Category: Good/Interesting Studies

Tilting Trains and Technological Dead-Ends

The history of tilting trains is on my mind, because it’s easy to take a technological advance and declare it a solution to a problem without first producing it at scale. I know that 10 years ago I was a big fan of tilting trains in comments and early posts, based on both academic literature on the subject and existing practices. Unfortunately, this turned into a technological dead-end because the maintenance costs were too high, disproportionate to the real speed benefits, and further work has gone in different directions. I bring this up because it’s a good example of how even a solution that has been proven to work at scale can turn out to be a dead-end.

What is tilting?

It is a way of getting trains to run at higher cant deficiency.

What is cant deficiency?

Okay. Let’s derive this from physical first principles.

The lateral acceleration on a train going on a curve is given by the formula a = v^2/r. For example, if the speed is 180 km/h, which is 50 m/s, and the curve radius is 2,000 meters, then the acceleration is 50^2/2000 = 1.25 m/s^2.

Now, on pretty much any curve, a road or railway will be banked, with the outer side elevated above the inner side. On a railway this is not called banking, but rather superelevation or cant. That way, gravity countermands some of the centrifugal force felt by the train. The formula on standard-gauge track is that 150 mm of cant equal 1 m/s^2 of lateral acceleration. The cant is free speed – if the train is perfectly canted then there is no centrifugal force felt by the passengers or the train systems, and the balance between the force on the inner and outer rail is perfect, as if there is no curve at all.

The maximum superelevation on a railway is 200 mm, but it only exists on some Shinkansen lines. More typical of high-speed rail is 160-180 mm, and on conventional rail the range is more like 130-160; moreover, if trains are expected to run at low speed, for example if the line is dominated by slow freight traffic or sometimes even if the railroad just hasn’t bothered increasing the speed limit, cant will be even lower, down to 50-80 mm on many American examples. Therefore, on passenger trains, it is always desirable to run faster, that is to combine the cant with some lateral acceleration felt by the passengers. Wikipedia has a force diagram:

The resultant force, the downward-pointing green arrow, doesn’t point directly toward the train floor, because the train goes faster than the balance speed. This is fine – some lateral acceleration is acceptable. This can be expressed in units of acceleration, that is v^2/r with the contribution of cant netted out, but in regulations it’s instead expressed in theoretical additional superelevation required to balance, that is in mm (or inches, in the US). This is called cant deficiency, unbalanced superelevation, or underbalance, and follows the same 150 mm = 1 m/s^2 formula on standard-gauge track.

Note also that it is possible to have cant excess, that is negative cant deficiency. This occurs when the cant chosen for a curve is a compromise between faster and slower trains, and the slower trains are so much slower the direction of the net force is toward the inner rail and not the outer rail. This is a common occurrence when passenger and freight trains share a line owned by a passenger rail-centric authority (a freight rail-centric one will just set the cant for freight balance). It can also occur when local and express passenger trains share a line – there are some canted curves at stations in southeastern Connecticut on the Northeast Corridor.

The maximum cant deficiency is ordinarily in the 130-160 mm range, depending on the national regulations. So ordinarily, you add up the maximum cant and cant deficiency and get a lateral acceleration of about 2 m/s^2, which is what I base all of my regional rail timetables on.

You may also note that the net force vector is not just of different direction from the vertical relative to the carbody but also of slightly greater magnitude. This is an issue I cited as a problem for Hyperloop, which intends to use far higher cant than a regular train, but at the scale of a regular train, it is not relevant. The magnitude of a vector consisting of a 9.8 m/s^2 weight force and a 2 m/s^2 centrifugal force is 10 m/s^2.

Okay, so how does tilt interact with this?

To understand tilt, first we need to understand the issue of suspension.

A good example of suspension in action is American regulations on cant deficiency. As of the early 2010s, the FRA regulations depend on train testing, but are in practice, 6″, or about 150 mm. But previously the blanket rule was 3″, with 4-5″ allowed only by exception, mocked by 2000s-era advocates as “the magic high-speed rail waiver.” This is a matter of carbody suspension, which can be readily seen in the force diagram in the above secetion, in which the train rests on springs.

The issue with suspension is that, because the carbody is sprung, it is subject to centrifugal force, and will naturally suspend to the outside of the curve. In the following diagram, the train is moving away from the viewer and turning left, so the inside rail is on the left and the the outside rail is on the right:

The cant is 150 mm, and the cant deficiency is held to be 150 mm as well, but the carbody sways a few degrees (about 3) to the outside of the curve, which adds to the perceived lateral acceleration, increasing it from 1 m/s^2 to about 1.5. This is typical of a modern passenger train; the old FRA regulations on the matter were based on an experiment from the 1950s using New Haven Railroad trains with unusually soft suspension, tilting so far to the outside of the curve that even 3″ cant deficiency was enough to produce about 1.5 m/s^2 of lateral force felt by the passengers.

By the same token, a train with theoretically perfectly rigid suspension could have 225 mm of cant deficiency and satisfy regulators, but such a train doesn’t quite exist.

Here comes tilt. Tilt is a mechanism that shifts the springs so that the carbody leans not to the outside of the curve but to its inside. The Pendolino technology is theoretically capable of 300 mm of cant deficiency, and practically of 270. This does not mean passengers feel 1.8-2 m/s^2 of lateral acceleration; the train’s bogies feel that, but are designed to be capable of running safely, while the passengers feel far less. In fact the Pendolino had to limit the tilt just to make sure passengers would feel some lateral acceleration, because it was capable of reducing the carbody centrifugal force to zero and this led to motion sickness as passengers saw the horizon rise and fall without any centrifugal force giving motion cues.

Two lower cant deficiency-technology than Pendolino-style tilt are notable, as those are not technological dead-ends, and in fact remain in production. Those are the Talgo and the Shinkansen active suspension. The Talgo has no axles, and incorporates a gravity-based pendular system in which the train is sprung not from the bottom up but from the top down; this still isn’t enough to permit 225 mm of cant deficiency, but high-speed versions like the AVRIL permit 180, which is respectable. The Shinkansen active suspension is computer-controlled, like the Pendolino, but only tilts 2 degrees, allowing up to 180 mm of cant deficiency.

What is the use case of tilting, then?

Well, the speed is higher. How much higher the speed is depends on the underlying cant. The active tilt systems developed for the Pendolino, the Advanced Passenger Train, and ICE T are fundamentally designed for mixed-traffic lines. On those lines, there is no chance of superelevating the curves 200 mm – one freight locomotive at cant excess would demolish the inner track, and the freight loads would shift unacceptably toward the inner rail. A more realistic cant if there is much slow freight traffic is 80 mm, in which case the difference between 150 and 300 mm of cant deficiency corresponds to a speed ratio of \sqrt{(80+300)/(80+150)} = 1.285.

Note that the square root in the formula, coming from the fact that acceleration formula contains a square of the speed, means that the higher the cant, the less we care about cant deficiency. Moreover, at very high speed, 300 mm of cant deficiency, already problematic at medium speed (the Pendolino had to be derated to 270), is unstable when there is significant wind. Martin Lindahl’s thesis, the first link in the introduction, runs computer simulations at 350 km/h and finds that, with safety margins incorporated, the maximum feasible cant deficiency is 250 mm. On dedicated high-speed track, the speed ratio is then \sqrt{(200+250)/(200+130)} = 1.168, a more modest ratio than on mixed track.

The result is that for very high-speed rail applications, Pendolino-level tilting was never developed. The maximum cant deficiency on a production train capable of running at 300 km/h or faster is 9″ (230 mm) on the Avelia Liberty, a bespoke train that cost about double per car what 300 km/h trains cost in Europe. To speed up legacy Shinkansen lines, JR Central and JR East have developed active suspension, stretching the 2.5 km curves of the Tokaido Shinkansen from the 1950s and 60s to allow 285 km/h with the latest N700 trains, and allowing 360 km/h on the 4 km curves of the Tohoku Shinkansen.

What happened to the Pendolino?

The Pendolino and similar trains, such as the ICE T, have faced high maintenance costs. Active tilting taxes the train’s mechanics, and it’s inherently a compromise between maintenance costs and cant deficiency – this is why the Pendolino runs at 270 mm where it was originally capable of 300 mm. The Shinkansen’s active suspension is explicitly a compromise between costs and speed, tilted toward lower cant deficiency because the trains are used on high-superelevation lines. The Talgo’s passive tilt system is much easier to maintain, but also permits a smaller tilt angle.

The Pendolino itself is a fine product, with the tilt removed. Alstom uses it as its standard 250 km/h train, at lower cost than 350 km/h trains. It runs in China as CRH5, and Poland bought a non-tilting Pendolino fleet for its high-speed rail service.

Other medium-speed tilt trains still run, but the maintenance costs are high to the point that future orders are unlikely to include tilt. Germany has a handful of tilt trains included in the Deutschlandtakt, but the market for them is small. Sweden is happy with the X2000, but its next speedup of intercity rail will not involve tilting trains on mostly legacy track as Lindahl’s thesis investigated, but conventional non-tilting high-speed trains on new 320 km/h track to be built at a cost that is low by any global standard but still high for how small and sparsely-populated Sweden is.

In contrast, trainsets with 180 mm cant deficiency are still going strong. JR Central recently increased the maximum speed on the Tokaido Shinkansen from 270 to 285 km/h, and Talgo keeps churning out equipment and exports some of it outside Spain.

No Cafe Cars, Please

European and American intercity train planning takes it as a given that every train must have a car dedicated to cafeteria service. This is not the only way to run trains – the Shinkansen doesn’t have cafe cars. Cafe cars waste capacity that could instead be carrying paying passengers. This is the most important on lines with capacity limitations, like the Northeast Corridor, the West Coast Main Line, the LGV Sud-Est, and the ICE spine from the Rhine-Ruhr up to Frankfurt and Mannheim. Future high-speed train procurement should go the Shinkansen route and fill all cars with seats, to maximize passenger space.

How much space do cafe cars take?

Typically, one car in eight is a cafe. The standard European high-speed train is 200 meters long, and then two can couple to form a 400-meter train, with two cafes since the two 200-meter units are separate and passengers can’t walk between them. In France, the cars are shorter than 25 meters, but a TGV has two locomotives and eight coaches in between, so again one eighth of the train’s potential passenger space does not carry passengers but rather a support service. Occasionally, the formula is changed: the ICE4 in Germany is a single 12-car, 300-meter unit, so 1/12 of the train is a cafe, and in the other direction, the Acela has six coaches one of which is a cafe.

A 16-car Shinkansen carries 1,323 passengers; standard class has 5-abreast seating, but even with 4-abreast seating, it would be 1,098. The same length of a bilevel TGV is 1,016, and a single-level TGV is 754. The reasons include the Shinkansen’s EMU configuration compared with the TGV’s use of locomotives, the lack of a cafe car in Japan, somewhat greater efficiency measured in seat rows per car for a fixed train pitch, and a smaller share of the cars used for first class. An intermediate form is the Velaro, which is an EMU but has a cafe and three first-class cars in eight rather than the Shinkansen’s three in 16; the Eurostar version has 902 seats over 16 cars, and the domestic version 920.

The importance of the first- vs. second-class split is that removing the cafe from a European high-speed train means increasing seated capacity by more than just one seventh. The bistro car is an intermediate car rather than an end car with streamlining and a driver’s cab, and if it had seats they’d be second- and not first-class. A German Velaro with the bistro replaced by a second-class car would have around 1,050 seats in 16 cars, almost even with a 4-abreast Shinkansen even with four end cars rather than two and with twice as many first-class cars.

How valuable are cafes to passengers?

The tradeoff is that passengers prefer having a food option on the train. But this preference is not absolute. It’s hard to find a real-world example. The only comparison I am aware of is on Amtrak between the Regional (which has a cafe) and the Keystone (which doesn’t), and Regional fares are higher on the shared New York-Philadelphia segment but those are priced to conserve scarce capacity for profitable New York-Washington passengers, and at any rate the shared segment is about 1:25, and perhaps this matters more on longer trips.

Thankfully, the Gröna Tåget project in Sweden studied passenger preferences in more detail in order to decide how Sweden’s train of the future should look. It recommends using more modern seats to improve comfort, making the seats thinner as airlines do in order to achieve the same legroom even with reduced pitch, and a number of other changes. The question of cafes in the study is presented as unclear, on PDF-p. 32:

Food and RefreshmentsWillingness to Pay
Coffee machine (relative to no service at all)3-6%
Free coffee and tea in each car6%
Food and drink trolley11%
Cafeteria14%
Restaurant with hot food17%

Put another way, the extra passenger willingness to pay for a cafeteria compared with nothing, 14%, is approximately equal to the increase in capacity on a Velaro coming from getting rid of the bistro and replacing it with a second-class car. The extra over a Shinkansen-style trolley is 3%. Of course, demand curves slope down, so the gain in revenue from increasing passenger capacity by 14% is less than 14%, but fares are usually held down to a maximum regulatory level and where lines are near capacity the increase in revenue is linear.

Station food

Instead of a bistro car, railroads should provide passengers with food options at train stations. In Japan this is the ekiben, but analogs exist at major train stations in Europe and the United States. Penn Station has a lot of decent food options, and even if I have to shell out $10 for a pastrami sandwich, I don’t think it’s more expensive than a Tokyo ekiben, and at any rate Amtrak already shorts me $90 to travel to Boston. The same is true if I travel out of Paris or Berlin.

Even better, if the station is well-designed and placed in a central area of the city, then passengers can get from the street to the platform very quickly. At Gare de l’Est, it takes maybe two minutes, including time taken to print the ticket. This means that there is an even broader array of possible food options by buying on the street, as I would when traveling out of Paris. In that case, prices and quality approach what one gets on an ordinary street corner, without the premium charged to travelers when they are a captive market. The options are then far better than what any bistro car could produce, without taking any capacity away from the train at all.

Poor Rich Countries and Isomorphic Mimicry

A curious pattern can be found in subway construction costs around the world, based on GDP per capita. On the one hand, poor countries that have severe cultural cringe, such as former colonies, have high construction costs, and often the worst projects are the ones that most try to imitate richer countries, outsourcing design to Japan or perhaps China. On the other hand, poor-rich countries, by which I mean countries on the periphery of the developed world, have similar cultural cringe and self-hate for their institutions, and yet their imitation of richer countries has been a success; for example, Spain copied a lot of rail development ideas from Germany and France. This can be explained using the development economic theory of isomorphic mimicry; the rub here is that a poor country like India or Ethiopia is profoundly different from the richer countries it tries to imitate, whereas a poor-rich country like Spain is actually pretty similar to Germany by global standards.

What is isomorphic mimicry?

In the economic development literature, the expression isomorphic mimicry refers to when a poor country sets up institutions that aim to imitate those of richer countries in hope that through such institutions the country will become rich too, but the imitation is too shallow to be useful. A common set of examples is well-meaning regulations on safety, labor, environmental protection, and anti-corruption that are not enforced due to insufficient state capacity. Here is a review of the concept by Andrews, Pritchett, and Woolcock, with examples from Mozambique, Uganda, and India, as well as some history from the American private sector. More examples using the theory can be found in Turczynowicz, Gautam, Rénique, Yeap, and Sagues concerning Peru’s one laptop per child program, in Evans’ interpretation of Bangladesh’s domestic violence laws, and in Rajagopalan and Tabarrok on India’s poor state of public services.

While the theory regarding institutions is new, analogs of it for tangible goods are older. Postwar developmental states engaged in extensive isomorphic mimicry, building dams, steel plants, and coal plants hoping that it would transform them into wealthy states like the United States, Western Europe, and Japan; for the most part, they had lower economic growth than did the developed world until the 1980s. The shift within international development away from tangible infrastructure and toward trying to fix institutions came about because big projects like the Aswan Dam failed to create enduring economic growth and often had ill side effects on agriculture, the environment, or human rights.

How does isomorphic mimicry affect public transportation?

The best example of isomorphic mimicry leading to bad transit that I know of is the Addis Ababa light rail system. This is funded by China, whose ideas of global development are similar to those of the postwar first and second worlds, that is providing tangible physical things, like railroads. Unfortunately, usage is low, because of problems that do not exist in middle-income or rich countries but are endemic to Ethiopia. Christina Goldbaum, the New York Times’ transit reporter, who lived in East Africa and reported from Addis Ababa, mentioned four problems:

  1. Electricity is unreliable, so the trains sometimes do not work. In early-20th century America, electric railroads and streetcar companies built their own power supply and were sometimes integrated concerns providing both streetcar and power service; but in more modern countries, there is reliable power for urban rail to tap.
  2. Not many people work in city center rather than in the neighborhood they live in. This, again, has historical analogs – there were turn-of-the-century Brooklynites who never visited Manhattan. Thus, a downtown-centric light rail system won’t get as much ridership as in a more developed city.
  3. The train is expensive relative to local incomes, so many people stick with buses or ride without paying.
  4. The railroad cuts through streets at-grade, to save money, and blocks off pedestrian paths that people use.

The Addis Ababa light rail system at least had reasonable costs. A more typical case for countries that poor is to build urban rail at premium cost, and the poorer the country, the higher the cost. The reason is most likely that such countries tend to build with Chinese or Japanese technical assistance, depending on geopolitics, and therefore import expensive capital for which they pay with weak currencies.

In India, the most functional and richest of the countries in question, there is much internal and external criticism that its economic growth is not labor-intensive, that is the most productive firms are not the ones employing the most people, and this stymies social development and urban growth. I suspect that this also means there is reluctance to use labor-intensive construction methods, that is cut-and-cover with headcounts that would be typical in New York, Paris, and Berlin in the early 20th century, or perhaps mid-20th century Milan and Tokyo. International consultancies are centered on the rich world and recommend capital-intensive methods to avoid hiring too many sandhogs at a fully laden employment cost of perhaps 8,000€ a month; in India, that is the PPP-adjusted gross salary of an experienced construction worker per year, and if capital is imported then multiply its cost by 3 to account for the rupee’s exchange rate value.

Poor-rich countries

Poor-rich countries are those on the margin of the developed world, such as the countries of Eastern and Southern Europe, Turkey, Israel, to a lesser extent South Korea, and the richer countries of Latin America such as Chile. These are clearly poorer than the United States or Germany. Their residents, everywhere I’ve asked, believe that they are poorer and institutionally inferior; convincing a Spaniard or an Italian that their country can do engineering better than Germany is a difficult task. Thus, these countries tend to engage in mimicry of those countries that they consider the economic center, which could be Germany in Southern Europe, Japan in South Korea, or the US or Spain in Spanish America.

However, being a poor-rich country is not the same as being a poor country. Italy is, by American or German standards, poor. Wages there are noticeably lower and living standards are visibly poorer, and not just in the South either. But those wages remain in the same sphere as American and German wages. The labor-capital cost ratios in Southern Europe are sufficiently similar to those of Northern Europe that it’s not difficult to imitate. Spain even mixed and matched, using French TGV technology for early high-speed rail but preferring the more advanced German intercity rail signaling system, LZB, to the French one.

Such imitation leads to learning. Spain imported German and French engineering ideas but not French tolerance for casual rioting or German litigiousness, and therefore can build infrastructure with less NIMBYism. Turkey invited Italian consultants to help design the early lines of the Istanbul Metro, but subsequently refined their ideas domestically in order to build more efficiently, for example shrinking station footprint and tunnel diameter to reduce costs. Seoul has a subway system that looks like Tokyo’s in many ways, but has a cleaner network shape, with far fewer missed connections between lines. As a result, all three countries – Spain, Turkey, Korea – now have innovative domestic programs of rail construction and can even export their expertise elsewhere, as Spain is in Ecuador.

Openness to novelty

Andrews-Pritchett-Woolcock stress the importance of openness to novelty in the public sector, and cite examples of failure in which bureaucrats at various levels refused to implement any change, even one that was proven to be positive, because their goal was not to rock the boat.

Cultural cringe is in a way a check on that. Isomorphic mimicry is an attempt to combine agenda conformity and closeness to novelty with a desire to have what the richest countries have. But in poor-rich countries, isomorphic mimicry is real imitation – there is ample state penetration in a country like Spain or Turkey rather than outsourcing of state capacity to traditional heads of remote villages, and education levels are high enough that many people know how Germany works and interact with Germany regularly. A worker who earns 2,000€ a month net and a worker who earns 3,000€ a month can exchange tips about how to apply for jobs, how to prepare food, what brands of consumer goods to buy, and where to go on vacation. They cannot have this conversation with a worker who earns 10,000€ a month net.

Within the rich world, what matters then is the realization that something is wrong and the solution is to look abroad. It doesn’t matter if it’s a generally poor-rich region like Southern Europe or a region with a poor-rich public sector like the United States – there’s enough private knowledge about how successful places work, but what’s needed is a public acknowledgement and social organization encouraging imitation and lifting voices that are most expert in implementing it.

And for all the jokes about how the United States or Britain is like a third-world country, they really aren’t. Their public-sector dysfunctions are real, but are still firmly within the poor-rich basket; remember, for example, that despite its antediluvian signaling capacity, the New York City Subway manages to run 24 trains per hour per track at the peak, which is better than Shanghai’s 21. Health and education outcomes in the United States are generally better than those of middle-income and poor countries on every measure. This is a public sector that compares poorly with innovation centers in Continental Europe and democratic East Asia, but it still compares; to try to do the same comparison in a country like Nigeria would be nonsensical.

The upshot then is that implementing best practices in developed countries that happen to be bad at one thing, in this case public transportation in the United States, can work smoothly, much like Southern Europe’s successful assimilation of and improvements on Northern European engineering, and unlike the failures in former colonies in Africa and Asia. But people need to understand that they need to do it – that the centers of innovation are abroad and are in particular in countries that speak English non-natively.

Sorry Eno, the US Really Has a Construction Cost Premium

There’s a study by Eno looking at urban rail construction costs, comparing the US to Europe. When it came out last month I was asked to post about it, and after some Patreon polling in which other posts ranked ahead, here it goes. In short: the study has some interesting analysis of the American cost premium, but suffers from some shortcomings, particularly with the comprehensiveness of the non-American data. Moreover, while most of the analysis in the body of the study is solid, the executive summary-level analysis is incorrect. Streetsblog got a quote from Eno saying there is no US premium, and on a panel at Tri-State a week ago T4A’s Beth Osborne cited the same study to say that the US isn’t so bad by European standards, which is false, and does not follow from the analysis. The reality is that the American cost premium is real and large – larger than Eno thinks, and in particular much larger than the senior managers at Eno who have been feeding these false quotes to the press think.

What’s the study?

Like our research group at Marron, Eno is comparing American urban rail construction costs per kilometer with other projects around the world. Three key differences are notable:

  1. Eno looks at light rail and not just rapid transit. We have included a smattering of projects that are called light rail but are predominantly rapid transit, such as Stadtbahns, the Green Line Extension in Boston, and surface portions of some regional rail lines (e.g. in Turkey), but the vast majority of our database is full rapid transit, mostly underground and not elevated. This means that Eno has a mostly complete database for American urban rail, which is by construction length mostly light rail and not subways, whereas we have gaps in the United States.
  2. Eno only compares the United States with other Western countries, on the grounds that they are the most similar. There is a fair amount of Canada in their database, one Australian line, and a lot of Europe, but no high-income Asia at all. Nor do they look at developing countries, or even upper-middle-income ones like Turkey.
  3. Eno’s database in Europe is incomplete. In particular, it looks by country, including lines in Britain, Spain, Italy, Germany, Austria, the Netherlands, and France, but even there it has coverage gaps, and there is no Switzerland, little Scandinavia (in particular, no ongoing Stockholm subway expansion), and no Eastern Europe.

The analysis is similar to ours, i.e. they look at average costs per km controlling for how much of the line is underground. They include one additional unit of analysis that we don’t, which is station spacing; ex ante one expects closer station spacing to correlate with higher costs, since stations are a significant chunk of the cost and this is especially notable for very expensive projects.

The main finding in the Eno study is that the US has a significant cost premium over Europe and Canada. The key here is figure 5 on takeaway 4. All costs are in millions of PPP dollars per kilometer.

Tunnel proportionMedian US costMedian non-US cost
0-20%$56.5$43.8
20-80%$194.4$120.7
80-100%$380.6$177.9

However, the study lowballs the US premium in two distinct ways: poor regression use, and upward bias of non-US data.

Regression and costs

The quotes saying the US has no cost premium over Europe come from takeaways 2 and 3. Those are regression analyses comparing cost per km to the tunnel proportion (takeaway 3) or at-grade proportion (takeaway 2). There are two separate regression lines for each of the two takeaways, one looking at US projects and one at non-US ones. In both cases, the American regression line is well over the European-and-Canadian line for tunneled projects but the lines intersect roughly when the line goes to 0% underground. This leads to the conclusion that the US has no premium over Europe for light rail projects. Moreover, because the US has outliers in New York, the study concludes that there is no US premium outside New York. Unfortunately, these conclusions are both false.

The reason the regression lines intersect is that regression is a linear technique. The best fit line for the US construction cost per km relative to tunnel proportion has a y-intercept that is similar to the best fit line for Europe. However, visual inspection of the scattergram in takeaway 3 shows that at 0% underground, most US projects are somewhat more expensive than most European projects; this is confirmed in takeaway 4. All this means that the US has an unusually large premium for tunneled projects, driven by the fact that the highest-cost part of the US, New York, builds fully-underground subways and not els or light rail. If instead of Second Avenue Subway and the 7 extension New York had built high-cost els, for example the plans for a PATH extension to Newark Airport, then a regression line would show a large US premium for elevated projects but not so much for tunnels.

I tag this post “good/interesting studies” and not just “shoddy studies” because the inclusion of takeaway 4 makes this clear: there is a US premium for light rail, it’s just smaller than for subways, and then regression analysis can falsely make this premium disappear. This is an error, but an interesting one, and I urge people who use statistics and data science to study the difference between takeaways 2 and 3 and takeaway 4 carefully, to avoid making the same error in their own work.

Upward bias

Eno has a link to its dataset, from which one can see which projects are included. It’s notable that Eno is comprehensive within the United States, but not in Europe. Unfortunately, this introduces a bias into the data, because it’s easier to find information about expensive projects than about cheap ones. Big projects are covered in the media, especially if there are cost overruns to report. There is also a big-city premium because it’s more complicated to build line 14 of a metro system than to build line 1, and this likewise biases incomplete data because it’s easier to find what goes on in Paris than to find what goes on in a sleepy provincial town like Besançon. Yonah Freemark thankfully has good coverage of France and includes low-cost Besançon, but Eno does not – its French light rail database is heavy on Paris and has big gaps in the provinces. French Wikipedia in fact has a list, and all of the listed systems, which are provincial, have lower costs than Paris.

There is also no coverage of German tramways; we don’t have such coverage either, since there are many small projects and they’re in small cities like Bielefeld, but my understanding is that they are not very expensive. Traditionally German rail advocates held the cost of a tramway to be €10 million/km, which is clearly too low for the 2010s, but it should lower the median cost compared to the Paris-heavy, Britain-heavy Eno database.

Who Should Bear the Risk in Infrastructure Projects?

The answer to the question is the public sector, always. It’s okay to have private-sector involvement in construction, but the risk must be borne by the public sector, or else the private sector will just want more money to compensate for the extra risk.

The biggest piece of evidence for this is emerging out of our construction costs project, so it will appear in the report and not in a blog post. But for now, I’d like to point out examples from media, the academic literature, and one interview of particular interest.

PPP, Gangnam style

A transportation planner in Korea named Abdirashid Dahir has been giving Eric and me a lot of detailed information about Korean construction costs. We were already aware that Line 9 in Seoul had been built as a PPP, but what we learned was more complicated.

Line 9 is a partnership – the last P in PPP. This means, part of the construction is done by the private sector, and part by the public sector, namely the Seoul Metropolitan Government. The private consortium, led by Hyundai, was responsible for the design and for the construction of the systems, including the tracks, signaling, and rolling stock. SMG was responsible for the civil infrastructure. The total cost of the first phase was 1,167.7 billion won for 25.5 km, split as 492.2 billion in municipal construction and 675.8 billion in private investment.

The importance of this split is that civil infrastructure is the least certain part of underground construction. There are always geotechnical surprises, most small, a few potentially leading to large cost and schedule overruns. These are especially likely during station construction – the tunnels in between tend to be simpler with modern TBMs. Systems, in contrast, are relatively straightforward. Installing rail tracks is the same task regardless of whether it’s in solid rock in an exurban area that has no significant archeology, or through sand that had to be frozen, partly underwater, in the oldest parts of Berlin.

The upshot here is that while low-cost countries do use PPPs, this project keeps the riskiest aspects of construction public and not private. Privatization is fine for less risky, more commoditized situations.

How private bidders respond to risk

Two examples come to mind, both from the United States.

First, in New York, Brian Rosenthal’s seminal New York Times article cited Denise Richardson of the General Contractors’ Association saying that the contractors are barely making any profit and are bidding high because of risks imposed on them by the public sector. I don’t think this is a very high-quality source – it’s extremely biased, for one – but in context, it makes some sense.

Second, we do have more quantifiable data on this, thanks to the work of the Stanford Graduate School of Business economist Shosh Vasserman and Hoover Institute economist Valentin Bolotnyy. They look at highway maintenance contracts in Massachusetts and compare scaling auctions, in which the contracts are itemized, with lump sum auctions, in which they are not. Based on actual differences in price and estimates of contractor risk-aversion, they estimate that itemizing saves 10% of the cost through lower risk.

Supporting structures for public-sector risk assumption

There’s always the problem of moral hazard. Of note, even with this problem, costs are lower with itemized contracts in Massachusetts than with lump-sum contracts. But this does suggest a number of ways to reduce costs through better risk management:

  • Itemized contracts, in enough detail that changes do not need litigation.
  • Fixed profit rates – Spanish contracts are done with a fixed profit rate over the items named in the bid.
  • Public oversight – there needs to be tighter supervision of risky things, which most likely means no PPPs for civil infrastructure.

It is unfortunate that American trends in the last 20 years have been away from those principles and toward greater privatization of the state, and equally unfortunate that American (and British) soft power has led to similar reforms in the wrong direction in the rest of the Anglosphere. But it’s possible to do better and imitate Korean practices to get Korean costs.

Surplus Extraction

Ever since reading Brooks-Liscow on the growth in American road construction costs since the 1960s, I’ve been interested in the surplus extraction theory of costs. The authors call their main theory citizen voice, in which local groups can use litigation to extract the social surplus generated by infrastructure construction. I’d like to go more deeply into what this theory is and what it implies.

What is surplus?

Normally, a competitive market has no surplus. The owner of a restaurant, the developer of a building in an unconstrained area like suburban Texas, the seller of cloth masks on Etsy, the freelance web developer – none of them is making a killing. People enter the market until profits are driven down to levels low enough to essentially be the owner-manager’s wage. Companies can only make a large profit if they operate at enormous scale, which takes a long time to develop – the profit margins on a single Walmart or Carrefour or Lidl are small, but the profit margins on 10,000 stores add up to a couple billion dollars a year.

Infrastructure is not a competitive market, for a number of different reasons:

  • The construction of transportation infrastructure has strong positive externalities, through enabling agglomeration. In a country with cars, the construction of public transportation also helps mitigate the negative externalities of cars.
  • Infrastructure is not meaningfully competitive. The largest city in the world, Tokyo, has around two competing rail operators per suburban region. In Tokyo, it’s a natural duopoly; in just about every smaller city, it’s a natural monopoly.
  • The barriers to entry are so steep that some kind of price regulation is obligatory. The result is extensive consumer surplus for riders who are not poor.
  • Government involvement means that regulations that make it easier or harder to build infrastructure have large impact, which can create or destroy social surplus.

The upshot is that at non-New York costs, infrastructure construction in New York generates enormous social surplus. I could break this down by component, but for brevity I won’t, and just cite what looks like the upper limit of what the publics in the United States and Europe are willing to pay for urban and regional rail: around $50,000 per projected weekday trip. Lines teetering on the edge of cancellation, like M18 in Paris, Second Avenue Subway Phase 2 in New York, and Crossrail 2 in London, all cluster around this figure.

If we take $50,000/rider as the lowest possible benefit-cost ratio that gets a project built, around 1.2-1.3 in countries that conduct such analyses, then Second Avenue Subway Phase 2, currently projected around $60,000/rider, is 1. But at the median global cost, which exists in France and Germany, it would cost $700 million, or $7,000/rider, for a benefit-cost ratio of 8.5. At costs that exist in Southern Europe, Scandinavia, Switzerland, and Korea, make it $400 million, or $4,000/rider, for a benefit-cost ratio of 15. That’s a big net profit for New York City Transit (or, it would be if its operating costs were not abnormally high too), and a huge net social surplus for New York. Every group that wants a piece of that surplus then has an incentive to make noise and raise costs.

How can surplus be extracted?

People who wish to seize public resources have a variety of methods with which to do so. Some are net transfers of surplus from society to one special interest, but most are net destruction of value in the sense that the loss of social surplus exceeds the gain to the special interest, usually by a large margin.

The technique for surplus extraction is usually the threat of a lawsuit, but in some cases it can be direct political lobbying. The actual lawsuit is almost never important – in the US and Germany, at least, the state usually wins these suits, and the impact of litigation is to delay and to deny political capital.

However, surplus can also vanish into the ether through poor planning. Consultants who are not under pressure to save money may well propose oversize infrastructure just because that’s what they are used to, or to avoid sharing right-of-way across railroads; this has led to unusual cost premiums in the United States for everything that touches mainline rail, whereas the subway and light rail premiums are, outside New York, bad but less onerous.

The demands made by special interests that extract surplus vary. They include any of the following:

  • Gratuitous tunneling instead of above-ground construction. This is usually a demand made of high-speed rail, but there are some gratuitous tunnels in suburban rail as well, for example Crossrail 2. The surplus here is that NIMBYs do not like to see trains from their houses; the emotional value of their views is naturally a fraction of that of the cost of tunneling.
  • Compromise alignments that either increase costs or reduce benefits. This is usually about avoiding specific places; Brooks-Liscow give an example of a Detroit highway swerving around a Jewish community center. But sometimes it can be the opposite – in fact, early US freeway builders expected that communities would lobby for highways near them, not far from them. Los Angeles County’s advocacy for a high-speed rail detour through Palmdale is one such example.
  • Extortion of community benefits to activists, for example demands for larger stations to act as neighborhood centers. A large degree of the cost explosion of the Green Line Extension in Boston came from the policy of accommodating local demands, leading to oversize stations. But such overbuilding can also occur absent extortion – the surplus can vanish into poor practices, representing incompetence rather than malice, as in the oversize viaducts of California High-Speed Rail.
  • Contracts to favored companies. This led to cost explosion in Italy in the 1970s and 80s, especially in Rome but also Milan; unlike the other items on this list, this is generally illegal, and costs in Italy came down after crackdowns on corruption in the 1990s. However, legal versions exist – sometimes the government is just used to doing business with a company with a poor track record, for example the “the devil we know” attitude in California toward Tutor Perini. The surplus in the latter case vanishes not quite into someone’s pockets but more into the state’s unwillingness to oversee contractors more tightly.
  • Labor demands. If the demands are purely about wages then the surplus is distributed without being destroyed. However, these demands are in all cases I know of also about other things. For example, the sandhogs in New York opposed the use of more efficient tunnel boring instead of more dangerous but more labor-intensive dynamite. Protectionism also leads to inferior equipment in addition to higher costs.

Who can extract surplus?

Surplus extraction works through informal mechanisms. The purpose of the nuisance lawsuit is not to win, but to extract a settlement. The threat is delay and loss of political favor for the project rather than outright cancellation. The NIMBY lawsuit in Silicon Valley against California High-Speed Rail was right on the technical merit – the Pacheco Pass route, which would pass through the richest suburbs was technically inferior to the Altamont Pass route, which wouldn’t – still lost; Pacheco was favored due to another kind of surplus extraction, namely Rod Diridon’s desire for shorter Los Angeles-San Jose trip times.

Because surplus extraction works through politics and not clear rules, it benefits those with the most political power. In this way, the rise in NIMBYism in the 1960s and 70s, for example the freeway revolts, contrasts with the contemporary free speech movement, which used formal lawsuits with the intent of winning to expand the boundaries of free speech in America.

The free speech movement celebrated protections for communist Berkeley professors and for pornographers; people with normative professions and normative political views were already protected. In contrast, NIMBYism was most powerful in already rich areas, like Jane Jacobs’ Greenwich Village, or Boston’s South End. Baltimore’s racially integrated freeway revolt was exceptional. New York built freeways through working-class neighborhoods easily, and only encountered political obstacles in the Village, which was by the 1950s gentrified (Jacobs was a journalist with some college education, married to an architect, and her father was a doctor), a new development that hadn’t happened in urban history before and thus the city elites had missed it. Moreover, Jacobs’ remedy of creating and empowering community boards has ensured that only powerful people and powerful communities could change city decisions.

Even more recent attempts to create equity have failed. Slowing down the state and empowering community is always bad for equity, because the community is where inegalitarian traditions live. Black leaders now can derail transit plans just as white leaders can; non-leaders have no voice in neighborhood politics, and it’s those non-leaders who work outside the neighborhood who rely on public transit.

Surplus extraction remains the domain of people with political and cultural cachet. One can fight redevelopment in San Francisco on behalf of a mural to Cesar Chavez; fighting it on behalf of pornographers is harder. Similarly, the unions that have been the best at extracting surplus are traditional ones, doing jobs that existed 100 years ago, at productivity levels that remain stuck in that era, mainly the trades.

Conclusion: saying no

Surplus extraction theory does not say it is impossible to reduce costs. Italy’s sharp fall in costs in the 1990s and Turkey’s gentle fall in the 2010s both suggest that cost reduction is possible. What it does say is that the role of the state is to safeguard surplus and keep it socialized, against demands from many special interests, which should be disempowered through legal changes making lawsuits harder and reducing the ability of consultants and unions to drive up costs.

In that sense, the role of the planner is to say no – and moreover, to say no to charismatic groups representing much-romanticized people. No, dear mother with children, we will not build you a noise wall just because you think 140 km/h electric trains will reduce your quality of life. No, dear tradesman much-profiled as a non-college white voter, we will not hire you for $110/hour when there exist people who will do your job better than you can at $35/hour. No, dear third-generation business owner, we will not listen to what you think about traffic as we replace parking spots with bus lanes. No, dear anti-gentrification activist, we will not pay you as an equity consultant, we will just build the subway in the city. No, dear white flight homeowner, we will not build you a tunnel just to avoid taking a few houses through eminent domain. No, dear deindustrialized city leader, we will not require companies to set up factories in your city at high cost when we can get cheaper imports. It’s never going to be no, dear criminal, or no, dear Nazi, because criminals and Nazis are not used to making such requests and having people listen.

It’s optimistic in a sense, because much cost control comes just from knowing that it’s possible and having the nerve to say no to people who are used to hearing yes. The engineering factors that lead to low costs are important, but first of all, it’s necessary to believe that they are feasible, over local objections.

More on Consultants and Design-Build

A few months ago, there appeared an article comparing construction costs for subways in the US and Europe. It has a little table, not PPP adjusted, with cases from elsewhere, but the bulk of the reporting covers differences between the US and Europe. It’s interesting and I urge everyone to read it – but read it critically. It has a long list of bullet points naming various differences, some already covered here, some new but still within reason.

One aspect that seems especially apt is this:

The construction cost [in the US] represents slightly more than 50% of the overall program cost, while soft costs and stakeholders’ commitments at 45% are significantly higher in comparison with other types of major projects or similar projects in other global regions.

Labor cost and construction schedule are the most important factors affecting the construction cost. Labor cost is often driven by labor union rules which vary significantly among states and cities. One of the highest labor costs of tunnel construction workers is the Sandhogs in New York which can be as high as $110/hr and on an overtime basis, it can reach over two to three times this value. Their rates are higher than other tunnel workers in the country and significantly higher than European or Asian workers rates. Also, the number of workers assigned in the tunnel in New York is significantly more than other parts of the country and as much as 4 times more than tunnel workers assigned to comparable projects in Europe. Tunneling being linear structures, the opportunities to accelerate the construction schedule in order to reduce overall labor cost are limited.

That said, I’d like to caution about fully accepting everything the article says. The key issue is that the authors’ experience is as consultants – they work for AECOM. This means that to at least some extent, their expertise is informed by their work as outside consultants, which means that they are the most familiar with projects that at some point invite consultants in.

This is important, because this may be an important difference between low- and medium-cost countries. I am not sure – I’m trying to investigate those differences more carefully, but this involves listening to German complaints about NIMBYism and trying to figure out how relevant it is that NIMBYs are far less empowered in Southern Europe, counting Turkey as part of that region since it acts much like a peripheral European country in construction. I don’t think that low-cost countries in Southern Europe use international consultants – Milan and Madrid at least don’t, and Istanbul used Italian consultants at one point but nowadays seems mostly to design things itself.

What’s more, AECOM’s experience is not just in countries that use AECOM’s advice regularly, but also in specific projects that bought its services. This is relevant to the claim that,

European owners spend less time and money on planning, studies, conceptual developments, and detailed design. Most projects are implemented using the Design-Build model with the detailed design provided by the contractor during construction to suit his means and methods; this results in efficiency and eliminates repeating of design work.

There’s the rub: design-build does exist in Continental Europe. Turkey uses it, and France is glancing in that direction. But it’s uncommon – Italy and Spain do not use this method, and France largely does not either and I think neither do Germany or the Nordic countries. Moreover, design-build in Turkey means there is extensive in-house oversight, much more so than in American or British design-build projects.

French design-build is even more tightly overseen, because its purpose is not to forgo public planning. Rather, France traditionally maintains the separation of public planning, private design, and private construction, in order to fight corruption and guarantee fair procurement. This separation leads to problems when projects require redesign in case they are very complex, and as a result, Grand Paris Express exists as a large public-sector planning agency to facilitate coordination between the design and construction teams. Technically this can be called design-build, but it has approximately nothing to do with American design-build projects that pay Skanska or Dragados a large sum of money to dig a subway and have extensive public regulations and red tape but little public engineering. The role of the public sector in American, British, and increasingly rest-of-Anglosphere eyes is to make sure companies follow capricious rules but not to actively build infrastructure or, perhaps, change the rules to be more favorable to swift action.

Regrettably, in the coda the authors buy into this mentality that the public sector cannot change the rules. They list various action items that can be undertaken to reduce costs, all of which are very good – those items include streamlining regulations, improving risk sharing mechanisms, and offloading some peripheral costs, among others, rather than expanding design-build. They’re missing a few things that we’re learning from the low-cost world – for example, Istanbul makes an effort to site stations in parks in order to be able to build them more easily and reduce their costs, which I believe is also true of Milan. But for the most part, the list of things that the US needs to do to have what France and Germany have cannot be too dissimilar to that produced by the authors.

But then the authors throw it all away and say it’s unlikely that the US could match European costs. They give a bare-bones explanation that boils down to saying “these recommendations won’t really be implemented.” I agree to some extent – it’s plausible, though not yet certain, that New York will need to union-bust the sandhogs and probably also the other trades, and these are politically powerful unions that know very well that they earn several times what their labor is worth and fight to preserve this. But, first of all, not every recommendation is that fraught; questions of risk sharing, public planning, and procurement do not lend themselves to political populism and remain unreformed mostly because the Northeastern US has timid, reactive governance.

And second, the authors say it’s unlikely the US could match European costs even if their recommendations are followed. They don’t explain why – there are few intangibles in the article, and they mostly seem peripheral to the main question, for example the fact that the US is an auto-oriented society. I can’t tell if it’s just uncertainty, which does not appear in the body of the piece, or if there’s more to it. It could just be a writing artifact and what they meant to say was that their recommendations could help New York match Parisian costs but they’re skeptical their recommendations are politically palatable to New York.

I emphasize the criticism, even though it’s generally a good overview, because all of the experts we talk to have biases. These could be consultant biases, or political biases (Turkey is far more polarized than any mature democracy), or engineering biases, or language biases. Even reading my blog is to some extent a bias – people who read me and think well of my analysis might well look for reasons in their own domain why design-build is bad, which means that to be certain I am correct in my prescription against it, we need to cleanroom this, for example by interviewing people who do not know me directly (or at all) and asking how engineering is done where they are.

Transportation Renaissance

Ada Palmer posts rarely, but when she does, it’s always worth reading. She alternates between writing about her science fiction and writing about academic history; her most recent post is the latter, covering the historiography of the Renaissance. She notes that the idea of a three-age system, in which great Ancient knowledge was lost in the Middle Ages and rediscovered in the Renaissance, was first promoted in the Renaissance itself, even if the word renaissance was only used starting in the 19th century, and traces why this idea was accepted then and why it’s remained popular since. In short: it provided political legitimacy to the coterie of thugs (“aristocracy”) who launched coups and counter-coups in the Italian states, who could hire historians to portray them as harbingers of a new era of revival of ancient glory.

This is a paragraph-long summary of a 13,000-word post that summarizes an in-progress book, so I’m glossing over a lot of detail and I recommend that people read the post if they want to talk about Renaissance historiography. I bring this up because this is relevant to transportation, and to some extent urbanism in general, in a number of ways.

The three-age schema

Ada notes that medieval Europeans divided the world into two ages: before and after Jesus. The Renaissance began a trend of a three-age system: Antiquity, a medieval dark age, and the Renaissance or modernity. She further traces the intellectual history of this not just in the Italian Renaissance but also in more recent times, going over the use of the language of renaissance in Johan Burkhardt’s work to argue for a new modernity replacing medieval superstition.

Stepping away from professional historians, I do not know to what extent the average educated Westerner thinks in terms of three ages. The answer is clearly “a great deal,” but I do not know to what extent it is universal. I was taught this schema uncritically in primary and middle school, but what I see in the online discourse is less consistent – for example, Paul Krugman’s writings on Malthusianism back a two-age model, before and after the beginning of the Industrial Revolution. But even with the caveat that economic historians don’t view things this way, the Nike swoosh model of Roman greatness, medieval decline, and modern resurgence still exercises enormous cultural influence.

The relevance of this is that people who propose a change to something often default to the three-age model, transplanted into a specific context. The emergent view of most American and European advocates for rail transport is that rail had a golden age from its invention until the middle of the 20th century, declined subsequently, and is supposed to enter a renaissance now. This is usually connected with urbanism, with a model of the growth of traditional cities, decline through suburban sprawl, and renaissance; variants depend on politics, but Strong Towns, myriads of consultants telling cities how to attract talent, most YIMBYs, and most of the left agree on this picture.

Revival of ancient learning

Renaissance Italy had a MIGA obsession. In an era of the Avignon Papacy and intensifying warfare between different factions and city-states, the appeal of Roman unity and peace is not hard to understand; it’s not as if 14th- and 15th-century Italians had better models. Here’s Ada again:

The solution Petrarch proposed to what he saw as the fallen state of “my Italy” was to reconstruct the education of the ancient Romans.  If the next generation of Florentine and, more broadly, Italian leaders grew up reading Cicero and Caesar, the Roman blood within them might become noble again, and they too might be more loyal to the people than to their families, love Truth more than power, and in short love their cities as the Romans loved Rome.  Such men would, he hoped, be brave and loyal in strengthening and defending their homelands.  Rome started as one city, and did not make itself master of the world without citizens willing to die for it.

“Petrarch says we can become as great as the ancients by studying their ways!  Let’s do it!”  Petrarch’s call went out and, with amazing speed, Italy listened.  Desperate, war-torn city states like Florence who hungered for stability poured money into assembling the libraries which might make the next generation more reliable.  Wealthy families who wanted their sons to be princely and charismatic like Caesar had them read what Caesar read.  Italy’s numerous tyrants and newly-risen, not-at-all-legitimate dukes and counts filled their courts and houses and public self-presentation with Roman objects and images, to equate themselves with the authority, stability, competence and legitimacy of the Emperors.  No one took this plan more to heart than Petrarch’s beloved Florentine republic, and, within it, the Medici, who crammed their palaces with classical and neoclassical art, and with the education of Lorenzo succeeded in producing a classically-educated scion who was more princely than princes.

This provided the template for every Western narrative of decline that I’m familiar with, and a good number of non-Western ones: we were great, we’ve gone into decline, we will reverse the decline by restoring our ancient values. It’s unavoidable in every narrative of American decline; it’s there in the Brexit conception of British nationalism; it’s there in cross-national narratives of the decline of the left since the 1970s. In non-Western countries, it was there in a lot of early colonial rebellions (the Indian Rebellion of 1857 tried to restore the Mughal Empire). Even Japan went through a restorationist phase in the wake of its forced opening, though it famously went in a very different direction once the Meiji restoration happened.

This schema is used at a subnational level extensively. Regions that view themselves as declining, like the American Rust Belt, Northern England, or East Germany, cling fiercely to distinctive local institutions. This includes extensive study of local history and local affairs. It’s unavoidable in, say, Belt Publishing. Sometimes, this history is studied critically; in the broad public, it usually isn’t. The number of times I’ve heard New Yorkers contrast how the First Subway was built in four years (and not, say, 40) with how long subways take today is beyond mortals’ ability to count.

With rail transport specifically, advocacy is usually bundled into railfan interests. This, as per the usual paradigm, dovetails into very deep, usually uncritical, study of the history of the technology back when it was supposedly great. Go on Railroad.net and you will see people talk about the minutiae of historical steam and diesel engines and also brush off every piece of knowledge that was not generated in American mainline railroading. Interest in rail technology as a solution for the future gets bundled into romanticism for steam locomotives and for the particulars of how private railroads chose to operate service in the early 20th century.

The Renaissance Man as the innovator

Finally, Ada’s insight about why the idea of the Renaissance was accepted so quickly matters when looking at modern technology. Here, the three-age model is less relevant. The same emphasis on the innovator bringing the company/city/nation/world into a golden age is produced by other models. The accelerating growth model of the technological singularity produces the same effect even without the need to learn history, and is therefore widely popular among rationalists.

In transportation, the best recent example of this is the idea of the Hyperloop. What it is, underlyingly, is a new technology for running rail service, like maglev but capable of running at higher speed. All aspects of rail service planning with the exception of propulsion remain mostly the same (mostly, because the higher speeds do have special implications, though I don’t think they’re any different from what one can extrapolate from existing high-speed rail). This means that what it takes to build Hyperloop is similar to what it takes to build ordinary rail plus more money. I think Hyperloop One and Virgin understand that, but Elon Musk does not.

The importance of history as legitimacy cannot be discounted here. Court historians were hired to write hagiographies, just as artists were hired to paint and sculpt the likenesses of the biggest thugs (“royalty”). This does not usually apply to modern academic history – historians have political biases but there are layers insulating high-prestige academic historians from donors. But it does apply to a lot of popular writing, especially business journalism. I forget where I’ve read – I think it was in the context of New York real estate – that 2010s journalism is alive and well in trade media, but writing critical investigative pieces about powerful players is not always expected or rewarded in publications that make money as internal trade papers.

The upshot is that analyzing history, whether general or specific, as an abrupt positive change serves to empower people who can claim that they are the new world, and that any and all criticism is just the old way of thinking. It’s a form of epistemic narrowing that blocks off knowledge those people don’t have or can’t easily control.

Costs are Rising, US Highway Edition

There’s a preliminary paper circulating at Brookings, looking at American infrastructure construction costs. Authors Leah Brooks and Zachary Liscow have tabulated the real costs of the American Interstate program over time, from the 1950s to the 1990s, and find that they increased from $5.3 million per km ($8.5 million/mile) in 1958-63 to $21.3 million/km ($34.25 million/mile) in 1988-93.

Moreover, they have some controls for road difficulty, expressed in slope (though not, I believe, in tunnel quantity), urbanization, and river and wetland crossings, and those barely change the overall picture. They go over several different explanations for high American infrastructure costs, and find most of them either directly contradicted by their results or at best not affirmed by them.

I urge readers to read the entire paper. It is long, but very readable, and it is easy to skip the statistical model and go over the narrative, including favored and disfavored explanations, and then poke at the graphs and tables. I’m going to summarize some of their explanations, but add some important context from cross-national comparisons.

Why costs (probably) aren’t rising

The authors identify four hypotheses they rule out using their research, in pp. 19-23 (they say five but only list four):

Difficult segments postponed and built later – they have some controls for that, as mentioned above. The controls are imperfect, but the maps depicted on pp. 59-61 for the Interstate network’s buildout by decade don’t scream “the segments built after 1970 were harder than those built before.”

Time-invariant features – these include cross-national comparisons, since the United States has always been the United States. I will discuss this in a subsequent section, because two separate refinements of what I’ve seen from cross-national comparisons deal with this issue specifically.

Input prices – this is by far the longest explanation the authors deal with. Anecdotally, it’s the one I hear most often: “labor costs are rising.” What the authors show is that labor and materials costs did not rise much over the period in question. Construction worker wages actually peaked in real terms in 1973 and fell thereafter; materials costs jumped in the aftermath of the oil crisis, but came down later, and were back at pre-crisis levels by the 1990s (p. 48). Land costs did rise and have kept rising, but over the entire period, only 17.7% of total costs were preliminary engineering and land acquisition, and the rest were in construction.

Higher standards – the authors looked and did not find changes in standards leading to more extensive construction.

There are several more incorrect explanations that jump from the data. I was surprised to learn that throughout the 1970s and 80s, completion time remained mostly steady at 3-3.5 years of construction; thus, delays in construction cannot be the explanation, though delays in planning and engineering can be.

The authors themselves list additional explanations that have limited evidence but are not ruled out completely from their data, on pp. 32-35. Construction industry market concentration may be an explanation, but so far data is lacking. Government fragmentation, measured in total number of governments per capita, has no effect on the result (for example, California has high costs and not much municipal fragmentation); I’ll add that Europe’s most municipally fragmented country, France, has middle-of-the-road subway construction costs. State government quality, as measured by corruption convictions, has little explanatory power – and as with fragmentation, I’ll add that in Europe we do not see higher costs in states with well-known problems of clientelism and corruption, like Italy and Greece. Work rules requiring the addition of more workers may be relevant, but unionization and left-right politics are not explanatory variables (and this also holds for rail costs).

Economies of scale look irrelevant as well: there is negative correlation between costs and construction, but the causality could well go the other way. Finally, soft budget constraints are unlikely, as the federal government can punish states that mismanage projects and take more money; it’s possible that as the Interstate program ended states felt less constrained because there wouldn’t be money in the future either way (“end of repeated game”), but the fact that costs keep rising in subway construction suggests this is not relevant.

Favored explanations

Two explanations stand out to the authors. The first is that nearly the entire increase in construction costs over time can be attributed to a mix of higher real incomes and higher house prices. While the construction workers themselves did not see their wages rise in the late 1970s and 80s, a richer population may demand more highways, no matter the cost.

Higher real estate costs could have an impact disproportionate to the share of land acquisition in overall costs by forcing various mitigations that the paper does not control for, such as sound walls and tunnels, or by sending roads over higher-cost alignments.

The second explanation is what the authors call citizen voice. Regulatory changes in the 1960s and early 70s gave organized local groups greater ability to raise objections to planning and force changes, reducing community impact at the cost of higher monetary expenditures. The authors give an example from suburban Detroit, where a highway segment that disrupted a Jewish community center took 25 years to be built as a result of litigation.

The authors don’t say this explicitly, but the two explanations interact well together. The citizen voice is very locally NIMBY but is also pro-road outside a handful of rich urban neighborhoods. Higher incomes may have led to public acceptance of higher costs, but local empowerment through citizen voice is the mechanism through which people can express their preference for higher costs over construction inconvenience.

How time-invariant are national features, anyway?

The authors contrast two proposed explanations – higher incomes and property values, and stronger NIMBY empowerment – with what they call time-invariant features, which could not explain an increase in costs. But can’t they?

I spent years plugging the theory that common law correlates with high subway construction costs, and it does in the developed world, but upon looking at more data from developing countries as well as from before the last 25 years, I stopped believing in that theory. It started when I saw a datapoint for Indonesia, a civil-law country, but even then it took me a few more years to look systematically enough, not to mention to wait for more civil-law third-world countries to build subways, like Vietnam. By last year I was giving counterexamples, including Montreal, low rail electrification costs in some common law countries, and the lack of a London cost premium over Paris until the late 20th century.

In lieu of common law, what I use to explain high costs in the US relative to the rest of the world, and to some extent also in most first-world common law countries as well as third-world former colonies, is weak civil service. In the developed world, the theory behind this is called adversarial legalism, as analyzed by Robert Kagan. Adversarial legalism enforces the law through litigation, leading to a web of consent decrees. Some are naked power grabs: for example, in Los Angeles, a union sued a rolling stock vendor for environmental remediation and agreed to drop the lawsuit in exchange for a pledge that its factory be unionized, which may play a role in why the trains cost around 50% more than equivalent European products.

American litigiousness developed specifically in the 1970s – it’s exactly how what the authors of the paper call citizen voice is enforced. In contrast, on this side of the Channel, and to some extent even generally on this side of the Pond, laws are enforced by regulators, tripartite labor-business-government meetings, ombudsmen, or street protests. French riotousness is legendary, but its ability to systematically change infrastructure is limited, since rioting imposes a real cost on the activist, namely the risk of arrest and backlash; in contrast, it is impossible to retaliate against people who launch frivolous lawsuits.

I bring up the fact that I said most of this last year, and the rest at the beginning of this year, whereas I was not aware of the paper under discussion until it was released a few hours ago, to make it clear that I’m not overfitting. This is something that I’ve been talking about for around a year now, and a jump in American construction costs in the 1970s and 80s – something that also looks to be the case in subway construction – is fully compatible with this theory.

Corey Johnson’s Report on City Control of the Subway

Yesterday, New York City Council speaker and frontrunner in the 2021 mayoral race Corey Johnson released a document outlining his plan to seek city control of the subway and buses. In addition to the governance questions involved in splitting the state-run MTA between a city-owned urban transit agency and state- or suburb-owned commuter rail, it talks about what Johnson intends to do to improve public transit, befitting a mayor in full control of subway and bus operations. There are a lot of excellent ideas there, but also some not so good ones and some that require further work or further analysis to be made good.

Governance

Johnson proposes to spin the urban parts of the MTA into a new agency, called BAT, or Big Apple Transit. The rump-MTA will remain in control of suburban operations and keep MTA Capital Construction (p. 35), and there will be a shared headquarters. Some cooperation will remain, such as contributions toward cheaper in-city commuter rail fares, but there is no call for fully integrated fares and schedules: the recommendation “all trains and buses in the city will cost the same and transfers will be free” does not appear anywhere in the document.

Johnson also proposes that the BAT board will be required to live in the city and use transit regularly. There is a serious problem today with senior managers and board members driving everywhere, and the requirement is intended to end this practice. Cynically, I might suggest that this requirement sounds reasonable in 2019 but would have been unthinkable until the 2000s and remains so in other American cities, even though it would be far more useful there and then; the off-peak frequency-ridership spiral is nowhere nearly as bad in New York as it is in Washington or Boston.

One strong suggestion in this section involves appointing a mobility czar (p. 36), in charge of the NYC Department of Transportation as well as BAT. Given the importance of the subway, this czar would be in effect the new minister of transportation for the city, appointed by the mayor.

Ultimately, this section tends toward the weaker side, because of a problem visible elsewhere in the report: all of the recommendations are based on internal analysis, with little to no knowledge of global best practices. Berlin has city-controlled transit in full fare union with Deutsche Bahn-run mainline rail, but there has been no attempt to learn how this could be implemented in New York. The only person in New York who I’ve seen display any interest in this example is Streetsblog’s David Meyer, who asked me how DB and Berlin’s BVG share revenue under the common umbrella of the Berlin Transport Association (or VBB); I did not know and although I’ve reached out to a local source with questions, I could not get the answer by his filing deadline.

Finance and costs

This is by far the weakest section in the proposal. The MTA funds itself in large part by debt; Johnson highlights the problem of mounting debt service, but his recommendations are weak. He does not tell New Yorkers the hard truth that if they can’t afford service today then they can’t afford it at debt maturity either. He talks about the need to “address debt” but refrains from offering anything that might inconvenience a taxpayer, a rider, or an employee (pp. 42-43), and offers a melange of narrow funding sources that are designed for maximum economic distortion and minimum visible inconvenience.

In fact, he calls transit fares regressive (pp. 59, 61) and complains about century-long fare increases: real fares have risen by a factor of 2.1 since 1913 – but American GDP per capita has risen by a factor of 7.7, and operating costs have mostly risen in line with incomes.

He brings up ways to reduce costs. In operations these involve negotiations with the unions; even though the report mentions that drivers get paid half-time for hours they’re not working between the morning and afternoon peaks (“swing shift,” p. 48), it does not recommend increasing off-peak service in order to provide more mobility at low marginal cost. There is no mention of two-person crews on the subway or of the low train operator efficiency compared with peer cities – New York City Transit train operators average 556 revenue hours per year, Berlin U-Bahn operators average 829.

In capital construction the recommendations are a mixed bag of good and bad, taken from a not-great RPA report from a year ago. Like the RPA, Johnson recommends using more design-build, in flagrant violation of one of the rules set by global cost reduction leader Madrid. However, to his credit, Johnson zooms in on real problems with procurement and conflict resolution, including change orders (pp. 50-51), and mentions the problem of red tape as discussed in Brian Rosenthal’s article from the end of 2017. He suggests requiring that contractors qualify to bid, which is a pretty way of saying that contractors with a history of shoddy work should be blacklisted; I have heard the qualify-to-bid suggestion from some sporadic inside sources for years, alongside complaints that New York’s current bid-to-qualify system encourages either poor work or red tape discouraging good contractors. Unfortunately, there is no talk of awarding bids based on a combination of technical score and cost, rather than just cost.

Overall the talk of cost is better than what I’ve seen from other politicians, who either say nothing or use high costs as an excuse to do nothing. But it has a long way to go before it can become a blueprint for reducing subway construction costs, especially given the other things Johnson proposes elsewhere in the document.

Accessibility

Another mixed part of the document is the chapter about accessibility for people with disabilities. Johnson recounts the lack of elevators at most subway stations and the poor state of the bus network, featuring drivers who are often hostile to people in wheelchairs. However, while his analysis is solid, his recommendations aren’t.

First of all, he says nothing of the cost of installing elevators on the subway. An MTA press release from last year states the cost of making five stations accessible as $200 million, of $40 million per station. This figure contrasts with that of Madrid, where a non-transfer station costs about 5 million to equip with elevators, and a transfer station costs about 5 million per line served (source, PDF-pp. 11-12). In Berlin, which is not a cheap city for subway construction, the figure is even lower: about 2 million per line served, with a single elevator costing just 800,000.

And second, his proposal for finding money for station accessibility involves using the zoning code, forcing developers to pay for such upgrades. While this works in neighborhoods with ample redevelopment, not all city neighborhoods are desirable for developers right now, and there, money will have to come from elsewhere. For a document that stresses the importance of equality in planning, its proposals for how to scrounge funds can be remarkably inequitable.

That said, in a later section, Johnson does call for installing bus shelters (p. 74). A paper referenced in a TransitCenter report he references, by Yingling Fan, Andrew Guthrie, and David Levinson, finds that the presence of shelter, a bench, and real-time arrival information has a large effect on passengers’ perceived wait times: in the absence of all three amenities, passengers perceive wait time as 2-2.5 times as long as it actually is, rising to a factor of almost 3 for 10-minute waits among women in unsafe areas, but in the presence of all three, the factor drops to around 1.3, and only 1.6 for long waits for women in unsafe areas. Unfortunately, as this aspect is discussed in the bus improvement section, there is no discussion of the positive effect shelter has on people with disabilities that do not require the use of a wheelchair, such as chronic pain conditions.

I do appreciate that the speaker highlights the importance of accessibility and driver training – drivers often don’t even know how to operate a wheelchair lift (p. 63). But the solutions need to involve more than trying to find developers with enough of a profit margin to extract for elevators. Bus stops need shelter, benches, and ideally raised curbs, like the median Berlin tramway stations. And subway stations need elevators, and they need them at acceptable cost.

Bus improvements

By far this is the strongest part of the report. Johnson notes that bus ridership is falling, and recommends SBS as a low-cost solution. He does not stop at just making a skeletal light rail-like map of bus routes to be upgraded, unlike the Bloomberg and de Blasio administrations: he proposes sweeping citywide improvements. The call for bus shelter appears in this section as well.

But the speaker goes beyond calling for bus shelters. He wants to accelerate the installation of bus lanes to at least 48 km (i.e. 30 miles) every year, with camera enforcement and physically-separated median lanes. The effect of such a program would be substantial. As far as I can tell, with large error bars caused by large ranges of elasticity estimates in the literature, the benefits in Eric Goldwyn’s and my bus redesign break down as 30% stop consolidation (less than its 60% share of bus speedup since it does involve making people walk longer), 30% bus lanes, 30% network redesign, 10% off-board fare collection.

There is no mention of stop consolidation in the paper, but there is mention of route redesign, which Johnson wishes to implement in full by 2025. The MTA is in support of the redesign process, and allowing for integrated planning between NYCDOT and the MTA would improve the mutual support between bus schedules and the physical shape of the city’s major streets.

Moreover, the report calls for transit signal priority, installed at the rate of at least 1,000 intersections per year. This is very aggressive: even at the average block spacing along avenues, about 80 meters, this is 80 kilometers per year, and at that of streets, it rises to 200+ km. Within a few years, every intersection in the city would get TSP. The effects would be substantial, and the only reason Eric’s and my proposal does not list them is that they are hard to quantify. In fact, this may be the first time an entire grid would be equipped with TSP; some research may be required to decide how to prioritize bus/bus conflicts at major junctions, based on transportation research as well as control theory, since conditional TSP is the only way to truly eliminate bus bunching.

Reinforcing the point about dedicated lanes, the study calls for clawing back the space given to private parking and delivery. It explicitly calls for setting up truck routes and delivery zones in a later section (pp. 86-87); right now, the biggest complaint about bus lanes comes from loss of parking and the establishment of delivery zones in lieu of letting trucks stop anywhere on a block, and it is reassuring to see Johnson commit to prioritizing public transit users.

Livable streets

This is another strong section, proposing pedestrian plazas all over the city, an expansion of bike lanes to the tune of 80 km (50 miles) a year with an eye toward creating a connected citywide bike lane network, and more bike share.

If I have any criticism here, it’s that it isn’t really about city control of the MTA. The bus improvements section has the obvious tie-in to the fact that the buses are run by the MTA, and getting the MTA and NYCDOT on the same page would be useful. With bikes, I don’t quite understand the connection, beyond the fact that both are transportation.

That said, the actual targets seem solid. Disconnected bike lane networks are not really useful. I would never bike on the current network in New York; I do not have a death wish. I wasn’t even willing to bike in Paris. Berlin is looking more enticing, and if I moved to Amsterdam I might well get a bike.

Conclusion

The sections regarding costs require a lot of work. Overall, I get the impression that Johnson based his recommendations on what he’s seen in the local press, so the suggestions are internal to the city or occasionally domestic; the only international comparisons come from the RPA report or from Eric’s and my invocation of Barcelona’s bus redesign. This works for such questions as how to apportion the MTA’s debt service or how to redesign the bus network, but not so much for questions involving subway capital construction.

New York has a large number of fluent Spanish speakers. It should have no problem learning what Spanish engineers know about construction costs, and the same is true for other communities that are well-represented in the cities, such as Korean-, Russian-, Chinese-, Brazilian-, and Polish-New Yorkers. Moreover, in most big cities that don’t send large communities to New York, such as those of Northern Europe, planners speak English. Johnson should not shy from using the expertise of people outside New York, ideally outside the United States, to get subway construction costs under control.

The speaker’s plan is still a very good first step. The proposed surface improvements to buses, bikes, and street allocation are all solid, and should be the city’s consensus for how to move forward. What’s needed is something to tie all of this together with a plan to move forward for what remains the city’s most important transportation network: the subway.