocks. And this is without taking into account destinations in New Jersey on the waterfront, which don’t form any neat circle with those city destinations (for example, Fort Lee is well to the north of Morningside Heights and Harlem).

In practice, then, circumferential lines have to go where it is possible, making compromises along the way. This is why it’s so important to connect to every radial, with as short a walk as practical: they never connect the strongest destinations and therefore have to live off of transfers. The G, which does connect the two largest job centers in the region outside Manhattan, fails because of the poor transfers. IBX works as a compromise alignment, connecting to interesting secondary destinations, with transfers to the most important ones, like Flushing and Jamaica. It is fortunate that the route is not purely residential: the neighborhoods are all on net bedroom communities, but some have the potential to grow to be more than that through both processes that are already happening and ones that good rapid transit can unlock.

(I’m aware that I’ve been posting more slowly than usual; you’ll be rewarded with train stations soon.)

I saw a tweet by Strong Towns that compared traditional cities with the suburbs, and the wrongness of everything there reminded me of how much urbanists lie to themselves about what cities were like before cars. Strong Towns is more on the traditional urbanism side (to the point of rejecting urban rail on the grounds that it leads to non-gradual development), but a lot of what I’m critiquing here is, regrettably, commonly believed across the urbanist spectrum.

The basic problem with this comparison is that there was never such a thing as traditional urbanism. There are others; all of the claims in the comparison are false – for example, the line about “makes communities brittle” misses how little community empowerment cities had in the 19th and early 20th centuries, before zoning, and the line about top-down versus bottom-up energy misses how centralized coal and hydroelectric plants were at the turn of the century whereas left-voting NIMBY suburbs today are the most reliable place to find decentralized rooftop solar plants. But the fundamental problem is that Strong Town, and most urbanists, assume that there was a relatively fixed urban model around walkability, which cars came in and wrecked in the 20th century.

What’s true is that before mass motorization, people didn’t use cars to get around. But beyond that tautology, every principle of urban walkability was being violated in one pre-automobile urban typology or another.

Local commuting

Pre-automobile industrial cities were not 15-minute cities by any means. Marchetti’s constant of commuting goes back to at least the early 19th century; people in pre-automobile New York or London or Berlin commuted to a commercializing city center. This was to some extent understood in the second half of the 19th century: the purpose of rapid transit in New York, first steam els and then the subway, was to provide a fast enough commute so that the working class of the Lower East Side would get out of its tenements and into lower-density houses where they’d be turned from hyphenated Jews and Italians into proper Americans.

There has been a real change in that, in Gilded Age New York (and, I believe, in third-world cities today like Nairobi), people worked either locally or in city center. There was very little crosstown commuting, and so the Commissioners’ Plan for Manhattan in 1811 emphasized north-south commuting to Lower Manhattan, while private streetcar concessionaires likewise built routes to city center and rarely crosstown. Nor was there much long-distance travel except by the people who did work in city center: there were people who lived their entire lives in Brooklyn without visiting Manhattan, which became unthinkable by the early 20th century already. But this hardly makes Gilded Age Brooklyn a 15-minute city, any more than a modern suburb where most people do not visit city center out of fears of crime is anything but a suburb of the city, living off of the income generated by people who do commute in.

In truly premodern city, the situation depended on the time and place. Medieval European cities famously had little commuting – shopkeepers would live in the same building that housed their store, sleeping on an upper floor. But in Tang-era Chang’an, people did commute (my reference is the History of Imperial China series, no link, sorry). This is very far from the result of thousands of years of tinkering, when each time and place did something different before industrialization, and then went to yet another set of layouts after.

Local infrastructure

Pre-automobile industrial cities mixed top-down and bottom-up approaches, same as today. The grid plans favored in the United States, China, and the Roman Empire were more top-down than the unplanned street networks of most medieval and Early Modern European cities, each designed for a different cultural context. (In Imperial Rome much of the context was about following military manuals, for those cities that descend from forts.) In the medieval Muslim world, cities had cul-de-sacs long before cars, because this way each clan could have its own walled garden, so to speak.

Widely divergent contexts

Premodern cities developed in widely divergent contexts. Based on these contexts, they could look radically different. The comparison mentions war and peace; well, defensive walls were a fixture in many cities, and these mattered for their urban development. They were not nice strolls the way some embankments are today. There aren’t any good examples of walls in North America, but there are star forts, and they’re not usually pleasant walks – their purpose was to make the day of besieging troops as bad as possible, not to make tourists feel good about the city’s history. Medieval walls were completely different from star forts, and didn’t make for a walkable environment, either – in Paris I would routinely walk to the park and to the exterior of the Château de Vincennes, and while the park was pleasant, the castle has a moat and none of the street uses that activate a street, like retail or windows. The modern equivalents of such fixtures should be compared with prisons and modern military bases (some using the historic star forts), not touristy palaces.

Even the concept of city center is, as mentioned above on commuting, neither timeless (it didn’t exist in premodern Europe) nor a product of cars (it did exist in 19th-century America and Europe). Joel Garreau points out, either in Edge City or in some of the articles he’s written about the concept, that the traditional downtown was really only a fixture for a few generations, from the early 19th century to the middle of the 20th.

The issue of fragility

The entire comparison is grating, but smoehow the thing that bothers me most there is not the elementary errors, but the last point, about how traditional cities were antifragile for millennia before modern suburbia came in and wrecked them with debt.

This, to be very clear, is bullshit. Premodern cities could depopulate with one plague, famine, or war; these often co-occurred, such as when Louis XIV’s wars led to such food shortages that 10% of France’s population died in two famines spaced 15 years apart (put another way: France underwent a Reign of Terror’s worth of deaths every two weeks for a year and a half, and then a second for somewhat less than a year). In 1793, 10% of Philadelphia’s population died of yellow fever within the span of a few months. After repeated sacks and economic decline, Jaffa was abandoned in much of the Early Modern era.

Industrial cities generally do not undergo any of these things. (They can be subjected to genocide, like the Jews of Europe in the Holocaust, but that’s not at all about urbanism.) But that’s hardly a millennia-old tradition when it only goes back to about the middle of the 19th century, after the Great Hunger. In the UK, the Great Hunger affected rural areas like Ireland and Highland Scotland, but in a country that was at the time majority-rural – Britain would only flip to an urban majority in 1851 – it’s hardly a defense. Nor did the era after 1850 feature much stability in the cities; boom-and-bust cycles were common and the risk of unemployment and poverty was constant.