Category: Urban Design

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.

Small is not Resilient

I wrote about how the future is not retro, and Daniel Herriges Strong Towns just responded, saying that traditional development is timeless. I urge all readers to click the last link and read the article, which makes some good points about how cars hollowed out what both Daniel and I call the traditional prewar Midwestern town. There are really two big flaws in the piece. First, it makes some claims about inequality and segregation that are true in American cities but false in the example I give for spiky development, Vancouver. And second, it brings up the resilience of the traditional small town. It’s the second point that I wish to contest: small is not resilient, and moreover, as the economy and society evolve, the minimum size required for resilience rises.

Small cities in the 2010s

In the premodern era, a city of 50,000 was a bustling metropolis. In 1900, it was still a sizable city. In 2019, it is small. The difference is partly relative: a migrant to the big city had the option of moving to a few 200,000 cities in 1900 and one of about ten 1,000,000+ cities, whereas today the same migrant can move to many metro areas with millions of people. But part of it has to do with changes in the economy.

In Adam Smith’s day, big businesses were rare. If you had five employees, you were a big employer. Then came the factory system and firm size grew, but even then companies were small by the standards of today’s specialized economy. A city of 50,000 might well specialize in a single product, as was common in the American manufacturing belt (Krugman mentions this on pp. 11-12 here), but there would be many factories each with a few hundred employees.

But as the economy grows more complex, firm size grows, and so does the interdependence between different firms in the same supply chain. Moreover, the support functions within a city grow in complexity: schools, a hospital, logistics, retail, and so on. The proportion of the population employed in the core factory is lower, as the factory’s high productivity supports more non-manufacturing employees. The upshot is that it’s easy for a town of 50,000 to live off of a single firm and its supply chain. This is not resilient: if the firm fails, the town dies.

Occasionally, cities of that size can have more resilience. Perhaps they’re suburbs of a larger city, in which case they live off of commuting to a more diverse economic center. Perhaps they happen to live off of an industry that cannot die so easily, such as a state capital or a university. On social media one of my followers brought up farming as an example of an activity whose towns have held up in the Midwest better than manufacturing towns; farming is in fact extremely risky, but it has been subsidized since the 1930s, so it has some resilience thanks to subsidies from more internally resilient parts of the country.

Large cities and resilience

I read Ed Glaeser not so much for his observations about the housing market – he’s a lot of things but he’s not a housing economist – as for his economic history. He has a pair of excellent papers describing the economic histories of Boston and New York respectively. Boston, he argues, has reinvented itself three times in the last 200 years after declining, using its high education levels to move up the value chain. New York was never in decline except in the 1970s, and has resiled from its 1980 low as well.

These as well as other large cities have economic diversity that small cities could never hope to have. At the time Glaeser wrote his paper about New York, in 2005, the city seemed dominated by finance and related industries. And yet in the 2007-9 recession, which disproportionately hit finance, the metro area’s per capita income relative to the national average barely budged, falling from 135.3% to 133.8%; in 2017 it was up to 137.5%. The New York region is a center of finance, yes, but it’s also a center of media, academic research, biotech, and increasingly software.

New York is extremely large, and has large clusters in many industries, as do London, Paris, Tokyo, and other megacities. But even medium-size cities often have several clusters, if not so many. This is especially evident in Germany, where Munich, Hamburg, Stuttgart, and Frankfurt are not particularly large. Munich is the center of conglomerates in a variety of industries, including cars (BMW, far and away the largest employer, but also MAN), general industry (Siemens), chemicals (Linde), and finance (Allianz).

What’s true is that these large cities have much more knowledge work than menial work – yes, even Munich, much more a center of engineering than of menial production. But the future is not retro in the mix of jobs any more than it is in its urban layout. The nostalgics of the middle of the 20th century taxed productive industrial cities to subsidize farmers, treating industrial work as the domain of socialists, Jews, immigrants, and other weirdos; the nostalgics of the early 21st century propose to tax productive knowledge economies to subsidize menial workers, and in some specific cases, like American protection of its auto industry, this has been the case for decades.

Small cities as suburbs

In Germany, Switzerland, and the Netherlands, unlike in the United States or France, there is a vigorous tradition of historic small cities becoming suburbs of larger cities while retaining their identity. This doesn’t really involve any of Strong Towns’ bêtes noires about roads and streets – in fact pretty much all of these cities have extensive sprawl with big box retail and near-universal car ownership. Rather, they have tight links with larger urban cores via regional rail networks, and German zoning is less strict about commercialization of near-center residential areas than American zoning. There was also no history of white flight in these areas – the white flight in Germany is in the cores of very large cities, like Berlin, which can replace fleeing whites one to one with immigrants.

In this sense, various Rhineland cities like Worms and Speyer do better than Midwestern cities of the same size. But even though they maintain their historic identities, they are not truly economically independent. In that sense, a better American analogy would be various cities in New England and the mid-Atlantic that have fallen into the megalopolis’s orbit, such as Salem, Worcester, Providence, Worcester, New Brunswick, and Wilmington. Many of these are poor because of the legacy of suburbanization and white flight, but their built-up areas aren’t so poor.

However, the most important link between such small cities and larger urban core, the regional railway, heavily encourages spiky development. In Providence, developers readily build mid-rise housing right next to Providence Station. If the quality of regional rail to Boston improves, they will presumably be willing to build even more, potentially going taller, or slightly farther from the station. Elsewhere in the city, rents are not high enough to justify much new construction, and Downcity is so weak that the tallest building, the Superman Building, is empty. In effect, Providence’s future economic value is as part of the Boston region.

The relatively even development of past generations is of less use in such a city. The economy of a Providence or a Wilmington is not strong enough that everyone can work in the city and earn a good wage. If the most important destination is a distant core like Boston or Philadelphia, then people will seek locations right near the train station. Driving is not by itself useful – why drive an hour from Rhode Island when cheaper suburbs are available within half an hour? Connecting from local transit would be feasible if the interchange were as tightly timed and integrated as in Germany, but even then this system would be oriented around one dot – the train station – rather than a larger walkable downtown area.

A bigger city is a better city

Resilience in the sense of being able to withstand economic shocks requires a measure of economic diversity. This has always been easier in larger cities than in smaller ones. Moreover, over time there is size category creep: the size that would classify a city a hundred years ago as large barely qualifies it to be medium-size today, especially in a large continental superpower like the US. As global economic complexity increases, the size of businesses and their dedicated supply chains as well as local multipliers rises. The city size that was perfectly resilient in an economy with a GDP per capita of $15,000 is fragile in an economy with a GDP per capita of $60,000.

Usually, the absolute richest or more successful places may not be so big. There are hundreds of American metro areas, so a priori there is no reason for New York to be at the top, just as there is no reason for it to be at the bottom. Nonetheless, the fact that larger cities are consistently richer as well as at less risk of decline than smaller cities – New York is one of the richest metro areas, just not the single richest – should give people who think small is beautiful pause.

Whatever one’s aesthetic judgment about the beauty of the upper Mississippi versus that of the lower Hudson, the economic and social system of very large places weathers crises better, and produces more consistent prosperity. Economically and socially, a bigger city is a better city, and national development policy should reject nostalgia and make it possible for developers to build where there is demand – that is, in the richest, most populated metro areas, enabling these regions to grow further by infill as well as accretion. Just as 50,000 was fine in 1900 but isn’t today, a million is fine today but may not be in 2100, and it’s important to enable larger cities to form where people want to live and open businesses.

Cars-and-Trains Urbanism

For all of the rhetoric about banning cars and the inherent conflict between public transportation and private automobiles, the dominant political view of urbanism in large chunks of the world is the cars-and-trains approach. Under this approach, cities build extensive infrastructure for cars, such as parking, wide arterials, and some motorways, as well as for trains, which are as a rule always rapid transit, never streetcars. In the midcentury developed world this was the unanimous view of urban development, and this remains the preference of mainline center-right parties like CDU, the French Republicans, and the British and Canadian Tories; various 1960s urbanist movements with roots in the New Left arose in specific opposition to much of that mentality, which is why those movements are usually NIMBY in general.

In the post-consensus environment of political conflict in most issues, in this case between auto- and transit-oriented urbanism, it’s tempting to go back to the midcentury elite consensus as a compromise, and call for making cities friendly to both transit users and drivers. This is attractive especially to people who hope to defuse culture war issues, either because they identify as political moderates or because they identify as socialists and have some nostalgia for the Old Left. However, this kind of urbanism does not really work. While a destination can sometimes be friendly to both drivers and transit users, the city overall cannot be; the majority of the points of interest in a successful transit city are hostile to cars and vice versa.

Moreover, this cars-and-transit failure is not just historical. It keeps going on today. Middle-income countries waste vast sums of money on building two separate transportation networks that do not work well together. The United States, too, has adopted this mentality in the cities that are building new light rail lines, resulting in large urban rail systems whose ridership is a rounding error since most of the city isn’t oriented around public transportation.

What is cars-and-trains urbanism?

Postwar West Germany built a number of subway networks in its large cities, such as Munich, Frankfurt, Cologne, Dortmund, Essen, and Hanover. With the exception of Munich and Nuremberg, these are subway-surface systems, in which the trains are underground in city center but run in streetcar mode farther out. For the most part, these systems were built with the support of the driver lobby, which wanted the streetcars out of city center in order to be able to drive more easily, and once those systems opened, the cities dismantled the streetcars. Most of West Germany thus eliminated the streetcars that did not feed into the tunnels, just as the US eliminated nearly all of its streetcars except the ones that were part of a subway-surface system in Boston, Philadelphia, and San Francisco.

In the United States, such development only happened in San Francisco, where Muni buried the main streetcar trunk in conjunction with the construction of BART along the same alignment on Market Street. More commonly, cars-and-trains urbanism led to the development of park-and-rides in the suburbs. An early example is the Green Line D branch in Boston, designed for suburban commuters rather than urban residents using the line for all purposes and not just work. Subsequently, light rail lines have been built with park-and-rides, as have full rapid transit systems in the suburb of Atlanta, Washington, and San Francisco. In the same period, American mainline rail networks evolved to be car-oriented, replacing city center stations with park-and-rides for commuter as well as intercity rail uses.

American cars-and-trains development was not without conflict. The auto lobby opposed trains, believing buses were cheaper; top civil servants in what is now the Federal Highway Administration advocated for bus lanes to create more capacity at the peak into city centers such as Washington’s. However, the trains that were built in this era followed the same mentality of creating more peak capacity in areas where widening roads was too expensive because of high city center land prices.

In the US as well as in Europe, and nowadays in developing countries, construction of rapid transit in the biggest cities and high-speed rail between them is paired with large highway systems for everything else. When the Tories won the 2010 election, they proclaimed the end of Labour’s so-called war on motorists, but maintained their support for Crossrail in London and High Speed 2 from London to the major provincial cities. And in Toronto, even Rob and Doug Ford, for all their anti-walkability demagogy, support subways, just not at-grade streetcars that would take lanes away from cars.

How does cars-and-trains transportation fail?

In the United States, public transportation is divided into three groups. There is transit-oriented urbanism, which covers about half to two thirds of New York, and very small segments of Chicago, Boston, San Francisco, Washington, and Philadelphia. There are people riding public transportation out of poverty. And there is cars-and-trains behavior, common in the outer parts and suburbs of cities with urban rail networks. In the major American metropolitan areas with urban rail other than New York, people who commute by public transport actually outearn people who drive alone, because so much transit ridership consists of rich suburban commuters. Because of the weight of those commuters and because American metro areas with public transportation are richer than the rest of the country, the national gap in income between drivers and transit commuters is small and shrinking. And yet, fuel consumption as a proportion of overall consumption is constant around 3.5% in the bottom nine deciles.

In other words: the United States has spent a lot of money on attracting the rich to public transportation, and has succeeded in the sense that transit commuters earn about the same as car commuters, but the rich still drive so much that they consume as much fuel as the poor relative to their total spending. This is not because rich people inherently like driving – rich Manhattanites don’t drive much. This is because the postwar American transportation network does not provide adequate public transportation for non-commute trips. Off-peak frequencies are low, and service to destinations outside city centers is weak.

In Germany, the politics of cars-and-trains infrastructure is still around. A few months ago, when some Berlin Greens proposed congestion pricing, CDU came out in opposition, saying that without park-and-rides, how can people be expected to use the U- and S-Bahn? Walking or biking to the station is apparently not possible in outer Berlin, per CDU.

How does cars-and-trains urbanism fail?

The problem with cars-and-trains urbanism is not just about lack of frequency. The off-peak frequency on some of the American light and heavy rail systems serving park-and-rides is not terrible for regional rail – trains come every 10 or 12 or 15 minutes. But the development repels non-commuter uses of the system. The stations are surrounded by parking rather than high-density office or residential development. People who already own cars will drive them wherever it’s convenient: they’ll shop by car since retail has no reason to cluster in the central business district, and they’ll probably drive to jobs that do not have such agglomeration benefits as to have to be in city center.

That is not just an American problem. Western Europe, too, has built extensive infrastructure to extend auto-oriented postwar suburbia into older city centers, including motorways and parking garages. If the streets are narrow, then the sidewalks may be extremely narrow, down to maybe a meter in Florence. This encourages anyone who can afford to do so to drive rather than walk.

If there is no transit-oriented core to the city, then the result is a standard auto-oriented city. Examples include Los Angeles and Dallas, both of which have large urban rail networks with approximately no ridership. In the three-way division of American transit ridership – New York (and to a small extent a handful of other city cores), suburban commuters, very poor people – Los Angeles’s transit ridership is mostly very poor, averaging half the income of solo drivers. Public transit construction in this case has been a complete waste without policies that create a transit city, which must include both liberalization (namely, zoning liberalization near stations) and coercion (such as higher car and fuel taxes and removal of parking).

If there is a transit-oriented core, then the result cleaves the metro area in two. To people who live in the transit zone, the auto-oriented parts are inaccessible, and vice versa. A few places at the boundary can be crosshatched, but the city itself cannot be entirely crosshatched – the sea of single-family houses in the suburbs is not accessible except by car, and transit-oriented cities have no room for the amount of parking or road capacity required for auto-centric density.

Does rapid transit mean cars-and-trains?

No. In opposition to the postwar elite consensus and the center-right’s support of cars-and-trains urbanism, the New Left tends to be hostile to rapid transit, on the theory that it’s only good for cars and that tramways with dedicated lanes are as good as subways. This theory is hogwash – enough cities built metros before mass motorization in order to avoid streetcar and horsecar traffic jams – but it’s attractive to people who associate subways with the failings of CDU and its equivalents in other countries.

Paris provides a positive example of rejecting cars-and-trains urbanism while building rapid transit. Postwar France was thoroughly cars-and-trains in its mentality, but 21st-century Paris is the opposite. Mayor Anne Hidalgo has narrowed roadways and removed freeways in order to make the city pedestrian-friendlier. Ile-de-France is expanding its tramway network, but it’s at the same time investing enormous amounts of money in expanding the Metro and RER. I do not think there is any city outside China with more underground route-km built than Paris in 2000-30 – Indian metros are mostly above-ground. In my under-construction database, which largely omits China and Russia due to difficulties of finding information in English, Grand Paris Express is 10% of the total route-length.

Postwar Japan is another example of rapid transit without cars-and-trains typology. Unlike present-day Paris, which is ideologically leftist and green, Japanese development has been in an ideological environment similar to the center-right elite consensus, called dirigism in France. Nonetheless, Tokyo’s motorway network is not large relative to the city’s population, and suburban development has been quite dense and rail-oriented. The private rail operators have preferred to build high-density housing at their suburban stations to encourage more ridership, rather than park-and-rides.

It’s one or the other

Drivers are most comfortable on high-speed arterial streets with generous shoulders and setbacks, with parking right next to their destinations. This encourages dispersal – just try building parking for all the jobs of Midtown Manhattan or Central Tokyo on-site. Pedestrians would need to walk long distances along noisy, polluted streets and cross them at inconvenient signal times or places or risk being run over. Public transit users fare little better, as they turn into pedestrians at their destination – and what’s more, public transportation requires destinations to cluster at a certain density to fill a train at a usable frequency.

This situation works in reverse in a transit city. On a robust public transportation network, the most desirable locations are in the very center of the city, or at key interchanges. Usually the density at those nodes grows so high that drivers have to contend with heavy traffic. Widening roads is not possible at reasonable cost in dense centers of economic production; the very reason for cars-and-trains urbanism as opposed to just 100% cars is that it was never economic to build 20-lane highways in city centers.

On the street, too, conflict is inevitable. A lane can be shared, which means dominated by cars so long as a car with one person inside it gets the same priority as a bus or tram with 40; or it can be dedicated to buses and trams, which means cars have less space. And then there are pedestrians, who need adequate sidewalks even in historic city centers where the street width from building to building is 10 meters rather than the more modern 30.

Defusing conflict is attractive, but this is not possible. A city cannot be friendly to drivers and to non-drivers at the same time. The urban designs for the two groups are too different, and for the most part what most appeals to one repels the other. Trying to build two redundant transportation networks may be attractive to people who just like the idea of visible development with its construction jobs, but both will end up underused and overly costly. Good transit has to convert drivers into non-drivers – sometimes-drivers are too expensive to serve, because the urbanism for them is too peaky and expensive.

As a corollary of this, political structures that have to give something to drivers too have to be eliminated if public transportation is to succeed. For example, infrastructure funding formulas that give set amounts of money to the two modes, like the 80% cars, 20% transit split of American federal funding, are bad and should ideally be reduced to 0 if the formula itself cannot be changed; the investment in highways is making public transportation less useful, both through direct competition and through incentives for auto-oriented development. The same is true of schemes that are really fronts for highway widening, like some bus rapid transit in the US and India. Good transit activists have to oppose these, even if it means less money in overall spending, even if it means less money in spending specific for some public transit programs. The cost of highways is just too high to try to maintain a culture truce.

The Future is not Retro

One faction of urbanists that I’ve sometimes found myself clashing with is people who assume that a greener, less auto-centric future will look something like the traditional small towns of the past. Strong Towns is the best example I know of of this tendency, arguing against high-rise urban redevelopment and in favor of urbanism that looks like pre-freeway Midwestern main streets. But this retro attitude to the future happens everywhere, and recently I’ve had to argue about this with the generally pro-modern Cap’n Transit and his take about the future of vacations. Even the push for light rail in a number of cities has connections with nostalgia for old streetcars, to the point that some American cities build mixed-traffic streetcars, such as Portland.

The future was not retro in the 1950s

The best analogy for a zero-emissions future is ironically what it seeks to undo: the history of suburbanization. In retrospect, we can view midcentury suburbanization as a physical expansion of built-up areas at lower density, at automobile scale. But at the time, it was not always viewed this way. Socially, the suburbs were supposed to be a return to rural virtues. The American patrician reformers who advocated for them consciously wanted to get rid of ethnic urban neighborhoods and their alien cultures. The German Christian democratic push for regional road and rail connections has the same social origin, just without the ethnic dimension – cities were dens of iniquity and sin.

At the same time, the suburbs, that future of the middle of the 20th century, were completely different from the mythologized 19th century past, before cities like New York and Berlin had grown so big. Most obviously, they were linked to urban jobs; the social forces that pushed for them were aware of that in real time, and sought transportation links precisely in order to permit access to urban jobs in what they hoped would be rural living.

But a number of other key differences are visible – for one, those suburbs were near the big cities of the early 20th century, and not in areas with demographic decline. In the United States, the Great Plains and Appalachia kept depopulating and the Deep South except Atlanta kept demographically stagnating. The growth in that era of interregional convergence happened in suburbs around New York, Chicago, and other big then-industrial cities, and in parts of what would soon be called the Sunbelt, namely Southern California, Texas, and Florida. In Germany, this history is more complicated, as the stagnating region that traditionalists had hoped to repopulate was Prussia and Posen, which were given to Poland at the end of the war and ethnically cleansed of their German populations. However, we can still see postwar shifts within West Germany toward suburbs of big cities like Munich and Frankfurt, while the Ruhr stagnated.

The future of transit-oriented development is not retro

People who dislike the auto-oriented form of cities can easily romanticize how cities looked before mass motorization. They’d have uniform missing middle built form in most of the US and UK, or uniform mid-rise in New York and Continental Europe. American YIMBYs in particular easily slip into romanticizing missing middle density and asking to replace single-family housing with duplexes and triplexes rather than with anything more substantial.

If you want to see what 21st-century TOD looks like, go to the richer parts of East Asia, especially Tokyo, which builds much more housing than Hong Kong and Singapore. The density in Tokyo is anything but uniform. There are clusters of high-rise buildings next to train stations, and lower density further away, even small single-family houses fronting narrow streets far enough from train stations that it’s not economical to redevelop them. It offends nostalgic Westerners; the future often does.

In the context of a growing city like New York or London, what this means is that the suburbs can expect to look spiky. There’s no point in turning, say, everything within two kilometers of Cockfosters (or the Little Neck LIRR station) into mid-rise apartments or even rowhouses. What’s the point? There’s a lot more demand 100 meters from the station than two kilometers away, enough that people pay the construction cost premium for the 20th floor 100 meters from the stations in preference to the third floor two kilometers away. The same is true for Paris – there’s no solution for its growth needs other than high-rises near RER stations and key Metro stations in the city as well as the suburbs, like the existing social housing complexes but with less space between buildings. It may offend people who associate high-rises with either the poor or recent high-skill immigrants, but again, the future often offends traditionalists.

The future of transportation is not retro

In countries that do not rigidly prevent urban housing growth the way the US does, the trend toward reurbanization is clear. Germany’s big cities are growing while everything else is shrinking save some suburbs in the richest regions, such as around Munich. Rural France keeps depopulating.

In this context, the modes of transportation of the future are rapid transit and high-speed rail. Rapid transit is preferable to buses and surface trains in most cities, because it serves spiky development better – the stations are spaced farther apart, which is fine because population density is not isotropic and neither is job density, and larger cities need the longer range that comes with the higher average speed of the subway or regional train over that of the tramway.

High-speed rail is likewise preferable to an everywhere-to-everywhere low-speed rail network like that of Switzerland. In a country with very large metro areas spaced 500 km or so apart, like the US, France, or Germany, connecting those growing city centers is of crucial importance, while nearby cities of 100,000 are of diminishing importance. Moreover, very big cities can be connected by trains so frequent that untimed transfers are viable. Already under the Deutschlandtakt plan, there will be 2.5 trains between Berlin and Hanover every hour, and if average speeds between Berlin and the Rhine-Ruhr were increased to be in line with those of the TGVs, demand would fill 4-6 trains per hour, enough to facilitate untimed transfers from connecting lines going north and south of Hanover. The Northeast Corridor has even more latent demand, given the huge size of New York.

The future of travel is not retro

The transportation network both follows and shapes travel patterns. Rapid transit is symbiotic with spiky TOD, and high-speed rail is symbiotic with extensive intercity travel.

The implication is that the future of holidays, too, is not retro. Vacation trips between major cities will become easier if countries that are not France and Japan build a dense network of high-speed lines akin to what France has done over the last 40 years and what Japan has done over the last 60. Many of those cities have thriving tourism economies, and these can expect to expand if there are fast trains connecting them to other cities within 300-1,000 kilometers.

Sometimes, these high-speed lines could serve romanticized tourist destinations. Niagara Falls lies between New York and Toronto, and could see expansion of visits, including day trips from Toronto and Buffalo and overnight stays from New York. The Riviera will surely see more travel once the much-delayed LGV PACA puts Nice four hours away from Paris by train rather than five and a half. Even the Black Forest might see an expansion of travel if people connect from high-speed trains from the rest of Germany to regional trains at Freiburg, going from the Rhine Valley up to the mountains; but even then, I expect a future Germany’s domestic tourism to be increasingly urban, probably involving the Rhine waterfront as well as the historic cities along the river.

But for the most part, tourist destinations designed around driving, like most American national parks as well as state parks like the Catskills, will shrink in importance in a zero-carbon future. It does not matter if they used to have rail access, as Glacier National Park did; the tourism of the leisure class of the early 20th century is not the same as that of the middle class of the middle of the 21st. Grand Canyon and Yellowstone are not the only pretty places in the world or even in the United States; the Hudson Valley and the entire Pacific Coast are pretty too, and do not require either driving or taking a hypothetical train line that, on the list of the United States’ top transportation priorities, would not crack the top 100. This will offend people whose idea of environmentalism is based on the priorities of turn-of-the-century patrician conservationists, but environmental science has moved on and the nature of the biggest ecological crisis facing humanity has changed.

The non-retro future is pretty cool

The theme of the future is that, just as the Industrial Revolution involved urbanization and rural depopulation, urban development patterns this century involve growth in the big metro areas and decline elsewhere and in traditional small towns. This is fine. The status anxieties of Basil Fawlty types who either can’t or won’t adapt to a world that has little use for their prejudices are not a serious public concern.

Already, people lead full lives in big global cities like New York and London without any of the trappings of what passed for normality in the middle of the 20th century, like a detached house with a yard and no racial minorities or working-class people within sight. The rest will adapt to this reality, just as early 20th century urbanites adapted to the reality of suburbanization a generation later.

It’s not even an imposition. It’s opportunity. People can live in high-quality housing with access to extensive social as well as job networks, and travel to many different places with different languages, flora and fauna, vistas, architecture, food, and local retail. Even in the same language zone, Northern and Southern Germany look completely different from each other, as do Paris and Southern France, or New England and Washington. Then outside the cities there are enough places walking distance from a commuter rail line or on the way on a high-speed line between two cities that people can if they’d like go somewhere and spend time out of sight of other people. There’s so much to do in a regime of green prosperity; the world merely awaits the enactment of policies that encourage such a future in lieu of one dominated by small-minded local interests who define themselves by how much they can pollute.

Megaregions, Redux

Remember how ten years ago the American urbanist conversation was all about carving the country up into megaregions? The America 2050 project drew some lines connecting metro areas into regions, designed to imitate the Boston-Washington corridor in concept, and asserted that this would be the future of American growth. The concept seems to have dropped off the discourse, and for good reason, but it may be useful to have a second look. The Boston-Washington megalopolis is a genuine megaregion, and it’s useful to see which regions elsewhere in the world share its characteristics.

The key takeaway is that rich cities do not have to be in megaregions. The Northeast Corridor is a rich megaregion, and San Francisco, Los Angeles, and Chicago anchor smaller megaregions of their own; but in Europe, among the richest cities only Frankfurt and Amsterdam are in megaregions, while London, Paris, Hamburg, and Munich are not. Megaregions are areas of high population density and interlinked social networks. Their size may give them economic advantage, but it doesn’t have to; urbanists and urban geographers must avoid overselling their importance.

What is a megaregion?

The original Boston-Washington megalopolis was defined in the 1960s, as a linear region with continuous suburban sprawl. The core comes from New York and Philadelphia, which share some suburbs in Central Jersey, their regional rails meeting at Trenton. However, continuous sprawl goes north to New Haven, Hartford, and Springfield, with only a few tens of km of separation from Providence and Worcester on the way to Boston; and southwest to Baltimore and Washington, with suburbs spaced closely together along the I-95 corridor.

There are extensive academic connections. Academics are generally hypermobile, but form especially thick metropolitan connections. Living in Boston and reverse-commuting to Brown is normal, and people at Brown would sometimes go up to Harvard or MIT for seminars when sufficiently important or interesting people gave talks. Connections up and down the central part of the corridor are extensive as well, stretching from Yale down to Penn. There is a gap between New Haven and Providence, as Hartford and Springfield aren’t academic centers; perhaps for academics the megaregion only stretches from New Haven to Washington, but even so, at least two-thirds of the megaregion remains intact.

Socially, there are strong connections along the corridor as well. They’re rarely end-to-end, but people in fandom routinely go a state or two over for conventions, so conventions in Connecticut and Rhode Island draw from New York and Boston, conventions in New Jersey draw from Philadelphia and New Haven, and conventions in Maryland draw from Philadelphia and Northern Virginia. On some stretches, weekend trips are normal, like the Columbia students who’d go back to visit parents in suburban Philadelphia every weekend, or people in New York who dated people in New Haven and didn’t even really think of it as a long-distance relationship.

Which regions qualify as megaregions?

Outside the Northeast, it is difficult for me to judge the extent of social connections, with a few key exceptions. However, I can judge how continuous urbanization is and, using American survey data on commuting, whether two adjacent core urban areas share suburbs. In Europe, I do not have commuting data, but it is easy to look at regional rail maps and see when S-Bahn networks touch.

Asymmetric megaregions

In the United States, the three largest core metropolitan areas outside the Northeast – Los Angeles, Chicago, and San Francisco – all anchor megaregions. However, in all three cases, the big core metro area dominates the broader region. Los Angeles has continuous sprawl down the coast to San Diego, and the two metro areas’ commuter rail networks touch; Chicago similarly has continuous sprawl up to Milwaukee, and if Milwaukee bothered to run regional trains then they would probably go down to Kenosha and connect to Metra; the Bay Area’s high housing costs have driven many people to the San Joaquin Delta, most of the way to Sacramento, and the Amtrak route connecting San Jose and Oakland with Sacramento is largely planned as regional rail nowadays.

New York is of course much larger than the other core regions of the megalopolis, but its metro area has at most half the population of the region, and even that requires making the broadest assumptions on what counts as part of the metro area and the narrowest ones on what counts as part of the megalopolis. If metro New York excludes mostly economically independent areas like New Haven and Central Jersey, and the megalopolis includes some inland areas like Albany and Harrisburg, then New York is only one third of the megalopolis. In contrast, the five-county Los Angeles metro area has three quarters of Southern California’s population, the Bay Area has about two thirds of its megaregion’s population, and metro Chicago has about 85% of the combined population of Chicago and Milwaukee.

Suburb sharing in smaller megaregions

High population density and suburban sprawl can lead some core urban areas to share suburbs, forming a megaregion with much lower population than the megalopolis. Florida supplies at least one such example: out of 237,000 employed residents in Polk County, 26,000 commute to Orlando’s Orange County and 29,000 commute to Tampa’s Hillsborough County and St. Petersburg’s Pinellas County; the western parts of Polk County have a higher density of Tampa-bound commuters and the eastern parts have a higher density of Orlando-bound commuters, but there is a fair amount of mixing, as well as anywhere-to-anywhere commuting within the county. By all accounts, Orlando and Tampa should be placed into one megaregion.

South Florida is arguably a megaregion as well. It is treated as a metro area stretching from Miami or even Key West north to West Palm Beach, but its northern, central, and southern areas have distinct urban cores. Miami-Dade County has 982,000 employed residents, of whom only 28,000 work in Palm Beach County; in the other direction, 29,000 workers from Palm Beach commute to Miami-Dade out of 513,000. This megaregion stretches even further north – St. Lucie County has 13,000 out of 100,000 workers commuting to Palm Beach County – but there is a gap in both population density and commuting zones between Port St. Lucie and Space Coast. Socially, too, the people I know on Space Coast don’t have ties to South Florida, and barely have any to Orlando. So the bulk of Florida is really two linear megaregions, one north-south and one southwest-northeast, which may be close but do not merge.

Finally, crossing the Pond, Northern England features a megaregion out of core metro areas of similar size to those of Central Florida. Liverpool and Manchester are two historic cores and are formally two distinct metro areas, but are so interlinked they are arguably a single metro area, and are certainly a single multicore megaregion. There is contiguous suburban sprawl connecting the two cities with small gaps, and were British regional rail services better, their frequent urban rail networks would have touched. There are even some ties crossing the Pennines to Leeds; Britain has attempted to improve infrastructure between historic Lancashire and Yorkshire, using the language of megaregions to argue that this would boost the area’s economic profile.

Leapfrog urban connections

Western Germany and the Netherlands do not have contiguous sprawl in the same way that most developed countries do. On a satellite photo, the commuting zone of New York, Paris, Madrid, Toronto, or any other major city in their respective countries looks largely as a single blob of gray. The population density of this gray blob is higher in France than in the United States, but in both countries, a metropolitan area is made out of a single contiguous built-up area plus a handful of surrounding low-density exurbs.

In contrast, in Germany and the Netherlands there are undeveloped areas between adjacent cities. Most definitions of metropolitan agglomeration in Europe recognize that Cologne and Bonn are one metro area, but the two cities’ built-up areas barely touch and have farmland in between. The metro area of Frankfurt similarly contains multiple core cities with recognizable centers and some rural gaps between them, such as Darmstadt and Mainz. Urban areas with slightly bigger gaps do not necessarily fall into one metro area, but certainly comprise a single megaregion, including Germany’s largest, the Rhine-Ruhr with its roughly 11 million people and extensive internal S-Bahn connections.

Randstad is likewise a megaregion. The Netherlands zealously protects its high-yield farmland from urban sprawl, so suburbs are usually not contiguous with the cities they serve as bedroom communities for. There are agricultural gaps between Amsterdam, the cities of Flevoland, Utrecht, Rotterdam, and the Hague, and not too much commuting between the southern and northern edges of the combined region, and yet intermediate commuting and tight economic links mean it must be viewed as more than two or three disparate metro areas.

More controversially, I claim that the lower reaches of the Upper Rhine, from Frankfurt and Mainz up to Karlsruhe, form a single megaregion, and may even stretch farther up all the way into Basel. The gaps in urbanization between Frankfurt and Mannheim are not large – there is a city every few kilometers on both rail lines connecting the two cities. Moreover, the Frankfurt and Rhine-Neckar regions’ S-Bahns touch at Mainz, the Mainz-Mannheim line having recently been designated as S-Bahn quality and appearing on the regional schedules. The Rhine-Neckar S-Bahn in turn serves Karlsruhe. South of Karlsruhe the population density is high but less so, and the gaps between the cities are larger. But even without Baden south of Karlsruhe, the combined region has nearly 10 million people, and certainly has the highest GDP in Germany, as it is much richer than the Rhine-Ruhr.

Remember the Blue Banana?

In 1989, a group of French geographers led by Roger Brunet coined the term blue banana for a European megalopolis. As defined, it stretched from London or even Liverpool and Manchester in the north, across the Channel to the Low Countries, up the Rhine to Switzerland, and then across the Alps to Milan. The original definition deliberately omitted Paris from this zone, arguing that French urban geography was dominated by internal national links centered around the capital rather than the polycentrism of the Low Countries, western Germany, Switzerland, and Italy.

The last 30 years have not been kind to the Blue Banana. Much of Continental Europe was beset by a period of slow growth in the 1990s, sometimes called eurosclerosis; parts of it have slowly recovered in the 2000s and 2010s, most notably Germany, while others have stagnated, most notably Italy. In the 1990s, it was plausible to view Milan as more like Northern Europe than like Southern Italy. Today, it is no longer tenable. Before the 2008 crisis, Lombardy was as rich as Hamburg and southern Hesse and much richer than Stockholm and Copenhagen; today it is slightly behind Stockholm and slightly ahead of Copenhagen, and well behind Hamburg and southern Hesse.

The story of growth in the last generation has mostly been one of states, not regions. Northern Italy is much richer than Southern Italy, just as it has always been, but the entire country has equally stagnated. French growth has not been spectacular over this period, but it’s been better than Italian growth. Belgium, within the Blue Banana, has done better than France in the last generation, but not by much. In this entire period, the most notable subnational per capita income changes have been that London has pulled ahead while Northern England has stagnated, and that East Germany has grown faster than West Germany.

Megaregions and wealth

In the United States, the big megaregions have been loci of wealth, particularly the megalopolis. This has intensified in the current century. According to BEA data, since 2000, economic growth in the four core Northeast combined metro areas has exceeded the national average, gaining about 4 percentage points relative to the rest of the country in terms of both per capita income (from all sources) and net earnings (i.e. income from work). But even there, this is not the whole story, since Seattle, which is not in any megaregion, has had even faster growth.

Moreover, in Europe, there is no real correlation between megaregions and growth. The largest single megaregion in Europe, the Rhine-Ruhr, has slower economic growth than both the surging cities of southern Germany and the converging ones of the East. Paris and London are doing just fine as independent metro areas, Munich is still the richest city region in the EU, and Berlin is steadily converging to West German income levels.

Of course, no correlation and negative correlation are two different things. Just as the Rhine-Ruhr is slowly stagnating, the Frankfurt-Mannheim megaregion is growing, and Randstad has managed to recover from the recession alongside the rest of the Netherlands.

To the extent that there’s a link between megaregions and wealth, it’s that in developing countries, or even in midcentury America, poorer regions are mostly rural, and their cities tend to be small and less likely to interlink to form large metro areas. Thus, Eastern China has three megaregions with tens of millions of people each – Beijing-Tianjin, the Yangtze Delta, and the Pearl River Delta – underlying the wealth and urbanization of these regions; in contrast, the Indo-Gangetic Plain’s lower level of economic development means that even though population density from Bangladesh up the Ganges toward Delhi is as high as in southern Jiangsu, the cities are too small and too separated to form a Bangladeshi or West Bengali or Doabi megaregion.

But in a first-world context, the urbanization rate is about 100%. Even on-paper rural areas are within city regions and just happen to be small municipalities whose residents can drive in half an hour to a larger number of people than any premodern village pedestrian could interact with over a lifetime.

What this suggests is that the right way to think of first-world megaregions is not in terms of economic output, but in terms of density. In dense areas like the Netherlands, western Germany, England, and the Northeastern US, megaregions are likely to form out of links between adjacent cities. Not for nothing, the only part of the American Sunbelt where I’m comfortable describing metro areas as linking to form megaregions, Florida, also has the highest population density. The economies of Atlanta, Dallas, and Houston are a lot stronger than that of Central Florida, which is frankly a basket case, but cities in Texas and the Deep South are too far apart to function as megaregions.

Does high background density lead to higher incomes? Maybe. Strong urban networks really do allow for more economic specialization. But then these networks can be global, untethered from where one can travel by regional rail or urban highways. It’s an interesting question of economic geography, but on the level of a sanity check, some of the richest cities in Europe are doing just fine without the polycentric megaregional links going up and down the Rhine.

Job Centralization in the City

The table below collates job centralization not by CBD as in this post but by central city. Parisian data comes from INSEE, here and here; American data comes from Wikipedia for population and OnTheMap for job counts. In general, I tried making the central city definition about 18% of the metro area to be comparable with Paris, but there is still a lot of variation, so this table should absolutely not be read as a ranking of metro areas by job centralization.

Metro area Population Jobs Central city Central pop’n Central jobs Central job share
Ile-de-France 12,082,144 5,682,048 Paris 2,206,488 1,797,745 31.6%
New York 19,979,477 8,364,410 Manhattan, Brooklyn 4,313,498 2,905,675 34.7%
Los Angeles 13,291,486 5,372,008 Downtown LA to Santa Monica ~1,500,000 1,051,648 19.6%
Chicago 9,498,716 4,142,542 Chicago ex-O’Hare 2,705,994 1,198,562 28.9%
Dallas 7,539,711 3,146,973 Dallas 1,345,047 809,077 25.7%
Houston 6,997,384 2,791,647 Inside 610 + Uptown ~650,000 749,661 26.9%
Washington 6,249,950 2,717,790 District, Arlington, Alexandria 1,100,496 859,751 31.6%
Miami 6,198,782 2,308,048 Miami, Miami Beach 563,221 324,260 14%
Philadelphia 6,096,372 2,570,460 Philadelphia 1,584,138 628,423 24.4%
Atlanta 5,949,951 2,374,233 Fulton County 1,050,114 780,259 32.9%
Boston 4,875,390 2,381,555 Boston, Cambridge 805,234 687,237 28.9%
Bay Area 4,729,484 2,121,580 San Francisco 883,305 642,375 30.3%

The Sunbelt

There appears to be a fair amount of job centralization in the Sunbelt cities, right? In Metro Atlanta, Fulton County has a slightly higher proportion of regional jobs than Paris with a slightly lower share of residential population.

But actually, no. Absolute densities matter in addition to relative centralization of jobs versus residences. In Houston and Los Angeles the central areas are drawn to encircle the downtown and near-downtown job centers – both cities preferentially annex suburban job sites so using municipal boundaries is not useful. A hefty share of area jobs are in these centers, especially in Houston. But ultimately it’s still not a lot of jobs in a very large land area, around 300 square kilometers for both, compared with 100 for the city of Paris or for San Francisco. Fulton County is vast, and the jobs are distributed all over Atlanta and its northern suburbs within the county.

Houston is a particularly good example of monocentrism with a weak center. There are not a lot of strong suburban job centers in Houston – nothing like Silicon Valley, Downtown Newark, the Route 128 corridor, La Defense, Burbank, or Tysons Corner. The city itself has about two thirds of area jobs, thanks to selective annexations. But the share of the CBD in area jobs is low, just 150,000 jobs in the 45/69/10 beltway, or 5.3% of area jobs. Outside the CBD job density plummets, as the outlying job centers making the difference between 5.3% and 26.9% are located at haphazard locations all over 610.

Older American cities

The extent of centralization in the Northeast, Chicago, and San Francisco is greater. New York in particular is a lot like Paris, with about a third of area jobs in a high-density contiguous blob consisting of less than one fifth of regional population. It has nothing like La Defense in the suburbs, but its suburban job centers, while much smaller, include some recognizably dense ones, especially Newark and the Jersey City waterfront. One needs to go well into suburbia to see the difference between Paris, where the suburbs have a structure of density with mid- and high-rise residential development as well as offices next to train stations, and New York, where the job centers in farther-out suburbia, like Central Jersey, have no such structure and are located exclusively based on auto access.

Boston, Washington, and San Francisco all have varying degrees of centralization. I mentioned last year that Boston is increasingly an example of European-style job sprawl, in which jobs spill over from the CBD to nearby areas rather than to faraway office parks. New York has long had such spillover – Long Island City is such a job center, and may at this point have more jobs than Downtown Brooklyn; the Jersey City waterfront is another such example, as is the growth of the Meatpacking District around Google. In Boston the equivalents are Kendall Square and the Seaport; in San Francisco it’s SoMa; in Washington it’s jobs in Arlington around the Orange Line, where older TOD was residential.

Chicago and Philadelphia are the least centralized. Chicago has a well-defined supertall skyline with about 500,000 people working in or near the Loop. But outside that central area, job density craters. Chicago’s share of metro area jobs is about 1.5% higher than its share of metro population, and if we remove the airport, surrounded by suburbia, this difference drops to 0.5%. Philadelphia’s share of metro area jobs is actually lower than its share of metro area population by 1.5%. In these regions, if you’re not working in city center, you’re working at an office park in a middle-class-to-rich suburb built without regard for the area’s vast legacy mainline rail network.

Trip Chaining, Redux

There’s been an ongoing conversation about how public transport can be used for non-work trips (and what it means for women) that makes me go back to something I wrote in 2012 about trip chaining. In that post I asserted a distinction between long and short trips, but I didn’t make it very clear. The importance of this distinction is that even though a large majority of trips are not work trips, the sort of urban layout that makes long trips (including work trips) usable by train tends to also make other trips doable on foot.

Trip length and purpose

Mobilität in Deutschland periodically reports on national travel patterns. The 2017 MiD report includes mode shares, trip lengths, and purposes, some broken down by state. Unlike in the Anglosphere or in France, the headline modal share is for all trips, not just work or school trips, and therefore the numbers for public transit look lower and those for walking and cycling look higher.

The important statistic for trip-chaining comes from a table on p. 19. There were 42 million work trips and 41 million shopping trips nationwide in 2017, but the work trips were on average more than three times as long, 16 vs. 5.3 kilometers. The only trip category longer than work was business trips, on average 19 km, including an extensive number of intercity trips, and the only category close to work trips was recreational trips, averaging 15.5 km, also including extensive intercity travel; the median work trip was by a fair margin the longest, 8 km, whereas the median shopping trip was 2 km. Likewise, errand trips were 10.2 km on average with a median of 3.6.

MiD doesn’t break down this data by region, unfortunately. So I can only speculate that if the median trip that people talk about when they talk about trip chaining is 2 km long, then the median trip in the parts of Germany with good public transit is short enough to be done on foot, probably shorter than a kilometer.

Short and long trips

I think it’s useful to collapse the distinction between trips into a binary one: short versus long. Trip length is of course a continuous variable, but a good classification scheme is “can it be done internally to a neighborhood or town?”. If the answer is yes then the trip is short, otherwise it is long.

The commute is an example of a long trip. Commuting to school is usually a long trip as well; even in an environment with school zoning and no selection or choice, a secondary school draws from too large an area to be a single neighborhood except in an extremely large and dense city. Social trips can be long as well – if I go to a gaming convention or a performance in Berlin, or if someone who cares about sports goes to see a football match, it’s a long trip.

Short trips include shopping, errands, eating out, and daycare. The common aspect to them is that they involve common activities with small draws. The supermarket draws from a community of a few thousand, as does the neighborhood restaurant. In contrast, the performance is unique – while many people go to concerts, different people are fans of different artists, so a single band may need to visit a city of millions to fill an auditorium.

Making transit useful for non-work long trips

I bring up the example of going to a sports game as a long trip because American transit agencies deal with that routinely even if they otherwise only care about work trips. Commute trips tend to happen at specific times of day, especially if you’re from the same middle class that transit managers are drawn from. Other long trips have different peaks. Leisure trips tend to happen in the evening and on weekends. Business trips within metropolitan areas tend to happen in the middle of the day during work hours. Trips to the airport depend on time zones – in New York the ones to JFK are concentrated in the afternoon peak, but it’s hard to make generalizations.

Like work trips, non-work long trips are not isotropic – people travel to specific places. A few are as a rule outside city center, such as sports stadiums and airports. Others are within city center to appeal to a wide cross-section of residents, such as event spaces for performances; conventions run the gamut, but richer and more important conventions are likelier to shell out money for city center real estate. Universities may be in or outside city center, depending on the city. Museums are usually city center or in neighborhoods just outside it, such as the Upper East and West Sides in New York or Balboa Park in San Diego.

The length means that the optimal transit network for all non-work trips is largely the same. If trains arrive at a reasonable frequency all day, every day, and form a coherent radial network, then passengers will able to use them for all long trips, even ones that are not for work. The major destinations that are outside city center should whenever possible be junctions between different branches, or get circumferential and not just radial service.

Moreover, there is little point in trying to vary modes for work and non-work trips. Surface transit that averages 15 km/h but saves you a 1-minute trip down to the subway is no more useful for going to a concert than for going to work. If poor urban planning has resulted in an airport that’s nowhere on the rail network or in regional convention centers that are impossible to serve, then buses can fill in the gap, but that’s not optimizing for non-work trips but rather fixing past design mistakes, no different from doing the same when suburban office parks are built far from the train.

The one serious change one needs to make is that the definition of city center needs to be broader than the few square blocks that comprise most American cities’ downtowns. The London Underground’s conception of Central London is not just the City, and likewise cities need to ensure that their West Ends (like, again, San Diego’s Balboa Park) are served as if they were central rather than peripheral areas.

Short trips

It is wrong for cities to try optimizing public transportation for short trips. Most short trips can be done by foot; if they can’t, something is wrong with the city’s urban design. The minimum density required for people to be able to walk to retail is not high – I have a choice of supermarkets within walking distance, and Berlin is not an especially dense city. In Paris, which unlike Berlin is especially dense, I walked to the hypermarket.

Occasionally, when a short trip needs to be done on mechanized transportation, if the city has good transit-oriented commercial development then it is doable by riding the trains a few stops. I recently bought a mattress at Hermannplatz, 3 stops away on U7, longer than most people inside the Ring have to go to such a store, and mattresses are a special case in that dragging them on the streets for a kilometer isn’t fun.

Suppression of auto use is especially valuable for short trips. The reason is that in auto-oriented areas, short as well as long trips are done by car, and if businesses locate based on automobile scale, then only transit can compete – walking and cycling take too long. A hefty proportion of the urban upper middle class prefers to own cars and drive them for short trips, which may induce short trip destinations to locate based on automobile scale even in a walkable city; when I lived in Providence, I walked to the supermarket, but it was located right next to a freeway exit and had ample parking.

Trip chaining

The concept of trip chaining – going directly between destinations in a row rather than just going back and forth between home and a destination – works best with the mode of transportation with the highest frequency and lowest access time: walking. Buying different items at different stores is so ubiquitous that shopping malls were invented specifically to make that experience more pleasant than that of chaining car trips.

Transit cities should not design themselves around trip chaining on transit, destinations for short trips are too difficult to serve. Many cluster on major corridors, but some don’t and stay on residential streets or at street corners. In walkable cities they tend to be fairly isotropic. With short average trips and no discernable centers, the optimal stop spacing on transit is extremely short, to the point of uselessness for all other purposes. If there’s trip chaining, the required frequency is so high that operating costs become unaffordable; a 5-minute wait for a bus may well be unconscionable.

Outside dense cities, suburbs should have a structure of density in which all the plausible destinations are within walking distance of the train station, permitting chaining walking trips with a transit trip. With such structure, the minimum viable density is lower, because buses can connect to the train with a timed transfer and have longer stop spacing as the destinations are all at the town center. In effect, such a structure gives the town center most of the convenience benefits of a shopping mall even without other features such as enclosure and single ownership of the real estate.

Infrastructure is scale-dependent. Public transportation makes this a lot clearer than cars – different modes are used at different scales, and the shape of the network can look visibly different as well. At the scale of short trips, the correct choice of public transportation mode is none – people can and should walk. If the city has generally viable public transit, its urban layout will equally well permit trip chaining on foot. If it doesn’t, then the priority should be to establish a transit city and not to try dragging buses every block.

Growth and Environmentalism

I’ve been asked to write about the issue of growth versus no growth. This is in the context of planning, so broader questions of degrowth are not within this post’s main scope. Rather, it’s about whether planning for more growth is useful in combating pollution and greenhouse gas emissions. The answer is yes, though the reasoning is subtle. Smart growth is the key, and yet it’s not a straightforward question of transit construction and transit-oriented development helping the environment; it’s important to figure out what the baseline is, since a large urban apartment still emits more CO2 than the closets people end up living in in parts of San Francisco and New York.

The argument for growth specifically is that a high baseline level of growth is what enables smart growth and TOD policies. Vancouver’s secular increase in transit usage, and to a lesser extent the ongoing revival in Seattle and that of Washington in the 2000s, could not happen in a region with Midwestern population growth.

Smart growth vs. no growth

VTPI has many references to studies about smart growth here. The idea of smart growth is that through policies that encourage infill development and discourage sprawl, it’s possible to redirect the shape of urban areas in a greener direction. Here’s one specific VTPI paper making this comparison directly on PDF-p. 3.

Unfortunately, the reality is that there are at least three poles: in addition to sprawl and smart growth, there is no growth. And moreover, many of the bureaucratic rules intended to encourage smart growth, such as comprehensive zoning plans, in fact lead to no growth. The following table is a convenient summary of housing permitting rate vs. my qualitative impression of how smart the growth is.

The permitting rate is absolute, rather than relative to birth rates, immigration, and internal migration pressure as seen in average incomes. Tokyo’s permitting rate is similar to Vancouver’s – Tokyo Prefecture’s rate of 10 annual units per 1,000 people and so is Metro Vancouver’s, but Japan’s population is falling whereas Canada’s is rising. See also European rates linked here and American rates here.

The infill vs. sprawl dimension is qualitative, and combines how transit-oriented the construction is with whether the development is mostly in the city or in the suburbs. Berlin’s suburbs are shrinking due to the depopulation of East Germany, and growth in the suburbs of Tokyo and West Germany is weak as well, but city growth is going strong. Paris is building a lot of public transit and is very dense, but there’s more development per capita in the suburbs, and likewise in California most development is in exurbs rather than in central cities; Seattle is penalized for having bad transit, and Atlanta for having no transit, but in both there’s a lot more development in the city than in the suburbs. Stockholm and Vienna have growth all over and excellent public transit.

The significance of the diagram is that by the standards of European transit cities, California is not an example of smart growth, but of no growth.

Shaping growth

In the high-growth area of the diagram, the most interesting case is not Tokyo, but Vancouver and Seattle. In these cities, there is a transit revival. Metro Vancouver’s mode share went up from 13% in 1996 to 20% on the eve of the Evergreen extension’s opening. Moreover, for most of this period Vancouver saw car traffic decrease, despite high population growth. Metro Seattle’s transit revival is more recent but real, with the mode share rising from the “no transit” to “bad transit” category (it is 10% now).

Both cities invested heavily in transit, Vancouver much more so than Seattle, but it was specifically transit aimed at shaping growth. Before the Expo Line opened, Downtown had few skyscrapers, Metrotown did not yet exist, New Westminster had a low-rise city center, and the areas around Main Street-Science World, Joyce-Collingwood, and Edmonds were nonresidential and low-density. The combination of fast growth and rapid transit ensured that new development would add to transit ridership rather than to road traffic. Moreover, the strong transit spine and growing employment at transit-oriented centers meant existing residents could make use of the new network as well.

The same situation also exists in Europe, though not on the same transformative scale as in Vancouver, since the cities in question came into the new millennium with already high transit usage. Stockholm just opened a regional rail tunnel doubling cross-city capacity and is expanding its metro network in three directions. This program is not available to lower-growth cities. Berlin has grandiose plans for U-Bahn expansion and has even safeguarded routes, but it has no active plans to build anything beyond the U5-U55 connection and S21 – the city just isn’t growing enough.

Public transit without growth

By itself, growth is not necessary for the existence of a robust transit network. Vienna proper had more people on the eve of WW1 than it has today, though in the intervening generations there has been extensive housing construction, often publicly subsidized (“Red Vienna”), increasing the working class’s standard of living. However, in a modern auto-oriented city – say, anything in North America other than New York – it is essential.

This becomes clear if we look at the next tier of American cities in transit usage after New York, that is Chicago, San Francisco, Washington, and Boston. Washington is the odd one – it had a transit revival before the Metro collapse of this decade, and got there through TOD in choice locations like Arlington. The others inherited a prewar transit network and made some improvements (like the Transbay Tube replacing the Key System), but froze urban development in time. Essentially all postwar development in those cities has been sprawl. Chicago had big enough a core to maintain a strong city center, but outside the Loop the job geography is very sprawled out. Boston and the Bay Area sprouted suburban edge cities that became metonyms for their dominant industries, with a transit modal share of about 0%.

Chicago’s transportation situation is difficult. The city is losing population; some specific neighborhoods are desirable and some around them are gentrifying, but the most optimistic prognosis is that it’s akin to New York in the 1970s. If there’s no population to justify a public transit investment today, there won’t be the population to justify it tomorrow. Any investment has to rely on leveraging the city’s considerable legacy mainline network, potentially with strategic cut-and-cover tunneling to connect Metra lines to each other.

And if Chicago’s situation is difficult, that of poorer, smaller cities is most likely terminal. Detroit’s grandiose plans are for urban shrinkage, and even then they run into the problem that the most economically intact parts of the region are in low-density suburbs in Oakland County, where nobody is going to agree to abandonment; the shrinkage then intensifies sprawl by weakening the urban core. Even in European cities where the shrinkage is from the outside in, there’s no real hope for any kind of green revival. Chemnitz will never have rapid transit; its tram-train has 2.6 million annual passengers.

Idyll and environmentalism

The environmental movement has from the start had a strong sense of idyll. The conservationism that motivated John Muir and Teddy Roosevelt was about preserving exurban wilderness for rich adventurers to travel in. The green left of the 1960s dropped the explicit classism but substituted it for new prejudices, like the racism embedded in population control programs proposed by Westerners for the third world. Moreover, the romantic ideals of Roosevelt-era environmentalism transformed into small-is-beautiful romanticism. Even Jane Jacobs’ love for cities was tempered by a romanticism for old low-rise neighborhoods; she predicted the Upper West Side with its elevator buildings would never be attractive to the middle class.

But what’s idealized and what’s green are not always the same. Lord of the Rings has a strong WW1 allegory in which the hobbits (Tolkien) leave the Shire (the English Midlands) to go to war and come back to find it scoured by industrialization. But on the eve of WW1, Britain was already a coal-polluted hellscape. Per capita carbon emissions would remain the same until the 1970s and thence fall by half – and in the first three quarters of the 20th century the fuel source shifted from coal to oil, which is less polluting for the same carbon emissions. The era that Tolkien romanticized was one of periodic mass deaths from smog. The era in which he wrote was one in which public health efforts were undertaken to clean up the air.

Likewise, what passes for environmentalism in communities that openly oppose growth freezes the idyll of postwar America, where suburban roads were still uncongested and the middle class had midsize houses on large lots. But American greenhouse gas emissions per capita were the same in 1960 as today, and had been the same in good economic times going back to the eve of the Great Depression. Only centenarians remember any time in which Americans damaged the planet less than they do today, and “less” means 14 tons of CO2 per capita rather than 16.5.

The upshot is that in the developed world, environmentalism and conservation are opposing forces. Conservation means looking back to an era that had the same environmental problems as today, except often worse, and managed to be poorer on top of it all.

Growth and environmentalism

Strictly speaking, growth is not necessary to reduce emissions. The low-growth city could just as well close its road network, ban cars, and forbid people to use electricity or heating generated by fossil fuels – if they’re cold, they can put on sweaters. But in practice, low-emission developed countries got to be where they are today by channeling bouts of economic growth toward clean consumption of electricity as well as transportation. Regulatory coercion and taxes that inconvenience the middle class are both absolutely necessary to reduce emissions, and yet both are easier to swallow in areas that have new development that they can channel toward green consumption.

The environmentalist in the Parises and Stockholms has the easiest time. Those cities have functioning green economies. There are recalcitrant mostly right-wing voters who like driving and need to be forced to stop, but a lifestyle with essentially no greenhouse gas emissions except for air travel is normal across all socioeconomic classes. The Vancouvers are not there but could get there in a generation by ensuring future development reinforces high local density of jobs and residences. The pro-development policies of the Pacific Northwest are not in opposition to the region’s environmentalism but rather reinforce it, by giving green movements a future to look forward to.

The environmentalist in the Clevelands and Detroits has the hardest time. It’s even worse than in the Chemnitzes – Saxony may be a post-industrial wasteland with 10% fewer people now than it had in 1905, but it’s coming into the 21st century with German emissions rather than American ones. These are cities with American emissions and economies based substantially on producing polluting cars, propped by special government attention thanks to the American mythology of the Big Three.

But whereas the Rust Belt has genuine problems, NIMBYvilles’ low growth is entirely self-imposed. New York and Los Angeles have the same per capita metro housing growth as Detroit, but only because they choose stasis; where the price signal in Detroit screams at people to run away, that in New York and California screams to build more housing. Their political institutions decided to make it harder to build any green future not only for their current residents but also for tens of millions who’d like to move there.

Shut Down the Brooklyn-Queens Expressway

New York’s high construction costs are not just a problem for public transit. Roads exhibit the exact same problem. Case in point: replacing 2.5 km of the deteriorating Brooklyn-Queens Expressway (BQE) in Brooklyn Heights is slated to cost $3-4 billion, take 6-8 years, and require temporarily closing the pedestrian promenade supported on top of the highway. This is not even a tunnel – some local NIMBYs have proposed one in order to reduce the impact of construction, but the cost would then be even higher. No: the projected cost, around $1.5 billion per kilometer, is for an above-ground highway replacement.

The section in question is between the Brooklyn-Battery Tunnel and the Brooklyn Bridge; the Promenade is the northern half of this section.

Is it worth it?

No.

There exist infrastructure projects that are worth it even at elevated cost. Second Avenue Subway Phase 1 cost $4.6 billion where it should have cost $700 million, but the expected ridership was very high, 200,000 per day, and so far ridership is on track to meet projections: the three new stations had a total of 138,000 boardings and alightings between them in 2017, and the revamped 63rd Street station went up by another 8,000. The BQE replacement is not such a project. Current traffic on the highway is stated as 153,000 vehicles per day, so on a per-vehicle basis it’s similar to Second Avenue Subway’s per-rider projection, around $23,000. But cars are not transit and cities need to understand that.

The construction of a subway creates noise and traffic disruption, but once the subway is up, all of that is done. Even elevated trains cause limited problems if built properly from materials that minimize noise – the trains on the viaducts on the Paris Metro are less noisy than the cars on the street below. There are operating costs involved with subways, but fixed costs are so dominant that even in New York a busy line like Second Avenue Subway should be at worst revenue-neutral net of costs; for reference, in Vancouver the projection for the Broadway subway extension’s operating costs is well below the revenue from the projected extra ridership.

Cars are not like that. They are noisy and polluting, and greenwashing them with a handful of expensive electric cars won’t change that. There are benefits to automobility, but the health hazards cancel out a lot of that. The Stern Review estimates the cost of unmitigated climate change at 20% of global GDP (e.g. PDF-p. 38), which in current terms approaches $500 per metric ton of CO2. The US has almost the same emissions intensity per dollar of production as the rest of the world; the negative impact of cars coming from climate change alone is comparable to the total private cost of transportation in the US, including buying the car, maintenance, fuel, etc. Now add car accidents, noise, and local air pollution.

In a region where cars are an absolute lifeline, there’s a case for building connections. The costs are low since grading a road for medium speed with level crossings is not expensive. In cities, the situation is different. Drivers will grumble if the BQE is removed. They will not lose access to critical services.

Is anyone proposing removing the BQE?

Yes, there are some proposals to that effect, but they’re so far only made haltingly. Council Speaker and 2021 mayoral frontrunner Corey Johnson’s report on municipal control of the subway includes the following line: “Before spending $4 billion to reconstruct a 1.5 mile stretch of highway, the City should study alternatives to the reconstruction of this Robert Moses-era six lane road, including the removal of the BQE in its entirety.” The halting part here is that to study does not mean to enact; Johnson himself opposes repurposing car lanes for bus service in his own district.

City Comptroller Scott Stringer, who has relied on a lot of the information I have brought up in this space in his reports, proposes to keep the BQE but only allow access to trucks. Bloomberg’s transportation commissioner Janette Sadik-Khan agrees with the idea and even pitches it as a brave alternative to the car. In other words, per the comptroller and former commissioner, billions of dollars are to be spent on the reconstruction of a somewhat narrower structure for 14,000 trucks per day. Stringer’s report even says that the comparable urban freeways that have been removed did not allow trucks in, which is incorrect for the Embarcadero Freeway in San Francisco and for the Voie Georges Pompidou in Paris (look for “camions” here). In reality, if closing the BQE means adding just 14,000 vehicles to surface streets, then it’s an almost unmitigated success of road dieting, since it means much less pollution and noise.

The Regional Plan Association proposes its usual quarter-measures as well, sold under the guise of “reimagining.” It does not mention closure at all – it proposes rebuilding the structure with four lanes, down from the current six, and even dares to cite the closure in Paris as precedent. Everything in its analysis points out to the benefits of full closure and yet the RPA feels too institutional to propose that. Presumably if the RPA had opined on lynchings in the midcentury American South it would have proposed a plan to cut total lynchings by 25% and if it had opined on Fourth Republic-era colonialism in Algeria it would have proposed to cut the incidence of torture by a third while referencing the positive precedent of British decolonization in India.

What should replace the BQE?

The BQE should be removed all the way from the Brooklyn-Battery Tunnel to the Williamsburg Bridge. Its curves in Downtown Brooklyn with the loops to the Brooklyn and Manhattan Bridges consume valuable real estate, and farther east they divide neighborhoods. The new Navy Yard developments are disconnected from the rest of Brooklyn because of the BQE.

Going east through Fort Greene, the BQE is flanked on both sides by Park Avenue. Buildings face the street, though many of the lots are empty or low-value. Thus, the surface streets have to stay. Selling what is now Park Avenue as parcels for residential and commercial development and mapping a street on the BQE’s 30-meter footprint is probably not viable. Instead, most of the footprint of the expressway should be parceled into lots and sold, converting Park Avenue into a one-way pair with streets about 12-15 meters in width each. East-west buses will continue running on Flushing and Myrtle, and north-south buses should probably not make stops at Park.

In contrast, going south through South Brooklyn, buildings do not face the abutting surface street, Hicks. They present blank walls, as if it was midblock. This is a prime opportunity to narrow the street as if the highway has never been there, creating an avenue perhaps 20 or 30 meters in width. The wider figure is more appropriate if there are plans for bus lanes and bike lanes; otherwise, if buses stay on Columbia, 20 is better.

In South Williamsburg, the road is nearly block-wide. The neighborhood is pro-development due to high birthrates among the Haredi population. Thus the footprint of the freeway must be used for private housing development. The area next to the Marcy Avenue subway station on the J/M/Z is especially desirable for the non-Haredi population, due to the proximity to Manhattan jobs. The city should retain an avenue-width roadway for Williamsburg Bridge access from the south, but beyond that it should restore the blocks of the neighborhood as they were before the BQE was built.

Heal, don’t placemake

If there’s a common thread to the various proposals by local politicians and shadow agencies (that is, the RPA), it’s an attempt at placemaking, defined to be any project that they can point to and say “I built that!”. A BQE rebuilt slightly narrower, or restricted to trucks, achieves that goal, with some greenwashing for what remains a waste of billions of dollars for motorist convenience.

But the same can be said of a park, as in one architect’s proposal for the BQE. I can see a case for this in Brooklyn Heights, where the Promenade is an important neighborhood destination, but elsewhere, the case is extraordinarily weak. In South Brooklyn, the most important benefit of removing the BQE is easier pedestrian access to the waterfront; recreation space should go there. Fort Greene and the Navy Yard are both rich in parks; BQE removal makes the large parks on both sides of the motorway easier to access. And Williamsburg is hungry for private development, whether near the subway for Manhattan workers or elsewhere for Haredi families.

Thirty years from now, nobody is going to walk on the remade street grid of South Williamsburg or the narrowed Hicks Street and wonder which politician set this up. But people may well notice the lower rents – and they may well notice them within a few years of the deconstruction of the road and the sale of the land for housing development. Ultimately city residents do notice if things are improving or deteriorating. It’s on the city to nudge infrastructure development in the direction of less pollution and fewer boondoggles.

The Boundary Between the Transit City and Auto-Oriented Suburbia

Public transportation use is higher in cities than in suburbs. Cities with stronger transit networks have larger transit-rich, auto-hostile cores, and some have good transit in lower-density suburbs, but ultimately the transit city has a limited radius, beyond which automobiles dominate. Successful examples of suburban transit, like Zurich, just keep the city-suburb gradient shallower than in other transit cities.

The most fascinating aspect of this is the boundary between the transit-oriented city and the auto-oriented suburbs. Uniquely in the metro area, the boundary region has good access by car as well as by transit, making it ideal for uses that want to interface with both modes of transportation. This specifically includes bus stations, stadiums, and big box retail, as well as more sporadic meeting points between urban and suburban residents.

Where the boundary is

Because the boundary zone is defined by good transit as well as highway access, it may not be the literal boundary as defined by modal split, car ownership, or any other metric of transportation usage. It can be the outer end of some rail line extending into the suburbs, and in that case it may be a salient into auto-oriented territory. There are a number of examples in the United States, where the postwar rapid transit projects have not been accompanied by much transit-oriented development, and thus their outer stations are in low-density suburbs where transit service functions as expensive S-Bahns. BART and most of the Washington Metro are like this, as are the suburban lines of the Boston subway.

For example, here is Newton Centre, on the Green Line D branch:

The light rail station is just to the left (south) of the street. This is a walkable suburban street with a train that comes pretty frequently all day, and yet the dominant mode of transportation here is clearly cars, as one can see in the parking lot to the left. Transit usage here is similar to the metro area’s average – Newton averages 11.9%, the Boston metro area 13.4% – but this says more about the rest of metro Boston than about Newton Centre. Nonetheless, such a location is convenient to access from the city if one lives near the Green Line, and is also reasonable convenient by car, as it is just 4 km from the freeway, and the majority of the distance is along the fast arterial that is Route 9.

The importance of highway access also works in reverse. In cities with strong transit networks and weak motorway network, there may be a freeway salient into the city, creating a zone that is car-friendlier than the rest. If it also has ample parking, which it usually does, then it will end up creating a boundary within an area that is on most metrics transit-oriented.

In London, the urban renewal zones around Stratford and Canary Wharf are examples – the city is unusually poor in freeway infrastructure, but two of the few radial motorways hit these two business districts. Here is Stratford:

The built-up density is high, and Stratford is one of the busiest Underground stations. But the roads are big for the city they’re in and there are large surface parking lots all over.

I’m deliberately including two examples with very different urban layouts and actual transit usage levels to hammer home the point that the boundary is defined merely by the existence of supportive infrastructure for both cars and public transit.

Can the entire city be friendly to both cars and public transit?

No.

There are several reasons for this. The first and most fundamental is that public transit is only successful if it can leverage scale. The adage frequency is freedom comes from this fact, but the same can be said about related issues of span, reach, and network effects. This is why frequency-ridership spirals are so dangerous – a small cut in service can lead to a much greater reduction in ridership.

The second reason is that drivers prefer a different urban layout from transit users, cyclists, and pedestrians. Cars are space-intensive on the road as well as on the parking lot, but can achieve high average speed if there’s no traffic, so they end up preferring spread-out development. Public and active transport are space-efficient but involve a lot of slow walking, so they prefer dense development at distinguished nodes with train stations, featuring strong commercial city centers with high job concentration. The boundary zone I speak of must be underlain by a strong enough transit network in the city core that people will fill the trains at all hours of day.

Concretely, neither the example of Newton nor that of Stratford can work citywide. Newton cannot work citywide because if every residential metro station is a parking lot, then nobody will ride the trains off-peak, and the city will de facto be exclusively auto-oriented as a result. Two years ago I compared the proportion of boardings at suburban stations that occur in the morning peak in New York (67% LIRR, 69% Metro-North) and Paris (46% on the SNCF network). Well, I would later find data for the Washington Metro, which has high off-peak frequency like the RER but low-density parking lot stations like the LIRR and Metro-North, and the proportion of riders in the morning peak is much closer to that of the LIRR than to that of the RER.

Likewise, Stratford can’t work citywide, because most of the city is not a reclaimed railyard with enormous space for all manners of new development. Building the expansive motorway network that would allow cars to rapidly reach every part of the city would normally require extensive neighborhood demolitions; American cities only managed to do so because to the road builders, destroying working-class (and often black) neighborhoods was a feature rather than a bug. Building a new city with ample road infrastructure is possible without this history, but then one gets Houston, hardly an example of good transit accessibility.

Land use at the boundary

The boundary zone’s unique accessibility by both cars and transit makes it ideally suited for land use that really wants both. Such land use has to have the following features:

  1. It needs to have a large regional draw, or else distinct neighborhood centers, some transit-oriented and some car-oriented, can do better.
  2. It needs to specifically benefit from good highway access, for example for deliveries, but also from good transit access.
  3. It is not so high-value that city center’s better transit access in multiple directions trumps access by transit in one direction and by cars in another.

Sporadic meetings satisfy all three criteria. For one personal example, in 2013 I visited New York and participated in a LARP taking place in a camp somewhere in Massachusetts, accessible only by car; I traveled with friends in the suburbs and we arranged that they would pick me up at Southeast, the northern end of the Metro-North Harlem Line’s electrification, so chosen because of its excellent multidirectional freeway access.

I bring up LARPing because it’s such a small community that it has to draw regionwide – in the case of the one I went to, participants came from all over Eastern New England and even beyond – and thus, anywhere with lower transit usage than New York, must appeal primarily to the driver, not the transit user. Nerdy conventions in general tend to either be enormous, like Comic-Con, or take place in cheap suburban edge city hotels, with meetings for carpools arranged at choice suburban train stations.

More common uses that like the boundary zones include major stadiums and big box retail. Stadiums appeal to a broad section of the population with little differentiation between city residents and suburbanites. They have to have good transit access even in auto-oriented American cities for reasons of capacity, but they also have to have good auto access for the use of drivers; stadiums are land-intensive enough that they can’t locate in city center at all, with its omnidirectional transit access, so instead they must be at the boundary zone. Thus Stratford hosts the London Stadium, the Stade de France is in Saint-Denis with good motorway as well as RER access, and Yankee Stadium is tucked at a corner of the Bronx with two subway lines and good expressway infrastructure.

Big box retail is more complicated – for one, its draw is so local that even a small city can support several Walmarts, Carrefours, and Aldis (Walmart is weak in big cities, but the big European retailers aren’t). Nonetheless, boundary zone stores exist: the big supermarket I’m most familiar with in Boston, Star Market at Porter, is on top of a subway station but also has a large parking lot, while the supermarket I shop at here in Berlin, Kaufland, is a two-story big box next to the Gesundbrunnen U- and S-Bahn station, with the ground floor devoted to parking.

I suspect the reason big box retail likes the boundary zone is that while it is local, there are extensive mixed areas rich in both drivers and non-drivers, where a big store must appeal to both in order to succeed. The Gesundbrunnen area is one of the city’s densest, but car ownership in Berlin is still higher than in Paris or New York. The same is true of the area around Porter Square in Cambridge and Somerville, albeit at lower density and with lower transit usage, so Star Market puts its parking on the surface rather than in a structure.

Bus station siting

The most interesting land use that prefers the boundary zone, and the origin of this post, is the intercity bus station. Here is Herbert in comments:

Can you do a post on the contradictory demands for the site of the main intercity bus station?

On the one hand, it is desirable that it is within easy reach from the highway. On the other hand it should be as close to downtown as possible and also easily reachable by public transit. And last but not least there should of possible be one interchange station for every city for connecting passengers.

It’s almost impossible to find a site that goes all requirements. Berlin ZOB certainly doesn’t…

Whereas train stations have obvious preferred sites – the central business district – bus stations have to balance centrality with highway access. In Paris, this is Gallieni. This station is just outside the city at the end of Metro Line 3, where the Boulevard Peripherique meets the A3 autoroute, which connects to further motorways with good access to the north, south, and east. Like Stade de France, Gallieni is a salient of the auto-oriented suburbs almost into city limits, in inner suburbs with high public transit usage.

In New York, there are a few sites that would work fine, but each points in a different direction, making interchange difficult. Port Authority is excellent for buses going to New Jersey and points west and south, and curbside buses tend to pick up in that general area as well, often near Hudson Yards; this is facilitated by a unique situation in which the Lincoln Tunnel has a dedicated inbound bus lane in the morning peak, which many area transit activists wish existed in both directions all day. Buses to Boston could depart from Yankee Stadium, which also benefits from being just beyond the outer end of subway express service, so that travel speeds to Manhattan are faster. However, in practice they depart from the same curbside location on the Far West Side as the buses to Philadelphia and Washington, frustrating riders who see their bus spend an hour in city traffic.

The situation of New York is unusual in that it is located next to two wide rivers with few crossings, and thus does not have a proper orbital motorway with a location like Gallieni. But New York is not unique in having difficult bus station siting choices. London has the same problem: for one, the M25 orbital is so far out of the city; and perhaps more importantly, British buses are priced cheaper than trains in order to control crowding levels on trains to London, and thus dumping bus passengers on a regional train to Central London would be strictly worse than just letting them ride the train the entire way for a reasonable fare.