Category: Urbanism

Safer Streets: Design is Better Than Enforcement

As some American cities are attempting to reduce the number of car accident fatalities, under the umbrella of Vision Zero, the growing topic is one of traffic enforcement. Streetsblog has long documented many instances in which the police treats any case in which a car runs over a pedestrian as a no-fault accident, even when the driver was committing such traffic violations as driving on the sidewalk. In addition to enforcement, there’s emphasis on reducing the speed limit in urban areas, from 30 to 20 miles per hour, based on past campaigns in Europe, where speeds were reduced from 50 km/h to 30. Unfortunately, street design for lower speeds and greater traffic safety has taken a back seat. This is not the best way to improve street safety, and is not the standard practice in the countries that have reduced car accident rates the most successfully, namely the UK and the Scandinavian countries.

On high-speed roads, one of the most important causes of fatal accidents is the combination of driver fatigue and sleepiness. For some studies on this problem, see here, here, and here. The second link in particular brings up the problem of monotony: if a road presents fewer stimuli to the driver, the driver is more likely to become less vigilant, increasing the probability of an accident. One study goes on and shows that higher speed actually increases monotony, since drivers have less time to register such stimuli as other cars on the road, but this was obtained in controlled conditions, and its literature review says that most studies find no effect of speed. I emphasize that this does not mean that lower speed limits are ineffective: there’s evidence that reducing highway speed limit does reduce accident rates, with multiple studies collected in a Guardian article, and lower accident rates in France since the state installed an extensive system of speed cameras.

But while speed limit reductions offer useful safety benefits, it is important to design the roads to be slower, and not just tell drivers to go slower. Road monotony is especially common in the United States; per the second study again,

While comparing self-reported driving fatigue in the US and Norway, Sagberg (1999) suggests that the higher prevalence of self reported drowsy driving found in the US may be due to differences in road geometry, design and environment, as well as exposure. He argues that the risk of falling asleep is higher on straight, monotonous roads in situations of low traffic, where boredom is likely to occur. This type of roads is more common in the US than in Norway.

The studies I have consulted look primarily at highways and rural roads; I have not found comparable literature on urban roads, except one study that, in a controlled simulation, shows that drivers are better at gauging their own alertness levels on urban arterials than on rural roads. That said, urban arterials share many design traits that lead to monotony, especially in the United States and Canada:

  • They are usually straight, forming a grid rather than taking haphazard routes originating from premodern or early-industrial roads.
  • They are wide: 4-6 lanes at a minimum, often with a median. Lanes are likely to be wide, closer to 3.7 meters than the more typical urban 3 meters.
  • Development on them usually does not form a strong enclosure, but instead commercial developments are only 1-2 stories, with setbacks and front and side parking lots.

Such roads are called stroads in the language of Charles Marohn, who focuses on issues of their auto-centric, pedestrian-hostile nature. Based on the studies about monotony, I would add that even ignoring pedestrians entirely, they are less safe than slower roads, which prime drivers to be more alert and to speed less. It is better to design roads to have more frequent stimuli: trees, sidewalks with pedestrians, commercial development, residential development to the extent people are willing to live on top of a busy road.

Regarding lane width, one study finds that roads are the safest when lanes are 3-3.2 meters wide, because of the effects of wider lanes on driver speeds. A CityLab article on the same subject from two years ago includes references to several studies that argue that wide lanes offer no safety benefit for drivers, but are hostile to pedestrians and cyclists.

This approach, of reducing speed via road design rather than enforcement, is common in Scandinavia. Stockholm has a few urban freeways, but few arterials in the center, and many of those arterials have seen changes giving away space from cars to public transit and pedestrians. Thus, Götgatan is partly pedestrianized, and Odengatan has center bus lanes and only one moving car lane in each direction; the most important of Stockholm’s streets, Sveavägen, has several moving car lanes in each direction, but is flanked on both sides by medium-rise buildings without setbacks, and speeds are rarely high.

When enforcement happens, the great successes, for example in France under the Sarkozy administration, involve automation. Red light cameras have a long history and are controversial, and in France, Sarkozy lowered the speed limits on many roads and stepped up speed camera enforcement. The UK has extensive camera enforcement as well. Human enforcement exists, but is less common than speed cameras. Thus, the two main policy planks Vision Zero should fight for in the US are,

  1. Road redesign: narrower lanes, wider sidewalks, trees, and dedicated bus and bike lanes in order to reduce the number of car lanes as well as provide more room for alternatives. Zoning laws that mandate front setbacks should be repealed, and ideally so should commercial height limits on arterials. In central cities, some road segments should be closed off to cars, if the intensity of urban activities can fill the space with pedestrians.
  2. Lower speed limits in the cities, enforced by cameras; fines should be high enough to have some deterrent effect, but not so high that they will drive low-income drivers bankrupt.

It is especially important to come up with solutions that do not rely on extensive human enforcement in the US, because of its longstanding problem with police brutality and racism. The expression “driving while black” is common in the US, due to bias the police in the US (and Canada) exhibits against black people. In Europe, even when bias against certain minorities is as bad as in the US, overall police brutality levels are lower in the US by factors ranging from 20 to 100 (see for example data here). In my Twitter feed, black American urbanists express reluctance to so much as call the police on nonviolent crime, fearing that cops would treat them as suspects even if they are the victims. When it comes to urban traffic safety – and so far, Vision Zero in the US is an urban movement – this is compounded by the fact that blacks and other minorities are overrepresented in the cities.

This means that, in the special conditions of US policing, it’s crucial to prevent Vision Zero from becoming yet another pretext for Driving While Black arrests. As it happens, it does not require large changes from best practices in Europe, because those best practices do not involve extensive contact between traffic police and drivers.

Recall last year’s post by Adonia Lugo, accusing Vision Zero of copying policy from Northern Europe and not from low-income American minority communities. As I said a year ago, Adonia is wrong – first in her belief that foreign knowledge is less important than local US knowledge, and second in her accusation that US Vision Zero advocates copy European solutions too much. To the contrary, what I see is that the tone among US street safety advocates overfocuses on punitive enforcement of drivers who violate the speed limit or break other law. Adapting a problem that in Europe is solved predominantly with street design and technology (speed cameras don’t notice the driver’s skin color), they instead call for more policing, perhaps because mainstream (i.e. white) American culture is used to accepting excessive police presence.

Greenbelts Help Cars

A number of major cities, most notably London, have designated areas around their built-up areas as green belts, in which development is restricted, in an attempt to curb urban sprawl. The towns within the green belt are not permitted to grow as much as they would in an unrestricted setting, where the built-up areas would merge into a large contiguous urban area. Seeking access to jobs in the urban core, many commuters instead live beyond the greenbelt and commute over long distances. There has been some this policy’s effect on housing prices, for example in Ottawa and in London by YIMBY. In the US, this policy is less common than in Britain and Canada, but exists in Oregon in the form of the urban growth boundaries (UGBs), especially around Portland. The effect has been the same, replacing a continuous sprawling of the urban area with discontinuous suburbanization into many towns; the discontinuous form is also common in Israel and the Netherlands. In this post, I would like to explain how, independently of issues regarding sprawl, such policies are friendlier to drivers than to rail users.

Let us start by considering what affects the average speed of cars and what affects that of public transit. On a well-maintained freeway without traffic, a car can easily maintain 130 km/h, and good cars can do 160 or more on some stretches. In urban areas, these speeds are rarely achievable during the day; even moderate traffic makes it hard to go much beyond 110 or 120. Peak-direction commutes are invariably slower. Moreover, when the car gets off the freeway and onto at-grade arterial roads, the speed drops further, to perhaps 50 or less, depending on density and congestion.

Trains are less affected by congestion. On a well-maintained, straight line, a regional train can go at 160 km/h, or even 200 km/h for some rolling stock, even if headways are short. The busiest lines are typically much slower, but for different reasons: high regional and local traffic usually comes from high population density, which encourages short stop spacing, such that there may not be much opportunity for the train to go quickly. If the route is curvy, then high density also makes it more difficult to straighten the line by acquiring land on the inside of the curves. But by and large, slowdowns on trains come from the need to make station stops, rather than from additional traffic.

Let us now look at greenbelts of two kinds. In the first kind, there is legacy development within the greenbelt, as is common around London. See this example:

greenbelt1

 

The greenbelt is naturally in green, the cities are the light blue circles with the large central one representing the big city, and the major transportation arteries (rail + freeway) are in black. The towns within the greenbelt are all small, because they formed along rail stops before mass motorization; the freeways were built along the preexisting transportation corridors. With mass motorization and suburbanization, more development formed right outside the greenbelt, this time consisting of towns of a variety of sizes, typically clustering near the freeways and railways for best access to the center.

The freeways in this example metro area are unlikely to be very congested. Their congestion comes from commuters into the city, and those are clustered outside the greenbelt, where development is less restricted. Freeways are widened based on the need to maintain a certain level of congestion, and in this case, this means relatively unimpeded traffic from the outside of the green belt right up until the road enters the big city. Under free development, there would be more suburbs closer to the city, and the freeway would be more congested there; travel times from outside the greenbelt would be longer, but more people would live closer to the center, so it would be a wash.

In contrast, the trains are still going to be slowed down by the intermediate stops. The small grandfathered suburbs have no chance of generating the rail traffic of larger suburbs or of in-city stops, but they still typically generate enough that shutting them down to speed traffic is unjustified, to say nothing of politically impossible. (House prices in the greenbelt are likely to be very high because of the tight restrictions, so the commuters there are rich people with clout.) What’s more, frequency is unlikely to be high, since demand from within the greenbelt is so weak. Under free development, there might still be more stops, but not very many – the additional traffic generated by more development in those suburbs would just lead to more ridership per stop, supporting higher frequency and thus making the service better rather than worse.

Let us now look at another greenbelt, without grandfathered suburbs, which is more common in Canada. This is the same map as before, with the in-greenbelt suburbs removed:

greenbelt2

In theory, this suburban paradigm lets both trains and cars cruise through the unbuilt area. Overall commutes are longer because of the considerable extra distance traveled, but this distance is traversed at high speed by any mode; 120 km/h is eminently achievable.

In practice, why would there be a modern commuter line on any of these arteries? Commuter rail modernization is historically a piecemeal program, proceeding line by line, prioritizing the highest-trafficked corridors. In Paris, the first commuter line to be turned over to the Metro for operation compatible with city transit, the Ligne de Sceaux, has continuous urban development for nearly its entire length; a lightly-trafficked outer edge was abandoned shortly after the rest of the line was electrified in 1938. If the greenbelt was set up before there was significant suburbanization in the restricted area, it is unlikely that there would have been any reason to invest in a regional rail line; at most there may be a strong intercity line, but then retrofitting it to include slower regional traffic is expensive. Nor is there any case for extending a high-performing urban transit line to or beyond a greenbelt. Parts of Grand Paris Express, namely Lines 14 and 11, are extended from city center outward. In contrast, in London, where the greenbelt reduces density in the suburbs, high investment into regional rail focuses on constructing city-center tunnels in Crossrail and Crossrail 2 and connecting legacy lines to them. In cities that do not even have the amount of suburban development of the counties surrounding London, there is even less justification for constructing new transit.

Now, you may ask, if there’s no demand for new urban transit lines, why is there demand for new highways? After all, if there was not much regional travel into these suburbs historically, why would there be enough car traffic to justify high investment into roads? The answer is that at low levels of traffic, it’s much cheaper to build a road than to build and operate a railway. This example city has no traffic generators in the greenbelt, except perhaps parks, so roads are cheap to build and have few to no grade crossings to begin with, making it easier to turn them into full freeways. The now-dead blog Keep Houston Houston made this point regarding a freeway in Portland, which was originally built as an arterial road in a narrow valley and had few at-grade intersections to be removed. At high levels of demand, the ability to move the same number of people on two tracks as on fourteen lanes of freeway makes transit much more efficient, but at low demand levels, rail still needs two tracks or at least one with passing sidings, and high-speed roads need four lanes and in some cases only two.

The overall picture in which transit has an advantage over cars at high levels of density is why high levels of low-density sprawl are correlated with low transit usage. But I stress that even independently of sprawl, greenbelts are good for cars and bad for transit. A greenbelt with legacy railway suburbs is going to feature trains going at the normal speed of a major metro area, and cars going at the speed of a more spread out and less populated region. Even a greenbelt without development is good urban geography for cars and bad one for transit.

As a single exception, consider what happens when a greenbelt is reserved between two major nodes. In that specific case, an intercity line can more easily be repurposed for commuting purposes. The Providence Line is a good example: while there’s no formal greenbelt, tight zoning restrictions in New England even in the suburbs lead to very low density between Boston and Providence, which is nonetheless served by good infrastructure thanks to the strength of intercity rail travel. The MBTA does not make good use of this infrastructure, but that’s beside the point: there’s already a high-speed electrified commuter line between the two cities, with widely spaced intermediate stops allowing for high average speeds even on stopping trains and overtakes that are not too onerous; see posts of mine here and here. What’s more, intercity trains can be and are used for commutes from Providence to Boston. For an analogous example with a true greenbelt, Milton Keynes plays a role similar to Providence to London’s Boston.

However, this exception is uncommon. There aren’t enough Milton Keyneses on the main intercity lines to London, or Providences on the MBTA, to make it possible for enough transit users to suburbanize. In cities with contiguous urban development, such as Paris, it’s easier. The result of a greenbelt is that people who do not live in the constrained urban core are compelled to drive and have poor public transportation options. Once they drive, they have an incentive to use the car for more trips, creating more sprawl. This way, the greenbelt, a policy that is intended to curb sprawl and protect the environment, produces the exact opposite results: more driving, more long-distance commuting, a larger urban footprint far from the core.

A Theory of Zoning and Local Decisionmaking

This weekend there’s a conference in the US, YIMBY 2016, by a national network of activists calling for more housing. I am not there, but I see various points raised there via social media. One is a presentation slide that says “NIMBYism is a collective action problem: no single neighborhood can lower prices by upzoning; might still be in everyone’s interest to upzone at city/state level.” I think this analysis is incorrect, and in explaining why, I’d like to talk about a theory of how homeowners use zoning to create a housing shortage to boost their own property values, and more generally how long-time residents of a city use zoning to keep out people who are not like them. In this view,zoning is the combination of a housing cartel, and a barrier to internal migration.

For years, I’ve had trouble with the housing cartel theory, because of a pair of observations. The first is that, contra the presentation at YIMBY, zoning is driven by homeowners rather than by renters; for an overview, see the work of William Fischel. The second is that restrictive zoning typically correlates with local decisionmaking, such as in a neighborhood or small city, while lax zoning typically correlates with higher-level decisionmaking, such as in a city with expansive municipal boundaries or in an entire province or country; see below for more on this correlation. These two observations together clash with the housing cartel theory, for the inverse of the reason in the above quote from the YIMBY presentation: it’s more effective to create a housing shortage in a large area than in a small one.

To a good approximation, land value equals (housing price – housing construction cost)*allowed density. If a small municipality upzones, then as in the quote, housing price doesn’t change much, but allowed density grows, raising the price a homeowner can get by selling their house to developers who’d build an apartment building. In contrast, if a large municipality upzones then housing prices will fall quite a bit as supply grows, and depending on the price elasticity, land value might well go down. If x = housing price/housing construction cost and e = price elasticity for housing, i.e. price is proportional to density^(-1/e), then maximum land value occurs when x = e/(e-1), provided e > 1; if e < 1 then maximum value occurs when x is arbitrarily large. Price elasticity is much higher in a small municipality, since even a large increase in local housing supply has a small effect on regional supply, limiting its ability to reduce prices. This implies that, to maximize homeowner value, small municipalities have an incentive to set density limits at a higher level than large municipalities, which will be seen in faster housing growth relative to population growth.

What we see is the exact opposite. Consider the following cases, none a perfect natural experiment, but all suggestive:

1. In the Bay Area, we can contrast San Francisco (a medium-size urban municipality), San Jose and generally Santa Clara County (San Jose is medium-size for a central city and very large for a suburb), and San Mateo County (comprising small and medium-size suburbs). San Mateo County is by far the stingiest of the three about permitting housing: over the last three years it’s averaged 1,000 new housing units per year (see here); in 2013, the corresponding figures elsewhere in the Bay Area were 2,277 new housing units in San Francisco and 5,245 in Santa Clara County. Per thousand people (not per housing unit), this is 2.63 in San Francisco, 2.73 in Santa Clara, and 1.31 in San Mateo. In Alameda County, comprising medium-size cities and suburbs, with a less hot housing market because of the distance from Silicon Valley jobs, growth was 2,474 units, 1.51 per 1,000 people. In small rich Silicon Valley municipalities like Palo Alto and Menlo Park, NIMBYs have effectively blocked apartment construction; in much larger and still rich San Jose, the city has a more pro-growth outlook.

2. Among the most important global cities – New York, Paris, London, and Tokyo – Tokyo has by far the fastest housing stock growth, nearly 2% a year; see article by Stephen Smith. In Japan, key land use decisions are made by the national government, whereas in Paris, London, and New York, decision is at a lower level. London builds more than New York and Paris; its municipal limit is much looser than Paris’s, with 8.5 million people to Paris’s 2.2 million even though their metro areas have similar populations. New York has a fairly loose limit as well, but the development process empowers lower-level community boards, even though the city has final authority.

3. Canada has a relatively permissive upzoning process, and in Ontario, the planning decisions are made at the provincial level, resulting in about 1.3% annual housing growth in Toronto in the previous decade; in the same period, San Jose’s annual housing growth was about 1% and San Francisco’s was 0.9%.

4. France has recently made a national-level effort to produce more housing in the Paris region, especially social housing, due to very high housing prices there. Last decade, housing production in Ile-de-France was down to about 30,000-35,000 per year, averaging to 2.6 per 1,000 people, similar to San Francisco; see PDF-pp. 4-5 here and the discussion here. With the new national and regional effort at producing more social housing, plans appear to be on track to produce 30,000 annual units of social housing alone in the next few years; see PDF-p. 6 here. With 7,000 annual units within city limits, Paris expects to build somewhat more per capita than the rest of the region.

In France, the combination of a national focus on reducing housing burden and the observation that higher-level decisionmaking produces more housing makes sense. But elsewhere, we need to ask how come homeowners aren’t able to more effectively block construction.

My theory is that the answer involves internal migration. Consider the situation of Palo Alto: with Stanford and many tech jobs, it is prime location, and many people want to move there. The homeowners are choosing the zoning rule that maximizes their ability to extract rents from those people, in both the conventional sense of the word rent and the economic sense. Now consider decisionmaking at the level of the entire state of California. California can raise housing prices even more effectively than Palo Alto can by restricting development, but unlike Palo Alto, California consists not just of residents of rich cities, but also of residents of other cities, who would like to move to Palo Alto. In the poorer parts of the state, there’s not much point in restrictive zoning, because there isn’t that much demand for new housing, except perhaps from people who cannot afford San Francisco or Los Angeles and are willing to endure long commutes. On the contrary, thanks to the strength of internal migration, a large fraction of prospective residents of Palo Alto live elsewhere in California. Nor do people in poor areas, where houses aren’t worth much as investments, gain much from raising house prices for themselves; the ability to move to where the good jobs are is worth more than raising housing prices by a few tens of thousands of dollars. This means that the general interest in California is to make Palo Alto cheaper rather than more expensive. The same is true of Japan and Tokyo, or France and Paris, or Ontario and Toronto.

While superficially similar to the point made in the presentation quoted at the beginning of this post, my theory asserts the opposite. The issue is not that individual municipalities see no benefit in upzoning since it wouldn’t reduce rents by much. It’s that they see net harm from upzoning precisely because it would reduce rents. It is not a collective action problem: it is a problem of disenfranchisement, in which the people who benefit from more development do not live in the neighborhoods where the development would be taking place. High-level decisionmaking means that people who would like to move to a rich area get as much of a vote in its development policy as people who already live there and have access to its amenities, chief of which is access to work. It disempowers the people who already have the privilege of living in these areas, and empowers the people who don’t but would like to.

Individual rich people can be virtuous. Rich communities never are. They are greedy, and write rules that keep others out and ruthlessly eliminate any local effort to give up their political power. They will erect borders and fences, exclude outsiders, and demagogue against revenue sharing, school integration, and upzoning. They will engage in limited charity – propping up their local poor (as San Francisco protects low-income lifelong San Franciscans via rent control), and engaging in symbolic, high-prestige giving, but avoid any challenge to their political power. Upzoning is not a collective action problem; it is a struggle for equal rights and equal access to jobs regardless of which neighborhood, city, or region one grew up in.

Modeling Anchoring

Jarrett Walker has repeatedly called transit agencies and city zoning commissions to engage in anchoring: this means designing the city so that transit routes connect two dense centers, with less intense activity between them. For example, he gives Vancouver’s core east-west buses, which connect UBC with dense transit-oriented development on the Expo Line, with some extra activity at the Canada Line and less intense development in between; Vancouver has adopted his ideas, as seen on PDF-page 15 of a network design primer by Translink. In 2013, I criticized this in two posts, making an empirical argument comparing Vancouver’s east-west buses with its north-south buses, which are not so anchored. Jarrett considers the idea that anchoring is more efficient to be a geometric fact, and compared my empirical argument to trying to empirically compute the decimal expansion pi to be something other than 3.1415629… I promised that I would explain my criticism in more formal mathematical terms. Somewhat belatedly, I would like to explain.

First, as a general note, mathematics proves theorems about mathematics, and not about the world. My papers, and those of the other people in the field, have proven results about mathematical structures. For example, we can prove that an equation has solutions, or does not have any solutions. As soon as we try to talk about the real world, we stop doing pure math, and begin doing modeling. In some cases, the models use advanced math, and not just experiments: for example, superstring theory involves research-level math, with theorems of similar complexity to those of pure math. In other cases, the models use simpler math, and the chief difficulty is in empirical calibration: for example, transit ridership models involve relatively simple formulas (for example, the transfer penalty is a pair of numbers, as I explain here), but figuring out the numbers takes a lot of work.

With that in mind, let us model anchoring. Let us also be completely explicit about all the assumptions in our model. The city we will build will be much simpler than a real city, but it will still contain residences, jobs, and commuters. We will not deal with transfers; neither does the mental model Jarrett and TransLink use in arguing for anchoring (see PDF-p. 15 in the primer above again to see the thinking). For us, the city consists of a single line, going from west to east. The west is labeled 0, the east is labeled 1, and everything in between is labeled by numbers between 0 and 1. The city’s total population density is 1: this means that when we graph population density on the y-axis in terms of location on the x-axis, the total area under the curve is 1. Don’t worry too much about scaling – the units are all relative anyway.

Let us now graph three possible distributions of population density: uniform (A), center-dominant (B), and anchored (C).

cityA cityBcityC

Let us make one further assumption, for now: the distributions of residences and jobs are the same, and independent. In city (A), this means that jobs are uniformly distributed from 0 to 1, like residences, and a person who lives at any point x is equally likely to work at any point from 0 to 1, and is no more likely to work near x than anyone else. In city (B), this means that people are most likely to work at point 0.5, both if they live there and if they live near 0 or 1; in city (C), this means that people are most likely to work at 0 or 1, and that people who live at 0 are equally likely to work near 0 and near 1.

Finally, let us assume that there is no modal splitting and no induced demand: every employed person in the city rides the bus, exactly once a day in each direction, once going to work and once going back home, regardless of where they live and work. Nor do people shift their choice of when to work based on the network: everyone goes to work in the morning peak and comes back in the afternoon peak.

With these assumptions in mind, let us compute how crowded the buses will be. Because all three cities are symmetric, I am only going to show morning peak buses, and only in the eastbound direction. I will derive an exact formula in city (A), and simply state what the formulas are in the other two cities.

In city (A), at point x, the number of people who ride the eastbound morning buses equals the number of people who live to the west of x and work to the right of x. Because the population and job distributions are uniform, the proportion of people who live west of x is x, and the proportion of people who work east of x is 1-x. The population and job distributions are assumed independent, so the total crowding is x(1-x). Don’t worry too much about scaling again – it’s in relative units, where 1 means every single person in the city is riding the bus in that direction at that time. The formula y = x(1-x) has a peak when x = 0.5, and then y = 0.25. In cities (B) and (C), the formulas are:

(B): y = \begin{cases}2x^2(1 - 2x^2) & \mbox{ if } x \leq 1/2\\ 2(1-x)^2(1 - 2(1-x)^2) & \mbox{ if } x > 1/2\end{cases}

(C): y = \begin{cases}(2x-2x^2)(1 - 2x + 2x^2) & \mbox{ if } x \leq 1/2\\ (2(1-x)-2(1-x)^2)(1 - 2(1-x) + 2(1-x)^2) & \mbox{ if } x > 1/2\end{cases}

Here are their graphs:

cityAcrowd cityBcrowd cityCcrowd

Now, city B’s buses are almost completely empty when x < 0.25 or x > 0.75, and city C’s buses fill up faster than city A’s, so in that sense, the anchored city has more uniform bus crowding. But the point is that at equal total population and equal total transit usage, all three cities produce the exact same peak crowding: at the midpoint of the population distribution, which in our three cases is always x = 0.5, exactly a quarter of the employed population lives to the west and works to the east, and will pass through this point on public transit. Anchoring just makes the peak last longer, since people work farther from where they live and travel longer to get there. In a limiting case, in which the population density at 0 and 1 is infinite, with half the population living at 0 and half at 1, we will still get the exact same peak crowding, but it will last the entire way from 0 to 1, rather than just in the middle.

Note that there is no way to play with the population distribution to produce any different peak. As soon as we assume that jobs and residences are distributed identically, and the mode share is 100%, we will get a quarter of the population taking transit through the midpoint of the distribution.

If anything, the most efficient of the three distributions is B. This is because there’s so little ridership at the ends that it’s possible to run transit at lower frequency at the ends, overlaying a route that runs the entire way from 0 to 1 to a short-turn route from 0.25 to 0.75. Of course, cutting frequency makes service worse, but at the peak, the base frequency is sufficient. Imagine a 10-minute bus going all the way, with short-turning overlays beefing frequency to 5 minutes in the middle half. Since the same resources can more easily be distributed to providing more service in the center, city B can provide more service through the peak crowding point at the same cost, so it will actually be less crowded. This is the exact opposite of what TransLink claims, which is that city B would be overcrowded in the middle whereas city C would have full but not overcrowded buses the entire way (again, PDF-p. 15 of the primer).

In my empirical critique of anchoring, I noted that the unanchored routes actually perform better than the anchored ones in Vancouver, in the sense that they cost less per rider but also are less crowded at the peak, thanks to higher turnover. This is not an observation of the model. I will note that the differences in cost per rider are not large. The concept of turnover is not really within the model’s scope – the empirical claim is that the land use on the unanchored routes lends itself to short trips throughout the day, whereas on the anchored ones it lends itself to peak-only work trips, which produce more crowding for the same total number of riders. In my model, I’m explicitly ignoring the effect of land use on trips: there are no induced trips, just work trips at set times, with 100% mode share.

Let us now drop the assumption that jobs and residences are identically distributed. Realistically, cities have residential and commercial areas, and the model should be able to account for this. As one might expect, separation of residential and commercial uses makes the system more crowded, because travel is no longer symmetric. In fact, whereas under the assumption the peak crowding is always exactly a quarter of the population, if we drop the assumption the peak crowding is at a minimum a quarter, but can grow up to the entire population.

Consider the following cities, (D), (E), and (F). I am going to choose units so that the total residential density is 1/2 and so is the total job density, so combined they equal 1. City (D) has a CBD on one side and residences on the other, city (E) has a CBD in the center and residences on both sides, and city (F) is partially mixed-use, with a CBD in the center and residences both in the center and outside of it. Residences are in white, jobs are in dark gray, and the overlap between residences and jobs in city (F) is in light gray.

cityD cityE cityF

We again measure crowding on eastbound morning transit. We need to do some rescaling here, again letting 1 represent all workers in the city passing through the same point in the same direction. Without computing, we can tell that in city (D), at the point where the residential area meets the commercial area, which in this case is x = 0.75, the crowding level is 1: everyone lives to the west of this point and works to its east and must commute past it. Westbound morning traffic, in contrast, is zero. City (E) is symmetric, with peak crowding at 0.5, at the entry to the CBD from the west, in this case x = 0.375. City (F) has crowding linearly growing to 0.375 at the entry to the CBD, and then decreasing as passengers start to get off. The formula for eastbound crowding is,

(F): y = \begin{cases}x & \mbox{ if } x < 3/8\\ x(5/2 - 4x) & \mbox{ if } 3/8 \leq x \leq 5/8\\ 0 & \mbox{ if } x > 5/8\end{cases}

cityDcrowd cityEcrowd cityFcrowd

In city (F), the quarter of the population that lives in the CBD simply does not count for transit crowding. The reason is that, with the CBD occupying the central quarter of the city, at any point from x = 0.375 east, there are more people who live to the west of the CBD getting off than people living within the CBD getting on. This observation remains true down to when (for a symmetric city) a third of the population lives inside the CBD.

In city (B), it’s possible to use the fact that transit runs empty near the edges to run less service near the edges than in the center. Unfortunately, it is not possible to use the same trick in cities (E) and (F), not with conventional urban transit. The eastbound morning service is empty east of the CBD, but the westbound morning service fills up; east of the CBD, the westbound service is empty and the eastbound service fills up. If service has to be symmetric, for example if buses and trains run back and forth and make many trips during a single peak period, then it is not possible to short-turn eastbound service at the eastern edge of the CBD. In contrast, if it is possible to park service in the center, then it is possible to short-turn service and economize: examples include highway capacity for cars, since bridges can have peak-direction lanes, but also some peaky commuter buses and trains, which make a single trip into the CBD per vehicle in the morning, park there, and then make a single trip back in the afternoon. Transit cities relies on services that go back and forth rather than parking in the CBD, so such economies do not work well for them.

A corollary of the last observation is that mixed uses are better for transit than for cars. Cars can park in the CBD, so for them, it’s fine if the travel demand graph looks like that of city (E). Roads and bridges are designed to be narrower in the outskirts of the region and wider near the CBD, and peak-direction lanes can ensure efficient utilization of capacity. In contrast, buses and rapid transit trains have to circulate; to achieve comparable peak crowding, city (E) requires twice as much service as perfect mixed-use cities.

The upshot of this model is that the land use that best supports efficient use of public transit is mixed use. Since all rich cities have CBDs, they should work on encouraging more residential land uses in the center and more commercial uses outside the center, and not worry about the underlying distribution of combined residential and job density. Since CBDs are usually almost exclusively commercial, any additional people living in the center will not add to transit crowding, even as they ride transit to work and pay fares. In contrast, anchoring does not have any effect on peak crowding, and on the margins makes it worse in the sense that the maximum crowding level lasts longer. This implies that the current planning strategy in Vancouver should be changed from encouraging anchoring to fill trains and buses for longer to encouraging more residential growth Downtown and in other commercial centers and more commercial growth at suitable nodes outside the center.

Local and Global Knowledge

Adonia Lugo has a post criticizing Vision Zero, an American movement that aims at reducing the number of pedestrian and cyclist deaths from car accidents to zero. Adonia makes a lot of criticisms regarding lack of diversity within US bike advocacy, which I’m not going to discuss because I’m only tangentially familiar with it, via the general urbanist connection to Streetsblog. Instead, I’m going to zoom on one criticism, in which Adonia also invokes transit: Vision Zero activists look to a slate of European countries for guidance on making streets safer, including Sweden (which, alongside Norway and Denmark, has nearly the lowest car accident death rates in the world), and Denmark and the Netherlands (which are famous for their urban cycling facilities). Adonia’s response is,

With my inclusion filter on, it sounded like another example of white bike advocates looking to Northern Europe for solutions instead of turning to urban communities in the U.S. to find out how they’ve managed to get by walking, biking, and using transit all these years.

This is where I lost sympathy. What Adonia is asking, essentially, is for more respect for her (and her peer group’s) local knowledge, which is based on American cities in which few people who can afford cars take other modes of transportation. In the entire US, the only city where significant numbers of people who can afford cars take public transportation is New York, and there is not a single city where significant numbers of people who can afford cars ride bikes to work. This means that any discussion of improving transit access must include at least some knowledge of what happens outside the US.

Local Knowledge and Denigration

The problem is that talking about what happens outside the US shifts the locus of expertise from people with local knowledge to people with global knowledge. If an American city talks about adopting ideas from one of its neighborhoods, or even from a nearby city, there’s a lot of local knowledge, in the form of people who live or have lived in that area, or know many people who live there, and can evaluate a policy as to its success or failure. Internationally, there isn’t any, outside specialized forums; even highly educated Americans are usually monolingual, have never lived outside the US, and aren’t really plugged into the political debates in other countries, except maybe Canada.

The result is denigration. I’m not very plugged into cycling advocacy, so I’m going to use public transit for concrete examples. I have accepted that whenever I propose that comes from another country, someone is going to say “that’s there, this is America.” I definitely got this response when I started proposing modernizing regional rail in New York: “you are not a real New Yorker.” New York is the worst in the US in that it resists any ideas from other cities, even domestically.

It’s ultimately a defense mechanism against something that’s literally foreign, which the activist cannot evaluate because they and the people they trust haven’t really seen this in action. Thus, many Americans choose to believe that US public transportation is not a failure, that it’s just in bad circumstances and has little to learn from Europe. I’ve seen New Yorkers make remarks such as “there is no history of underinvestment in Europe” (yes, there is – look at Berlin during the Cold War, or at the removal of streetcars in postwar France and West Germany).

For example, I’ve found that bringing up Stockholm as an example of good transit in the US gets me accused of trolling, repeatedly, more so than bringing up London or Paris. The reason is that, to New York-based readers, London and Paris are almost peer cities, and to other Americans, London and Paris are equivalent to New York; therefore, they match the perception that public transit works in old, huge cities, but not in smaller or newer ones. In some ways, I think Stockholm is a better example of what US cities should aspire to, precisely because it is a small city. It is also not as old as London or Paris; between 1950 and 2010, Stockholm County’s population grew by a factor of 1.9, whereas metro Philadelphia’s grew by a factor of about 1.6, Boston’s by a factor of 1.4, and Chicago’s by a factor of 1.7. Boston in particular had a very good public transit network in 1950, and it systematically dismantled it and bypassed the remains, so that the metro area public transit mode share is only 11%. Expressed differently, metro Boston has 55 annual rail trips per capita, whereas New York has 95 and Stockholm 200. Of course, the cities of the US Sunbelt have had far more postwar growth than Stockholm (though many are comparable to Vancouver) and even lower transit usage than Boston and Philadelphia, and there indeed wholesale imports of European ideas are less practical. But it says a lot that in the oldest US cities, with the street layout most similar to most of Europe’s cities’, transit usage is still very low.

Adonia denigrates ideas she considers racist, but this denigration cuts across political and tribal lines in the US. I have seen considerable denigration from American urbanists that city centers could ever be family-friendly whenever I mention generations of families living in the central parts of Tel Aviv, or Vancouver, or Stockholm. There’s even a Twitter account dedicated to this denigration, The Suburbanist. Of course, what’s missing is the history of white flight and racism – not that Israel, Canada, and Sweden are less racist than the US, but their racism did not involve leaving inner cities to low-income minorities. But mentioning that cities aren’t bad places for families reminds certain people that they’re leaving the cities because they don’t like minorities, so they lash out. Nowadays, the Suburbanist engages in open racism, but this wasn’t the case a few years ago, nor is it the case with a large number of Americans who, in comments on various blogs (never here as far as I remember), yell at me for bringing up foreign cities.

Not Invented Here, Periphery Version

When planners and managers denigrate foreign ideas, this is called Not Invented Here syndrome. It is common in American transportation planning. I believe the reason Vision Zero sticks to “it works in Scandinavia” is to at least try to confront those planners with the fact that, by international standards, they have failed to promote road safety, especially for pedestrians and cyclists. Certainly this is the reason I bring up the failure of every US city except New York to maintain respectable public transit usage.

Now, the two centers of public transportation innovation in the world – Europe and Japan – brim with their own NIH problems, toward each other. Their rolling stock markets are almost entirely distinct, due to a combination of protectionism and regulations. Japan is outside the European Train Control System umbrella and keeps developing its own signal systems, while ETCS in turn is based on the features of older systems in the major European countries and not in Japan. Japan lags Europe in automation (driverless metros are less common there), track capacity in trains per hour, and small-city cost-cutting innovations such as proof of payment. Europe in turn has higher big-city operating costs, more accidents, less punctual trains, and usually heavier trains. Both of those centers would benefit from adopting each other’s ideas.

And yet, things work. There is enough indigenous transit expertise in Japan that despite missing out on European innovations, Japanese transit systems work well. There has to be; Tokyo has comfortably not only the highest rail ridership in the world, but also the highest rail ridership per capita, about 400 annual trips, versus 200-250 in the most transit-oriented European cities. Of course, Europe’s own indigenous expertise is nothing to scoff at, either.

The US is not in the center of public transportation. I am going to develop this center-periphery dynamic in a later post, tentatively called Unbroken Country: The Periphery’s Manifesto, which will also go specifically into Israel’s domestic problems with public services. But, in short, the US acts as if it is in the center, since it is one of the centers of the global economy, and is the undisputed center of global society and culture. This is what leads to NIH syndrome and denigration – Americans think they’re doing well because, in most aspects, they are. But when it comes to transportation, the US is a peripheral region (even road construction techniques lag Europe’s), and thus, its NIH problems deprive the public discourse of much-needed knowledge.

For a concrete example, let us consider rail signaling. ETCS Level 2 is designed around the needs of the biggest European countries, where the main lines are at least double-track, there is much more passenger traffic than freight traffic, freight trains are light because bulk freight goes by sea, and the population density near the main lines is high. Neither the US nor Sweden fits this. Most importantly, both countries have highly-trafficked freight lines passing through remote territory – Norrland in Sweden, the Interior West in the US. Sweden, which does not have NIH syndrome with respect to the rest of Europe, worked on developing a lower-cost version of ETCS, called ERTMS Regional; but in the US, the freight railroads as well as the commuter railroads (even in the Northeast, where ETCS Level 2 is appropriate) ignored ETCS entirely and developed their own incompatible systems, on the grounds that ETCS doesn’t meet unique American needs.

The Mystery of the Foreign

People who don’t know something often consider people who do know it to be mysterious, almost magical. It is a commonplace that, in low-literacy cultures, illiterates viewed the written word as magical; see this account of Early Modern Italy, but also a counterpoint from Ancient Greece. Of course, literacy in the first world today is universal, but two to three more modern examples persist, of relevance to US transit advocacy:

  1. Math, among people who are not mathematically- or technically-minded. I was asked recently whether my background as a mathematician influences my blogging, and explained that I use fairly basic math, but I am not afraid of numbers, which means I am not afraid of trying to compute cost figures, train speeds, and so on. I am also secure enough in my mathematical knowledge that I am not afraid of nitpicking technical points, or of being nitpicked.
  2. Foreign languages, among monolinguals. I do not know enough monolingual Hebrew speakers to confirm this in generality, but monolingual Anglophones seem to treat foreign-language information as somewhat magical. For example, the vibe I have been getting both here and on Twitter is that if I cite a foreign-language Wikipedia this gets more respect than if I cite English Wikipedia. The monolingual Anglophone can verify an English Wikipedia citation, and maybe notice small mistakes in the article, but not a foreign-language citation.
  3. This may be the same as 2, but, foreign experience. Relatively few native-born Americans have lived outside the US, so people who do are treated as having unique expertise about the country or continent they were in.

Point 3 applies even to knowledge obtained by other means than living in a country. In 2005, when progressive pundits were talking about how to implement universal health care, there was so little knowledge about how universal health care systems worked that Ezra Klein became an A-list pundit out of a few short profiles of various countries’ health care systems, The Health of Nations (see 2007 version here). I, of course, have gotten a lot of mileage out of Googling various cities’ subway construction costs and putting them together.

The problem with viewing the foreign as mysterious is that it leads to wholesale import of ideas that may not work, or may require significant tweaks before working. Bus rapid transit, an efficient mode of travel in middle-income Bogota and Curitiba, does not port to high-income cities well: paying six bus drivers rather than one train driver to avoid spending money on rail construction is a bigger problem in a country with a GDP per capita of $40,000 than in a country with a GDP per capita of $13,000. There are successful tweaks, such as open BRT (see description here), but Jaime Lerner and ITDP have pushed Curitiba-style closed BRT. Here, the lack of detailed knowledge about what exactly makes BRT work leads American cities – and no European or Japanese cities – to propose ill-thought closed BRT.

Another example of a bad import caused by this kind of magical thinking is the mixed-traffic streetcar. Here, American transit advocates don’t just think in terms of “Europe has trams” but also in terms of “the US used to have trams but we ripped them all up in the 1950s.” Here, US cities import a mode of transportation that exists as a legacy around Europe, but is uncommon on new-build lines, and is used mainly as a compromise when the streets are so narrow it’s impossible to give streetcars dedicated lanes without closing the streets to car traffic. As the US does not have cities with such narrow streets, outside a few old neighborhoods in Boston and New York with good subway service, its import of mixed-traffic streetcars is bad transit.

This relates to the point I made above, about local knowledge and bullshit. I know that many people view me as somewhat mysterious for having such a different knowledge base from Americans. It means I can comfortably bullshit about many points. I don’t bullshit, but it’s likely I’m making some mistakes, and I try to encourage my commenters to check me on them. But this requires commenters who are also very technically-minded and don’t think that just because I say something, it must be true.

Trust

In a sociopolitical environment in which the public and the activists have very little knowledge about imported ideas, whether they support them (usually viewing them as magical) or oppose them (usually denigrating them) is based on whether they identify with and trust the people proposing the import. Adonia does not trust the people who promote Vision Zero, since she views them as too white and male and too insensitive to the concerns of nonwhites, for example regarding police enforcement of speed limits. Conservatives, in turn, do not trust those people because they view them as cosmopolitan liberal urbanites, whence Tea Party opposition to various commuter and intercity rail expansions.

Consider high-speed rail, which is entirely a foreign import. The political coalitions for and against HSR in the US are based entirely on cultural identification with the proposition that Europe is better at something than the US. In particular, business-class small-government conservatives, who tend to be big fans of HSR in the countries where it exists, hate it in the US; George Will claimed it would make Americans more amenable to collectivism, and in Texas, right-wing populists have tried blocking an entirely private HSR scheme and possibly connecting it to the Democrats. In contrast, the populist left in the US (for example, Robert Cruickshank) supports public transportation infrastructure because of the environmentalist tie-in; in contrast, in the UK, Jeremy Corbyn, who Robert is otherwise a big fan of, is at best lukewarm toward HS2. In Europe, the left is more pro-rail than the right, but the populists on both sides are more anti-rail, and the overall left-right gradient is small; in the US, the left-right gradient is large, and this comes from the issue of trusting the transportation program of countries that Americans associate with welfare-state social democracy.

The result is that any dialog based on foreign transit has to involve a certain amount of mystery and trust in the planners. I have no trust in the planners, because of various wheel reinventions proposed even by reformists, but I know enough to discuss technical items and not just the people. Generally, other people with this technical background come from a similar social background: educated, geographically mobile, white, male. The result is that, as with HSR, people’s opinions on these projects track their opinions of the tribe in the US that can talk at this level of technical detail. Usually it’s not even racial, not when it comes to transit – it’s mostly suburbanites looking for ways to screw the urbanites. If anything, nonwhite neighborhoods in the US are underserved relative to best practices, and agencies sometimes sandbag the idea of more service there. Adonia just weaponizes this in a different direction from the usual.

Local and Global Knowledge

I’m not going to rule out the possibility that there is valuable local knowledge in the US about cycling, but I know that there is very little such knowledge about transit, and given where the high cycling use is, I doubt cycling is much different. This means that American knowledge alone is worth approximately nothing. Jarrett Walker is of course American and has a lot to contribute, but as a consultant, he has extensive Australian and Canadian experience and some East Asian experience. The bus grid as an idea predates Jarrett – Jarrett attributes it to (at least) 1980s-era reforms in Portland – but by itself it’s not a game changer.

The problem here is that to implement something successfully, the people who run it need both local knowledge and knowledge about places that work, i.e. global knowledge. If there aren’t enough people with both, the solutions will not work, because people who can’t contradict what the planners are saying can’t exercise democratic accountability over them. One of the reasons Europe does transit better is that there’s more foreign knowledge here; see above for the contrast between how the US and Sweden handle rail signaling.

In fact, if you look at the examples above in the Mystery of the Foreign section, they both come from failure to adapt a successful foreign system to local conditions – namely, high wages in the case of BRT, and wide streets in the case of trams. I presume that the people who build mixed-traffic streetcars and BRT lines in the US have plenty of local knowledge, but they lack the global knowledge to appreciate what exactly makes those systems successes abroad. Conversely, international consultants don’t have the local knowledge to say “no, this is not a good fit for your needs” (besides, usually that’s not what they’re paid to say). This problem is especially acute with innovations in developing countries, such as BRT, since the large gap in incomes leads to different situations requiring major changes in adaptation, much more so than the relatively minor differences within the developed world.

Now, consultants can pick up local knowledge. Their trade is not just to possess global knowledge, but also to know how to acquire local knowledge rapidly when they’re working in a city. They run surveys, look at detailed breakdowns of costs and ridership to tease out patterns, quiz the in-house planners, and travel all over the city to gain ground-level impressions. The problem is that if the consultants are the only people who have both local and global knowledge, then there is no democratic accountability, and they have an incentive to bullshit. Of course, Jarrett specifically does not bullshit, but he has occasionally made mistakes (the main one, anchoring, I’ve been meaning to write about for two years), and of course my personal trust in one consultant is no substitute to systemic, institutional trust in the ability of the technocrats to response to what is essentially peer-review practiced by the community of local advocates.

It means the only way forward is for activists in US cities to pick up global knowledge and engage with such plans on the details. In the case of cycling, I could think of any number of reasons why US cities cannot emulate the success of Amsterdam and Copenhagen; but then again, it’s possible these reasons are all irrelevant, in the same manner many reasons Americans offer for why they cannot have the same per capita transit usage of Sweden are irrelevant.

I am also suspicious of the fact that, per Adonia, bike advocates look to Northern Europe as a source of examples of success. The biggest bike share systems in the world are all in China, and in Japan, bikes have largely replaced buses as the preferred mode of access to the train station in the suburbs. US bike advocates owe it to themselves and to their cities to be informed about Chinese and Japanese practices, and, if they clash with Dutch and Scandinavian practices, then to have opinions about which ones to pick and how to synthesize them in a local context. The only way forward for people in the periphery, by which I mean all of the US when it comes to any non-car transportation, is to know how the core works well enough that they can adapt its innovation without being so reliant on outside experts.

Cities and Immigration

There are various observations I would like to make about the urban geography of immigrants: where immigrants often land, what neighborhoods they prefer, how they differ both from the preference of natives, and how they differ from the policies that governments, run by enfranchised voters, implement. Many of the points I’m about to make I’ve made in comments before, on the Urbanophile and other urbanist blogs. I was compelled to write this by the news stories of the migration wave of Syrian refugees into Europe, but I would like to stress that I am writing about both labor migration and humanitarian migration, and that this post has been on my to-do list for years. The points here are often true of nearly all classes of immigrants: refugees, low-skill work migrants, high-skill work migrants; only family reunification is outside the scope of this post, but even family reunification usually consists of the family of a migrant immigrating as well.

The dominance of rich regions

Eurostat has regional per capita income figures for most of Europe. After subtracting rent and interest payments, incomes in London are 46% higher than in the United Kingdom as a whole, and twice as high as in depressed regions such as Birmingham and Sheffield. In Ile-de-France, the incomes are 38% higher than in France as a whole and 65% higher than in depressed regions such as Nord-Pas-de-Calais. In Northern Italy, the incomes are 80% higher than in Southern Italy, while if we compare the richer parts of the North (e.g. Lombardy) with the poorer parts of the South (e.g. Sicily and Naples), the gap grows to a factor of two, as in the UK. In all three countries, the rich regions have far more immigrants per capita than the poor regions. As of the 2011 census, 13.4% of the population of England and Wales is foreign-born, but in London, this rises to 36.7%. In France, 8% of the population consists of immigrants, but in Ile-de-France it rises to 17%: see PDF-p. 24 of an INSEE factsheet, and note also the table at the top of the page, showing far fewer immigrants live in rural areas than natives. In Italy, a breakdown per region shows 8-11% of the people in the Northern and Central regions are immigrants compared with 2-4% in the Southern ones.

Let us go over the reasons why. After all, in principle, both immigrants and natives are more interested in earning high incomes than in earning low incomes. So to see this, let us look at the situation from the point of view of someone who grew up in a poor region of such a country. The Brummie, the Sheffielder, and the Liverpudlian know that the Londoner makes more money than they do. But they can’t just move to London and expect to earn the same income a native Londoner earns. Their local social networks are precisely the ones they can rely on for job search tips, and after they’ve begun working they acquire local bosses who can give them reference letters, and neither group lives in London; this means that they’d make far less money than an equally qualified Londoner if they moved. This is on top of the personal disutility one suffers when moving, independently of the wage. This is less true of highly educated workers, who move in national and even international networks, whence the brain drain problem in rural and depressed areas.

Of course, immigrants short-circuit this, because immigrants usually come into the country without a social network in either its rich core or its depressed periphery. Logically, they go to where there are jobs, and to where the jobs pay more.

Immigrant networks

The situation I described above is true for first entrants. Once a community establishes itself in a city, the situation for the new immigrant changes. An Indian who wishes to emigrate to Canada can often rely on networks of Indian-Canadians, both first- and second-generation. This Indian’s situation is the exact opposite of that of the native of a depressed region: the native of Atlantic Canada, the poorest region of English Canada, has a social and professional network in their home area but not in Toronto or the other major cities; the Indian has a social network in Toronto and Vancouver but not in Atlantic Canada. This means that even when the income advantage of the traditionally rich cities disappears, immigrants will keep moving to them.

For three examples of this principle, let us look at the UK, Canada, and finally the US. In the UK, look at the table above again, and observe that, after London and the Southeast, the part of Britain with the highest foreign-born percentage is the West Midlands (the region, not the county), with 11.2%. This is because Birmingham used to be a rich city: Jane Jacobs compares it favorably with Manchester in The Economy of Cities, published in 1970. It declined in the 1970s, but by then the South Asian migration wave to Britain was already well underway. In Canada, Vancouver and Toronto remain rich, but Calgary has far surpassed them in incomes due to the oil boom, and is only now receiving comparable numbers of immigrants; 26% of its population is foreign-born, versus 40% of Metro Vancouver and 46% of the Greater Toronto Area (see data here). Finally, in the US, Los Angeles has remained one of the top destinations for immigrants, even though its incomes have slipped far below those of not only New York and San Francisco, but also Boston, Chicago, Minneapolis, Denver, and other cities that are only beginning to see the same immigration numbers Los Angeles has had for decades. In general, the states bordering Mexico have long had elevated numbers of Mexican immigrants, going back to the braceros and even before, ultimately tracing to the large Mexican presence in those states after the US conquered them in the Mexican War.

Once there is an established community of immigrants from a particular country or ethnic group, they of course encourage further migration, in addition to shaping the migration to reach the same regions and city neighborhoods. This can take the form of social networks for community support and for finding work, but also the form of knowledge of migration routes. See, for example, a Guardian article from yesterday explaining the Syrian migration wave as a result of years of social learning in Syria of the best routes for trekking into Western Europe. Conceivably this could also include legal knowledge of how to apply to asylum and which countries have the most favorable policies.

At the same time, as the national or ethnic community in the target country gets larger, it begins to exhibit domestic ethnic dynamics more than immigrant dynamics. Part of it is that the immigrants eventually naturalize and acquire voting rights and enough informal political power to have some influence over how their city is run. Part of it is that after a few decades there’s a rising cadre of well-assimilated second-generation immigrants. Part of it is that between the presence of a community and a natural trend of drift in which the relative incomes of cities in the target country change, immigrants eventually behave more like native Brummies and Sheffielders. As a result, most of what I say is true largely of recent immigrants, and gradually becomes less true of people who immigrated decades ago.

The primacy of work

Nearly all immigrants intend to work for a living. This is obviously true of work migrants, of all classes, but it’s also true of refugees, which leads many nativists to mock them for not really seeking asylum but taking jobs from natives. One particularly cruel article that appeared in my Twitter feed from multiple sources, proposing to detain asylum seekers and confine those who meet the criteria for refugees to restricted areas far from the job-rich core, makes the point that people who try to move to where there are jobs are (illegal) work migrants.

The reality is that one of people’s basic needs is work. Idleness is not a normal state of affairs for a person; when as many as a quarter of the people in the workforce are unemployed, it’s a depression and a national crisis. In developing countries there is a lot of covert unemployment, in the sense that (especially in rural areas) a large majority of workers may be redundant if first-world technology is imported, but people still work for a living and earn a wage. In India, to take an example of a third-world country in a state of peace, the unemployment rate was 2.7% as of 2013. To say that a migrant who wants work is necessarily a work migrant is equivalent to saying that a migrant who wants shelter is moving to the first world for its higher housing quality and that a migrant who wants their children to be able to go to school is moving to the first world for its better schools. This need for work drives everything: immigrants from poor countries will work under the table, take jobs far below their skill level, and scab, and they’ll make sure they stay employed, as they would at home, except that these compromises wouldn’t really be necessary, since the third world has much more unskilled work to do.

That said, the need to work in an environment where the migrant has no local social network is the primary determinant of where the migrant lives. Given free choice, immigrants tend to cluster where there is easy access to jobs, ideally on foot in order to avoid paying exorbitant sums of money for a car. A rapid transit network makes it easier for people to disperse; in its absence, as in Tel Aviv, the migrants will cluster in a few cheap central neighborhoods, but even when it exists, migrants will try living where they can get to work easily. The greatest concentration of immigrants in Ile-de-France is in Seine-Saint-Denis, an inner-suburban department that in most other countries would be an outer neighborhood of Paris.

Finally, I wish I didn’t have to explain this, but given that it’s a politically charged issue right now, we see a lot of nativist complaints that immigrants are not seeking work, but welfare. The above article is one example of the genre, ultimately defining every social service immigrants use, such as schools, as welfare. Another example is a report by the anti-immigration Center for Immigration Studies, which finds that under a definition of welfare that excludes programs used by retirees (i.e. a large majority of US social spending), immigrants to the US use welfare more than native-born Americans.

The “work or welfare?” question can be answered directly by looking at where immigrants go when they get the chance. And the answer is decisively work. Welfare is to a first-order approximation the same throughout England or France; and yet, immigrants don’t choose to live in cheap areas of those countries to stretch the pounds and euros longer, but instead cluster in the cities where the jobs are. Scotland has a more generous welfare state than England, but it actually has fewer immigrants, about 6.5%. Singapore, with no welfare state whatsoever, tops the list of countries that people in a global Gallup poll expressed a desire to move to relative to its population; it’s followed by Saudi Arabia, New Zealand, Canada, and Australia (all five have already taken in many immigrants, making this a global version of the point I made about established communities). New York and San Francisco, whose biggest government interventions in the market, their rent control and public housing schemes, only benefit natives and people who immigrated decades ago, keep getting new immigrants of all social classes who are willing to pay exorbitant rents to have access to their strong local job markets. In contrast, rich suburban school districts in the Northeastern US only get upwardly-mobile professional immigrants.

In the rest of this post, I will expound on what the primacy of work means for housing policy.

Housing choice, overcrowding, and prejudice

Within a given city, immigrants do not choose where to live on the same criteria as natives. First, and this applies to immigrants of all categories and even to some domestic migrants, they lack the prejudices of locals. New Yorkers know which neighborhoods of the city are good and which are bad, whatever good and bad mean. New York is globally famous due to the influence of American media; in Israel, all that’s penetrated the cultural barrier is that Manhattan is the center, Brooklyn exists and has a lot of Jews (I remember being puzzled at why Super Mario isn’t Jewish when I was 10), and Harlem is a poor black neighborhood. In 2006, a few weeks after I moved to New York, I was in Bedford-Stuyvesant for an event, and nothing about the neighborhood looked poor to me. With my American cultural knowledge today I’d be able to tell that project towers, certain kinds of bodegas, and large concentrations of black people in that part of Brooklyn all correlate with poverty, but at the time, I couldn’t. I’m not the only one: a white Canadian blogger I know who moved to New York a few years before I did walked around Bed-Stuy looking for an apartment and found it nice, and when they reported where they were on a forum, people’s reactions were a mix of horror and outrage: “you’re crazy, you could have been killed” and “you evil gentrifier.”

Second, as a subset of the principle that new immigrants are more likely to move to the rich core cities than to poorer peripheral cities, new immigrants tend to be in the center of the city than in the suburbs (and again, this also somewhat applies to domestic migrants). Suburban jobs often pay less – the highest-earners in the favored-quarter suburbs in the US commute to the primary CBD, whence for example Daniel Kay Hertz’s observation that in suburban Chicago and Philadelphia, transit riders (CBD-bound commuter rail riders) outearn drivers. Here, there is a split between skilled and unskilled migrants. Skilled migrants often move to a city because, in the specialized global economy, their skills are a good fit for its primary industry; this means that if they’re moving to the Bay Area, it’s usually to work in the software industry or at one of the universities, rather than to be lawyers or accountants, which means their housing choice is disproportionately oriented toward where those industries cluster. Unskilled migrants have to consider transportation costs, making it hard to live in the suburbs, and on top of that, unless they’ve already been matched to a suburban employer to get a work visa (for example, to work as a maid in a particular house), it’s easier for them to find work in the central city.

For migrants from developing countries, there is one more consideration, which leads to the most glaring feature of low-income immigrant neighborhoods: people in the third world make more compromises on housing space to have access to jobs, leading to overcrowding. It’s often a step up from where they’re from anyway. New York has a profile of each of its community boards, based on the most recent census; before the move from the long-form 2000 census to the short-form 2010 census, there was detailed data about income, education, and crowding in each census tract, and the most overcrowding in Manhattan was not in the poorest neighborhood (East Harlem) but in Chinatown.

The basic issue here is that low-income immigrants from developing countries are unlikely to make enough money to cover rent at what first-world natives consider a respectable living standard. There’s a certain minimum housing quality in the developed world: minimum unit size, insulation, indoor plumbing, electricity, construction materials. It’s hard to violate these regulations, because buildings are conspicuous – for the same reason, there’s no equivalent of Uber or Airbnb for housing that bypasses zoning laws. But as the Airbnb example shows, it’s easy enough to subvert or outright ignore regulations about who occupies a residential unit. Hence, immigrants economize on space, either living multiple unrelated adults to a room (as black refugees do in South Tel Aviv) or housing a large extended family in a suburban house meant for a nuclear family (as Hispanics do in various American suburbs, raising the ire of the local natives).

Transients

Many immigrants return to their countries of origin, or move elsewhere, after a few years. This fact is deemphasized in the public discourse, shaped by the US narrative of people from all over the world coming to live the American dream. But in reality, migration is often seasonal, and a significant fraction of immigrants return; see, for example, a write-up of Italian-American history. More recently, we see this with illegal Mexican workers in the US, who would move back and forth across the borders seasonally, until the tighter border controls built after 1986 made this so difficult they moved to the US permanently (this is the work of Douglas Massey, Jorge Durand, and Nolan Malone, summarized here and here). Many refugees return to their home countries after the war or crisis ends. Skilled migrants often move between countries, as I do.

This creates a situation in which many recent immigrants do not know where they will live in five years, not even on what continent, even excluding the possibility of deportation. This does not mean immigrants do not care about the areas they live in. On the contrary. But they lack the deep social ties that local neighborhood activists have, and this makes it harder to engage politically on a level that appeals to the local notables. It takes years just to learn who the local notables are!

Hence, the immigrant really is a transient. “Transient” is just a dysphemism for someone who does not have enough social capital in an area to know definitively that they’re going to stay there permanently. Unsurprisingly, since community decisions are made by people who know the local notables and their networks, those decisions do not have recent migrants in mind. Even domestic migrants, who unlike international ones have the right to vote, are excluded. This is where community hostility to more housing comes from: why worry about how high the rent is for people you look down on as transients?

As far as housing goes, YIMBY groups have begun to build a national US network for more construction, with some international reach, so that recent domestic migrants to New York, San Francisco, and other expensive cities can rely on their national social capital to compensate for their lack of local social capital. But this is necessarily going to address primarily the needs of the people who participate in YIMBY networks, who tend to be white, educated, and American. I happen to think more housing in a region will benefit all recent and prospective immigrants to it, but there’s a wealth of other local political issues that are not covered in the YIMBY umbrella (for example, policing), and there, the community’s ability to abuse residents who got here more recently than it would like is not limited.

Public housing

Finally, let me discuss the difference between how immigrants think and how governments elected by natives think immigrants ought to think. As I’ve established above, immigrants’ decisions are driven largely by the need for a job, even when the original purpose for the move was not work-related. This means that they will make compromises and live in a way that the native public deems substandard, as in various outrages of immigrant overcrowding.

The question is what to do about it. In capitalist countries (i.e. pretty much everywhere, except Cuba and a few other communist holdouts), the government professes to believe that people are economically rational. There are large sectors in which this is not true – for examples, health and education are mostly public in most developed countries – but in housing, most first-world countries use a free-market approach. Central cities often do provide extensive public housing, and zone tightly to prevent new construction that offends community sensibilities, but people can still buy and sell houses and move, and advocate for themselves politically so that they wouldn’t be stuck with housing that is by regional standards deficient.

Except, well, that people who lack voting rights can’t act politically except through their ties to enfranchised voters, and new migration waves lack these ties. The worst example of this is in Sweden, which provides refugees with public housing, but only where it’s cheap. Thus, instead of having a liberalized enough urban housing market so that refugees could live in overcrowded conditions in Stockholm, it either disperses them to peripheral towns where they know nobody and can’t work, or concentrates them in low-income ghettos. Malmö, which like Birmingham used to be a bustling city but deindustrialized and has high unemployment, is one of the prime locations for immigrants to Sweden; so is Södertälje, a Stockholm suburb infamous for its high unemployment.

One of the most salient features of being an immigrant is being a social problem. Every difference between the immigrant and the native will be used politically, in either direction, even if it is the result of normal variation between groups and economic sectors. And here, governments that refuse to consider immigrants’ own housing decisions are creating social problems for the future by creating new ghettos from scratch. For its own working class, Sweden built the Million Program; for immigrants, not a chance. Between overcrowding and joblessness, immigrants choose overcrowding, when they can. When they can’t, the government is choosing joblessness for them.

Penn Station Elimination Followup

Several commenters, both here and on Streetsblog, have raised a number of points about my proposal to eliminate above-ground Penn Station and reduce the station to a hole in the ground. A few of those points are things I’d already thought about when I wrote that post and didn’t want to clutter; others are new ideas that I’ve had to wrestle with.

Waiting

On Streetsblog, Mark Walker says, “Getting on a train at Penn is not like using the subway. Instead of a train that runs every five minutes, you’re waiting for a train that runs once per hour (more or less),” implying nicer waiting areas and lounges are needed. My proposal, of course, does not have dedicated waiting areas. (That said, there’s an immense amount of space on the platforms under the escalators, which could be equipped with chairs, tables, and newsstands.)

However, I take exception to the notion that when the train runs every hour, passengers wait an hour. When I lived in Providence, a few trips to Boston, New Haven, and New York taught me the exact amount of time it’d take me to walk from my apartment to the train station: 21 minutes. I learned to time myself to get to the station 2 minutes before the train would leave, and as I recall, I missed the train twice out of maybe 30 trips, and one of those was when I had a lot of luggage and was in a taxi and couldn’t precisely gauge the extra travel time. Walking is that reliable. People who get to Penn Station by subway have to budget some extra time to account for missed subway trains, but from much of the city, including the parts of the CBD not within walking distance from Penn, the required spare time is less than 10 minutes. Moreover, Penn is at its most crowded at rush hour, which is precisely when subway frequency is the highest, and people can reliably time themselves to within less than 5 minutes.

Outlying train stations in Switzerland are deserted except a few minutes before a train shows up, because the connecting transit is all timed to meet the train. This is of course inapplicable at very large stations with many lines, but the modes of transportation that most Penn Station users take to the station are reliable and frequent, if you can even talk of frequency for walking. The result is that the amenities do not need to be extravagant on account of waiting passengers, and do not need to be more than those of a busy subway station in a busy area.

Shelter

Several commenters raised the idea of shelter. One option, raised by James Sinclair, is an arched glass roof over the station, on the model of Milan. This involves above-ground infrastructure, but the arched structure is only supported at the margins of the compound, which means that the primary feature of a hole-in-the-ground station, the lack of anything that the track area must support the weight of, is still true. I do not think it’s a bad idea; I do, however, want to raise three additional options:

Do nothing. A large proportion of the usable area of the platforms would be located under the walkways above, or under the escalators and staircases. Having measured the depth more precisely, through Plate 14 here, I found it is 13 meters from street level to top of rail, or 12 from street level to platform level, translating to 21 meters of escalator length, plus 2.2-2.5 meters on each side for approach (see page 23 here). About 16 of those 21 (18.5 out of 25.7, counting approaches) meters offer enough space for passengers to stand below the escalators, leading to large areas that could be used for shelter, as noted in the waiting section above.

Build a simple shelter. Stockholm-area train stations have cheap corrugated metal roofs over most of the length of their platforms. These provide protection from rain. Of course those roofs require some structural support at the platform, but because they’re not supposed to hold anything except rainwater, those supports are narrow poles, easy to move around if the station is reconfigured.

Build a street-level glass pane. This may be structurally intricate, but if not, it would provide complete shelter from the elements on the track level, greatly improve passenger circulation, and create a new public plaza. But in summer, the station would be a greenhouse, requiring additional air conditioning.

Note that doing nothing or building a simple shelter would not protect any of the track level from heat or cold. This is fine: evidently, open-air stations are the norm both in cities with hotter summers than New York (Milan is one example, and Tokyo is another) and in cities with colder winters (for example, Stockholm). Passengers are usually dressed for the weather anyway, especially if they’re planning on walking to work from Penn or from the subway station they’re connecting to.

Architecture

Multiple commenters have said that public art and architecture matter, and building spartan train stations is unaesthetic, representing public squalor. I agree! I don’t think a hole-in-the-wall Penn Station has to be drab or brutalist. It can showcase art, on the model of the mosaics on the subway, or the sculptures on the T-Bana. It can use color to create a more welcoming environment than the monotonous gray of many postwar creations, such as the Washington Metro. The natural sunlight would help a lot.

But more than that, the walkways themselves could be architectural signatures. The best way to build them without supporting them on the track level is some variant on the arch bridge – either the classical arch bridge (which would require three or four spans), or a through-arch. This gives a lot of room to turn the bridges into signature spans. The design work would raise their cost, but short pedestrian bridges tend not to display the same cost structure as massive vehicular ones; the Bridge of Strings, a Calatrava-designed light rail bridge on a line that cost far more to build than light rail should cost, was $70 million for 360 meters. The walkways would not carry light rail, and would be about 140 or 150 meters in span.

TOD

Commenters both here (Caelestor) and on Streetsblog (Bolwerk, Matthias, C2check) have brought up transit-oriented development as a reason to allow a tall building on top of the station. With respect, I think on top of a train station is exactly the wrong place to build a tower. Let’s Go LA has an explanation for why the engineering for air rights is so complicated, although he stresses that Penn Station and Grand Central, which were built with the expectation of future high-rise air rights, are exceptions. I’ll add that Penn Station track simplification would also remove many crossovers and switches, making it easier to build air rights. That said, the track spacing is not friendly to the column spacing he proposes.

In New York, the tallest and most expensive recent private-sector office tower on solid ground, the Bank of America Tower, cost around $6,000 per square meter of floor space, in today’s money. Some of the luxury residential towers are more expensive; so are the new World Trade Center buildings, e.g. One World Trade Center was $12,000 per m^2. But the office towers cluster in a specific band of cost, around $2,500 to $5,000 per square meter, with taller towers generally more expensive. The Hudson Yards air rights towers cost in the $10,000-14,000 per square meter range, as much as One World Trade Center. Contrary to Bloomberg’s promises of windfall property tax revenues as his justification for the 7 extension, the city has had to offer tax abatement to encourage developers to build at those prices. Amtrak’s plan for Penn Station South assumes the block immediately south of Penn Station would cost $769 million to $1.3 billion to acquire; when I roughly computed its floor area by counting floors per building, I got 100,000 m^2, which means the price of real estate in that area, $7,700-13,000/m^2, is no higher and may be lower than the construction cost of air rights towers.

In contrast, some sites on firm ground immediately surrounding Penn Station are ripe for redevelopment. The block south of Penn Station, as noted above, has about 100,000 m^2, for a block-wide floor area ratio of 6.7. The Empire State Building’s floor area ratio is 33, so replacing the block with closely spaced supertall towers would require developers to burn just 20% of their profit on acquiring preexisting buildings. To the north of Penn Station, the two sites at 7th and 8th Avenues, flanking One Penn Plaza, are flat; so is nearly all of the western part of the block northeast of Penn, between 33rd and 34th Streets and 6th and 7th Avenues. Eighth Avenue is not developed intensely at all in that latitude – it only becomes important near Times Square. Supertall buildings surrounding Penn Station could even be incorporated into the station complex: railroads using the station might decide to lease offices in some of them, and the exteriors of some of those buildings could incorporate large clocks, some signage, and even train departure boards.

Phasing

TheEconomist, who has had some truly out-of-the-box ideas, raises a very good point: how to phase the deconstruction of Penn Station in ways that allow service to continue. I don’t have a complete answer to that. Arch bridges, in particular, require extensive falsework, which may complicate matters. However, a general phase plan could consist of knocking down the above-ground buildings, then removing the upper concourse (leaving only the lower), and then removing arms of the lower concourse one by one as the walkways above them are built.

Passenger Throughput

In comments here, people have suggested several alternatives to my proposal to reconfigure Penn Station to have 12 tracks and 6 island platforms between them. There should be 6 approach tracks, as I outlined here: southern approach tracks, combining new Hudson tunnels with a link to Grand Central (which I call Line 2); central tracks, combining the preexisting Hudson tunnels with the southern East River Tunnels (Line 1); and northern tracks, combining the realigned Empire Connection and West Side Yard with the northern East River Tunnels (Line 3).

In my view, each approach track should split into two platform tracks, flanking the same platform. In this situation, there is no need to announce track numbers in advance, as long as the platform is known. Stockholm does this on the commuter lines at Stockholm Central: the northbound lines use tracks 15 and 16 and the southbound lines use tracks 13 and 14, with a platform between each of these track pairs, and until a few minutes before a train arrives, it’s signed on the board as “track 13/14” or “track 15/16.”

The compound looks 140 or 150 meters wide; the maps are unclear about to what extent Penn extends under 31st and 33rd, but according to a diagram Joey shared in comments, it extends quite far, giving 150 meters or even a bit more. Under my proposal, this is enough for 6 platforms of 17 or 18 meters. It sounds like a lot, but it isn’t, especially on Line 3, where Penn Station is the only CBD train station, which implies entire trains would empty at Penn in the morning rush hour. (Line 2, which I expect to be the busiest overall because it’d serve both Penn and Grand Central, is the one I expect to have the least platform crowding problems, precisely because it’d serve both Penn and Grand Central.)

Staircases should be 3 meters wide. Escalators with 1-meter steps have 1.6-meter pits; their capacity is theoretically 9,000 passengers per hour, but practically only 6,000-7,000. Clearing 30 entire trains per hour, filled to seating capacity with 4 standees per square meter of standing space, requires moving about 75,000 passengers per hour. (Per meter of train length, this is comparable to the 4/5 trains and the RER A at their peaks.) With 6 access points, this requires 2 up escalators per access point. The minimum is then 3 escalators, running 2-and-1 at the peak; 4 is better.

In comments, Ari Ofesvit proposes the Spanish solution, which I’ve discussed in previous posts. I’m now convinced it is not the right solution, simply because it compels platforms to be too narrow (about 8.6 meters), which has room for exactly half of what a standard platform twice the width would have, without the possibility of running 4 escalators 3-and-1 at the peak. My comment in that post has more detail, albeit with the assumption that the compound is 140 meters wide.

Fbfree proposes something else: more platforms for intercity trains. Giving intercity trains more platforms (as is done in Stockholm, which has just two approach tracks to the south) gives them more time to dwell; unfortunately, it also narrows the platforms for the regional trains, precisely the ones that can expect the most crowding. Even a single-track platform would take up space out of proportion to the number of passengers it would serve.

Pedestrian throughput is, at the maximum, 81 people per meter of walkway width per minute; this assumes two-way flow, but the numbers for one-way and multiway flow aren’t too different. This is a little less than 5,000 per meter-hour. An escalator bank with two up escalators then needs almost 3 meters of unobstructed platform width on one side (the other side can be used as overflow, but most passengers would use the side of the platform the train discharged them on). This is easy to supply with a 4-escalator bank on a 17-meter platform (there would be 3.8 meters); on an 8.6-meter Spanish platform, there’s only one up escalator per bank, so half the width is required, and is indeed obtainable. But if there are extra platforms for intercity trains, this becomes more strained.

For maximum throughput, it is necessary to minimize separation between escalators on the platform, down to about 6 meters plus approaches, in order to allow wider walkways, which in this case would make the walkways about 25 meters wide. The point here is that the walkways have to have very high pedestrian capacity, since each of them is fed by escalators from all platforms. At 25 meters, the capacity is about 15% less than that of two up escalators per access point (121,500 vs. 144,000), which is fine since some platforms (Line 2 in both directions, Line 3 eastbound in the morning and westbound in the afternoon) would not have so much traffic. But putting in elevators would disrupt this flow somewhat.

I see two ways to increase capacity in the future, if train traffic warrants it: first, build the glass floor/ceiling I outlined above, in the shelter section. This is the simplest possibility. Second, build three more walkways, midway between 7th and 8th Avenues and the two walkways already discussed, and have each walkway or avenue serve only half the platforms – one serving eastbound platforms, one serving westbound platforms. At this point the station would be half-covered by walkways, if they are all about 24 meters wide, but the walkways could be narrowed; as long as they are longer than 15 meters, any passenger arriving on a platform by any of the included access points would be sheltered by the walkway serving platforms in the opposite direction. Elevators should go from each walkway to each platform still, which would facilitate transfers, but the workhorse escalators would spread the load among different walkways.

Concessions

I’d originally thought that the walkways could host retail and food concessions. The calculation in the preceding section suggests that this wouldn’t be possible, unless the walkways are widened beyond the escalators, with concessions on the outside. Every meter of walkway width would be required for passenger circulation. Even information pamphlets might be restricted to the very edges of the walkways; train departure boards would have to be mounted in the air, for example on the support cables if the through-arch option were chosen for the walkways.

However, there is ample room directly beneath the escalators, staircases, and walkways. With the caveat that escalators of such length need an extra midway support point, they would still have a lot of space underneath: 15-16 meters with sufficient clearance for people to stand comfortably (say, at least 2.5 meters of clearance above); with the upper approaches and the walkways, this is 60-62 meters of largely unobstructed space, for a 60*10 space that could be used in almost any way. Even in the 5-6 meters with less clearance above to the escalator, it’d be possible to use the space at least partly – for example, for sitting, or for bathrooms, the minimum clearance is reduced (I’m writing this post from my apartment, where the ceilings slope down, and the ceiling height above my couch is about 1.5 meters).

There would be two such 60*10 spaces per platform, plus two smaller spaces, near 7th and 8th Avenues, depending on exact placement of access points to the subway. This gives us twelve 60*10 spaces. I doubt that they could ever host high-end concessions, such as full-service restaurants: passengers would probably not go out of their way, to a platform that they weren’t planning on using. This means newsstands could succeed, but not much else; food would have to be shunted to the streets, and presumably restaurants would pay extra to locate right outside the compound. In lieu of concessions, those spaces could host sundry uses, including additional circulation space, information pamphlets, busker performance space, waiting areas for passengers, public art displays, and waiting areas for train crew and cleaners.

Homeowner’s Bill of Rights to Preempt State and Local Zoning Laws

After weeks of fraught negotiation, House of Representatives Speaker John Boehner (R-Ohio) announced that both houses of Congress had reached agreement on passing the Homeowner’s Bill of Rights (HOBOR), which uses the preemption doctrine to abolish most local planning restrictions. President Obama announced that he would sign the bill, which includes several provisions pushed by urban environmentalists. While the majority of Republicans announced their intention to vote yes and the majority of Democrats announced they would vote no, HOBOR relies on cross-bench support, as several prominent Republican lawmakers identified with the Tea Party, including presidential hopefuls Senators Ted Cruz (R-Texas) and Rand Paul (R-Kentucky), announced they would oppose the bill on the grounds of federal overreach.

Despite early environmentalist hopes that the bill would be narrowly targeted at suburban single-family zoning, HOBOR casts a wide net. It preempts any separation of residential, commercial, and industrial uses; maximum heights and floor area ratios; open space requirements; environmental restrictions including noise limits and endangered species protections; urban growth boundaries; parking minimums and maximums; single-family mandates; form-based codes; anti-McMansion ordinances and minimum lot sizes; affordable housing mandates; and setback requirements. It also requires the federal government to study privatizing federal land adjacent to urban areas and to consider the effects of growth controls on the housing market, a move that is expected to liberalize construction in the West. It does not preempt private deed restriction, despite an attempt by urban Democrats to ban it, but does ban cities from giving public incentives for it.

Boehner’s office released a statement, “The Homeowner’s Bill of Rights will prevent power grabs by special interests and by the federal government, and reduce the level of regulation in America’s cities.” Governor Greg Abbott (R-Texas), who recently proposed a similar law in Texas before Congress federalized the issue, credited Texas’s strong economy to loose zoning, and specifically praised Houston’s lack of zoning as an engine of economic growth.

On the Democratic side, New York City Mayor Bill de Blasio offered tepid support for the bill, saying that he expected the increased pace of construction to create jobs and affordable housing in the city, but added that the city would maintain its rent stabilization program. New York housing advocates were involved in obtaining necessary bipartisan support for the bill, and the city’s all-Democratic Congressional delegation is planning to vote for it, with the exceptions of Reps. Carolyn Maloney and Joseph Crowley. Crowley said in a statement that “the city’s planning laws are a cornerstone of neighborhood protection, and it’s hypocritical that the Republican Party, which claims it supports states’ rights, uses the federal government’s power so blatantly when it suits its needs.”

In San Francisco, opponents took to the street, protesting in front of the office of Senator Dianne Feinstein, the most prominent Senate Democrat to support HOBOR, with signs saying “gentrification = violence” and “the developer’s bill of rights.” A group of protesters attacked a shuttle bus ready to leave for Silicon Valley; the leaders of the main group of the protesters disclaimed the attack, and blamed agents provocateurs, but added that destruction of property is different from violent crime and that to compare the two is itself a form of violence.

On the ideological right, reactions are mixed. National Review has written in favor of the bill, while Reason continues to reject it. Joel Kotkin has editorialized that the bill “paves the way toward high-rises that Americans continue to reject.” Tea Party support is split, but largely negative; several groups have vowed to sue, connecting Democratic support with Agenda 21, the UN position paper encouraging more urbanization and restrictions on suburban sprawl. Senator Ted Cruz threatened to filibuster the bill, and openly called for a constitutional challenge. In contrast, Senator Marco Rubio (R-Florida) plans to vote for the bill. In his statement, Rubio pointed to redevelopment in Miami as “affordable housing provided by the free market without government subsidies paid by tax money” and welcomed Democratic support.

All around the nation, municipalities, business groups, homeowners, landlords, and tenants are preparing for the entry of the bill into force, which is scheduled for this September 1st. New York, San Francisco, Houston, and Chicago have all already written draft planning laws designed to comply with HOBOR restrictions, but city planners are still debating how to adapt to a situation without zoning rules to shape urban growth.

Several real estate companies are planning new skyscrapers in central business districts of multiple cities. In Washington, The Related Companies is planning a 1,330 foot tall, 4.3 million square foot tower in Farragut. In New York, Harry Macklowe, Forest City Enterprises, and Durst Organization are all expected to race to develop the tallest skyscraper in the city, in the East Midtown area; real estate analysts speaking on background expect towers exceeding 2,000 feet in pinnacle height, to overtake One World Trade Center, but closer to 1,500 feet in roof height.

Outside city centers, development is slower, but analysts expect it to accelerate in the coming years. Facebook has already announced an expansion of its campus as well as the construction of apartment buildings in its home city of Menlo Park, California, as well as Atherton and Palo Alto, to house its growing workforce. However, when asked if this trend means less demand in San Francisco and less demand for tech shuttles, a senior Facebook human resources manager speaking on condition of anonymity said, “Most of our new hires still prefer to live in San Francisco, so we may end up seeing more commuters from the city, at the expense of the East Bay.”

Ultimately, analysts agree, it is difficult to gauge the long-term effect of HOBOR this early. However, as an early indication that there would be a move to established business districts, stocks of publicly-traded companies involved in purpose-made redevelopment districts, such as the Boston Seaport and New York’s Hudson Yards, are down by an average of 3% since Boehner announced that he had secured support for the bill, whereas those of other major developers have been sharply rising, by 2-15%. But when asked whether they will scale back their plans, officials in Boston have replied negatively, and have even suggested a $2 billion Silver Line expansion to serve the Seaport.

The Ultimate Authoritarian Anti-Urbanism

Cairo is a dense megacity, without the infrastructure such cities require for high living standards. The city proper, according to Wikipedia, has 10 million people, living at a density approaching 20,000 per km^2, and the metro area has 20 million. With a subway system fit for a city a tenth its size, Cairo is heavily motorized for its income level, congested, and polluted. Despite high construction costs, urgent investment in public transportation is required. Ignoring this need, the current military government has just announced plans to build a new capital outside the city, eventually to house 7 million people, with all the public monuments of a planned city, at a cost of $300 billion (exchange rate dollars, not PPP), about the same as Egypt’s annual GDP. The first phase alone will be $45 billion.

Cairo itself is already suffering from neglect and disinvestment. There are 2 million cars in the city. This is enough to cause so much traffic congestion it costs Egypt 4% of its GDP. Cairo’s air pollution is legendary: pollution levels are akin to smoking a pack of cigarettes per day. At least as of 1997, lead pollution caused by cars using leaded gasoline reduced Cairene children’s IQ by 4 points. The poor transportation options have led to a housing crunch, forcing half a million people to live in a historic necropolis as squatters.

The Cairo Metro would be a solution to these problems to a large extent, but is very small relative to Cairo’s size: it has 3 lines, totaling 78 route-km. Other cities of comparable size have many hundreds of route-km of urban rail, with a handful of exceptions infamous for their sprawl (such as Los Angeles) or pollution (such as Sao Paulo). Despite its small size, the Cairo Metro gets about 1.6 billion passengers per year, by far the highest number of passengers per route-km in the world, nearly twice as high as on the legendarily overcrowded Tokyo subway. Cairo has high construction costs, but in exchange rate dollars they only amount to about $130 million per km; a fully underground expansion of the subway to 400 km, somewhat more than the length of New York’s subway lines and less than that of Beijing and Shanghai’s, would cost about $40 billion, less than the cost of the new capital’s first phase alone. This is on top of all other possible infrastructure investments Egypt should consider: sanitation, sewage, water treatment, electrification, hospitals, schools, the Suez Canal. I bring up the Metro since so many of Cairo’s pressing problems would be substantially reduced if it had the capacity to transport a large share of the city’s population.

The problem is that the Egyptian government’s first priority is not to serve the needs of the Egyptian population. It is an authoritarian military government; it is not accountable to the broad public. I bring this up, because it’s a necessary check on things I have said in the past, attacking local American governance as authoritarian. Andrew Cuomo and Chris Christie have the power to overrule useful spending bills and cause traffic jams in cities run by political opponents. Abdel Fattah al-Sisi has the power to jail political opponents without trial, and execute them by the hundreds after show trials.

Autocrats love planned cities, for two reasons. First, planned cities are monuments to their greatness, lasting long into the future. The people the autocrats trample will be forgotten. Tourists visit the Taj Mahal, and not museums commemorating the churches and temples Shah Jahan destroyed. They visit the Great Wall of China, and not any commemoration of the million-odd people who died in its construction. They visit the Old City of Jerusalem, while nobody commemorates any of the locals Herod taxed to build its monuments – even Judaism only commemorates the destruction of the Temple and the beginning of the Diaspora, generations later. Autocrats know this. Even in antiquity, they knew monuments would make them more famous. And even in modern democratic regimes, politicians like signature initiatives that have their names on them; going back to Andrew Cuomo, his proposed Queens convention center is a typical example. But Cuomo still faces some democratic checks and balances. Sisi does not.

And second, planned cities can be built in ways that enhance social control. City Metric compares the new planned capital with Naypyidaw, Burma’s capital, built in the era of military rule to replace Yangon. Purpose-built capitals can be (and are) built around the needs of the national elite, keeping the poor out of sight. They have street and building design plans that make it easy to bring in the military to quell riots: wide streets, buildings that do not touch, no central square where protests could happen. They also disallow squatters, without going through the difficult and controversial move of evicting squatters from the preexisting city. One rhetorical question I have seen on Twitter is, where will this city’s Tahrir be? An article on Cairobserver doesn’t make this exact argument, but does note that this plan disinvests in what will still remain Egypt’s largest city, and could only come about as a result of Egypt’s complete lack of democracy.

One of the bigger influences on my views of democracy is Brad DeLong and Andrei Shleifer’s paper from 1993, Princes and Merchants. I do not fully agree with the point they make, but one of the key components of it, on the spending priorities of an absolute ruler, is crucial to understanding the benefits of democracy. Per DeLong and Shleifer, absolutism chokes economic growth, since the absolute ruler will overtax the economy to maximize revenue. One may ask if actually, hereditary rulers would want to stimulate more economic growth in order to bequeath a stronger kingdom to their heirs. DeLong and Shleifer answer that no: even with clear rules of inheritance, succession wars are so common that kings have to constantly be on the guard against rebellion to make sure their heirs get to inherit anything.

For Sisi, it is perfectly rational to spend so much money building a capital city that would make an uprising against him less likely. The money is not going to come from his pocket, but from the pockets of people he need not care about too much – the Egyptian people. The personal benefits to Sisi are invaluable: Sisi’s two predecessors, Mohamed Morsi and Hosni Mubarak, were both overthrown and immediately charged with crimes, for which they were guilty (under Sisi’s influence, Mubarak was exonerated from most). Why not remove himself and the apparatus of the Egyptian state from the city where they were overthrown?

When I talk of infrastructure democracy in democratic first-world countries, I complain about (much) smaller versions of this exercise. One could reason with a democratic Egyptian government that there are better uses of the money in Cairo itself. One cannot reason this way with a military government. The same is true of the soft authoritarianism found in governments with a democratic deficit, from the European Commission to local American governments. Their power is ultimately limited by other layers of government, which are more transparent, and they are incapable of killing off political opponents, but they still do not have to listen to the people they impact, leading to decisions that are at times obviously ridiculous. Egypt’s new capital is this autocracy, taken to its logical end. A dictator, of the kind who the infrastructurists might praise as someone who can cut through the red tape and gets things done, is spending the country’s annual GDP on a plan to disinvest in the capital and build a monument to himself and his regime from scratch.

Height Limits: Still a Bad Idea

In a pair of recent articles on Strong Towns, Charles Marohn, best known in the urbanist community for introducing the term stroad (street+road) for a pedestrian-hostile arterial street, argues for height limits as a positive force for urbanism. He does not make the usual aesthetic argument that tall buildings are inherently unpleasant (“out of scale”), or the usual urbanist one that tall buildings lead to neighborhood decline; instead, he makes an economic argument that allowing tall buildings greatly raises land costs, and makes redevelopment of vacant lots less likely. He uses the following example:

Let’s say the local code allows [a] vacant lot to be developed as a one story strip mall, but nothing higher. If the strip mall is worth $500,000, then the vacant lot is going to be somewhere around $75,000.

Okay, but what if the development code allows that vacant lot to be developed as a sixteen story tower? If the tower is worth $20,000,000, then that vacant lot is going to fetch a much higher price, maybe as much $2.5 million.

You own that vacant lot. I come to you with an offer to buy it for $75,000. What are the odds you are going to sell it at that price when you look to the other side and see the same piece of property going for millions? Not very good.

In most cities, as Charles notes, there is not enough demand to redevelop every vacant lot as a high-rise, and therefore, if high-rises are permitted, a few vacant lots will be redeveloped as high-rises, while the rest remain vacant. This is not the case in large cities, which Charles specifically exempts in his article (see also Daniel Kay Hertz’s response), but part of the problem with the argument, as we will see, is that the boundary between large cities and small ones is fuzzy.

Let me now explain why this argument fails, like all the other arguments for zoning restrictions: it makes implicit assumptions on future uncertainty. The reason the vacant lot owners are not willing to sell for $75,000 is that they hope to get $2.5 million. In a stable market, with low enough population that most lots cannot fetch such a high price, the lot owners know that holding off on $75,000 offers is a gamble and that they are unlikely to ever get a higher offer. People have optimism bias and might overrate the probability that they’ll get the $2.5 million offer, but also have risk aversion; in most cases in economics, risk aversion dominates, so that safer assets cost more and have lower returns.

So when do we see holdouts? Risk aversion predicts that the probability of obtaining a $2.5 million offer should be higher than the total demand for new towers divided by the number of vacant lots. If we explicitly assume that the cost figures in Charles’ example, including land costs, are unchangeable, then this means vacant lot owners expect there to be more high-rise towers in the future, which comes out of growth regions. Charles’ example is based on Sarasota, which like most of Florida has high population growth.

The other possibility is regulatory uncertainty. In a competitive market, land costs are already as low as they can be while letting lot owners cash out on past investments. Developer profits are also as low as possible, and represent the developer’s wage for managerial work. However, zoning restrictions will greatly raise both figures, and a lot owner who expects future developments to brush up against the present zoning code can hold out until prices rise.

This is the danger of a system that is based on arbitrary rules (Charles proposes up to two floors or 1.5 times the average present height, whichever is higher), and arbitrary distinctions between small cities in which height restrictions are desirable and large cities in which they are not: these introduce political discretion in the details, which introduces additional uncertainty among lot owners. True windfalls usually involve the boundary between regulatory regimes, and this creates political incentive to game the system in order to be one of the few owners whose lots can be developed as high-rises. In contrast, once a ground rule is established that there is no zoning, such as in Houston, introducing zoning is difficult, even when there are rules that are zoning in all but name, such as parking minimums.

Once we get into the realm of cities with a large proportion of their lots developed, as Charles proposes, future development can only replace old development, and this introduces a key difference between new development and redevelopment: redevelopment requires buying out the preexisting property. If a two-floor building is replaced by a three-floor building, then the developer has to not only pay construction costs for three floors, but also buy out two floors, effectively paying for five floors. But the revenue is still only that of a three-floor building, which bids up effective costs by a factor of five thirds. The formula is that if it’s possible to multiply the total built-up area by a factor of x then the buy-out factor will raise the cost of each housing unit by a factor of 1 + 1/x.

This effect is why, in major cities, we usually see buildings replaced by much larger buildings: for example, a three- or four-floor Manhattan building may be replaced by a fifteen- or twenty-story tower on a base. Charles laments that this is not small-scale or incremental, but even his example of good incremental development is similar: in Houston, single-family houses are replaced by low-rise apartment buildings, generating similarly high ratios of the floor areas of redevelopments with the buildings they replaced. Incrementalism in these cases consists of replacing small buildings by much larger ones, gradually, until a few decades later the entire neighborhood is tall.

One way around redevelopment’s need to buy out preexisting buildings is to mandate that future buildings be built to allow adding floors on top of them. Chicago’s Blue Cross Blue Shield Tower is an example. This is a regulation that increases the average cost of construction but reduces the marginal cost and thus the price. It’s also a regulation that only really matters in situations when it is difficult to have a high ratio of new to old floor area, such as in areas that are already high-rise, especially major city CBDs. (It is easy to quintuple floor area ratio when the preexisting buildings have three floors, but not so much when they have twelve.) The current styles of construction of most small buildings, for example sloping roofs common in American and European urban and suburban houses, tend to make adding floors impossible. Of course, the implication that such a regulation should only apply for buildings above a certain height introduces political discretion and hence uncertainty, but at least this is uncertainty that would apply equally to all buildings in an area, which is not always the case for zoning.

What Charles proposes, to develop all vacant lots first and only then start going taller, is then a recipe for high marginal costs, because of the buyout factor. In a small city uniformly developed up to one or two floors, it is difficult to spread the new development across many buildings up to three floors, precisely because there is no way to build single-family houses that are recognizable as such to Americans or Europeans from countries I’ve been to (It’s different in Canada, but this is considered a feature of the low quality of Vancouver’s housing) and that can have floors added to them. In such an environment, building tall is the only way to avoid high housing costs.