Category: Urbanism

Edge Cities With and Without Historic Cores

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

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

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

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

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

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

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

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

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

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

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

The Four Quadrants of Cities for Transit Revival

Cities that wish to improve their public transportation access and usage are in a bind. Unless they’re already very transit-oriented, they have not only an entrenched economic elite that drives (for example, small business owners almost universally drive), but also have a physical layout that isn’t easy to retrofit even if there is political consensus for modal shift. Thus, to shift travel away from cars, new interventions are needed. Here, there is a distinction between old and new cities. Old cities usually have cores that can be made transit-oriented relatively easily; new cities have demand for new growth, which can be channeled into transit-oriented development. Thus, usually, in both kinds of cities, a considerably degree of modal shift is in fact possible.

However, it’s perhaps best to treat the features of old and new cities separately. The features of old cities that make transit revival possible, that is the presence of a historic core, and those of new cities, that is demand for future growth, are not in perfect negative correlation. In fact, I’m not sure they consistently have negative correlation at all. So this is really a two-by-two diagram, producing four quadrants of potential transit cities.

Old cities

The history of public transportation is one of decline in the second half of the 20th century in places that were already rich then; newly-industrialized countries often have different histories. The upshot is that an old auto-oriented place must have been a sizable city before the decline of mass transit, giving it a large core to work from. This core is typically fairly walkable and dense, so transit revival would start from there.

The most successful examples I know of involve the restoration of historic railroads as modern regional lines. Germany is full of small towns that have done so; Hans-Joachim Zierke has some examples of low-cost restoration of regional lines. Overall, Germany writ large must be viewed as such an example: while German economic growth is healthy, population growth is anemic, and the gradual increase in the modal split for public transportation here must be viewed as more intensive reuse of a historic national rail network, anchored by tens of small city cores.

At the level of a metropolitan area, the best candidates for such a revival are similarly old places; in North America, the best I can think of for this are Philadelphia, Boston, and Chicago. Americans don’t perceive any of the three as especially auto-oriented, but their modal splits are comparable to those of small French cities. But in a way, they show one way forward. If there’s a walkable, transit-oriented core, then it may be attractive for people to live near city center; in those three cities it’s also possible to live farther away and commute by subway, but in smaller ones (say, smaller New England cities), the subway is not available but conversely it’s usually affordable to live within walking distance of the historic city center. This creates a New Left-flavored transit revival in that it begins with the dense city center as a locus of consumption, and only then, as a critical mass of people lives there, as a place that it’s worth building new urban rail to.

New cities

Usually, if a city has a lot of recent growth from the era in which it has become taken for granted that mobility is by car, then it should have demand for further growth in the future. This demand can be planned around growth zones with a combination of higher residential density and higher job density near rail corridors. The best time to do transit-oriented development is before auto-oriented development patterns even set in.

There are multiple North American examples of how this works. The best is Vancouver, a metropolitan area that has gone from 560,000 people in the 1951 census to 2.6 million in the 2021 census. Ordinarily, one should expect such a region to be entirely auto-oriented, as most American cities with almost entirely postwar growth are; but in 2016, the last census before corona, it had a 20% work trip modal split, and that was before the Evergreen extension opened.

Vancouver has achieved this by using its strong demand for growth to build a high-rise city center, with office towers in the very center and residential ones ringing it, as well as high-density residential neighborhoods next to the Expo Line stations. The biggest suburbs of Vancouver have followed the same plan: Burnaby built an entirely new city center at Metrotown in conjunction with the Expo Line, and even more auto-oriented Surrey has built up Whalley, at the current outer terminal of the line, as one of its main city centers. Housing growth in the region is rapid; YIMBY advocacy calls for more, but the main focus isn’t on broad development (since this already happens) but on permitting more housing in recalcitrant rich areas, led by the West Side, which will soon have its Broadway extension of the Millennium Line.

Less certain but still interesting examples of the same principle are Calgary, Seattle, and Washington. Calgary, a low-density city, planned its growth around the C-Train, and built a high-rise city center, limiting job sprawl even as residential sprawl is extensive; Seattle and the Virginia-side suburbs of Washington have permitted extensive infill housing and this has helped their urban rail systems achieve high ridership by American standards, Seattle even overtaking Philadelphia’s modal split.

The four quadrants

The above contrast of old and new cities misses cities that have positive features of both – or neither. The cities with both positive features have the easiest time improving their public transportation systems, and many have never been truly auto-oriented, such as New York or Berlin, to the point that they’re not the best examples to use for how a more auto-oriented city can redevelop as a transit city.

In North America, the best example of both is San Francisco, which simultaneously is an old city with a high-density core and a place with immense demand for growth fueled by the tech industry. The third-generation tech firms – those founded from the mid-2000s onward (Facebook is in a way the last second-generation firm, which generation began with Apple and Microsoft) – have generally headquartered in the city and not in Silicon Valley. Twitter, Uber, Lyft, Airbnb, Dropbox, and Slack are all in the city, and the traditional central business district has expanded to South of Market to accommodate. This is really a combination of the consumption-oriented old-city model, as growing numbers of employees of older second-generation firms chose to live in the city and reverse-commute to Silicon Valley, and the growth-oriented new-city model. Not for nothing, the narrower metropolitan statistical area of San Francisco (without Silicon Valley) reached a modal split of 17% just before corona, the second highest in the United States, with healthy projections for growth.

But then there is the other quadrant, comprising cities that have neither the positive features of old cities nor those of new cities. To be in this quadrant, a city must not be so old as to have a large historic core or an extensive legacy rail network that can be revived, but also be too poor and stagnant to generate new growth demand. Such a city therefore must have grown in a fairly narrow period of time in the early- to mid-20th century. The best example I can think of is Detroit. The consumption-centric model of old city growth can work even there, but it can’t scale well, since there’s not enough of a core compared with the current extent of the population to build out of.

Stop Imitating the High Line

I streamed a longer version of this on Twitch on Tuesday, but the recording cut out, so instead of uploading to YouTube as a vlog, I’m summarizing it here

Manhattan has an attractive, amply-used park in the Meatpacking District, called the High Line. Here it is, just west of 10th Avenue:

It was originally a freight rail branch of the New York Central, running down the West Side of Manhattan to complement the railroad’s main line to Grand Central, currently the Harlem Line of Metro-North. As such, it was a narrow el with little direct interface with the neighborhood, unlike the rapid transit els like that on Ninth Avenue. The freight line was not useful for long: the twin inventions of trucking and electrification led to the deurbanization of manufacturing to land-intensive, single-story big box-style structures. Thus, for decades, it lay unused. As late as 2007, railfans were dreaming about reactivating it for passenger rail use, but it was already being converted to a park, opening in 2009. The High Line park is a successful addition to the neighborhood, and has spawned poor attempt at imitation, like the Low Line (an underground rapid transit terminal since bypassed by the subway), the Queensway (a similar disused line in Central Queens), and some plans in Jersey City. So what makes the High Line so good?

  1. The neighborhood, as can be seen above in the picture, has little park space. The tower-in-a-park housing visible to the east of the High Line, Chelsea-Elliott Houses, has some greenery but it’s not useful as a neighborhood park. The little greenery to the west is on the wrong side of 12th Avenue, a remnant of the West Side Highway that is not safe for pedestrians to cross, car traffic is so fast and heavy. Thus, it provides a service that the neighborhood previously did not have.
  2. The area has very high density, both residential and commercial. Chelsea is a dense residential neighborhood, but at both ends of the line there is extensive commercial development. Off-screen just to the south, bounded by Eighth, Ninth, 15th, and 16th, is Google’s building in New York, with more floor area than the Empire State Building and almost as much as One World Trade Center. Off-screen just to the north is the Hudson Yards development, which was conceived simultaneously with the High Line. This guarantees extensive foot traffic through the park.
  3. The linear park is embedded in a transit-rich street grid. Getting on at one end and off at the other is not much of a detour to the pedestrian tourist, or to anyone with access to the subway near both ends, making it a convenient urban trail.

These three conditions are not common, and trying to replicate the same linear park in their absence is unlikely to produce good results. For example, consider the Rockaway Cutoff, or Rockaway Beach Branch:

The Cutoff has two competing proposals for what to do with this disused LIRR branch: the Queenslink, aiming to convert it to a rapid transit branch (connecting to the subway, not the LIRR), and the Queensway, aiming to convert it to a linear park. The Queenslink proposal is somewhat awkward (which doesn’t mean it’s bad), but the Queensway one is completely drunk. Look at the satellite photo above and compare to that of the High Line:

  1. The area is full of greenery and recreation already, easily accessible from adjoining areas. Moreover, many residents live in houses with backyards.
  2. The density is moderate at the ends (Forest Hills and Woodhaven) and fairly low in between, with all these parks, cemeteries, and neighborhoods of single-family houses and missing middle density. Thus, local usage is unlikely to be high. Nor is this area anyone’s destination – there are some jobs at the northern margin of the area along Queens Boulevard (the wide road signed as Route 25 just north of the LIRR) but even then the main job concentrations in Queens are elsewhere.
  3. There is no real reason someone should use this as a hiking trail unless they want to hike it twice, one way and then back. The nearest viable parallel transit route, Woodhaven, is a bus rather than a subway.

The idea of a park is always enticing to local neighborhood NIMBYs. It’s land use that only they get to have, designed to be useless to outsiders; it is also at most marginally useful to neighborhood residents, but neighborhood politics is petty and centers exclusion of others rather than the actual benefits to residents, most of whom either don’t know their self-appointed neighborhood advocates or quietly loathe them and think of them as Karens and Beckies. Moreover, the neighborhood residents don’t pay for this – it’s a city project, a great opportunity to hog at the trough of other people’s money. Not for nothing, the Queensway website talks about how this is a community-supported solution, a good indication that it is a total waste of money.

But in reality, this is not going to be a useful park. The first park in a neighborhood is nice. The second can be, too. The fifth is just fallow land that should be used for something more productive, which can be housing, retail, or in this case a transportation artery for other people (since there aren’t enough people within walking distance of a trail to justify purely local use). The city should push back against neighborhood boosters who think that what worked in the Manhattan core will work in their explicitly anti-Manhattan areas, and preserve the right-of-way for future subway or commuter rail expansion.

Quick Note on Los Angeles and Chicago Density and Modal Split

A long-running conundrum in American urbanism is that the urban area with the highest population density is Los Angeles, rather than New York. Los Angeles is extremely auto-oriented, with a commute modal split that’s only 5% public transit, same as the US average, and doesn’t feel dense the way New York or even Washington or Chicago or Boston is. In the last 15 years there have been some attempts to get around this, chiefly the notion of weighted or perceived density, which divides the region into small cells (such as census tracts) and averaged their density weighted by population and not area. However, even then, Los Angeles near-ties San Francisco for second densest in the US, New York being by far the densest; curiously, already in 2008, Chris Bradford pointed out that for American metro areas, the transit modal split was more strongly correlated with the ratio of weighted to standard density than with absolute weighted density.

DW Rowlands at Brookings steps into this debate by talking more explicitly about where the density is. She uses slightly different definitions of density, so that by the standard measure Los Angeles is second to New York, but this doesn’t change the independent variable enough to matter: Los Angeles’s non-car commute modal split still underperforms any measure of density. Instead of looking at population density, she looks at the question of activity centers. Those centers are a way to formalize what I tried to do informally by trying to define central business districts, or perhaps my attempts to draw 100 km^2 city centers and count the job share there (100 km^2 is because my French data is so coarse it’s the most convenient for comparisons to Paris and La Défense).

By Rowlands’ more formal definition, Los Angeles is notably weaker-centered than comparanda like Boston and Washington. Conversely, while I think of Los Angeles as not having any mass transit because I compare it with other large cities, even just large American cities, Brookings compares the region with all American metropolitan areas, and there, Los Angeles overperforms the median – the US-wide 5% modal split includes New York in the average so right off the bat the non-New York average is around 3%, and this falls further when one throws away secondary transit cities like Washington as well. So Los Angeles performs fairly close to what one would expect from activity center density.

But curiously, Chicago registers as weaker-centered than Los Angeles. I suspect this is an issue of different definitions of activity centers. Chicago’s urban layout is such that a majority of Loop-bound commutes are done by rail and a supermajority of all other commutes are done by car; the overall activity center density matters less than the raw share of jobs that are in a narrow city center. Normally, the two measures – activity center density and central business district share of jobs – correlate: Los Angeles has by all accounts a weak center – the central 100 km^2, which include decidedly residential Westside areas, have around 700,000 jobs, and this weakness exists at all levels. Chicago is different: its 100 km^2 blob is uninspiring, but at the scale of the Loop, the job density is very high – it’s just that outside the Loop, there’s very little centralization.

Quick Note on Transit Expansion and Development

I’ve been thinking a lot about where subway extensions can go in New York. One of the appendices we’re likely to include down the line in the Transit Costs Project is a proposal for what New York could do if its construction costs were more reasonable, and this means having to think about plausible extensions. Leaving aside regional rail and systematic investments for now, this may roughly be it:

The full-size image (warning: 52 MB) can be found here.

The costs depicted are about twice as high as what I wrote in 2019 with Nordic costs as the baseline, because nominal Nordic costs have doubled since then, partly due to updating price levels from the early 2010s to the early 2020s, but mostly because of the real cost explosion in the Nordic countries. These costs are about $200 million/km in outlying areas, $300 million/km in Manhattan or across water, somewhat less than $100 million/km above ground or in an open trench, and higher than $300 million/km when reconstruction of existing tunnel complexes is proposed; everything is rounded to the nearest $100 million, which creates some rounding artifacts for short extensions that cancel one another out.

But the precise map is not what I think is the most interesting. The point is to build to the frontier of the cost per rider that is acceptable in American cities today, so by definition the marginal line for inclusion on the map, such as the D extension to Gun Hill Road to meet with the 2 train, is also socioeconomically marginal. What I think is more interesting is how important transit-oriented development is for the prospects of lines beyond the most obvious ones (Second Avenue Subway Phase 2, 125th Street, Utica, Nostrand, IBX, and maybe also the 7 to College Point).

The current land use in New York is largely frozen from the middle of the 20th century; the 1961 zoning law was the watershed. Since then, change has been slow, in contrast with rapid redevelopment in places that have chosen a pro-growth path. If the pace of change stays slow, then fewer lines are viable; if the city instead chooses not to keep anti-developmental neighborhood interests in the loop, then more are.

This, in turn, feeds into growth plans. Nordic and Italian planning bundles the question of where the regional housing growth goes with where the subway goes. (Our other positive case study, Turkey, works differently; the answer to both questions is “everywhere.”) This means that subway service goes to areas where substantial quantities of transit-oriented development will be permitted and built, often in negotiations with NIMBY municipalities that would rather just get the infrastructure without the housing; in Stockholm the scale involved is tens of thousands of units per tranche of Nya Tunnelbanan.

In the case of New York, this affects the shape of the map above more than anything. The 6 extension to Coop City is likely good either way, but the other radial extensions in the Bronx are more questionable and depend on where new housing in the borough will be built. The same is true in Queens: more housing in Northeast Queens may argue even in favor of further lines not depicted on the map, for example extending the 7 even further.

Meme Weeding: Rich West, Poor East

There’s a common line in global history – I think it’s popularized through Eric Hobsbawm – that there is a universal east-west divide in temperate latitude cities. The idea is that the west side of those cities is consistently richer than the east side and has been continuously since industrialization, because prevailing winds are westerly and so rich people moved west to be upwind of industrial pollution. I saw this repeated on Twitter just now and would like to push back. Some cities have this pattern, some don’t, some even have the opposite pattern. Among cities the casual urbanist reader is likely to be familiar with, about the only one where this is true is Paris.

London

London famously has a rich west and poor east. I think this is why the line positing this directional pattern as universal is so common. Unfortunately, the origin of this pattern is too recent to be about prevailing winds.

In an early example of data visualization, Charles Booth made a block by block map of London in 1889, colored by social class, with a narrative description of each neighborhood. The maps indeed show the expected directionality, but with far more nuance. The major streets were middle-class even on the East End: Mile End Road was lined with middle-class homes, hardly what one would expect based on pollution. The poverty was on back alleys. South London exhibited the same pattern: middle-class major throughfares, back alleys with exactly the kind of poverty Victorian England was infamous for. West London was different – most of it was well-off, either middle-class or wealthier than that – but even there one can find the occasional slum.

East London in truth had a lot of working poor because it had a lot of working-class jobs, thanks to its proximity to the docks, which were east of the City because ports have been moving downriver for centuries with the increase in ship size. Those working poor did not always have consistent work and therefore some slipped into non-working poverty. The rich clustered in enclaves away from the poverty and those happened to be in the west, some predating any kind of industrialization. Over time the horizontal segregation intensified, as slums were likelier to be redeveloped (i.e. evicted) in higher-property value areas near wealth, and the pattern diffused to the broader east-west one of today.

Berlin

Berlin has a rich west and poor east – but this is a Cold War artifact of when West Berlin was richer than East Berlin, and the easternmost neighborhoods of the West were poor because they were near the Wall (thus, half their walk radius was behind the Iron Curtain) and far from City West jobs.

Before WW2, the pattern was different. West of city center, Charlottenburg was pretty well-off – but so was Friedrichshain, to the east. The sharpest division in Berlin was as in London, often within the same apartment building, which would house tens of apartments: well-off people lived facing the street, while the poor lived in apartments facing internal courtyards, with worse lighting and no vegetation in sight.

Tokyo

Tokyo has a similar east-west directionality as London, but with its own set of nuances. This should not be too surprising – it’s at 35 degrees north, too far south for the westerlies of Northern Europe; the winds change and are most commonly southerly there. The directionality in Tokyo is more about the opposition between uphill Yamanote and sea-level Shitamachi (the Yamanote Line is so named because the neighborhoods it passes through – Ikebukuro, Shinjuku, and Shibuya – formed the old core of Yamanote).

What’s more, the old Yamanote-Shitamachi pattern is also layered with a rich-center-poor-outskirts pattern. Chuo, historically in Shitamachi, is one of the wealthiest wards of Tokyo, thanks to its proximity to CBD jobs and the high rents commanded in an area where businesses build office towers.

The American pattern

The most common American pattern is that rich people live in the suburbs and poor people live in the inner city; the very center of an American city tends to be gentrified, creating a poverty donut surrounding near-center gentrification and in turn surrounded by suburban wealth. Bill Rankin of Radical Cartography has some maps, all as of 2000, and yet indicative of longer-term patterns.

New York is perhaps the best example of the poverty donut model: going outside the wealthy core consisting of Manhattan south of Harlem, inner Brooklyn, and a handful of gentrified areas in Jersey City and Hoboken near Manhattan, one always encounters poor areas before eventually emerging into middle-class suburbia. Directionality is weak, and usually localized – for example, the North Shore of Long Island is much wealthier than the South Shore, but both are east of the city.

Many American cities tend to have strong directionality in lieu of or in addition to the poverty donut. In Chicago, the North Side is rich, the West Side is working-class, and the South Side is poor. Many cities have favored quarters, such as the Main Line of Philadelphia, but that’s in addition to a poverty donut: it’s silly to speak of rich people moving west of Center City when West Philadelphia is one of the poorest areas in the region.

Where east-west directionality exists as in the meme, it’s often in cities without westerly winds. Los Angeles is at 34 degrees north and famously has a rich Westside and a poor Eastside – but those cannot possibly emerge from a prevailing wind pattern that isn’t consistent until one travels thousands of kilometers north. Houston is at 30 degrees north. More likely, the pattern in Los Angeles emerges from the fact that beachfront communities have always been recreational and the rich preferred to live nearby, and only the far south near the mouth of the river, in San Pedro and Long Beach, had an active industrial waterfront.

Sometimes, the directionality is the opposite of that of the meme. Providence has a rich east and poorer west. This is partly a longstanding pattern: the rivers flow west to east and north to south, and normally you’d expect rich people to prefer to live upriver, but in Providence the rivers are so small that only at their falls was there enough water power for early mills, producing industrial jobs and attracting working-class residents. However, the pattern is also reinforced with recent gentrification, which has built itself out of Brown’s campus on College Hill, spreading from there to historically less-well off East Side neighborhoods like Fox Point; industrial areas have no reason to gentrify in a city the size of Providence, and, due to the generations-long deindustrialization of New England, every reason to decline.

Growth Without Urbanization

Last year, I poked around developing-country urbanization rates. The starting point is that in 2000-20, India grew from 28% urban to 35% urban. This is an anemic growth rate: it’s lower in absolute numbers than in the United States, which took not 20 years to grow at this rate but 10, from 1880 to 1890. And this is especially offensive in the context of a high-growth developing country – India has high economic growth, and by one measure in the 19 years before corona went from the GDP per capita the US had in 1847 to that the US had in 1899. In 19 years, it caught up with 52 years of US growth, but not quite 10 years of US urbanization. Why?

Is it unavoidable in developing countries?

No. Urbanization rates in East Asia were healthy during its period of catchup growth, which is still to a large extent happening in China. South Korea and China both took seven years to grow from 28% urban to 35%.

There’s been a lot of historical rewriting in the last 10 or so years, treating East Asia as always having been developed or at least having had the state capacity to grow, in contrast with laggards elsewhere in the world. This is often bundled with racism positing East Asians as a peer master race to white people, contrasted with Southeast Asia (for example, in Garett Jones), South Asia, and of course Africa. But in the last third of the 20th century, people commenting on East Asian growth did not distinguish East and Southeast Asia, and until the 1997 financial crisis, anti-communist autocracies Indonesia and the Philippines weren’t obviously different from South Korea and Taiwan; the divergence has been mostly in the last 25 years.

In urbanization, at any rate, Southeast Asia has been mostly showing rapid historic growth as well. Indonesia took the same 7 years as South Korea and China to grow from 28% to 35% urban, and its urbanization rate has grown from 42% to 57% since 2000. This is slower than China (36-61%), but in the context of weaker post-1997 growth, it’s moderate growth and moderate urbanization, rather than growth without urbanization as in India. Vietnam has fast growth and fast urbanization – 24-38% over the same period that India grew 28-35%, with similar per capita income trajectory as India. Thailand has exploded from 31% to 52% since 2000.

In Indian discourse, a growing comparison case is Bangladesh. It’s right nearby, it’s famous for being extremely poor, and in reality it’s barely any poorer than India. Moreover, it has the relatively unregulated labor-intensive manufacturing growth that Indian neoliberals wish India had, and less strict urban zoning restrictions. Well, Bangladesh has grown from 24% urban in 2000 to 39% last year, with exactly the same GDP per capita growth as India – 4.7%/year from 2000 to 2021 vs. 4.6% in India, albeit with India suffering a setback during corona and better-masked Bangladesh maintaining positive growth in 2020.

Is it unique to India?

Not exactly. The thread linked in the lede brings examples from all over Asia and Africa; Pakistan has even slower urbanization than India, albeit in a context of weak income growth. Africa is hard to compare with India because it has both low economic growth for how poor it is and slow urbanization, and its faster-growing states don’t necessarily urbanize fast, for example Sudan. The African country most discussed as a growth case in neoliberal English-language media, Ghana, has had a decent pace of urbanization – 44-58% since 2000 – but the accolades one sees to it must be viewed as drawing a target around where the arrow landed. To round up the English-speaking African states, Nigeria and Tanzania have had fairly healthy urbanization growth as well, but Kenya and Uganda have not.

So it’s not exactly just an Indian problem. But it’s a problem that does appear worse in India (and perhaps Pakistan) than in other developing countries, especially in contrast with India’s truly fast pace of income growth.

Why?

One answer is strict zoning. The density in Indian cities is very high (due to overcrowding), but it’s still lower than in the most direct comparison case, Dhaka.

But this is not a satisfying answer, and I worry that Indian urbanists overfocus on the maximum floor area ratio. Anup Malani, a Chicago law professor with economics background, tweeted a graphic summarizing the maximum floor area ratios (FARs)/floor space indices (FSIs) in various cities, showing how much Indian cities fall short. I picked this example because I saw it a week ago but it’s typical of Indian urbanist discourse to say something like “Mumbai permits a maximum FSI of about 4, New York permits 12.” But this is not quite accurate – Indian urban FSI limits tend to apply citywide, or at least in very large swaths of the city, whereas North American FARs apply at the level of the individual block; little of New York permits residential FAR 12, largely just the avenues and two-way streets on the Upper East and West Sides, and the vast majority of residential land permits FAR 1.5-3.

In this way, Indian zoning is more like traditional European zoning, which assumes high uniform density, with FARs of about 2.5-3.5 in the larger cities. It’s not quite the same because Parisian zoning prefers regulating height to regulating FAR, and Indian urban housing in the recently-built formal sector is much more likely to be tall-and-thin (as in, say, Vancouver) than mid-rise-and-thick as in Europe, but in terms of the pattern of density, India unwittingly tries to be Europe.

What’s true is that housing construction rates in India are lagging. A report by Knight Frank looked at new housing completions (“launches”) in the eight largest cities in 2018 and 2019. Relative to 2011 census population, in 2019, housing construction per 1,000 people reached 6.4 units in Mumbai, 8.9 in Pune, 4 in Bangalore, 1.4 in Delhi, 2 in Hyderabad, 1.6 in Chennai, 1.4 in Ahmedabad, and 1.3 in Kolkata. Maharashtra liberalized its zoning in the late 2010s, boosting Mumbai FSI from 1.33 to about 4, and this might be why Mumbai’s housing growth rate was not so bad (that is, it’s about comparable with that of Ile-de-France or Stockholm County and still lags Seoul and Tokyo), but elsewhere growth rates are extremely low. Government-funded housing heavily favors rural areas even more than their share of the population, but Mumbai rents are such that privately-funded housing should be viable at much higher rates than 80,000 units a year (in a city of 12.5 million).

How Tunneling in New York is Easier Than Elsewhere

I hate the term “apples-to-apples.” I’ve heard those exact three words from so many senior people at or near New York subway construction in response to any cost comparison. Per those people, it’s inconceivable that if New York builds subways for $2 billion/km, other cities could do it for $200 million/km. Or, once they’ve been convinced that those are the right costs, there must be some justifiable reason – New York must be a uniquely difficult tunneling environment, or its size must mean it needs to build bigger stations and tunnels, or it must have more complex utilities than other cities, or it must be harder to tunnel in an old, dense industrial metropolis. Sometimes the excuses are more institutional but always drawn to exculpate the political appointees and senior management – health benefits are a popular excuse and so is a line like “we care about worker rights/disability rights in America.” The excuses vary but there’s always something. All of these excuses can be individually disposed of fairly easily – for example, the line about worker and disability rights is painful when one looks at the construction costs in the Nordic countries. But instead of rehashing this, it’s valuable to look at some ways in which New York is an easier tunneling environment than many comparison cases.

Geology

New York does not have active seismology. The earthquake-proofing required in such cities as Los Angeles, San Francisco, Tokyo, Istanbul, and Naples can be skipped; this means that simpler construction techniques are viable.

Nor is New York in an alluvial floodplain. The hard schist of Manhattan is not the best rock to tunnel in (not because it’s hard – gneiss is hard and great to tunnel in – but because it’s brittle), but cut-and-cover is viable. The ground is not going to sink 30 cm from subway construction as it did in Amsterdam – the hard rock can hold with limited building subsidence.

The underwater crossings are unusually long, but they are not unusually deep. Marmaray and the Transbay Tube both had to go under deep channels; no proposed East River or Hudson crossing has to be nearly so deep, and conventional tunnel boring is unproblematic.

History and archeology

In the United Kingdom, 200 miles is a long way. In the United States, 200 years is a long time. New York is an old historic city by American standards and by industrial standards, but it is not an old historic city by any European or Asian standard, unless the standard in question is that of Dubai. There are no priceless monuments in its underground, unlike those uncovered during tunneling in Mexico City, Istanbul, Rome, or Athens; the last three have tunneled through areas with urban history going back to Classical Antiquity.

In addition to past archeological artifacts, very old cities also run into the issue of priceless ruins. Rome Metro Line C’s ongoing expansion is unusually expensive for Italy – segment T3 is $490 million per km in PPP 2022 dollars – because it passes by the Imperial Forum and the Colosseum, where no expense can be spared in protecting monuments from destruction by building subsidence, limited by law to 3 mm; the stations are deep-mined because cut-and-cover is too destructive and so is the Barcelona method of large-diameter bores. More typical recent tunnels in Rome and Milan, even with the extra costs of archeology and earthquake-proofing, are $150-300 million/km (Rome costing more than Milan).

In New York, in contrast, buildings are valued for commercial purposes, not historic purposes. Moreover, in the neighborhoods where subways are built or should be, there is extensive transit-oriented development opportunity near the stations, where the subsidence risk is the greatest. It’s possible to be more tolerant of risk to buildings in such an environment; in contrast, New York spent effort shoring up a building on Second Avenue that is now being replaced with a bigger building for TOD anyway.

Street network

New York is a city of straight, wide streets. A 25-meter avenue is considered narrow; 30 is more typical. This is sufficient for cut-and-cover without complications – indeed, it was sufficient for four-track cut-and-cover in the 1900s. Bored tunnels can go underneath those same streets without running into building foundations and therefore do not need to be very deep unless they undercross older subway lines.

Moreover, the city’s grid makes it easier to shut down traffic on a street during construction. If Second Avenue is not viable as a through-route during construction, the city can make First Avenue two-way for the duration. Few streets are truly irreplaceable, even outside Manhattan, where the grid has more interruptions. For example, if an eastward extension of the F train under Hillside is desired, Jamaica can substitute for Hillside during construction and this makes the cut-and-cover pain (even if just at stations) more manageable.

The straightforward grid also makes station construction easier. There is no need to find staging grounds for stations such as public parks when there’s a wide street that can be shut down for construction. It’s also simple to build exits onto sidewalks or street medians to provide rapid egress in all directions from the platform.

Older infrastructure

Older infrastructure, in isolation, makes it difficult to build new tunnels, and New York has it in droves. But things are rarely isolated. It matters what older infrastructure is available, and sometimes it’s a boon more than a bane.

One way it can be a boon is if older construction made provisions for future expansion. This is the most common in cities with long histories of unrealized plans, or else the future expansion would have been done already; worldwide, the top two cities in such are New York and Berlin. The track map of the subway is full of little bellmouths and provisions for crossing stations, many at locations that are not at all useful today but many others at locations that are. Want to extend the subway to Kings Plaza under Utica? You’re in luck, there’s already a bellmouth leading from the station on the 3/4 trains. How about going to Sheepshead Bay on Nostrand? You’re in luck again, trackways leading past the current 2/5 terminus at Flatbush Avenue exist as the station was intended to be only a temporary terminal.

Second Avenue Subway Phase 2 also benefits from such older infrastructure – cut-and-cover tunnels between the stations preexist and will be reused, so only the stations need to be built and the harder segment curving under 125th Street crossing under the 4/5/6.

Vancouver, Stockholm, and the Suburban Metro Model

I was asked by an area advocate about SkyTrain, and this turned into a long email with various models to compare Vancouver with. In my schema contrasting suburban metro systems and S-Bahns, Vancouver is firmly in the first category: SkyTrain is not commuter rail, and Vancouver’s commuter rail system, the West Coast Express, is so weak it might as well not exist. The suburban metro model forces the region to engage in extensive transit-oriented development, which Vancouver has done. Has it been successful? To some extent, yes – Vancouver’s modal split is steadily rising, and in the 2016 census, just before the Evergreen Line opened, was 20%; supposedly it is 24% now. But it could have done better. How so?

Could Vancouver have used the S-Bahn model?

No.

There is a common line of advocacy; glimpses of it can be found on the blog Rail for the Valley, by a writer using the name Zweisystem who commented on transit blogs like Yonah and Jarrett‘s in the 2000s. Using the name of Karlsruhe’s tram-train as inspiration, Zwei has proposed that Vancouver use existing commuter rail corridors in suburban and exurban areas and streetcars in the urban core.

The problem with this is that Vancouver has very little legacy mainline rail infrastructure to work with. There are two mainlines serving city center: the Canadian Pacific, and Canadian National. The CP line hugs the coast, full of industrial customers; the CN line is farther inland and has somewhat more fixable land use, but the Millennium Line partly parallels it and even after 20 years its ridership is not the strongest in the system. Most of the urban core is nowhere near a rail mainline.

This is completely unlike the Central European S-Bahn-and-streetcars systems, all of which have legacy commuter lines radiating in all directions, and use legacy streetcars rather than newly-built light rail lines. In the last generation they’ve expanded their systems, building connections and feeding rapid transit, but none of these is a case of completely getting rid of the streetcars and then restoring them later; the busiest system that’s entirely new, that of Paris, is largely orbitals and feeders for the Métro and RER.

Vancouver did in fact reuse old infrastructure for the suburban metro concept. The Expo Line involved very little greenfield right-of-way use. Most of the core route between the historic core of Vancouver and New Westminster is in the private right-of-way of a historic BC Electric interurban; this is why it parallels Kingsway but does not run elevated over it. The tunnel in Downtown Vancouver is a disused CP tunnel; this is why the tracks are stacked one over the other rather than running side by side – the tunnel was single-track but tall enough to be cut into two levels. This limited the construction cost of the Expo Line, which the largely-elevated Millennium Line and the partly underground, partly elevated Canada Line could not match.

The Stockholm example

In my post about S-Bahns and suburban metros, I characterized Stockholm as an archetypal suburban metro. Stockholm does have an S-Bahn tunnel nowadays, but it only opened 2017, and ridership so far, while rising, is still a fraction of that of the T-bana.

Stockholm’s choice of a full metro system in the 1940s, when it had about a million people in its metro area, had its critics at the time. But there wasn’t much of a choice. The trams were fighting growing traffic congestion, to the point that some lines had to be put in a tunnel, which would later be converted for the use of the Green Line as it goes through Södermalm. Working-class housing was overcrowded and there was demand for more housing in Stockholm, which would eventually be satisfied by the Million Program.

And there were too few commuter lines for an S-Bahn system. Swedes were perfectly aware of the existence of the S-Bahn model; Berlin and Hamburg both had S-Bahns running on dedicated tracks, and Copenhagen had built its own system, called S-Tog in imitation of the German name. But they didn’t build that. None of this was the integrated Takt timetable that Munich would perfect in the 1970s, in which branches could be left single-track or shared with intercity trains provided the regular 20-minute headways could be scheduled to avoid conflicts; the track sharing required in the 1940s would have been too disruptive. Not to mention, Stockholm had too few lines, if not so few as Vancouver – only two branches on each of two sides of city center, with most of the urban core far from the train.

So Stockholm built the T-bana, with three highly branched lines all meeting at T-Centralen, the oldest two of the three having a cross-platform transfer there and at the two stations farther south. The roughly 104 km system (57 km underground) cost, in 2022 US dollars, $3.6 billion. Stockholm removed all the regular streetcars; a handful running all or mostly in private rights-of-way were retained with forced transfers at outlying T-bana stations like Ropsten, as was the narrow-gauge Roslagsbana (with a forced transfer at KTH, where I worked for two years).

At the same time the T-bana was under construction, the state built the Million Program, and in the Stockholm region, the housing projects were designed to be thoroughly oriented around the system. The pre-Million Program TOD suburb of Vällingby was envisioned as part of a so-called string of pearls, in which towns would radiate from each T-bana station, with local retail and jobs near the station surrounded by housing. In 2019, the T-bana had 1,265,900 riders per workday, Citybanan had 410,300, and the remaining lines 216,100; Sweden reports modal split for all trips and not just work trips, but the commute modal split appears to be 40% or a little higher, a figure that matches Paris, a metro area of 13 million that opened its first metro line in 1900.

So why is Stockholm better?

There are parallels between Stockholm and Vancouver – both are postwar cities with 2.5 million people in their metropolitan areas with rapid growth due to immigration. Their physical geographies are similar, with water barriers inhibiting the contiguous sprawl of many peers. Both extensively employed TOD to shape urban geography around the train: Stockholm has Vällingby and other, less famous examples of TOD; Vancouver has Metrotown and smaller examples of residential TOD along the Expo Line, alongside a famously high-rise downtown. But the T-bana has more than twice the annual ridership of SkyTrain, and Stockholm has around twice the modal split of Vancouver – this is not a matter of Canadians riding buses more than Europeans do. So what gives?

Part of it is about TOD models. Stockholm is an exceptionally monocentric city, and this has created a lot of demand for urban rail to Central Stockholm. But Vancouver’s high-rise city center has a lot of jobs, and overall, around 30% of Metro Vancouver jobs are in the city or the University Endowment Lands (that is, UBC), and the proportion of Stockholm County jobs within an equivalent area is similar. Vancouver has never built anything as massive as the Million Program, but its housing growth rate is one of the highest in the world (around 11 gross units/1,000 people per year in the 2010s), and much of that growth clusters near the Expo Line and increasingly also near the worse-developed Millennium and Canada Lines.

I suspect that the largest reason is simply the extent of the systems. SkyTrain misses the entire West Side of Vancouver west of Cambie, has poor coverage in Surrey and none in Langley, and does not cross the Burrard Inlet. The T-bana has no comparable lacunae: Roslag is served by Roslagsbanan, and the areas to be served by the under-construction extensions are all target TOD areas with much less present-day density than North Vancouver, the cores of Fairview and Kitsilano, or the town centers in Surrey other than Whalley.

What’s more, Stockholm’s construction costs may be rising but those of Vancouver (and the rest of Canada) are rising even faster and from a higher base. Nya Tunnelbanan is currently budgeted at $3.6 billion in PPP terms – 19 underground km for about the same cost as the existing 104 – but Vancouver is building half of the most critical SkyTrain extension, that under Broadway, for C$2.83 billion (US$2.253 billion in PPP terms) for just 5 km, not all underground. The projected cost per rider is still favorable, but it’s less favorable for the planned extension to Langley, and there’s no active plan for anything to the North Shore.

The silver lining for Vancouver is that the West Side is big and underdeveloped. The region has the money to extend SkyTrain not just to Arbutus as is under construction but all the way to UBC, and the entire swath of land between Central Broadway and UBC screams “redevelop me.” The current land use is a mix of mid-rise, townhouses (“missing middle”), and single-family housing; Shaughnessy, whose northern end is within a kilometer of under-construction SkyTrain stations, is single-family on large lots, and can be redeveloped as high-rise housing alongside closer-in areas. Canada does not have Europe’s allergy to tall buildings, and this is a resource that can be used to turn Vancouver into a far more transit-oriented city along the few corridors where it can afford to build. The suburban metro is always like this: fewer lines, more development intensity along them.

Public Transportation in the Southeastern Margin of Brooklyn

Geographic Long Island’s north and south shores consist of series of coves, creeks, peninsulas, and barrier islands. Brooklyn and Queens, lying on the same island, are the same, and owing to the density of New York, those peninsulas are fully urbanized. In Southeastern Brooklyn, moreover, those peninsulas are residential and commercial rather than industrial, with extensive mid-20th century development. Going northeast along the water, those are the neighborhoods of Manhattan Beach, Gerritsen Beach, Mill Basin, Bergen Beach, Canarsie, Starrett City, and Spring Creek. The connections between them are weak, with no bridges over the creeks, and this affects their urbanism. What kind of public transportation solution is appropriate?

The current situation

The neighborhoods in the southeastern margin of Brooklyn and the southern margin of Queens (like Howard Beach) are disconnected from one another by creeks and bays; transportation arteries, all of which are currently streets rather than subway lines, go north and northwest toward city center. At the outermost margin, those neighborhoods are connected by car along the Shore Parkway, but there is no access by any other mode of transportation, and retrofitting such access would be difficult as the land use near the parkway is parkland and some auto-oriented malls with little to no opportunity for sprawl repair. The outermost street that connects these neighborhoods to one another is Flatlands, hosting the B6 and B82 buses, and if a connection onward to Howard Beach is desired, then one must go one major street farther from the water to Linden, hosting the B15.

For the purposes of this post, the study area will be in Brooklyn, bounded by Linden, the Triboro/IBX corridor, and Utica:

This is on net a bedroom community. In 2019, it had 85,427 employed residents and 39,382 jobs. Very few people both live and work in this area – only 4,005. This is an even smaller proportion than is typical in the city, where 8% of employed city residents work in the same community board they live in – the study zone is slightly smaller than Brooklyn Community Board 18, but CB 18 writ large also has a lower than average share of in-board workers.

In contrast with the limited extent of in-zone work travel, nearly all employed zone residents, 76,534, work in the city as opposed to its suburbs (and 31,685 of the zone’s 39,382 jobs are held by city residents). Where they work looks like where city workers work in general, since the transportation system other than the Shore Parkway is so radial:

Within the zone, the southwestern areas, that is Mill Basin and Bergen Beach, are vaguely near Utica Avenue, hosting the B46 and hopefully in the future a subway line, first as an extension of the 4 train and later as an independent trunk line.

To the northeast, Canarsie, Starrett City, and Spring Creek are all far from the subway, and connect to it by dedicated buses to an outer subway station – see more details on the borough’s bus map. Canarsie is connected to the L subway station named after it by the B42, a short but high-productivity bus route, and to the 3 and 4 trains at Utica by the B17, also a high-productivity route. Starrett City does not have such strong dedicated buses: it is the outer terminus of the circumferential B82 (which is very strong), but its dedicated radial route, the B83 to Broadway Junction, is meandering and has slightly below-average ridership for its length. Spring Creek is the worst: it is a commercial rather than residential area, anchored by the Gateway Center mall, but the mall is served by buses entering it from the south and not the north, including the B83, the B84 to New Lots on the 3 (a half-hourly bus with practically no ridership), the rather weak B13 to Crescent Street and Ridgewood, and the Q8 to Jamaica.

The implications for bus design

The paucity of east-west throughfares in this area deeply impacts how bus redesign in Brooklyn ought to be done, and this proved important when Eric and I wrote our bus redesign proposal.

First, there are so few crossings between Brooklyn and Queens that the routes crossing between the two boroughs are constrained and can be handled separately. This means that it’s plausible to design separate bus networks for Brooklyn and Queens. In 2018 it was unclear whether they’d be designed separately or together; the MTA has since done them separately, which is the correct decision. The difficulty of crossings argues in favor of separation, and so does the difference in density pattern between the two boroughs: Brooklyn has fairly isotropic density thanks to high-density construction in Coney Island, which argues in favor of high uniform frequency borough-wide, whereas Queens grades to lower density toward the east, which argues in favor of more and less frequent routes depending on neighborhood details.

Second, the situation in Starrett City is unacceptable. This is an extremely poor, transit-dependent neighborhood, and right now its bus connections to the rest of the world are lacking. The B82 is a strong bus route but many rush hour buses only run from the L train west; at Starrett City, the frequency is a local bus every 10-12 minutes and another SBS bus every 10-12 minutes, never overlying to produce high base frequency. The B83 meanders and has low ridership accordingly; it should be combined with the B20 to produce a straight bus route going direct on Pennsylvania Avenue between Starrett City and Broadway Junction, offering neighborhood residents a more convenient connection to the subway.

Third, the situation in Spring Creek is unacceptable as well. Gateway Center is a recent development, dating only to 2002, long after the last major revision of Brooklyn buses. The bus network grew haphazardly to serve it, and does so from the wrong direction, forcing riders into a circuitous route. Only residents of Starrett City have any direct route to the mall, but whereas Starrett City has 5,724 employed residents (south of Flatlands), and Spring Creek has 4,980 workers, only 26 people commute from Starrett City to Spring Creek. It’s far more important to connect Spring Creek with the rest of the city, which means buses entering it from the north, not the south. Our bus redesign proposal does that with two routes: a B6/B82 extension making this and not Starrett City the eastern anchor, and a completely redone B13 going directly north from the mall to New Lots and thence hitting Euclid Avenue on the A/C and Crescent Street on the J/Z.

What about rail expansion?

New York should be looking at subway expansion, and not just Second Avenue Subway. Is subway expansion a good solution for the travel needs of this study zone?

For our purposes, we should start with the map of the existing subway system; the colors indicate deinterlining, but otherwise the system is exactly as it is today, save for a one-stop extension of the Eastern Parkway Line from New Lots to the existing railyard.

Starrett City does not lie on or near any obvious subway expansion; any rail there has to be a tram. But Canarsie is where any L extension would go – in fact, the Canarsie Line used to go there until it was curtailed to its current terminus in 1917, as the trains ran at-grade and grade-separating them in order to run third rail was considered impractically expensive. Likewise, extending the Eastern Parkway Line through the yard to Gateway Center is a natural expansion, running on Elton Street.

Both potential extensions should be considered on a cost per rider basis. In both cases, a big question is whether they can be built elevated – neither Rockaway Parkway nor Elton is an especially wide street most of the way, about 24 or 27 meters wide with 20-meter narrows. The Gateway extension would be around 1.3 km and the Canarsie one 1.8 km to Seaview Avenue or 2.3 km to the waterfront. These should cost around $250 million and $500 million respectively underground, and somewhat less elevated – I’m tempted to say elevated extensions are half as expensive, but this far out of city center, the underground premium should be lower, especially if cut-and-cover construction is viable, which it should be; let’s call it two-thirds as expensive above-ground.

Is there enough ridership to justify such expansion?

Let’s start with Canarsie, which has 28,515 employed residents between Flatlands and the water. Those workers mostly don’t work along the L, which manages to miss all of the city’s main job centers, but the L does have good connections to lines connecting to Downtown Brooklyn (A/C), Lower Manhattan (A/C again), and Midtown (4/5/6, N/Q/R/W, F/M, A/C/E). Moreover, the density within the neighborhood is uniform, and so many of the 28,515 are not really near where the subway would go – Rockaway/Flatlands, Rockaway/Avenue L, Rockaway/Seaview, and perhaps Belt Parkway for the waterfront. Within 500 meters of Rockaway/L and Rockaway/Seaview there are only 9,602 employed residents, but then it can be expected that nearly all would use the subway.

The B42 an B17 provide a lower limit to the potential ridership of a subway extension. The subway would literally replace the B42 and its roughly 4,000 weekday riders; nearly all of the 10,000 riders of the B17 would likely switch as well. What’s more, those buses were seeing decreases in ridership even before corona due to traffic and higher wages inducing people to switch away from buses – and in 2011, despite high unemployment, those two routes combined to 18,000 weekday riders.

If that’s the market, then $500 million/18,000 weekday riders is great and should be built.

Let’s look at Gateway now. Spring Creek has 4,980 workers, but first of all, only 3,513 live in the city. Their incomes are very low – of the 3,513, only 1,030, or 29%, earned as much as $40,000/year in 2019 – which makes even circuitous mass transit more competitive with cars. There’s a notable concentration of Spring Creek workers among people living vaguely near the 3/4 trains in Brooklyn, which may be explained by the bus connections; fortunately, there’s also a concentration among people living near the proposed IBX route in both Brooklyn and Queens.

The area is the opposite of a bedroom community, unlike the other areas within the study zone – only 1,114 employed people live in it. Going one block north of Flatlands boosts this to 1,923, but a block north of Flatlands it’s plausible to walk to a station at Linden at the existing railyard. 51% of the 1,114 and 54% of the 1,923 earn at least $40,000 a year. Beyond that, it’s hard to see where neighborhood residents work – nearly 40% work in the public sector and OnTheMap’s limitations are such that many of those are deemed to be working at Brooklyn Borough Hall regardless of their actual commute destination.

There’s non-work travel to such a big shopping center, but there are grounds to discount it. It’s grown around the Shore Parkway, and it’s likely that every shopper in the area who can afford a car drives in; in Germany, with generally good off-peak frequency and colocation of retail at train stations, the modal split for public transit is lower for shopping trips than for commutes to work or school. Such trips can boost a Gateway Center subway extension but they’re likely secondary, at least in the medium run.

The work travel to the mall is thankfully on the margin of good enough to justify a subway at $50,000/daily trip, itself a marginal cost. Much depends on IBX, which would help deliver passengers to nearby subway nodes, permitting such radial extensions to get more ridership.