Category: Urbanism

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.

Stroads and Strails

In 2011, Chuck Marohn of Strong Towns coined the word stroad for a street that functions as a road. Chuck argues that there should be a separation between streets, which are destinations in and of themselves and are to be lined with walkable retail, and roads, which exist to move people between destinations. In contrast, auto-oriented arterials function as both: they are designed for high speed for through-traffic but also have extensive streetside destinations built at automobile scale, hence the portmanteau stroad.

In the last seven years this mentality has become quite popular within online urbanist circles. Unfortunately, it misses why major streets arise in the first place. Moreover, this is not just an issue for cars and car traffic – other modes of transportation want to funnel local and interregional traffic through the same corridors, creating a number of arteries that are in essence strails, like the Berlin S-Bahn. Good planning has to recognize that where people to go through and where people want to go to are often the same, and provide road and rail infrastructure of sufficient size to accommodate.

What is a street, anyway?

The main purpose of a city street is to connect destinations within the city. Major streets routinely form out of trails, post roads, and turnpikes connecting the city with villages that it swallows as it industrializes and grows. Broadway in New York started out as an Indian trail, the Strand grew as a road connecting London with Westminster and had previously been part of an intercity Roman road, Champs Elysees was built as a promenade into the periphery of Paris and gradually filled in with palaces, the Sveavägen/Götgatan axis goes back to the Early Modern era with connections from Stockholm to Roslag to the north and Götland in the south.

Not every street has this intercity or suburban history, but the important ones frequently do. The Manhattan grid was mapped as an entirely urban street network, but the wide north-south avenues were designed for easy access to the Lower Manhattan core from future residential areas. In ungridded cities, usually you can tell which streets are the oldest because they are longer, more continuous, and more commercially developed, and the exceptions come from heavyhanded state planning, like the shift from Rue Saint-Jacques to Boulevard Saint-Michel in Haussmannian Paris.

The importance of through-streets within cities continues even today, and even when cars are not too relevant. People who walk or take transit are likelier to do so on the main streets, and as a result, businesses prefer locating there. In Manhattan there’s even an expression for this: avenue rents versus street rents. In Vancouver, I could walk on any street, but crossing wasn’t any harder on the main streets than on the side streets, and there was more interesting stuff to look at on the main streets; even ignoring zoning, retail would prefer to locate on the main streets because that’s where all the other retail is. There’s a wealth of good restaurants I discovered just by walking next to them, to say nothing of the gaming store on 4th Avenue near MacDonald, which I saw from the bus to UBC.

All of this is magnified in cities that do not have consistent grids, like Paris, Berlin, and even Stockholm. In those cities, zoning does not micromanage use as much as in North America, and yet businesses locate on major streets where possible. Here is a map of the area I live in: the green dot is where I live, and the red dot is a government office I went to last week to register.

Walking east or west, I exclusively use Bernauer Strasse, the street the M10 tramway runs on; walking north or south, I use Brunnen Strasse, which hosts U8. Other streets can function as shortcuts, but with parks and small changes interrupting the grid, they’re less reliable for through-walking. And indeed, they are much quieter and largely residential, with retail mostly at street corners.

The invention of the stroad

The early American roads connected distinct cities, or linked cities with rural hinterlands. Within the cities, they fed preexisting arterial streets. For the most part these arterial streets were fairly wide – they were mapped in the 19th century based on 19th-century design standards, often 30 meters of width, rather than the narrow medieval streets London is famous for – but they still filled with cars fast. Two parking lanes and four moving lanes in a dense city with busy crossings aren’t much. American cities had traffic jams in the 1920s already.

My two go-to references about the history of American roadbuilding – Owen Gutfreund’s 20th-Century Sprawl, and Earl Swift’s The Big Roads – both explain what happened beginning in the 1920s: cities built bypasses. The idea was that the bypasses would segregate through-traffic from urban traffic, separating roads from streets properly.

This never happened. For the same reason preindustrial roads turned into busy streets, bypasses turned into busy auto-oriented streets. Retailers found that the best place to locate was where all the cars were. These bypasses became congested roads themselves, partly due to the induced auto-oriented development and partly due to general growth in car traffic volumes. This trend intensified after WW2, with the freeways leading another cycle of bypasses around congested urban roads becoming congested with urban traffic themselves. Wal-Mart and Carrefour invented the hypermarket in 1962-3, and in the 1960s office space began suburbanizing as well, since traffic conditions were better than in congested city centers.

This is not an obscure history, and Chuck is fully aware of it: among his complaints about stroads is that they reduce the tax base of the city by encouraging retail to decamp for the suburbs. He just fails to follow this through to the logical conclusion: the most intense demand for real estate is near the busiest through-routes. There is no real separation between the street and the road; the best you can do for walkability is run better public transit to the urban core and make sure the roads have street-facing retail rather than front parking lots.

Strails

The principle that the best place for local traffic is where long-distance traffic is is equally true of trains. An intermediate station on an intercity railway sited a convenient commute away from the city will soon fill with suburban travelers. The term commuter itself derives from the discounted commutation tickets American intercity railroads offered regular riders, starting in New York and Boston in the middle of the 19th century.

19th-century railways were not a complex system of branched lines dedicated to regional traffic. Such lines existed, for example the Ligne de Saint-Germain-en-Laye, now part of the RER A, but most of the lines continued onward to long-distance destinations, or had been built with the intention of continuing so. Look at this map of extant London-area railways by year of construction: there aren’t that many branches predating the Late Victorian era, and the branches that do exist tend to be reverse-branches in South London offering service to either a City station like Cannon Street or Blackfriars or a West End station like Victoria. The remainder are loop lines, built to offer four tracks’ worth of capacity on lines that had originally been built with only two, but then both routes filled with local traffic, making it harder to schedule express trains; for an example easily visible on the map, see the Lea Valley lines connecting to Cheshunt.

In contrast with the London loop lines, Prussian State Railways made sure to rebuild the Ringbahn and Stadtbahn to have adequate capacity, that is four tracks, two for local service and two for longer-distance service; the Ringbahn had initially been built with two tracks, but would be expanded to four in the 1880s and 90s. But even here, there are seams. German Wikipedia explains that the Stadtbahn had to take a less desirable route to avoid expensive takings on Leipziger Strasse, and has a winding route with S-curves between Alexanderplatz and Jannowitz Brücke. Moreover, some individual branches only have two tracks even if they are the best intercity routes: the S2 route is the most direct route to Dresden, but with two tracks, heavy local traffic, and only DC electrification, it cannot host intercity trains, and thus intercity trains to Dresden spend 20 minutes out of a 2-hour trip getting around this line.

Berlin at least has the good fortune that four tracks here are enough. Tokyo is so big and strongly-centered that it has ten tracks going south of Tokyo on the Tokaido Line and eight going north on the Tohoku Line, including four for local service, two for Shinkansen service, and two or four for medium-distance express regional trains. Widening railways to serve city centers is expensive, and only done when absolutely necessary, and yet JR East spent considerable money on widening the innermost Tohoku trunk from six to eight tracks.

Even high-speed rail can induce the same development effect as a freeway. It doesn’t have closely-spaced stations, but people might demand stations as a mitigation of construction impact and train noise. The Tohoku Shinkansen diverges from the Tohoku Main Line a few kilometers north of Tokyo, but the local communities demanded local service as well as a mitigation, and as a result Japan National Railways built a four-track line, with two Shinkansen tracks and two local tracks for the Saikyo Line.

Main streets want to be everything

Major streets are the best location for every destination and every mode of transportation. This extends beyond walking. Buses prefer wide streets optimized for higher traffic speed – and the few main streets that are not so optimized, such as the Manhattan crosstown streets (since traffic is optimized for north-south avenue throughput), have buses that win awards for how slow they are. Bicyclists prefer riding on major streets as well, which is why Copenhagen prioritizes bike infrastructure on major streets rather than on side streets – on side streets car traffic is so light and slow that mixed traffic is not so bad, but the desirable through-routes remain the major streets.

The problem is that every mode of transportation requires some piece of the street, whereas street width is finite. Brunnen Strasse is 40 meters wide, and hosts very wide sidewalks including a dedicated path for on-sidewalk cycling, a combination of parallel and angled parking, two moving lanes in each direction, and a generous road median. Even that width does not include dedicated public transit infrastructure: U8 runs underneath the street, leaving the street’s width for sidewalks and roadways.

The same situation occurs on railroads: all uses want the same piece of infrastructure, leading to the usual problems of mixing trains of different speed classes on the same tracks. Freight bypasses are possible, but passenger bypasses are rare – train passengers tend to want to go to the city rather than to some suburb, and unlike cars, trains have prescribed stop patterns. By rail as by road, bigger infrastructure is needed: four tracks for a mixed local and interregional railway, or about 36-40 meters or even more on a main street.

Wide enough streets don’t exist everywhere. New England streets are narrow. Midwestern streets are wider, but at least the one I’m most familiar with, Ann Arbor’s Washtenaw Avenue, is only around 25 meters wide – it only gets up to 40 if one includes setbacks. Road widening would be needed, which is exactly the opposite of what the Strong Towns approach prescribes. Cities this small could mix decent local and intercity rail service on two tracks with timed overtakes, but that would require them to run any passenger rail service to begin with, and to make sure to have enough development near the stations, both residential and commercial, that people would ride the trains.

But on a 30-meter wide street, something has to give. There simply is not enough room for everything. Give pedestrians their 4 or 5 meters of sidewalk in each direction, cyclists their 2 meters of bike lane, and cars their parking lane and two moving lanes, and you’re already at 30-32 meters. You can go with complete streets and reduce the extent of car infrastructure, for example by turning a moving lane per direction into a bus or tram lane, or by getting rid of street parking, but unless you’re in a city with high transit mode share, you’re driving away eyeballs from retailers. Paris can definitely do it, New York and Berlin can do it, even Boston can do it. Can a small American city where planners aspire to run a handful of buses every 15 minutes do it? Probably not.

Technology and Public Transit

I have noticed a trend in tech media in the last few years: people assert that new technology is about to make public transportation and the walkable urbanism that underlies it obsolete, and therefore it’s a waste of time to invest in the latter. The top examples of this are ride-hailing apps and autonomous cars, but electric cars are also a common excuse not to build urban rail. In addition, there are knock-on effects, causing transit agencies to neglect core functions like good service in favor of tech gimmicks, like Andrew Cuomo’s genius challenge.

In contrast, I’d like to present two much-anticipated technological changes that have the opposite effect: they should make the case for public transit easier. In no case is this directly about public transportation. Rather, it’s about making it easier to design cities for the exclusive use of pedestrians, cyclists, and public transit riders. One of these changes is still in the proof-of-concept stage; the other is already happening, and it’s on cities to capitalize on it.

Drone delivery

There is ongoing experimentation about using aerial drones to deliver goods. The examples Wikipedia has are high-value, low-weight, such as passports and drugs. The current state of technology is such that delivering such goods by drone is feasible, though not yet at commercial scale, but there is research into bigger drones.

The impact of drone delivery is on how cities are built for freight movement. All freight transportation in cities today is done by truck, except for the occasional low-end bike delivery. Rail freight is completely infeasible: it operates at long ranges – in fact, two papers, one by Vassallo-Fagan and one by Furtado, find that 45% of the difference in rail freight modal share between the US and Europe is an artifact of longer distance for inland transportation in the US. Moreover, whatever rail freight exists is of low value – in the US, rail had 4% of the total value of goods shipped and 47% of ton-km in 2002. The stuff drones can plausibly carry goes by truck at any distance today.

So the potential is there for drones to take some of the most critical goods away from trucks, reducing city truck traffic, and with it, the demand for car-friendly street design. The socioeconomic class most opposed to giving public transit higher priority (at least in New York), the shopkeepers, cites deliveries as the primary reason to maintain curbside access.

Of note, drone delivery is also useful for rural areas with bad roads – it makes goods more easily available there. The likely effect of widespread drone delivery on urbanity has two components: reducing the consumption amenities of cities, since a more efficient transportation network makes it easier to ship goods to remote areas; and increasing the production amenities of cities, since it’s easier to design cities for maximum transportation efficiency of people, not to mention the office jobs created by the need to maintain drone software (the latter point also made by Masahita Fujita re new economic geography).

Automation of manufacturing

The increase in automation of manufacturing means that manufacturing employment is trending down. This is not an artifact of offshoring: Dani Rodrik’s paper about premature deindustrialization finds that the share of manufacturing in total employment is trending down in a large variety of poor and middle-income countries, and even in South Korea the manufacturing share peaked in 1989. Rather, there is a shift in the nature of low- and medium-skill work away from industry and toward services.

This is good for any attempt to get people to commute by public transit. Factories have not been conducive to public transportation for a hundred years. Electrification has encouraged single-story atria with plenty of space, replacing cramped multistory buildings like the Triangle Shirtwaist Factory. Moreover, the rise of trucking has meant that the best site for a factory is one with very good highway access. The industrial site of the last few generations is not walkable, and any worker who earns enough to drive will. Serving such a site by transit is in theory possible, but employment is so spread out that the bus or train would underperform.

But today, manufacturing is increasingly irrelevant to commuting. Working-class employment concentrates in areas that are part of the middle class’s regular travel routine: hotels, casinos, and airports are destinations for middle-class travelers, shopping centers are destinations for middle-class consumers, hospitals and universities are large employers across all social classes from professors down to unskilled workers. With the exception of airports, these destinations are already fairly walkable or at least can be built this way, and in some cases, like that of the French Riviera, this could lead to public transit serving the working class better than the middle class.

In most of the top transit cities in the developed world, this process has already run its course. There is practically no industry left in New York, London, and Paris. But it does matter to some cities, such as Singapore, with its vast port with no passenger rail service. Los Angeles is not a transit city and it’s not because it has relatively high industrial employment for an American city, but the high manufacturing concentration does not help. Understanding that these jobs are slowly disappearing, not from one country but from the world, will help cities plan accordingly, especially in lower- and middle-income countries.

Public Transit is Greener Than It Seems

The main way to judge how good public transportation is for the environment is to measure how many car trips it displaces. But in reality, it’s better, and I’d like to explain why. As a warning, this is a theoretical rather than empirical post. My main empirical evidence for it is that European car usage is lower relative to American levels than one might expect given public transit mode shares; in a way, it’s an explanation for why this is the case.

While the explanation relies on changes in land use, it is not purely a story of zoning. The population density in much of my example case of auto-oriented density – Southern California – is well below the maximum permitted by zoning, thanks to the lack of good transit alternatives. Thus, even keeping zoning regimes mostly as they are, public transportation has an impact on land use and therefore on car pollution.

Transit always displaces the longest car commutes

In an auto-oriented city, the limiting factor to the metro area’s density is car traffic. Adding density with cars alone leads to extra congestion. Devin Bunten’s paper entitled Is the Rent Too High? finds that, assuming no changes in travel behavior (including no change in the option of public transit), zoning abolition would actually reduce American welfare by 6%, even while increasing GDP by 6%, because of much worse congestion; optimal upzoning would increase GDP by 2.1% and welfare by 1.4%, which figures are lower than in the Hsieh-Moretti model.

The upshot is that if there is no public transportation, people live at low density just because the alternative is the traffic jams of dense car-oriented cities; Los Angeles is the most familiar American example, but middle-income examples like Bangkok are denser and worse for it. Low density means people travel longer to reach their jobs, by car, increasing total vehicle travel.

In the presence of mass transit, people don’t have to sprawl so far out. Los Angeles’s “drive until you qualify” mentality is such that, if there were room for a million transit users in the inner parts of the region, then no matter which exact group of million people from the five-county area started taking transit, ultimately the shuffle would be such that there would be a million fewer people driving in from Antelope Valley, Victor Valley, and the Inland Empire.

The model

Consider a city that comprises concentric rings, as in the following diagram:

The average density of the city region is 1,660 people per square kilometer, and the weighted density is about 3,400; both figures are typical for the denser American Sunbelt cities, like Los Angeles, San Diego, Miami, and Las Vegas (see table as of 2000 here).

Let us assume that the amount of v-km per inhabitant within each concentric circle is proportional to the outer radius of the circle, so people in the outermost ring drive 5 times as long as those in the inner circle. For concrete numbers, let us assume these figures are 5,000, 10,000, 15,000, 20,000, and 25,000 v-km per year; they average about 13,550 v-km/capita, which is somewhat less than the US average, just below 16,000 per FRED. Note that the outermost ring has 10.8% of the city’s population and 20% of its v-km.

If the modeled density is close to optimal for congestion management given the current state of public transit, then adding transit means subtracting people from the outer ring, not from the inner rings. Say the city builds rapid transit reaching the inner two rings, allowing these areas to densify by exactly 22.5%, which is the ratio of the outer ring’s population to the inner two’s total’s. The total non-auto mode share will rise by 10.8 percentage points, divided between public transit and walking because people in dense, walkable neighborhoods have the option of non-motorized transport; but v-km and the attending greenhouse gas emissions will fall 20%.

If the city keeps growing, the situation is even more extreme. We can add a sixth ring, on the same model, with a density of 250 people per km^2, 30,000 annual v-km per capita, and population equal to 6.6% of the total of the five existing rings or 6.2% of the six-ring total. This 6.6% increase in population raises v-km by 14.7%; in contrast, a transit system capable of supporting this population increase would show an increase of 6.2 points in the non-auto mode share even while avoiding a 14.7% increase in car traffic.

European car usage

We can obtain total v-km per capita by country from a table of traffic accident fatalities: the OECD reports numbers per capita and per v-km, so if we go to PDF-p. 60 of its report, divide the per-capita figure by the per-v-km figure, and multiply by a scaling factor of 10,000, we get v-km per capita. In the US, this figure is just short of 16,000, just as in the FRED graph. The US’s transit mode share for work trips is 5%, so this is about as close as possible to a purely auto-oriented country.

In the Western European countries for which there’s data, including France and Germany, the figure is just short of 10,000. This is close to INSEE’s figure of 756 billion passenger-km in 2016, the difference accounted for by the fact that sometimes multiple people ride in the same car.

The reason people here travel 40% less by car than in the US is not that they instead travel the same distance by public transit. INSEE reports 132 billion passenger-km in buses, trams, and trains excluding TGVs in 2016, and this includes a fair amount of intercity bus and rail travel (9 billion p-km on intercity rail as of 2010 per p. 53 here). Overall, the French modal split is 70% car, 15% transit, 6.7% walk, 4.3% work from home, 4% bike and motorcycle. The American one is 85% car, 5% transit, 2.7% walk, 5.2% work from home. Even relative to the volume of car commuters, the Americans drive 40% further than the French.

Much of my understanding of how provincial France works comes from the Riviera. The Riviera is not the best representative: Alpes-Maritimes is among the richest departments outside Ile-de-France, is among the most conservative, and near-ties Toulouse’s Haute-Garonne and Strasbourg’s Bas-Rhin for third highest provincial transit mode share (13%, behind Rhone’s 23% and Bouches-du-Rhone’s 14%). But it’s a good representative nonetheless of a major provincial city region. There, the coastal towns as well as some interior ones are filled with sprawl, even going up the mountains. There is density in Monaco and Nice, and public transit ridership mostly consists primarily of people who live in Nice and secondarily of people who commute to Monaco. It’s the tramway, the buses, and the general walkability that permit Nice to be what it is, coexisting alongside the offices parks of Sophia-Antipolis and the low-density sprawl up the mountains.

What about zoning?

Devin’s paper is about the economic cost of zoning. Even with the assumption of no change in built form or in transportation modal choice, it does find welfare gains from upzoning, saying that high-demand areas would gain 10-15% in population. This implies that realizing the full environmental gains from public transit requires upzoning areas near stations, to permit the inner two rings in my model city to gain residents who would have otherwise populated a sixth ring.

And yet, the appropriate zoning to some extent already exists. California abolished single-family zoning in 2016 and 2017: accessory dwelling units, or ADUs, are permitted anywhere that residential development is permitted, and homeowners are free to build ADUs in their backyards or carve out ADUs out of their existing buildings. Moreover, in select zones, cities have encouraged transit-oriented development through upzoning or relaxing parking minimums: San Francisco’s TDM process abolished parking minimums anywhere that buildings with at least 10 apartments are permitted, and San Diego slashed parking minimums in an attempt to encourage TOD in North Park along the University Avenue corridor.

The results of TDM in San Francisco are still unclear – the program passed too recently. The same is true of ADUs – existing homeowners react slowly, and new developers may build more two-family houses and fewer single-family houses, but new tract housing would go in the exurbs, not in the coastal cities. But in San Diego the results are clear: developers build more parking than the required minimum at University and 30th, because the public transit option there is a north-south bus that comes every 15 minutes and an east-west bus that comes every 10, which is not actually enough to persuade people who can afford a car not to drive one.

Conclusion

It is difficult to build TOD without public transport. The urban middle class of the 21st century expects travel convenience, which can come in the form of a large rapid transit network or in that of cars and freeways. Thus, even when development sites are available, even in expensive cities, developers sometimes build less than they are allowed to, or insist on more parking than is required, if alternative transportation is inadequate.

The upshot is that adding the layer of transit is likely to stimulate development in the affected urban neighborhoods. The people who would live in this development would not otherwise drive to the outer margin of the city to save on rent, but they would still drive, displacing people would then drive further. The exact details of the churn matter less than the net impact, which is that absent urban transit, cities end up sprawling farther out, forcing people to drive ever-longer distances to work and to other destinations.

A city that succeeds in replacing half of its car trips by public transit, such as Paris, will end up replacing far more than just half of its vehicle-km by transit. Even if the trains are densest within the city core, as is the case even in Paris and other cities with expansive regional rail, the net impact of the transit network is reduction in car travel in the outer parts of the built-up area, where distances are the longest. Planetoscope’s figures for car travel and average distance in Ile-de-France point to a total of just 2,900 v-km/capita in this region – less than one third the national average, and barely one half the national average per car commuter.

The benefit of transit thus goes well beyond the people who use it. The car trips it displaces, even if indirectly, are the ones that cause the worst problems – congestion, pollution, car accidents, greenhouse gas emissions – because they are the longest. Building urban rapid transit can have twice the direct mitigating effect on the harms of car travel as might appear based purely on counting mode choice. With twice the apparent positive environmental impact, mass transit must become a higher priority: nearly every new rapid transit line that’s judged as good must be a top priority for public investment, and many projects that appear marginal must be reevaluated and constructed as planned.

Difficult Urban Geography Part 2: Hilly Topography

This is the second and last part of a series about difficult urban geography for public transit, following a Patreon poll. Part 1 covers narrow streets.

A few years ago, Sandy Johnston remarked that Jerusalem had the least gridded street network he ever saw, and this complicates any surface transit planning there. At the time he was familiar with New England already, but Jerusalem seemed different.

Here are street maps of West Jerusalem and Boston, at the same scale:

Boston has some gridded sub-areas, like Back Bay, but Downtown Boston is as messy as Jerusalem, and on the level of arterial streets, even the rest of the city isn’t too different. The real issue affecting Jerusalem is the hilly topography. Once one gets out of the core of West Jerusalem, the city turns into a mess of hills with internal street networks and poor connectivity between them. Boston maintains a coherent structure of arterial streets that host buses and tramways, with a cobweb structure that feeds the subway efficiently; in Jerusalem, there is little chance of that.

Surface vs. rapid transit

Rapid transit is mostly insensitive to hills. A subway can be built across hills, partly underground, partly elevated. This is the case in Upper Manhattan, where the 1 train runs in a mix of cut-and-cover subway, elevated structures, and mined deep-level tunnel.

Even if the hills slope down into the natural arterial, this is not such a problem. Train stations can incorporate escalator access and have exits at different elevations. New York manages this in the same neighborhood where the 1 runs, in Washington Heights, on the A train. Monaco, on a sloping hill, manages the same at its train station, which is located underground, using elevator access from multiple neighborhoods at different altitudes.

The deep mining required for such construction doesn’t even raise costs that much. If it’s possible to secure horizontal access to the station site, construction becomes easier. Moreover, running elevated through the valleys, as the 1 does in Manhattan Valley and Inwood, cuts costs rather than increasing them.

Evidently, the hilliness of Rome has not prevented the city from building a subway. Line C’s construction costs were very high, but not because of topography but because of millennia-old archeology, which is not really a question of the street network.

Since rapid transit is not affected as much by hills as surface transit, a city with hilly topography should be biased toward rapid transit and against surface transit. This does not mean every flat city should be content with surface transit and every steep city should build subways and els, but it does mean that the population and density thresholds for rapid transit are smaller in hillier cities.

Pod development

Some cities are very hilly, but this does not affect their street networks. San Francisco is famous for this: north of Market, in neighborhoods like Telegraph Hill and Russian Hill, the street grid continues mostly uninterrupted, and the result is famously steep streets. In these cities, transit network planning need not pay much attention to the topography: the only concession that need be made is that agencies should preferentially electrify and run trolleybuses, which have better hill-climbing performance than diesel buses – as San Francisco Muni in fact has, retaining trolleybuses rather than replacing them with diesels as nearly all other American cities have.

The more interesting and difficult case is when the street network respects the hills. It can naturally turn the city’s street layout into that of multiple distinct pods, each surrounding a different hill. This is popular in Jerusalem, especially the settlements within East Jerusalem, but also in some of the newer parts of West Jerusalem. There is not much connectivity between these different pods: there may be a single arterial road with the rest of the city, as is the case for the settlements of Pisgat Ze’ev, Ramot, and Ramat Shlomo.

This kind of pod development is popular in a lot of auto-oriented suburbia. The cul-de-sac is a defining feature of many an American suburb. However, in Jerusalem we see it happen even in the context of a dense city: Jerusalem proper has a density of 7,200 people per square kilometer, and all the settlements in question are within the jurisdiction of the city. It comes out of a combination of modernist central planning (Israeli neighborhoods and cities are designed top-down, rather than expanding piecemeal as in North America or France) and the hilly terrain.

Transit planning for such a city is a chore. In theory, choke points are good for transit, because they have high intensity of travel, where dedicated lanes can make buses very efficient. In practice, choke points work for transit only when there are coherent corridors on both sides for the buses to feed. For example, on a wide river spanned by few bridges, buses can run on the bridges, and then continue on the arterials feeding them on either side. Pod development, in contrast, has no coherent arterials within each pod, just collector roads feeding the main drag. Buses can still run on these streets, but there is no structure to the density that encourages them to serve particular locations and not others.

One solution is a type of transit that is overused in flatter cities: the direct express bus, or open BRT. This bus runs local within each pod and then continues on the arterial, making few stops; it could run as open BRT if the arterial has enough development to justify such service, or as a nonstop express service if it is a full freeway. This form of transit developed for both low-density American suburbia and Israeli pod development towns (where this is buttressed by the tendency of the ultra-Orthodox to travel in large families, in which case transfer penalties are much higher, encouraging low-frequency direct service).

Another solution is to go in the air. Gondola lifts are seeing increasing use in extremely hilly cities, where surface transit must wend its way through switchbacks. Medellin’s Metrocable has a vertical rise of 400 meters. Even in cities that are less steep, gondolas could be a solution if arterial roads are simply not available. In the Arab neighborhoods of East Jerusalem, arterials are rarely available, and gondolas bridging ravines could be of use. Gondolas could also be useful for neighborhoods that are only connected by arterial in a radial rather than circumferential direction – they could again bridge ravines to connect peripheral neighborhoods to one another rather than just to the center.

When Transit Serves the Poor Better Than the Rich

In major transit cities, rich areas have better access to public transportation than poor areas – in fact, what makes them valuable is precisely the easy access to high-paying jobs. Even in cities with bad transit, this is often the case: the transit systems of cities with mode shares in the 10-15% area, like Boston and Chicago, tend to be good at serving city center and little else, and city center workers tend to be richer because professional work tends to cluster whereas low-skill work tends to disperse.

However, there are exceptions to this rule. One, the French Riviera, occurs in a city region with a transit mode share of 13%, comparable to that of American city regions where transit commuters outearn solo drivers. Two more cities are would-be exceptions, for opposite reasons: Providence has no public transit to speak of, but if it invested in creating a transit network, the natural corridors would serve the poor better than the rich; and Vancouver currently has better SkyTrain service in working-class areas than in richer ones, but its current investment is in middle-class areas, and moreover its extensive transit-oriented development has been middle-class as well.

Moreover, all three cities have patterns that generalize. The situation in the Riviera arises because of the classed nature of work there, and generalizes to other places with extensive tourism. That in Providence arises because of the city’s industrial history, and may generalize to other deindustrialized small cities with underutilized legacy rail networks. In Vancouver, part of this situation is because easy rail corridors were more readily available in poorer areas for an essentially random reason, but another part is extensive transit-oriented development concentrating working-class jobs near train stations.

The Riviera: the casinos are walkable, the tech jobs aren’t

Before I go any further, I’d like to stress something important: my observation of the Riviera is largely based on qualitative observations. I don’t know of INSEE data comparable to the Census Bureau’s Means of Transportation to Work by Selected Characteristics table, which could allow me to test the theory that transit ridership in the Riviera skews poor. All I am going by is what I have seen riding trains and occasionally buses as well as what I know of the distribution of jobs.

What I’ve seen is that transit use in the Riviera skews working class. Middle-class Parisians sometimes drive and sometimes take the trains. In contrast, the rich people who I’ve met in the Riviera have as far as I can tell never set foot on the TER. This is despite the fact that the TER is competitive with driving on the area’s main arterial road, the Moyenne Corniche, and is even competitive with the A8 freeway over short distances because the A8 has difficult access time to the relevant exits. Not for nothing, train stations in rich areas have very little ridership: per SNCF’s ridership data, stations in rich areas like Cap d’Ail and Cap Martin-Roquebrune have around 60,000 boardings plus alightings per year, so around 100 weekday boardings, whereas in working- and lower-middle-class Menton the annual total is 1.4 million, or around 2,300 weekday boardings.

The train stations, too, signal poverty. They’re not neglected, but what I’ve seen of them reminded me of working-class suburbs of Paris like Boissy much more than middle-class ones like Bures-sur-Yvette. I was even warned off of spending too much time near Nice’s train station by people echoing local middle-class prejudices. The buses look even poorer: the main east-west bus on the Moyenne Corniche is full of migrant workers.

A key clue for what is happening can be found when selecting a destination station at the fare machines in Menton. As far as I remember, the first option given is not Nice, but Monaco. SNCF’s data table doesn’t include ridership for Monaco, but Wikipedia claims 5.5 million a year without citation, and SNCF’s own blurb claims more than 6 million. Either figure is narrowly behind Nice’s 6.9 million for second in the Riviera and well ahead of third-place Cannes’s 3.2 million – and Nice also has some intercity traffic.

While Monaco’s residents are rich, its commuters are not. There are no corporate jobs in Monaco, because its tax haven status does not extend to corporations with substantial sales outside the city-state, only to local businesses like restaurants and stores. The commuters work low-pay service jobs at hotels and casinos, which they access by train, or perhaps on foot if they live in Beausoleil, as many a domestic service worker in Monaco does.

In contrast, the mass of middle-class jobs cluster in a purpose-built edge city in Antibes, called Sophia-Antipolis. While Antibes itself has a decent transit mode share for residents (10.5%, cf. Menton’s 14.8% and Nice’s 25.4%), and its train station gets 1.6 million annual boardings and alightings, the edge city is unwalkable and far from the train. There’s some traffic in the Riviera, but not enough that middle-class people, who can afford cars, clamor for transit alternatives to their suburban jobs.

The main lesson here is that while the jobs most likely to cluster are usually middle-class city center jobs, working-class tourism jobs cluster as well in regions that have plenty of them. Tourism in the Riviera is the most intense in Monaco specifically and in other coastal cities generally, which encourages travel along the linear corridor, where rail shines. It’s usually hard to see, because for the most part the top tourist destinations are enormous like London, Paris, and New York, but in specialized tourist regions the separation is clearer.

Already we see some evidence of this in Las Vegas, where working-class jobs cluster along the Strip. The city has a monorail, serving the hotels and casinos rather than city center. Were it interested in improving public transportation, it could build an elevated railroad on the Strip itself for better service.

Orlando is another potential example. I named it as a specific example of a region that would be difficult to retrofit for public transit earlier this year, but Disney World remains a major clustering of working-class jobs as well as some middle-class leisure travel. The problem there is that Disney World is far from the train and, unlike the Riviera, does not lie on any line with other potential ridership draws; nonetheless, a train connecting the Orlando CBD, the airport, and Disney World could get some traffic.

Finally, picturesque mountain resorts that happen to lie near rail could see working-class travel on the train to their tourism jobs. Many of these resorts are where they are specifically because a legacy rail trunk happened to be there and the railroad developed the area to generate demand for its services; this is the case for Jasper, Lake Louise, and Banff, all on the Alberta side of the Continental Divide. Aspen is not on a railroad, but is on a road where buses carry working-class commuters displaced by the town’s high housing costs.

Providence: once upon a time, there were factories near the railroad

When I lived in Providence seven years ago, I discussed transit improvements with local urbanists who I met through Greater City: Providence. We talked about improvements to both bus and rail; we had little appetite for the proposed city center streetcar, which has since been downgraded to a proposed frequent bus, and instead talked about improvements to the busiest buses as well as rail service along the main spine of the Northeast Corridor.

The improvements to the busiest buses were already under discussion by the state, including signal priority on key routes and investment in queue jump lanes and shelter amenities. The two routes that were by far the state’s busiest, the 99 on North Main and 11 on Broad, were permanently combined to a single through-running service branded as the R bus, for rapid, with limited-stop service. These routes serve very poor parts of the built-up area, including Pawtucket on the 99 and South Providence on the 11. This is a consequence of the fact that transit in Rhode Island is so bad that only the poor use it, and thus the preexisting busy routes serve poor areas; the best physical bus infrastructure is a bus tunnel to College Hill, the richest neighborhood in the city, but ridership there is weak and therefore the routes were never high priorities for further investment.

The improvements to rail never went beyond blogging; we didn’t have the pull of Boston’s TransitMatters, which itself is better at proposing small improvements than big ones that go up against political obstruction. What we called for was frequent local rail within the urban area: Peter Brassard wrote up the initial proposal, and I added some refinements. The Northeast Corridor, where the service would run, is primarily an intercity rail corridor, but there is room for four tracks in the right-of-way, and while there is freight traffic, it runs at the same approximate speed of a local passenger train.

As we discussed this proposal, Greater City’s Jef Nickerson noted something: what the train would do if implemented is produce better transit service in working-class areas than in more comfortable ones. Unlike the situation with the buses, this was not an intentional process. We would like Rhode Island to improve rail service using an existing right-of-way, which happens to serve Central Falls, Pawtucket, Olneyville, Hartford, Cranston, and Warwick, and miss the East Side and the middle-class suburbs. We realized that the city and inner-suburbs like Pawtucket are poorer than the proper suburbs, but that the train would serve Olneyville but not the East Side seemed like a coincidence.

But is it really a coincidence? Providence developed from east to west. The city was initially founded on the western side of what is now the East Side, sloping down to the river. What is now Downcity was only the second part of the city to develop. It became the center of the city because, as the Northeast Corridor was constructed, it was not possible to provide through-service via the hilly historic core of the city, only via the flatter areas that are now Downcity. A tunnel across College Hill opened in 1908, but by then the city’s basic urban geography was set: the university and port jobs on the East Side, industrial jobs to the west near the rail mainline.

The industrial jobs are long gone now. New England was the first part of America to industrialize and the first to deindustrialize, the mills moving to lower-wage Southern states already in the middle of the 20th century. In very large cities, declining industrial jobs can be replaced with urban renewal serving the middle class: the West India Docks became Canary Wharf, the freight railyards of Gare de Lyon became Bercy, the industrial Manhattan and Brooklyn waterfronts became sites for condos with nice views. In Providence-size cities, no such urban renewal is possible: there is no large mass of middle-class people clamoring to live or work in Olneyville, so the neighborhood became impoverished.

While factories may seem like attractive targets for transit commuting, they’re so clustered, in reality they have not been walkable ever since electrification made open-plan single-story factories viable. Factories are land-intensive and have been since around the 1910s. Moreover, whereas hotels and retail have a reason to locate in walkable areas for their consumption amenities – tourists like walking around the city – factories do not, and if anything depress an area’s desirability through noise and pollution. Working industrial districts are not attractive for transit, but post-industrial ones are, even if they are not gentrified the way so much of London, Paris, and New York have.

A large number of cities share Providence’s history as a medium-size post-industrial city. Nearly every English city except London qualifies, as do the cities of the American Northeast and Midwest below the size class of Boston and Philadelphia. Moreover, all of these cities have undergone extensive middle-class flight, with the racial dimension of white flight in the US but even without it in Britain; thus, the relatively dense neighborhoods, where transit service is more viable, are disproportionately poor. However, the feasibility of mainline rail service to post-industrial neighborhoods is uneven, and depends on local idiosyncrasies.

One positive example I’m more familiar with that’s a lot like Providence is in New Haven. Its best potential local rail route, the Farmington Canal Trail, serves lower middle-class areas like Hamden, and fortunately parallels the busiest bus route, the D-Dixwell. While Hamden is not poor, such service would still lead to the inversion we discussed for Providence, since the rich live in thoroughly auto-oriented suburbs or within walking distance of Yale. The main drawbacks are that it would require replacing an active trail with rail service, and that either street running or brief tunneling would be needed in the final few hundred meters in Downtown New Haven.

Vancouver: easy corridors and TOD for the working class

With a modal share of 21%, Vancouver is in a somewhat higher class of transit quality than the Riviera, Boston, or Chicago. However, it remains a far cry from the numbers beginning with a 3, 4, and 5 seen in New York and in European and Asian transit cities. As with the Riviera, I am somewhat speculating from my own observations, lacking a table that clearly states transit usage by socioeconomic class. However, two factors make me believe that transit in Vancouver serves the working class better than it does the middle class.

The first factor is the corridors served by SkyTrain. The first to be built, the Expo Line, runs in a preexisting interurban right-of-way, with minor greenfield elevated and underground construction; even the downtown tunnel is repurposed from a disused mainline rail branch. It passes through a mixture of working-class and lower middle-class neighborhoods on its way to Surrey, which is working-class and very negatively stereotyped. The second, the Millennium Line, branches east, to lower middle-class suburbs, running on a greenfield el. The third, the Canada Line, is a partially tunneled, partially elevated route through the middle-class West Side to working-class Richmond. Only the fourth line to be built, the Evergreen extension of the Millennium Line, finally serves a comfortable area, as will the next line, the Broadway extension of the Millennium Line deeper into the West Side.

The second factor is the job distribution within Metro Vancouver. Usually, we see concentration of professional jobs in city centers and dispersal of working-class jobs among many stores. In the Riviera this relationship between job concentration and income is only inverted because the working-class jobs are disproportionately in tourism while the professional ones are in an edge city. In Vancouver I don’t believe there is any such inversion, but there is leveling: jobs of either type are concentrated in transit-rich areas. This leveling is the result of extensive commercial transit-oriented development, most notably Metrotown, which has many office jobs on top of Canada’s third largest shopping mall.

The first factor is idiosyncratic. The easy corridors happened to serve poorer areas, on a line from East Vancouver to Surrey. The rich live in North Vancouver, which has a ferry and doesn’t have enough population density for a SkyTrain tunnel; on the West Side, which is separated from downtown by False Creek and was thus late to get a rail connection; and in Port Moody and Coquitlam, which were only connected to SkyTrain recently via the Evergreen extension.

The second factor is more systemic. While American and European cities rarely have big urban shopping malls, Canadian cities are full of them. The Metropolis at Metrotown has 27 million annual visitors, not far behind the 37 million of the Forum des Halles, at the center of a metro area five times the size of Metro Vancouver – and the Metropolis has more than twice the total commercial floor area. In this, Canada is similar to Israel and Singapore, which like Canada have harsh climates, only hot instead of cold. Moreover, Vancouver has encouraged this centralization through TOD: Burnaby built Metrotown from scratch in the 1980s, simultaneously with the Expo Line.

It is difficult to engage in concerted residential TOD for the working class, since it requires extensive housing subsidies. Vancouver’s residential TOD near SkyTrain stations is thoroughly middle-class. However, concerted commercial TOD is easier: hospitals, universities, and shopping centers all employ armies of unskilled workers (the first two also employing many professional ones), the first two while satisfying general social goals for health care and education provision and the last while making the owners a profit on the open market.

Moreover, Vancouver’s TOD within downtown, too, has made it easier to provide transit service for the working and lower middle classes. Where constraints on office towers lead to high office rents, only the most critical jobs are in city centers, and those are typically high-end ones; in the US, it’s common for big corporations to site their top jobs in the center of New York or Chicago or another large city but outsource lower-end office jobs to cheaper cities. In Vancouver, as elsewhere in Canada, extensive downtown commercialization means that even semi-skilled office jobs like tech support can stay in the center rather than at suburban office parks.

Conclusion

Based on my own observations, I believe the Riviera provides better public transportation for the working class than for the middle class, and to some extent so does Vancouver. Providence provides uniformly poor transit service, but its lowest-hanging fruit are in working-class urban neighborhoods.

The reasons vary, but the unifying theme is that, in the Riviera and Vancouver, there is none of the typical big-city pattern in which the rich work in walkable city centers more than the poor (e.g. in New York). In Vancouver it’s the result of commercial TOD as well as a Canadian culture of urban shopping centers; in the Riviera it’s the result of unique dependence on tourism. In Providence the situation is not about job concentration but about residential concentration: lower-income neighborhoods are likelier to arise near rail because historically that’s where industry arose, and all that remains is for Providence to actually run local passenger trains on the mainline.

It is not possible to replicate culture. If your city does not have the tourism dependence of Monaco, or the shopping mall culture of Vancouver, or the post-industrial history of Providence, there’s little it can do to encourage better urban geography for working-class transit use. At best, can build up more office space in the center, as Vancouver did, and hope that this encourages firms to locate their entire operations there rather than splitting them between a high-end head office and lower-end outlying ones. Fortunately, there exist many cities that do have the special factors of the Riviera, Vancouver, or Providence. In such cities, transit planners should make note of how they can use existing urban geography to help improve transit service for the population that most depends on it.

Transit-Oriented Suburbs

I did a Patreon poll last month with three options, all about development and transit: CBDs and job concentration in middle-income cities (e.g. auto-oriented Bangkok and Istanbul don’t have transit-oriented Shanghai’s CBD formation), dense auto-oriented city neighborhoods (e.g. North Tel Aviv), and transit-oriented low-density suburbia. This is the winning option.

In every (or almost every) city region, there’s a clear pattern to land use and transportation: the neighborhoods closer to the center have higher population density and lower car use than the ones farther away. Moreover, across city regions, there is such a strong negative correlation between weighted density and auto use that exceptions like Los Angeles are notable. That said, the extent of the dropoff in transit use as one moves outward into suburbia is not the same everywhere, and in particular there are suburbs with high transit use. This post will discuss which urban and transportation policies are likely to lead such suburbs to form, in lieu of the more typical auto-oriented suburbs.

What is a suburb?

Definitions of suburbia differ across regions. Here in Paris, anything outside the city’s 1860 limits is the suburbs. The stereotypical banlieue is in history, urban form, and distance from the center a regular city neighborhood that just happens to be outside the city proper for political reasons. It is hardly more appropriate to call any part of Seine-Saint-Denis a suburb than it is to call Cambridge, Massachusetts a suburb of Boston.

So if Seine-Saint-Denis is not a suburb, what is? When I think of suburbia, my prototype is postwar American white flight suburbs, but stripped of their socioeconomic context. The relevant characteristics are,

  • Suburbs developed at a time when mass motorization was widespread. In the US, this means from around 1920 onward in the middle class and slightly later in the working class; in the rest of the developed world, the boundary ranges from the 1920s to the 1960s depending on how late they developed. Note that many stereotypical suburbs were founded earlier, going back even to the 19th century, but grew in the period in question. Brookline is famous for refusing annexation to Boston in 1873, but its fastest development happened between 1910 and 1930, straddling the 1920 limit – and indeed in other respects it’s borderline between a rich suburb and rich urban neighborhood as well.
  • Suburbs have low population density, typical of single-family housing. Aulnay-sous-Bois, at 5,100 people per km^2, is too dense, but not by a large margin. Beverly Hills, which has mansions, has 2,300, and Levittown, New York, probably the single best-known prototype of a suburb, has 2,900. The urban typology can mix in apartments, but the headline density can’t be dominated by apartments, even missing middle.
  • Suburbs are predominantly residential. They can have distinguished town centers, but as broad regions, they have to have a significant number of commuters working in the city. This rules out low-density central cities like Houston and Dallas (although their individual neighborhoods would qualify as suburbs!). It also rules out Silicon Valley as a region, which represents job sprawl more than residential sprawl.

The three criteria above make no mention of whether the area is included in the central city. Most of Staten Island qualifies as suburban despite being part of New York, but Newark fails all three criteria, and Seine-Saint-Denis and most of Hudson County fail the first two.

Where are suburbs transit-oriented?

I do not know of any place where suburban transit usage is higher than city center transit usage. In theory, this suggests that the best place to look for transit-oriented suburbia is the cities with the highest transit mode shares, such as Tokyo, Singapore, and Hong Kong (or, in Europe, Paris). But in reality, Singapore and Hong Kong don’t have areas meeting the density definition of suburb, and Tokyo has few, mostly located away from its vast commuter rail network. Paris has more true suburbs, but like Tokyo’s, they are not what drives the region’s high rail ridership. All four cities are excellent examples of high-density suburban land use – that is, places that meet my first and third definitions of suburbia but fail the second.

Instead, it’s better to look at smaller, lower-density cities. Stockholm and Zurich are both good models here. Even the central cities are not very dense, at 5,100 and 4,700 people per km^2. Moreover, both are surrounded by large expanses of low-density, mostly postwar suburbia.

Winterthur, Zurich’s largest suburb, is a mix of early 20th century and postwar urban typology, but the other major cities in the canton mostly developed after WW2. At the time, Switzerland was already a very rich country, and car ownership was affordable to the middle class. The story of the Zurich S-Bahn is not one of maintaining mode share through a habit of riding transit, but of running frequent commuter rail to suburbs that did not develop around it from the 1950s to the 70s.

In Stockholm, there is a prominent density gradient as one leaves Central Stockholm. I lived in Roslagstull, at the northern end of Central Stockholm, where the density is 30,000 people per km^2 and the built-up form is the euroblock. Most of the rest of Central Stockholm is similar in urban form and not much less dense. But once one steps outside the city’s old prewar core, density nosedives. City districts to the west and south, like Bromma and Älvsjö, go down to 3,000 people per km^2 or even a little less. A coworker who used to live in Kista described the area as American-style suburban. Beyond these city districts lie the other municipalities, which together form a sizable majority of the county’s population. Of those, a few (Solna, Sundbyberg) are somewhat above the density cutoff, but most are far below it.

In both Zurich and Stockholm, the city is much more transit-oriented than the suburbs. Stockholm’s congestion pricing was a city initiative; the suburbs banded together to oppose it, and eventually forced a compromise in which congestion pricing remained in effect but the revenue would be deeded to urban freeways rather than to public transportation.

And yet, neither city has a big transit use gradient – at least, not so big as Paris, let alone London or New York. Stockholm is expecting 170,000 daily metro trips from its expansion program, which barely touches Central Stockholm. Existing T-bana ridership on the suburban tails is pretty high as well (source, PDF-p. 13), as is ridership on commuter rail, which, too, barely touches Central Stockholm.

The structure of density

In my previous post, I complained that Los Angeles’s density has no structure, and thus public transit ridership is very low and consists predominantly of people too poor to buy a car. The situation in Stockholm and Zurich is the reverse. Density has a clear structure: within each suburb, there is a town center near the commuter rail station.

The histories of Zurich and Stockholm are profoundly different. Each arrived in its structure from a different route. In Zurich, the suburbs come from historic town centers that existed long before cars, often long before industrialization. 20th-century urban sprawl arrived in the form of making these historic villages bigger and bigger until they became proper suburbs. The geography helps rail-oriented suburbanization as well: the ridge-and-valley topography is such that urban sprawl forms ribbons served by commuter rail lines, especially in the southerly direction.

Stockholm’s topography is nothing like Zurich’s. There are water boundaries limiting suburb-to-suburb travel, but the same is true of New York, and yet Long Island, New Jersey, and Westchester are thoroughly auto-oriented. Instead, the structure of density came about because of government planning. Sweden built public housing simultaneously with the Stockholm Metro, so the housing projects were sited near the train stations.

This does not mean that the suburbs of Zurich and Stockholm are actually high-density. Far from it: the housing projects in the Stockholm suburbs are surrounded by a lot of parking and greenery, and the suburbs have extensive single-family housing tracts. However, the density is arranged to grade down from the train station, and there are small clusters of walkable apartment buildings in a small radius around each station. In Zurich the same structure came about with private construction and topography.

To the extent this structure exists elsewhere, it leads to higher low-density transit ridership too, for example in London and the Northeastern United States. Various West Coast American transit bloggers, like Jarrett Walker and Let’s Go LA, keep plugging the West Coast grid over the Northeastern hierarchy of density. But this hierarchy of suburbs that formed around commuter rail to the CBD produces transit ridership that, while awful by Continental European standards, is very good by American ones. Many of the suburbs in question, such as in Westchester, have 15-20% of their commuters choose transit to get to work.

Getting to higher numbers means reinforcing the structure of density and the transit that works in the suburbs, that is, regional rail (or a metro network that goes far out, like the T-bana, if that’s an option). Stations must be surrounded by development rather than parking, and this development should facilitate a somewhat transit-oriented lifestyle, including retail and not just housing. Jobs should be accessible from as many directions as possible, forming CBDs rather than haphazard town centers accessible only by road. Only this way can suburbia be transit-oriented.

Meme Weeding: Los Angeles Density

If you’re the kind of total nerd that looks up tables on Wikipedia for fun, you may notice a peculiarity: the American built-up area with the highest population density is Los Angeles, followed by the Bay Area and New York. This is not what anyone experiences from even a slight familiarity with the two cities. Some people leave it at that and begin to make “well, actually Los Angeles is dense” arguments; this is especially common among supporters of cars and suburbs, like Randall O’Toole, perhaps because they advocate for positions the urbanist mainstream opposes and enjoy the ability to bring up an unintuitive fact. Others instead try to be more analytic about it and understand how Los Angeles’ higher headline density than New York coexists with its actual auto-centric form.

The answer that the urbanist Internet (blogs, then the Census Bureau, then Twitter) standardized on is that the built-up area of New York has some really low-density outer margins, where auto use is high, but the dense core is larger than that of Los Angeles. Here’s a log graph made by longtime Twitter follower Neil Patel:

New York’s 70th percentile of density (shown as 30 on the graph’s y-axis) is far denser than that of the comparison cities. The term the urbanist blogosphere defaulted to is “weighted density,” which is the average density of census tracts weighted by their population rather than area; see original post by the Austin Contrarian, in 2008.

But one problem remains: Los Angeles is by any metric still dense. Neil’s chart above shows its density curve Lorenz-dominating those of Chicago and Washington, both of which have far higher transit usage. Unfortunately, I haven’t seen too much analysis of why. Jarrett Walker talks about Los Angeles’s polycentrism, comparing it with Paris, and boosting it as a positive for public transit. The reality is the opposite, and it’s worth delving more into it to understand why whatever density Los Angeles has fails to make it have even rudimentary public transit.

Yes, Los Angeles is auto-oriented

The “well, actually Los Angeles is not autopia” line faces a sobering fact: Los Angeles has practically no transit ridership. In this section, I’m going to make some comparisons among American metropolitan statistical areas (MSAs); these exclude many suburbs, including the Inland Empire for Los Angeles and Silicon Valley for San Francisco, but Neil’s graph above excludes them as well, because of how the US defines urbanized areas. In the following table, income refers to median income among people driving alone or taking public transit, and all data is from the 2017 American Community Survey (ACS).

Place Workers Drive share Drive income Transit share Transit income
US 152,802,672 76.4% $38,689 5% $37,530
New York 9,821,147 50% $48,812 31% $44,978
San Francisco 2,371,803 57% $54,923 17.4% $62,500
Washington 3,320,895 66.4% $53,390 12.8% $60,420
Chicago 4,653,591 70% $41,817 12.2% $46,796
Los Angeles 6,434,177 75.4% $39,627 4.8% $21,153

The income numbers are not typos. In San Francisco, Washington, and Chicago, transit users outearn drivers. In New York the incomes are close, and US-wide they are almost even. But in Los Angeles, drivers outearn the few transit users almost 2:1. It’s not because Los Angeles has better transit in poor neighborhoods than in rich ones: this may have been true for a long while, but with the Expo Line open to Santa Monica, the Westside has bare bones coverage just like the rest of the city. Even with the coverage that exists, public transit in Los Angeles is so bad that people only use it if they are desperately poor.

When public transportation is a backstop service for the indigent, ridership doesn’t follow the same trends seen elsewhere. Transit ridership in Los Angeles rises and falls based on fares; new rail extensions, which have led to big gains in ridership in Seattle and Vancouver, are swamped by the impact of fare changes in Los Angeles. Gentrification, which in New York has steadily raised subway usage in hotspots like Williamsburg and which does the same in San Francisco, has instead (slightly) contributed to falling transit usage in Los Angeles (p. 53).

Job density and CBD job share

Los Angeles has high residential density by American standards – lower than in New York counted properly, but comparable to San Francisco, and higher than Chicago and Washington. However, job density tells a completely different story. New York, Chicago, San Francisco, and Washington all have prominent central business districts. Without a consistent definition of the CBD, I am drawing what look like the peak employment density sites from OnTheMap, all as of 2015:

Place CBD boundaries Area Jobs MSA share Density
New York 33rd, 3rd, 60th, 9th 3.85 825,476 8.4% 214,336
San Francisco Washington, Powell, 5th, Howard, Embarcadero 1.81 224,010 9.4% 123,558
Washington Rock Creek, P, Mass., 7th, Cons., 14th, H 3.26 240,505 7.2% 73,775
Chicago River, Congress, Michigan, Randolph, Columbus 1.61 368,910 7.9% 228,998
Los Angeles US 110, US 101, Alameda, 1st, Main, 7th 2.11 189,767 2.9% 89,937

The two main indicators to look for are the rightmost two columns: the percentage of jobs that are in the CBD, and the job density within the CBD. These indicators are highly not robust to changing the CBD’s definition, but expanding the definition moves them in opposite direction. Washington and San Francisco can be boosted to about 400,000 jobs each if the CBD is expanded to include near-CBD job centers such as Gallery Place, L’Enfant Plaza, SoMa, and Civic Center. Manhattan south of 60th has 1.9 million jobs in 22.2 km^2. Even in Chicago, where job density craters outside the Loop, the 9 km^2 bounded by Chicago, Halsted, and Roosevelt have 567,000 jobs. In making the tradeoff between job density and MSA share, I tried to use smaller CBD definitions, maximizing density at the expense of MSA share.

But even with this choice, the unusually low CBD share in Los Angeles is visible. This is what Jarrett and others mean when they say Los Angeles is polycentric: it is less dominated by its central business district than New York, Chicago, Washington, and San Francisco.

However, the comparisons between Los Angeles and Paris are wildly off-base. I am not including Paris in my above table, because INSEE only reports job numbers at the arrondissement level, and the city’s CBD straddles portions of the 1st, 2nd, 8th, and 9th arrondissements. Those four arrondissements total 405,189 jobs in 8.88 km^2, but in practice few of these jobs are in the outer quartiers, so a large majority of these jobs are in the central 4.64 km^2. The overall job density is then comparable to that of the Los Angeles CBD, but the similarity stops there: CBD employment is 7.1% of the total for Ile-de-France. If there is a US city that’s similar to Paris on the two CBD metrics of density and employment share, it’s Washington, not coincidentally the only big American city with a height-limited city center.

Secondary centers

In all of the American cities I’m comparing in this post except New York, the share of the population using public transit to get to work is not much higher than the share working in the CBD, especially if we add in near-CBD job centers served by public transit like Civic Center and L’Enfant Plaza (and all of the Manhattan core outside Midtown). This is not a coincidence. Outside a few distinguished locations with high job density, it’s easy enough to drive, and hard to take the train (if it even exists) except from one or two directions.

American cities are distinguished from European ones in that their non-CBD employment is likely to be in sprawling office parks and not in dense secondary centers. Paris is polycentric in the sense of having multiple actual centers: La Defense is the most conspicuous outside the CBD, but the city is full of smaller, lower-rise clusters: the Latin Quarter, Bercy, the Asian Quarter, Gare du Nord, the Marais. The 3rd, 4th, 5th, 6th, 7th, 10th, and 12th all have around 20,000-25,000 jobs per square kilometer, not much less than the Upper East Side (which has about 120,000 jobs between 60th and 96th Streets).

A polycentric city needs to have multiple actual centers. Does Los Angeles have such centers? Not really. Century City has 33,000 jobs in about 1.1 km^2. Here is the city’s second downtown, with a job density that only matches that of central Parisian neighborhoods that nobody would mistake with the CBD. The UCLA campus has around 15,000 jobs. Downtown Santa Monica has 24,000 in 2 km^2. El Segundo, which Let’s Go LA plugs as a good site for CBD formation, has 52,000 jobs in 5.2 km^2. Downtown Burbank has about 13,000 in 0.6 km^2. The dropoff in commercial development intensity from the primary CBD is steep in Los Angeles.

What Los Angeles has is not polycentric development. Paris is polycentric. New York is fairly polycentric, with the growth of near-CBD clusters like Long Island City, in addition to older ones like Downtown Brooklyn and Downtown Newark. Los Angeles is just weak-centered.

The structure of density

In his original posts about weighted density from 2008, Chris noted not just the overall weighted density of an American urban area but also the ratio of the weighted to standard density. This ratio is highest in New York, but after New York the highest ratios are in other old industrial cities like Boston and Chicago. This ratio is in stronger correlation with the public transit modal share than weighted density. Much of this fact is driven by the fact that Boston, Chicago, and Philadelphia have high-for-America transit usage and Los Angeles doesn’t, but it still suggests that there is something there regarding the structure of density.

In Chicago and Washington, the population density is low, but it follows a certain structure, with higher density in central areas and in distinguished zones near train stations. These structures are not identical. Chicago has fairly uniform density within each city neighborhood, and only sees this structure in the suburbs, which are oriented around commuter rail stations, where people take Metra to the city at rush hour (and drive for all other purposes). In contrast, in Washington commuter rail is barely a footnote, whereas Metro drives transit-oriented development in clusters like Arlington, Alexandria, Silver Spring, and Bethesda. In these islands of density, the transit-oriented lifestyle is at least semi-plausible.

Paris has fairly uniform density within the city, but it has strong TOD structure in the suburbs: high density within walking distance of RER stations, lower density elsewhere. Some RER stations are also surrounded by job clusters oriented toward the train station: La Defense is by far the biggest and best-known, but Cergy, Val d’Europe and Marne la Vallee, Issy, Noisy, and Saint-Denis are all walkable to job centers and not just housing. Within the city there is no obvious structure, but the density is so high and the Metro so ubiquitous that transit serves the secondary nodes well.

In Los Angeles, there is no structure to density. There are some missing middle and mid-rise neighborhoods, but few form contiguous blobs of high density that can be served by a rapid transit line. Koreatown is in a near-tie with Little Osaka for highest population density in the United States outside New York, but immediately to its west, on the Purple Line Extension, lie kilometers of single-family sprawl, and only farther west on Wilshire can one see any density (in contrast, behind Little Osaka on Geary lies continuous density all the way to the Richmond). With the exception of Century City, UCLA, and Santa Monica, the secondary centers don’t lie on any obvious existing or current transit line.

With no coherent structure, Los Angeles is stuck. Its dense areas are too far away from one another and from job centers to be a plausible urban zone where driving is not necessary for a respectable middle-class lifestyle. Buses are far too slow, and trains don’t exist except in a handful of neighborhoods. Worse, because the density is so haphazard, the rail extensions can’t get any ridership. The ridership projection for the Purple Line Extension is an embarrassing 78,000 per weekday for nearly 15 km and $8.2 billion. The construction cost is bad, but in a large, dense city should be offset by high ridership (as it is in London); but it isn’t, so the projected ridership per kilometer is on a par with some New York City Transit buses and the projected cost per rider is so high that it is usually reserved for airport connectors.

The way out

In a smaller, cheaper auto-centric city, like Nashville or Orlando, I would be entirely pessimistic. In Los Angeles there is exactly one way out: fix the urban design, and reinforce it with a strong rail network.

The fact that this solution exists does not mean it is politically easy. In particular, the region needs to get over two hangups, each of which is separately nearly insurmountable. The first is NIMBYism. Los Angeles is so expensive that if it abolishes its zoning code, or passes a TOD ordinance that comes close to it, it could see explosive growth in population, which would be concentrated on the Westside, creating a large zone of high density in which people could ride the trains. However, the Westside is rich and very NIMBY. Metro isn’t even trying to upzone there: the Purple Line Extension has a 3.2-km nonstop segment from Western to La Brea, since the single-family houses in between are too hard to replace with density. Redeveloping the golf courses that hem Century City so that it could grow to a real second downtown is attractive as well, but even the YIMBYs think it’s unrealistic.

The second obstacle is the hesitation about spending large amounts of money all at once. American politicians are risk-averse and treat all spending as risk, and this is true even of politicians who boldly proclaim themselves forward-thinking and progressive. Even when large amounts of money are at stake, their instincts are to spread them across so many competing goals that nothing gets funded properly. The amount of money Los Angeles voters have approved to spend on transportation would build many rapid transit lines, even without big decreases in construction costs, but instead the money is wasted on showcasing bus lanes (this is Metro’s official blog’s excuse for putting bus lanes on Vermont and not rapid transit) or fixing roads or the black hole of Metro operating costs.

But the fact that Los Angeles could be a transit city with drastic changes to its outlook on development and transportation investment priorities does not mean that it is a transit city now. Nor does it mean that the ongoing program of wasting money on low-ridership subway lines is likely to increase transit usage by the required amount. Los Angeles does not have public transportation today in the sense that the term is understood here or in New York or even in Chicago. It should consider itself lucky that it can have transit in the future if it implements politically painful changes, but until it does, it will remain the autopia everyone outside urbanism thinks it is.

Sunnyside Junction, Redux

Seven years ago, I wrote a pair of posts about Sunnyside Yards. The first recommends the construction of a transfer station through Sunnyside Yards, in order to facilitate transfers between Penn Station- and Grand Central-bound trains. The second recommends redeveloping the yards via a deck, creating high-density residential and commercial space on a deck on top of the yard. Recent news, both about an official plan to deck the yards and about leaks that Amazon is likely to move half of its second headquarters (HQ2) to Long Island City, make a Sunnyside Junction so much more urgent.

Here is how service would look:

The color scheme is inherited from my regional rail maps (see e.g. here) but for the purposes of this post, all it means is that green and blue correspond to the inner and outer tracks of the Park Avenue, purple is East Side Access, orange corresponds to LIRR trains going to the northern pair of East River Tunnels, and red corresponds to LIRR, Metro-North Penn Station Access, and Amtrak trains going to the southern pair of East River Tunnels. No track infrastructure is assumed except what’s already in service or funded (i.e. ESA and Penn Station Access), and only two infill stations are mapped: Astoria, which would be a strong location for a stop were fares integrated with the subway and frequency high, and Sunnyside Junction.

The infill stations that are not planned

An Astoria station was studied for PSA, but was dropped from consideration for two reasons. First, the location is legitimately constrained due to grades, though a station is still feasible. And second, under the operating assumptions of high fares and low off-peak frequency, few people would use it. It would be like Wakefield and Far Rockaway, two edge-of-city neighborhoods where commuter rail ridership is a footnote compared with slower but cheaper and more frequency subway service.

A Sunnyside Junction station was in contrast never considered. There are unfunded plan for an infill station to the west of the junction, served only by Penn Station-bound trains. Such a station would hit Long Island City’s job center well, but the walk from the platform to the office towers would still be on pedestrian-hostile roads, and if there’s political will to make that area more walkable, the city might as well just redevelop Sunnyside Yards (as already planned).

The reason there was never any plan for a station can be seen by zooming in on the area I drew as a station. It’s a railyard, without streets (yet). At today’s development pattern, nobody would use it as an O&D station, even if fares and schedules were integrated with the subway. The importance of the station is as a transfer point between Grand Central- and Penn Station-bound trains. The planned developments (both HQ2 and independent city plans) makes it more urgent, since the area is relatively far from the subway, but the main purpose of the station is a better transit network, rather than encouraging development.

The main benefit of the station is transfers between the LIRR and Metro-North. While nominally parts of the MTA, the two agencies are run as separate fiefs, both of which resisted an attempt at a merger. The LIRR opposed PSA on the grounds that it had a right to any empty slots in the East River Tunnels (of which there are around 8 per hour at the peak). Governor Cuomo intervened to protect PSA from Long Island’s opposition, but in such an environment, coordinated planning across the two railroads is unlikely, and the governor would not intervene to improve the details of the ESA and PSA projects.

Network improvements

East Side Access means that in a few years, LIRR trains will split between two Manhattan destinations. Conceptually, this is a reverse-branch: trains that run on the same route in the suburbs, such as the LIRR Main Line, would split into separate routes in the city core. In contrast, conventional branching has trains running together in the core and splitting farther out, e.g. to Oyster Bay, Port Jefferson, and Ronkonkoma. Reverse-branching is extremely common in New York on the subway, but is rare elsewhere, and leads to operational problems. London’s Northern line, one of the few examples of reverse-branching on an urban subway outside New York, is limited to 26 trains per hour through its busiest trunk at the peak, and long-term plans to segregate its two city trunks and eliminate reverse-branching would raise this to 36.

To ensure LIRR trains run with maximum efficiency, it’s necessary to prevent reverse-branching. This means that each trunk, such as the Main Line and the Hempstead Branch, should only ever go to one Manhattan terminal. Passengers who wish to go to the other Manhattan terminal should transfer cross-platform. Jamaica is very well-equipped for cross-platform transfers, but it’s at a branch point going to either Manhattan or Downtown Brooklyn, without a good Penn Station/Grand Central transfer. Without a good transfer, passengers would be stuck going to a terminal they may not work near, or else be forced into a long interchange. In London the reason the Northern line is not already segregated is that the branch point in the north, Camden Town, has constrained passageways, so eliminating reverse-branching requires spending money on improving circulation.

Unlike Camden Town, Sunnyside Junction is roomy enough for cross-platform transfers. The tracks should be set up in a way that LIRR trains going to East Side Access should interchange cross-platform with PSA and Port Washington Branch trains (which should go to Penn Station, not ESA), as they do not stop at Jamaica. Penn Station-bound LIRR trains not using the Port Washington Branch, colored orange on the map, should stop at Sunnyside too, but it’s less important to give them a cross-platform transfer.

This assignment would be good not just for LIRR passengers but also for PSA passengers. Unlike on the LIRR, on the New Haven Line, reverse-branching is unavoidable. However, passengers would still benefit from being able to get on a Penn Station-bound train and connecting to Grand Central at Sunnyside. Not least, passengers on the PSA infill stations in the city would have faster access to Grand Central than they have today via long walks or bus connections to the 6 train. But even in the suburbs, the interchange would provide higher effective frequency.

The connection with development

I don’t know to what extent decking Sunnyside Yards could attract Amazon. I wrote an article last year, which died in editing back-and-forth, lamenting that New York was unlikely to be the HQ2 site because there was no regional rail access to any of the plausible sites thanks to low frequency and no through-running. Long Island City’s sole regional rail access today consists of LIRR stations on a reverse-branch that does not even go into Manhattan (or Downtown Brooklyn) and only sees a few trains per day. It has better subway access and excellent airport access, though.

However, since Sunnyside Junction is so useful without any reference to new development, the plans for decking make it so much more urgent. Sunnyside Yards are in the open air today, and there is space for moving tracks and constructing the necessary platforms. The cost is likely to be in the nine figures because New York’s construction costs are high and American mainline rail construction costs are even higher, but it’s still a fraction of what it would take to do all of this under a deck.

Moreover, the yards are not easy to deck. Let’s Go LA discussed the problem of decking in 2014: columns for high-rise construction are optimally placed at intervals that don’t jive well with railyard clearances, and as a result, construction costs are a multiple of what they are on firma. Hudson Yards towers cost around $12,000/square meter to build, whereas non-WTC commercial skyscrapers in the city are $3,000-6,000 on firma. The connection with Sunnyside Junction is that preparing the site for the deck requires extensive reconfiguration of tracks and periodic shutdowns, so it’s most efficient to kill two birds with one stone and bundle the reconfiguration required for the station with that required for the deck.

In the other direction, the station would make the deck more economically feasible. The high construction costs of buildings on top of railyards makes decking unprofitable except in the most desirable areas. Even Hudson Yards, adjacent to Midtown Manhattan on top of a new subway station, is only treading water: the city had to give developers tax breaks to get them to build there. In Downtown Brooklyn, Atlantic Yards lost the developer money. Sunnyside Yards today are surrounded by auto shops, big box retail, and missing middle residential density, none of which screams “market rents are high enough to justify high construction costs.” A train station would at least offer very fast rail access to Midtown.

If the decking goes through despite unfavorable economics, making sure it’s bundled with a train station becomes urgent, then. Such a bundling would reduce the incremental cost of the station, which has substantial benefits for riders even independently of any development it might stimulate in Sunnyside.

How Transit and Green Tech Make Economic Geography More Local

The theme of winners and losers has been on my mind for the last few months, due to the politics of the Brooklyn bus redesign. In a rich country, practically every social or political decisions is win-lose, even if the winners greatly outnumber the losers. It’s possible to guarantee a soft landing to some of the losers, but sometime even the soft landing is disruptive, and it’s crucial that backers of social change be honest with themselves and with the public about this. Overall, a shift from an auto-oriented society to a transit-oriented one and from dirty energy to clean energy is positive and must be pursued everywhere, but it does have downsides. In short, it changes economic geography in ways that make certain regions (like Detroit or the Gulf Cooperation Council states) redundant; it reorients economies toward more local consumption, so oil, gas, and heavy industry jobs would not be replaced with similar manufacturing or mining clusters but with slightly more work everywhere else in the world.

Dirty production is exportable

The United States has the dirtiest economy among the large developed countries, so it’s convenient to look at average American behavior to see where the money that is spent on polluting products goes.

Nationally, about 15.9% of consumer spending is on transportation. The vast majority of that is on cars, 93.1% (that is, 14.7% of total consumer spending). The actual purchase of the car is 42% of transportation spending, or 6.7% of household spending. This goes to an industry that, while including local dealerships (for both new and used cars), mostly consists of auto plants, making cars in suburban Detroit or in low-wage Southern states and exporting them nationwide.

In addition to this 6% of consumer spending on cars, there’s fuel. Around 3% of American household spending is on fuel for cars. Overall US oil consumption in 2017 was 7.28 billion barrels, which at $52/barrel is 5% of household spending; the difference between 5 and 3 consists of oil consumed not by households. This is a total of about 2% of American GDP, which includes, in addition to household spending, capital goods and government purchases. This tranche of the American economy, too, is not local, but rather goes to the oil industry domestically (such as to Texas or Alaska) or internationally (such as to Alberta or Saudi Arabia).

Historically, when coal was more economically significant, it was exportable too. Money flowed from consumers, such as in New York and London, to producers in the Lackawanna Valley or Northeast England; today, it still flows to remaining mines, such as in Wyoming.

The same is true of much of the supply chain for carbon-intensive products. Heavy industry in general has very high carbon content for its economic value, which explains how the Soviet Union had high greenhouse gas emissions even with low car usage (15.7 metric tons per capita in the late 1980s) – it had heavy industry just as the capital bloc did, but lagged in relatively low-carbon consumer goods and services. The economic geography of steel, cement, and other dirty products is again concentrated in industrial areas. In the US, Pittsburgh is famous for its historical steel production, and in general heavy manufacturing clusters in the Midwestern parts of the Rust Belt and in transplants in specific Southern sites.

All of these production zones support local economies. The top executives may well live elsewhere – for example, David Koch lives in New York and Charles Koch in Wichita (whose economy is based on airplane manufacturing and agriculture, neither of which the Kochs are involved in). But the working managers live in city regions dedicated to servicing the industry, the way office workers in the oil industry tend to live in Houston or Calgary, and of course the line workers live near the plants and mines.

Clean alternatives are more local

The direct alternatives to oil, gas, and cars are renewable energy and public transportation. These, too, have some components that can be made centrally and exported, such as solar panel and rolling stock manufacturing. However, these components are a small fraction of total spending.

How small? Let’s look at New York City Transit. Its operating costs are about $9.1 billion a year as of 2016, counting both the subway and buses. Nearly all of this is wages, salaries, and benefits: $7.3 billion, compared with only $500 million for materials and supplies. This specifically excludes vehicle purchases, which in American transit accounting are lumped as capital costs. The total NYCT fleet is about 6,400 subway cars, which cost around $2.3 million each and last 40+ years, and 5,700 buses, which cost around $500,000 each and last 12 years, for a total depreciation charge of around $600 million a year combined.

Compare this with cars: New York has about 2 million registered cars, but at the same average car ownership rate as the rest of the US, 845 per 1,000 people, it would have 7.3 million cars. These 5.3 million extra cars would cost $36,500 each today, and last around 20 years, for a total annual depreciation charge of $9.7 billion.

Put another way, total spending on vehicles at NYCT is one sixteenth what it would take to raise the city’s car ownership rate to match the national average. Even lumping in materials and supplies that are not equipment, such as spare parts and fuel for buses, the total, $1.1 billion, is one ninth as high as buying New Yorkers cars so that they can behave like Americans outside the city, and that’s without counting the cost of fuel. In particular, there is no hope of maintaining auto plant employment by retraining auto workers to make trains, as Michael Moore proposed in 2009.

The vast majority of transit spending is then local: bus and train operations, maintenance, and local management. The same is true of capital spending, which goes to local workers, contractors, and consultants, and even when it is outsourced to international firms, the bulk of the value of the contract does not accrue to Dragados or Parsons Brinckerhoff.

Clean energy is similarly local. Solar panels can be manufactured centrally, but installing them on rooftops is done locally. Moreover, the elimination of carbon emissions coming from buildings has to come not just from cleaner electricity but also from reducing electricity consumption through passive solar construction. Retrofitting houses to be more energy-efficient is a labor-intensive task comprising local builders sealing gaps in the walls, windows, and ceilings.

Low-carbon economic production can be exported, but not necessarily from Detroit

A global shift away from greenhouse gas emissions does not mean just replacing cars and oil with transit and solar power. Transit is cheaper to operate than cars: in metro New York, 80.5% of personal transportation expenditure is still on cars, and the rest is (as in the rest of the country) partly on air travel and not transit fare, whereas work trip mode shares in the metropolitan statistical area are 56% car, 31% transit. With its relatively high (for North America) transit usage, metro New York has the lowest share of household spending going to transportation, just 11.4%. This missing consumption goes elsewhere. Where does it go?

The answer is low-carbon industries. Consuming less oil, steel, and concrete means not just consuming more local labor for making buildings more efficient and running public transit, but also shifting consumption to less carbon-intensive industries. This low-carbon consumption includes local purchases, for example going out to eat, or hiring a babysitter to look after the kids, neither of which involves any carbon emissions. But it also includes some goods that can be made centrally. What are they, and can they be made in the same areas that make cars and steel or drill for oil and gas?

The answer is no. First, in supply regions like the Athabascan Basin, Dammam, and the North Slope of Alaksa, there’s no real infrastructure for any economic production other than oil production. The infrastructure (in the case of North America) and the institutions (in the case of the Persian Gulf) are not suited for any kind of manufacturing. Second, in real cities geared around a single industry, like Detroit or Houston, there are still lingering problems with workforce quality, business culture, infrastructure, and other necessities for economic diversification.

Take the tech industry as an example. The industry itself is very low-carbon, in the sense that software is practically zero-carbon and even hardware has low carbon content relative to its market value. Some individual tech products are dirty, such as Uber, but the industry overall is clean. A high carbon tax is likely to lead to a consumption shift toward tech. And tech as an industry has little to look for in Detroit and Houston. Austin has booming tech employment, but Houston does not, despite having an extensive engineering sector courtesy of the oil industry as well as NASA. The business culture in the space industry (which is wedded to military contracting) is alien to that of tech and vice versa; the way workers are interviewed, hired, and promoted is completely different. I doubt the engineers oil and auto industries are any more amenable to career change to software.

On the level of line workers rather than engineers, the situation is even worse. A manufacturing worker in heavy industry can retrain to work in light industry, or in a non-exportable industry like construction, but light industry has little need for the massive factories that churn out cars and steel. And non-manufacturing exports like tech don’t employ armies of manufacturing workers.

In Germany the situation is better, in that Munich and Stuttgart may have little software, but they do have less dirty manufacturing in addition to their auto industries. It’s likely that if global demand for cars shifts to a global demand for trains then Munich will likely keep thriving – it’s the home of not just BMW and Man but also Siemens. However, the institutions and worker training that have turned southern Germany into an economically diverse powerhouse have not really replicated outside Germany. Ultimately, in a decarbonizing world, southern Germany will be the winner among many heavy industrial regions, most of which won’t do so well.

There’s no alternative to shrinkage in some cities

A shift away from fossil fuel and cars toward green energy and public transit does not have to be harsh. It can aim to give individual workers in those industries a relatively soft landing. However, two snags remain, and are unavoidable.

The first is that some line workers have deliberately chosen poor working conditions in exchange for high wages; the linked example is about oil rig workers in Alaska, but the same issue occurs in some unionized manufacturing and services, for example electricians get high wages but all suffer hearing loss by their 50s. It’s possible to retrain workers and find them work that’s at the same place on the average person’s indifference curve between pay and work conditions, but since those workers evidently chose higher-pay, more dangerous jobs, their personal preference is likely to weight money more than work conditions and thus they’re likely to be unhappy with any alternative.

The second and more important snag is the effect of retraining on entire regions. Areas that specialize to oil, gas, cars, and to some extent other heavy industry today are going to suffer economic decline, as the rest of the world shifts its consumption to either local goods (such as transit operations) or different economic sectors that have no reason to locate in these areas (such as software).

Nobody will be sad to see Saudi Arabia crash except people who are directly paid by its government. But the leaders of Texas and Michigan are not Mohammad bin Salman; nonetheless, it is necessary to proceed with decarbonization. It’s not really possible to guarantee the communities a soft landing. Governments all over the world have wasted vast amounts of money trying and failing to diversify from one sector (e.g. oil in the GCC states) or attract an industry in vogue (e.g. tech anywhere in the world). If engineering in Detroit and Houston can’t diversify on its own, there’s nothing the government can do to improve it, and thus these city regions are destined to become much smaller than they are today.

This is bound to have knock-on regional effects. Entire regions don’t die quietly. Firms specializing in professional services to the relevant industries (such as Halliburton) will have to retool. Small business owners who’ve dedicated their lives to selling food or insurance or hardware to Houstonians and suburban Detroit white flighters will need to leave, just as their counterparts in now-dead mining towns or in Detroit proper did. Some will succeed elsewhere, just as many people in New Orleans who were displaced by Katrina found success in Houston. But not all will. And it’s not possible to guarantee all of them a soft landing, because it’s not possible to guarantee that every new small business will succeed.

All policy, even very good policy, has human costs. There are ways to reduce these costs, through worker retraining and expansion of alternative employment (such as retrofitting older houses to be more energy-efficient). But there is no way to eliminate these costs. Some people who are comfortable today will be made precarious by any serious decarbonization program; put another way, these people’s entire livelihood depends on continuing to destroy the planet, and most of them are not executives at oil and gas companies. It does not mean that decarbonization should be abandoned or even that it should be pursued more hesitantly; but it does mean climate activists, including transit activists, have to be honest about how it affects people in and around polluting industries.