Talking to Marco Chitti about the history of Italian construction always fills me with hope. He’s been gathering data about metro construction in Milan and Rome, and told Elif, Eric, and me about the issue of building through constrained areas. Historic city centers are constrained because tunneling can damage buildings – the first two lines in Milan, built in the 1950s and 60s at abnormally low costs, caused some damage to buildings, since they involved cut-and-cover under streets only 12-15 meters wide. The good news is that tunneling with a tunnel boring machine is fine now. Stations remain an enormous challenge – but the conversation did fill me with optimism about future construction in cities that were not global imperial capitals 2,000 years ago.
Tunnel-boring machines have advanced to the point of being archeology-safe. Italian heritage protection laws from the 2000s forbid any risk to historic buildings and historic sites, but TBM technology at this point allows preserving artifacts. It involves injecting a gel ahead of the cutting edge, which is not supposed to be a cost-raiser.
The result is that tunneling is cheap. This is not a matter of low wages – in fact, Marco cites higher wages for Italian skilled workers who staff TBMs, up to €4,500 a month net, which rises to about €9,000 gross with social contributions. These are based on a nationwide scale that only weakly varies with location, which helps explain why Naples costs are not low despite the region’s low incomes.
Station construction costs vary immensely by location. In Rome, on the same project, stations in a suburban part of the city might be €60-70 million. This does not mean construction is trivially easy: Rome’s suburbs still often host historic sites, having been home to patrician villas in Antiquity, and in fact the word suburb dates to that era. However, it’s relatively safe, and I don’t think Line C ran into such sites.
Then in the most constrained parts of the city, things are different. The extension plans for Line C deeper into city center have station costs in the €400-600 million range. This is not what things cost everything within Rome, or even everywhere within the densely-built parts of the city. But the Line C extension passes through the most historic sites. An already-under construction segment will go to the Colosseum, and a planned extension deeper into city center is to go to Piazza Venezia, at the Wedding Cake, and it is that station that is projected to cost €600 million.
The reason for the high cost is that it is not possible to do archeology- and building-safe cut-and-cover. Piazza Venezia doesn’t quite have enough room for a cut-and-cover dig of a full-length station. It is fed by a wide street, the Via Fori Imperali, and I asked Marco why not build cut-and-cover there, but he pointed out that the street goes through the historic Forum. It is in fact elevated over the ruins; any cut-and-cover there would endanger the Forum, and is not acceptable.
Without cut-and-cover, the only alternative is to mine the stations. Rome investigated the option of large-diameter TBMs on the Barcelona L9 model and found it infeasible, since the tunnels are so big they might themselves cause some building damage. Once the stations are mined from a small shaft, their costs explode. Second Avenue Subway built stations using the same method, and had similar per-station construction costs.
The good news
Mined station construction is in practically all cases not necessary. New Yorkers talk about the city’s high built-up density as a reason why costs are high. But in terms of actual stuff in the way of a tunnel, there’s less in New York than in Rome or Istanbul, which has even lower construction costs.
In fact, there is a line in Rome that is rather similar in urban geography to Second Avenue Subway: the Line B1 branch. It runs under a 27 meter wide street flanked by modern buildings that are about 9 stories tall above ground but also have underground parking, Italy having such a car culture that the middle class expects to own cars even in Rome. The cost: €527 million for 3.9 km, in 2010-15.
Moreover, the hard rock in New York should make it easier to build stations while maintaining building safety. Manhattan’s schist is brittle and therefore requires concrete lining, unlike the more uniform gneiss of Stockholm, famously forming natural arches that are pretty to look at from within the tunnels. However, it is still better soil for construction than the sand of Berlin’s U5 extension, to be opened next month, or the alluvial soil of Amsterdam.
The explanation Marco gives concerning station construction is physical and not institutional. This means it should transplant well into another setting – which it does!
In Berlin, the city-center U5 extension, including U55, is in today’s money around €240 million/km. The stations look like cut-and-cover to me, and if they’re not then it comes from severe NIMBYism since the line goes under the very wide Unter den Linden, but one of the stations is basically under the river and another is under U6 and involves moving the U6 station, and the sandy soil is genuinely bad to tunnel through. Suburban extensions in Berlin, with easy cut-and-cover stations, are consistently in the €100-150 million/km range, which is barely higher than the non-Forum Italian range. So Berlin looks fine, and just needs to invest resources into U- and S-Bahn extensions and not into extending the A 100 motorway.
Can New York have what Italy has?
Almost certainly! Second Avenue is not an old or narrow street by Italian standards. Nor are any of the other streets slated for subway construction in New York, such as Nostrand, Utica, and even 125th. Importing construction techniques from Italy and Germany should be feasible. There may be problems with local politics – New Yorkers absolutely hate admitting that another city may be better than theirs in any way, and this makes learning harder. But it is not impossible, and so far there do not seem to be any physical or economic obstacles to doing so.
Matt Yglesias has a blog post called Make Blue America Great Again, about governance in rich liberal states like New York and California. He talks about various good government issues, and he pays a lot of attention specifically to TransitMatters and our Regional Rail project for the Boston region, so I feel obliged to comment more on this.
The basic point Matt makes is that the quality of governance in rich liberal American states is poor, and as a result, people do not associate them with wealth very consistently. He brings up examples about the quality of schools and health care, but his main focus is land use and transportation: the transportation infrastructure built in New York, California, etc. is expensive and not of high quality, and tight zoning regulations choke housing production.
That said, I think there’s a really important screwup in those states and cities that Matt misses: the problem isn’t (just) high costs, but mostly total unwillingness to do anything. Do-nothing leaders like Charlie Baker, Andrew Cuomo, Gavin Newsom, and Bill de Blasio aren’t particularly interested in optimizing for costs, even the first two, who project an image of moderation and reason.
The Regional Rail proposal’s political obstacles are not exactly a matter of cost. It’s not that this should cost $4 billion (without the North-South Rail Link) but it was estimated at $15 billion and therefore there’s no will to do it. No: the Baker administration seems completely uninterested in governing, and has published two fraudulent studies making up high costs for both the North-South Rail Link and rail electrification, as well as a more recent piece of fraud making up high costs for Boston-Springfield intercity rail. The no comes first, and the high costs come second.
This history – no first, then high costs – is also the case for New York’s subway accessibility program. The MTA does not want it; the political system does not care either. Therefore, when disability rights advocates do force some investment, the MTA makes up high costs, often through bundling unnecessary investments that it does want, like rebuilding station interiors, and charging these projects to the accessibility account. A judge can force an agency to build something, but not to build it competently and without siphoning money.
I want to emphasize that this does not cover all cases of high American costs. Second Avenue Subway, for example, is not the result of such a sandbag: everyone wants it built, but the people in charge in New York are not competent enough to build it affordably. This does accord with Matt’s explanation of poor Northeastern and West Coast governance. But not everything does, and it’s important to recognize what’s going on.
The other important point is that these do-nothing leaders are popular. Baker is near-tied for the most popular governor in the United States with another do-nothing Northeastern moderate Republican, Maryland’s Larry Hogan. Andrew Cuomo’s approval rate has soared since he got 43,000 people in the state killed in the corona crisis.
People who live in New York may joke that the city has trash on the street and cockroaches in apartments, but they’re pretty desensitized to it. They politically identify as Democrats, and once corona happened they blamed Trump, as did many people elsewhere in the United States, and forgave Democrats who mismanaged the crisis like Cuomo. Baker and Hogan are of course Republicans, but they perform a not-like-the-other-Republicans persona, complete with open opposition to Trump, and therefore Massachusetts Democrats who have a strong partisan identity in federal elections are still okay with do-nothing Republicans. People who really can’t stand the low quality of public services leave.
Construction cost reform is pretty drastic policy, requiring the destruction of pretty powerful political forces – the system of political appointments, state legislators and mayors with a local rather than national-partisan identity, NIMBYs, politically-connected managers, the building trades, various equity consultants (such as many Los Angeles-area urbanists). They are not legally strong, and a governor with a modicum of courage could disempower them, but to be a moderate in the United States means to be extremely timid and technologically conservative. Matt himself understands that last point, and has pointed this out in connection with moderates who hold the balance of power in the Senate, like Joe Manchin and Susan Collins, but use it only to slightly shrink proposed changes and never to push a positive agenda of their own.
So yes, this is a construction cost crisis, but it’s not purely that. A lot of it is a broader crisis of political cowardice, in which non-leftist forces think government doesn’t work and then get elected and prove it (and leftists think real change comes from bottom-up action and the state is purely for sinecures, courtesy of the New Left). I warned in the spring that corona is not WW2 – the crisis is big enough to get people to close ranks behind leaders, but not to get them to change anything important. These states are rich; comfortable people are not going to agitate for the destruction of just about every local political power structure just to get better infrastructure.
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.
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.
It increasingly looks like the cause of high construction costs in the English-speaking world is the trend of the privatization of the state since the 1980s. Instead of public planning departments, there is growing use of consultants. This trend is intensifying, for example with increasing use of design-build contracts, introduced into Canada just before costs exploded.
Q. Does this mean neoliberalism is to blame?
A. Not really.
Nearly every political and economic trend in the last 40 years in a developed country can be connected with neoliberalism. The transition in South Korea from military government to something like social democracy has been reasonably compatible with the Washington Consensus principles.
In fact, two opposite trends have both been criticized as neoliberal: the move from income support to workfare in the Clinton administration in the 1990s, but also calls from some liberals, greens, and social democrats today for basic income.
Even things that are mostly about things that are what people on the left criticize as neoliberalism are not necessarily about the privatization of the state. Any of the following agenda items can be plausibly called neoliberal:
- Privatization of state-owned enterprises like the mail, the national airline, the national railway, road maintenance, and health care.
- Reduction in top income tax rates from historic levels that were sometimes higher than 90% to something closer to today’s 50% in various rich Western countries.
- Liberalization of foreign exchange and foreign investment.
- Voucher systems for public services like schools.
- Fiscal and monetary austerity.
The key here is that none of these items is exactly privatization of planning. Germany had welfare reform in the Schröder era, Hartz IV, that SPD and the Greens don’t even like anymore. It’s had austerity budgets under Angela Merkel, and inflation has been below the 2% target. The Netherlands privatized health care. Sweden has contracted out operations of rail and many other infrastructure services.
However, the privatization of the state itself is mostly a British and American program, which has spread to other English-speaking countries through their cultural cringe. Under Macron, the most neoliberal of French leaders, Grand Paris Express staffed up as a public planning agency, rather than contracting everything out to consultants.
Even when France engages in design-build, it’s not the same as in the Anglosphere. Design-build in France means that the three teams that are typically kept separate – public planning, private design, private construction – talk to one another more regularly, still with public oversight. There is still strong civil service, and no impetus so far to privatize it or discount its advice on the American and increasingly British model.
There is neoliberalism in Japan, and in Germany, and in France, and in Scandinavia. And in none of these do we see Anglo construction costs. This matters.
Question. Are there any historical examples of construction costs actually falling in a city, rather than just rising slower than elsewhere?
Answer. Yes! Not many, though.
I know of three examples, but the first is fairly irrelevant and is included here for completeness.
Example 1. London’s District line, going by Wikipedia data, cost 3 million pounds, which in today’s money translates to $90 million per kilometer. This was astonishingly expensive, and even today London Underground extensions, as opposed to Crossrail, cost less than that relative to British GDP per capita. The reason for the high cost: the line was built cut-and-cover without any street to go under, so it needed to carve a new right-of-way through Kensington, demolishing houses in an expensive area. No further cut-and-cover lines were built. Costs fell to about $30 million per kilometer with the invention of deep-bore tunneling a generation later; today, bored tunnel costs more than cut-and-cover, but with the technology of the late 19th and early 20th century, this was not the case.
Example 2. Milan built its first two lines very cheaply; in today’s money, M1 cost around $50 million per kilometer. It was built using a method invented specifically for the city’s narrow Renaissance streets called the Milan method or cover-and-cut, allowing vertical construction with retaining walls rather than sloped ones that require more street width. M2 was very cheap as well, but M3’s costs were much higher, I believe around $250 million per km in today’s money, built in the 1980s at the peak of Milanese corruption. Costs fell dramatically after a series of anti-corruption prosecutions that put much of the Italian political elite in prison. The Passante Railway was in today’s money around $140 million per km, not all underground, but it’s regional rail with difficult city center construction under three older lines. The more recent lines, M5 and M4 (in this order), run up to $120-160 million per km.
Example 3. Istanbul began building its subway system with M2, M3, and M4; the first Istanbul Metro line, M1, is light rail and its original section had very little tunneling. It used Italian designs and costs were low, not much more than $100 million per kilometer, but subsequently value engineering has led to slightly lower costs. The city had a learning process in which it reduced station footprints to save money, engaged in more extensive prior engineering before putting out new lines to bid, and generally gained experience in managing a project. Newer lines have cost slightly less, for example around $80 million/km for M5, all underground.
The angle of cleaning up corruption and building up state capacity is probably relevant – probably. Italy and Turkey remain very corrupt and clientelist states. In Turkey, the former mayor of Istanbul openly said he was going to prioritize metro construction in neighborhoods that voted for AKP, and then when the opposition won the city election the state stopped giving it money for new lines; construction goes on because the new mayor went to the European Investment Bank for financing. In Italy, for all the clientelism elsewhere, public-sector engineering is fiercely depoliticized and professionalized nowadays.
I might even speculate, without much knowledge yet (we’re still early in the work in Istanbul and even earlier in Milan), that Southern Europe may have such reputation for corruption that it has mundane mechanisms that professionalize public works. The clientelism in Turkey as far as we can tell extends to macro-level decisions of where to build lines, and evidently Istanbul managed to identify alternative sources of financing to the Erdoganist state.
If I’m right, then these same mechanisms of anti-corruption and public-sector professionalization can also be replicated in other parts of the world with state capacity problems. This cannot possibly be everything – Milan reduced its costs from levels that were not extremely high, and Istanbul was cheap from the start – but it does point in a more optimistic direction.
I’ve been talking so much lately about integrated timed transfer in the context of Boston that people started asking me if it’s also applicable to New York. The answer is that the basic principles are not scale-dependent, but the implementation is, so in very large cities, public transport planning should not look like in Switzerland, a country whose largest metro area is staring at 2 million people from the bottom.
The one caveat here is that most cities are not huge. The developed world has seven megacities: Tokyo, Seoul, New York, Los Angeles, Osaka, London, Paris. And Los Angeles doesn’t really have public transportation, so we’re down to six. The middle-income world has a bunch more for sanity checking – Mexico City, São Paulo, Rio de Janeiro, Buenos Aires, Johannesburg, Moscow, Istanbul, Tehran, Beijing, Shanghai, Guangzhou, Shenzhen, Bangkok – but all are either still in convergence mode building up their networks or (mostly in Latin America) have given up. So much of this comes down to the idiosyncrasies of six cities, of which the largest three networks are substantially in the same planning tradition.
Demand is huge
Big cities have big centers, which can’t really be served by any mode except rapid transit. Even in Los Angeles, what passes for a central business district has around a 50% public transport modal split. This means that the transport network has to deliver high throughput to a relatively small city center. Even in a low-kurtosis city like Paris, most Métro lines converge on a narrow area ranging from Les Halles to Saint-Lazare; in a high-kurtosis one like New York or Tokyo, there are a few square kilometers with 200,000 jobs per km^2, which require an exceptionally dense network of rapid transit lines.
Some other network design principles follow from the need to amply serve city center. Specifically, high frequency is rarely a worry, because there’s so much demand even off-peak that usually megacity subway systems do not venture into the frequency range where long waits deter traffic; New York’s 10-minute midday gaps are bad, but that’s unusual and it comes from a combination of the legacy of postwar fear of subway crime suppressing demand and excessive branching.
But other principles require careful planning still.
Electronics before concrete, megacity version
The driverless lines in Paris support peak throughput of 42 trains per hour – a train every 85 seconds. CBTC on Line 13 without driverless operation supports 38 tph, and London’s CBTC-equipped lines support 36 tph when the branching isn’t too complex. It is imperative for other cities to learn from this and do whatever they can to reach similar headways. The difference between 21 tph, as in Shanghai, and Paris’s 42, is equivalent to building a brand new subway line. And what’s more, in a city in the size class we’re talking about, the primary concern is capacity – coverage is already good, so there really is no reason to build two 21 tph lines instead of one 42 tph one.
The situation in Paris is in a context with self-contained lines. That said, extremely busy self-contained lines do exist in other megacities – London has a bunch with near-Parisian levels of throughput, New York has some, Tokyo has a few, Seoul and Osaka are both more self-contained than Tokyo is.
Throughput and organization
The primacy of throughput means that it’s worthwhile to build small infrastructure upgrades, even with concrete, if they help with capacity. Right now the Northern line reverse-branches with the branches to the north recombining with those in the center, and Transport for London would like to split the line in two, reducing branching complexity, which would increase capacity. But doing so requires improving pedestrian circulation in the corridors of the branch point, Camden Town, where TfL expects very large transfer volumes if there’s a split and already there are circulation problems today without a split. Hence the plan in the medium term is to upgrade Camden Town and then split.
If there are bumper tracks at the end of a line, as at 8th Avenue on the L or Flushing-Main Street on the 7, then it’s useful to dig up the street for another block just to add some tail tracks. That way, trains could enter the station at full speed. This increases throughput, because the terminal interlocking has trains heading in opposite directions crossing each other at-grade, which imposes schedule constraints; it’s best if trains can go through the interlocking as fast as possible to reduce the time they’re in a constrained environment, but that in turn requires short tail tracks so that an overrun of a few meters is not catastrophic. Ideally the tail tracks should even extend a full train length past the platform to place the interlocking on the other side of it, as is done in Paris and Moscow; in that case, trains cross the interlocking out of service, when it’s easier to control their exact timings.
Such projects are disruptive, but the disruption is very localized, to just one transfer station for a deinterlining project as in London or one terminal as in New York, and the impact on capacity is very large, if not quite as large as the full suite of signaling and track upgrades that make the difference between a train every 3 minutes and a train every 1.5 minutes.
The ideal metro network is radial. Megacities already support that just because so many lines have to serve city center. However, it’s important to make sure every pair of lines intersects, with a transfer. No large metro network in the world achieves this ideal – Mexico City’s network is the largest without missed connections, but it is not radial and its only three radial lines are overburdened while the other lines have light ridership. Paris has just a single missed connection on the Métro proper, not counting the RER, but it has many pairs of lines that do not intersect at all, such as M1 and M3. London is more or less a pure radial, but there are a handful of misses, including one without any transfer between the two lines anywhere, namely the Metropolian line (including Hammersmith and City) and the Charing Cross branch of the Northern line.
Big cities that plan out a metro network have to make sure they do better. Missed connections reduce passenger ridership and lead riders to overload the lines that do get connections; for example, in Tokyo one reason cited for the high ridership of the Tozai Line is that until Fukutoshin opened it was the only one with a transfer to every other subway line, and in Shanghai, Line 1 was extremely congested as long as the alternatives going north either had critical missed connections (like Line 8) or avoided city center (like Line 3).
The role of regional rail
Regional rail as a basic concept is mostly scale-invariant. However, the design principles for trains that come every half hour are not the same as those for trains that come every 5 minutes. If trains come every half hour, they had better connect cities in a roundtrip time equal to an integer number of half hours minus turnaround times, so that they don’t have to loiter 25 minutes at a terminal collecting dust and depreciating. If they come every 5 minutes, they’re not going to loiter 25 minutes anyway, and the difference between a 5-minute turnaround and a 7-minute turnaround is not really relevant.
The design principles are then mostly about throughput, again. The most important thing is to build independent trunk lines for trains to serve city center. Even in a huge city, the finances of building a purely greenfield subway deep into suburbia are poor; Tokyo has done it with the Tsukuba Express but it’s mostly above-ground, and for the most part regional lines there and elsewhere come from taking existing suburban lines and linking them with city center tunnels.
Tokyo’s insistence on making these city center tunnels also form a coherent metro network is important. Only one non-Tokyo example is worth mentioning to add to all of this: this is Berlin, which is not a megacity but has three independent S-Bahn trunk lines. Berlin, unlike London and Paris, painstakingly made sure the S-Bahn lines would have transfers with the U-Bahn; its network has only one U-Bahn/S-Bahn missed connection, which is better than the situation in Tokyo, Paris, or (with Thameslink and Crossrail) London.
The role of development
All first-world megacities, and I believe also all megacities elsewhere, have high housing demand by domestic standards. All are very wealthy by domestic standards except Los Angeles, and Los Angeles is still incredibly expensive, it just doesn’t have the high wages to compensate that London and New York and Paris have. In such an environment, there’s no need to try to be clever with steering development to transit-oriented sites. Anywhere development is legal, developers will build, and the public transport system has a role to play in opening more land for more intense development through fast trips to the center.
A laissez-faire approach to zoning is useful in such an environment. This contrasts with smaller cities’ reliance on finger plans, like the original one in Copenhagen or the growing one in and around Berlin. No limits on development anywhere are required. The state’s planning role remains strong through transportation planning, and the suburbs may well form natural finger plans if developers are permitted to replace single-family houses with apartment buildings anywhere, since the highest-value land is near train stations. But state planning of where housing goes is counterproductive – high transit ridership comes from the impossibility of serving a large central business district by cars, and the risk of politicization and policy capture by homeowners is too great.
The advantage of this approach is also that because in a high-demand city public transport can to some extent shape and not just serve development, it’s okay to build lines that are good from the perspective of network coherence, even if the areas they serve are a bit light. This principle does not extend indefinitely – subway and regional rail lines should still go where people are – but for example building key transfer points in near-center neighborhoods that are not in high demand is fine, because demand will follow, as is building lines whose main purpose is to close some gap in the network.
The larger the city, the more important cost control is. This may sound counterintuitive, since larger cities have more demand – only in Manhattan could a $1.7 billion/km extension like Second Avenue Subway pencil out – but larger cities also have a bigger risk of cost blowouts. Already Tokyo has stopped building new rapid transit in the core despite very high crowding levels on the existing network, and London builds next to nothing as well. New York’s poor cost control led Philip Plotch to entitle his book about Second Avenue Subway The Last Subway. Even Paris builds mostly in the suburbs. Extensive city center and near-center construction continues in Seoul, in the context of very low construction costs.
The flip side is that a New York (or even London) that can build subways at the cost of Paris, let alone Seoul, is one that can rapidly solve all of its transport problems. My Assume Nordic Costs map fixates on a region of the world with small cities, but the construction costs in South Korea are if anything lower than in the Nordic countries. And even that map, given free reins for developers, is underbuilt – some lines would look ridiculous at current costs and zoning but reasonable given low costs and liberal zoning, for example something meandering through currently industrial parts of New Jersey.
Small cities designed their public transportation philosophy around scarcity: Switzerland really can’t just draw crayon and build it, because housing and transport demand there are finite and limited. Cities like New York and London, in contrast, should think in terms of abundance of infrastructure and housing, provided their regulations are set up in a way that permits the state to build infrastructure at low costs and private homebuilders to redevelop large swaths as they become easily accessible to city center.
I was asked a very good and very difficult question in comments yesterday:
What, specifically, are the best practices we all should be learning from the lower cost countries? I’m reading a lot of what not to do, but not on what do to.
I’ve gone a lot over bad industry practices leading to high costs in the Anglosphere, especially the United States, especially New York, and to some extent also on bad practices in developing countries like India. These I am contrasting with a set of good practices from a host of low-cost countries like Spain and Italy as well as medium-cost ones like Germany and France.
However, the question remains, what distinguishes low- and medium-cost countries? The differences between them are not small – underground rail extensions in German cities are averaging around 250 million euros per kilometer, and ones in French cities are around 200 million or just less than that, whereas Milan and Turin average around 100 million, and Spanish cities average even less. Germany is a higher-cost and higher-wage country than Italy and Spain, but Berlin wages are not higher than Madrid and Milan wages, and within these countries, richer cities don’t really have higher costs (Milan is cheaper to tunnel in than Naples, Madrid has lower costs than Barcelona and similar costs to the rest of Spain, the cheapest German tunneling seems to be in Hamburg of all places). No: this is almost certainly a real difference in institutions that enables Southern Europe, Scandinavia, South Korea, and Turkey to dig tunnels at one third to one half the cost of Germany.
This argues in favor of doing a deep dive case on a medium-cost example like Paris or Berlin, in addition to the work we’re doing on low-cost Milan and Istanbul. The problem is that it’s not clear, so far, what to even look at. I have a decent idea of what the difference between the high-cost world and the rest of the world is – but applying it to the low- and medium-cost world is dicey.
In-house engineering capacity
So much of the problem in the Anglosphere seems to come from the loss of in-house engineering capacity, and its replacement with private consultants. The latest iteration of this is the penchant for design-build contracts, in which the state contracts with one company to handle the entire process and doesn’t have much if any public-sector oversight. Design-build doesn’t exist in any of the countries in Continental Europe I have any familiarity with; France is looking into it as a reform in the future, but only under the aegis of a large public-sector planning team coordinating the private-sector design and construction. Moreover, Canada’s recent adoption of design-build, coming from an ideology imported from Britain and then falsely claimed to come from Madrid, preceded an explosion in costs.
However, this does not really explain the difference between France or Germany and Scandinavia or Southern Europe. Norway and Spain have separation of design and construction; so does France. Italy and Spain have in-house engineering teams responsible for a great deal of the design, but to some extent France does too, with a large in-house planning team overseeing the private-sector designs.
Procurement issues can’t really distinguish the low- from medium-cost world either. Madrid does not hand out lowest-bid contracts – at least in its big wave of expansion in the 1990s and 2000s, contracts were given 50% on the basis of a technical score marked by the in-house engineering team, 30% on that of cost, and 20% on that of how fast they could finish the project. Paris doesn’t have a 50-30-20 split but a 60-40 one; that may be significant, but I doubt it. Both systems contrast with the American system of lowest bid, or sometimes 30-70 in California. Moreover, Turkey is lowest-bid, but it’s a repeated game due to the country’s fast growth and construction – contractors who screw up do get penalized in future projects.
Citizen voice and NIMBYism
Germany has a huge problem with NIMBYism. Key segments of the national passenger rail network, for example Hamburg-Hanover, remain slow because local NIMBYs who don’t like fast trains have litigated high-speed rail to death. France has had anti-LGV NIMBYism in Provence as well, which NIMBYism is often extralegal (that is, aggrieved drivers blocking roads); this forced the state to change its plans for a high-speed railway to Nice from a mostly above-ground inland route to a tunnel-heavy coastal route through the Maritime Alps and, as the cost was prohibitive, eventually downgrade into a mixture of high- and low-speed rail line.
As I understand it, this is less of an issue in Southern Europe. I do not know to what extent it’s a problem in Scandinavia and Switzerland; Switzerland does have a lot of bucolic NIMBYism, where “bucolic” means “the city as it looked in 1957,” but I don’t think it’s had any that successfully scuttled infrastructure, and overall the political imperative there seems to reduce costs more than anything.
The NIMBY issue is also important in the US and UK. In the US, NIMBYs are not legally strong, but politicians prefer to avoid the appearance of controversy and therefore give local actors whatever they ask for, no matter the cost; many sources told Eric and me versions of this story regarding the high cost of stations on the Green Line Extension (which are, to be clear, maybe 20% of the cost of the whole project). Brooks-Liscow favor this explanation for the internal increase in the cost of highways in the US from the 1970s onward.
I do not know to what extent there’s an institutional explanation here. I do not even know if this is a real difference between on the one hand France, Germany, Austria, the Netherlands, most of the 2004-7 EU accession countries, and Japan, and on the other hand Southern Europe, Bulgaria, Turkey, and South Korea. It’s possible that this is a bigger problem in Northern Italy than I realize.
The most worrying possibility is that this is a real difference, and it comes not from something about institutions, but from surplus extraction. The European core and Japan are rich, and at $150 million/km, subways there would create immense social surplus and decent financial surplus. (The Japanese state is refusing to build at $500 million/km because it wants a 30-year financial payback). Southern Europe is less rich, so there is less social surplus to extract by local actors wanting to dip their beaks in state money; Switzerland and the Nordic countries are rich, but their cities are smaller and farther-apart, so there is less surplus there too.
There are a lot of objections that can be raised to the surplus extraction hypothesis: there is plenty of surplus in Seoul and not much in Vienna or Prague or Bucharest or Warsaw or Tel Aviv, Japan already reached $250 million/km in the 1970s when it was a lot poorer than Korea is today, the surplus hypothesis predicts that there should be higher costs in richer cities within the same country and yet this is not observed, local interference with Métro expansion in Paris unlike with LGVs doesn’t seem very significant.
There’s no good answer to what distinguishes low- from medium-cost countries. I wish more people here and in France were interested in this question – the activist sphere in Berlin seems far more interested in trams and bike lanes than in rapid transit. Nor do I imagine Germans and French are ready to hear that there’s something the Italians and Spaniards and Turks do better than they do. But it’s something Germany is going to need to learn to deal with if it wants better infrastructure; on the same budget, it can get 2-3 times as much as it’s getting now.
I think we have found the #2 city in urban rail construction costs, behind only New York. This is Hong Kong, setting a world record for the most expensive urban el and encroaching on Singapore for most expensive non-New York subway.
As we look for more data to add to our transit costs website, I looked at Hong Kong to see what was going on. I remembered that its costs were high, but didn’t remember details – I think the project I was thinking of was the longest, the Sha Tin to Central link, but I looked at all recent, under construction, and planned MTR lines. I summarized the results on Twitter, but I’d like to cover this in more detail here.
The projects and their costs
Tung Chung Line extension: a planned line for construction in 2023-30, a total of 1.8 km underground, HK$18.7 billion, or around US$3.1 billion, or $1,730 million per km. Even giving it 1.8 km seems like I’m doing Hong Kong a favor – the extension is 1.3 km, and the other 500 meters are overrun tracks at the Hong Kong Island end, which I don’t ever count elsewhere since it is not in-service trackage. In addition to the tunneling (and single underground station), there is a single at-grade infill station, whose contribution to the budget is approximately zero.
West Island Line: 3 km underground, HK$18.5 billion. This is around US$3.4 billion, or $1,130 million per km. Only six lines globally are more expensive than this: phase 6 of the Circle line in Singapore, and the five New York lines, of which three are not even open yet. This is not even regional rail, but construction is entirely within the Hong Kong CBD, explaining why it is so expensive even by local standards.
Sha Tin-Central: 17 km, HK$87.3 billion, or around US$14.5 billion. This is $850 million per km. The line is not even fully underground, just 90%: the northernmost segment, totaling around 10%, is elevated. This line near-ties Crossrail and the Melbourne Metro Tunnel for most expensive line in the world longer than about 5 km – New York is building short lines, the longest (Gateway) around 5 km depending on source. The line is partially regional rail: it includes a 6 km extension of the East Rail Line under Victoria Harbour toward Admiralty, but the other 10 km is not regional rail.
Tuen Mon South Extension: 2.4 km, HK$11.4 billion, all elevated, in an outlying residential area. This is $790 million per km, making it the world’s most expensive el – New York’s most recent els, the JFK and Newark Airport connectors, were positively reasonable by this standard, only around $270 million/km adjusted for inflation (but don’t worry, the PATH estimates in the near future are a lot worse).
Kwun Tong Line extension: 2.6 km, HK$7.2 billion (same source as West Island). This is around US$1.3 billion, or $500 million per km. It’s the standard high cost of projects around the world, common for regional rail tunnels and CBD tunneling, except that this is strictly on the Kowloon side without as much older infrastructure to cross – it even misses a connection to the East Rail Line.
South Island Line (East): 7 km, HK$16.9 billion, around US$3 billion – see same source as West Island, or SCMP reporting. This is $430 million per km. This is not a fully underground line: as explained here, 2 km is on viaduct, serving Ap Lei Chau. Notice also that the original cost estimate was HK$7 billion, but by the time construction rose the budget had risen to $12.4 billion, and the final budget was $16.9 billion.
Is Hong Kong in the Anglosphere?
I’ve argued before that the single biggest predictor of an urban rail project’s cost is whether it is in the Anglosphere – the correlation of an Anglosphere dummy in our database is 0.54, more than even whether the project is underground or elevated. So it’s worth asking, is Hong Kong in the Anglosphere? There are arguments both ways, but I believe the preponderance of evidence points to yes.
- Hong Kong was under British rule until 1997.
- The legal system is traditionally based on English common law, even if there’s been a recent shift toward Chinese law.
- There is extensive exchange of knowledge with the core (white) Anglosphere, with managers who’ve moved around like Jay Walder, political leaders who have second passports in the UK (like Carrie Lam) or sometimes Canada or Australia, and Anglo media that reprints MTR press releases about its property development model.
- The design layout of the MTR has obvious British influences, including for example the use of cross-platform transfers between the core lines. Similarities with China are the result of convergent evolution (China is influenced by the USSR, which was influenced by Britain). There are some similarities with Japan, like the smartcard system’s use as electronic money, but they are smaller.
- Hong Kong’s love of privatization and high inequality is very Thatcherite. Again, the similarities with Japan are smaller – Japan’s privatization is slower, and Japanese corporations rely on mutual obligations whereas Hong Kong (like Singapore) expects brutal working hours of employees without offering them lifetime employment in return.
The one non-British aspect of the MTR is its use of property development subsidies (and before anyone asks: no, the costs above are just infrastructure, not property development). MTR expansion is funded by a mixture of property development, for which the MTR receives land at below-market rates, and more direct subsidies.
However, this is still more an Anglo aspect than an Asian one. Democratic East Asia notably does not give corporations land for below-market prices, not in the 21st century. Moreover, the British fascination with the Hong Kong model, which fascination is not present in France or Germany or probably anywhere else with reasonable construction costs and democratic constraints on the state, suggests that the elites in Britain and the US would like to be governed this way, just as many would like to be governed by the Lee clan. There is, in contrast, almost no curiosity about democratic East Asian governance, even after that 200 million people region proved itself to deal with corona better than any other.
Corona is a little awkward to bring in because Hong Kong’s infection numbers look like those of an East Asian democracy (it has the civil service of one), whereas the most similar country to Hong Kong on most matters, Singapore, has those of a Gulf state full of indentured migrant workers who got infected at extremely high rates. But for engineering, it doesn’t seem terribly important what the immigration numbers are – for example, Sweden and Norway are extremely similar to Finland even though they have way more immigrants, and likewise Saudi Arabia is similar to the other, immigrant-heavier Gulf states. So overall, Hong Kong’s public transport situation can be seen as very similar to Singapore’s – and Singapore has very high costs as well.
What does this mean?
I don’t know. Singapore and Hong Kong’s costs are probably higher than those of the core Anglosphere, but I am uncertain – Singapore’s big projects are not unusually expensive by Canadian or British standards, and the Sha Tin-Central link is legitimately difficult, the kind that Sweden would build for $250 million/km rather than for $130 million/km. So it’s hard to tell whether there is something about Hong Kong that goes beyond standard Anglo dysfunction.
I do not know what Hong Kong’s historic costs were. I expect them not to be so high – Singapore’s weren’t through phases 1-5 of the Circle line, and only exploded with the Downtown and Thomson lines, and Canada’s only exploded in the late 2000s and 2010s as it decided to privatize state planning and adopt design-build contracting.
However, in the present and near future, Hong Kong is a model to study purely for its failures, much like Singapore. The leaders of Hong Kong, in their rush to emulate Chinese repression tactics, should perhaps also learn something from Chinese construction techniques – or, ideally, Korean ones, Korea being the only Asian country among the world’s cheapest. People in other countries should aim to study Hong Kong’s infrastructure construction as an example to avoid, and not one to emulate.
I’m probably going to write this up more precisely with Eric and send this to a journal, but for now, I’d like to use our construction costs database to discuss the cost ratio of subways to elevated lines. The table I’m working from can be found here; we’re adding projects and will do a major update probably at the end of the month, but I don’t expect the new data to change the conclusion. Overall, the data is consistent with a subway : el cost ratio in the 2-2.5 range, but it’s not possible to get more precise estimates despite the breadth of the data.
Our database has 11,559 km of total length, but not all of that comes with cost estimates yet; subtracting lines for which we don’t have costs, we get 11,095 km. The total cost of all the lines in our database is, in PPP-adjusted but not inflation-adjusted dollars, $2.302 trillion, for an average of $207 million/km. Nearly all of the items are recent – the majority by length are still under construction, and only 10% opened by 2010. So inflation adjustment is minor, though nontrivial.
Moreover, looking only at 100% underground lines, we get 3955.3 km, for a cost of $945.3 billion, averaging $239 million/km. The other lines are mixed or elevated. The purely elevated lines total 2490.4 km, for a cost of $408.1 billion, or $164 million.
To be slightly fancier but use the same underlying data, the linear estimate of cost per km, treating the tunnel proportion as the independent variable, is 153.1406 + 117.5787*tunnel-proportion; this has a larger spread than just averaging pure subways and pure els, coming from both the inclusion of more data and from not weighting by line length.
However, even the larger spread has a subway : el cost ratio of 1.77, lower than found elsewhere in the literature. Why?
Els are disproportionately build in higher-cost countries
The most important quantitative fact coming out of the analysis of construction costs is that the most important independent variables are country-level dummies. The correlation between the tunnel proportion and cost per km is just 0.163; the correlation between cost per km and a dummy variable that takes the value 1 in the US, Canada, Britain, Australia, New Zealand, and Singapore and 0 elsewhere, is 0.543. If we instead set the dummy variable to take the value 1 in the countries I consider cheap – Spain, Portugal, Italy, Greece, Bulgaria, Switzerland, Sweden, Norway, Denmark, Finland, Turkey, South Korea – then the correlation with plain cost is -0.18, and since linear correlation is better at detecting high outliers than low-but-positive ones, we can take the reciprocal of cost and then the correlation is 0.258.
So it’s useful to figure out where the most els are being built. For example, China has 5,933 km in our database – that is, a slight majority – of which 3,851 are confirmed tunnel and another 1,046 are unconfirmed (Hangzhou in particular is bad about reporting tunnel proportions). Excluding lines with unconfirmed information, we have 9,842.6 km of which 6,436.4 are in tunnel, or 65% – but China is 3,851/4,887, or 79%.
In the lowest-cost countries, els are not common. In Spain, 205.7 km out of 253.8 in our database are underground, or 81%. The Korean lines in our database are 100% underground, and as we add more data, this will hardly change. Overall, the countries I consider cheap have 927 km of rapid transit in the database, which number will rise as we add more Korean data, and of those, 730.1 are underground, a total of 79%. What’s more, one third of the non-underground length in cheap countries consists of a single 63 km item, tagged CR3, consisting of surface improvements for Marmaray (the tunnel is costed separately, as BC1); 63 km is hefty, but as a single item, it is less visible to unweighted correlation estimates like the regression.
So if els are uncommon in China and in cheap countries, where are they common? The answer is high-cost developing countries and Gulf states. India has 1,046.7 km in the database, of which only 235.8 are underground, or 23%; when I continue my series of posts on rapid transit traditions and get to India, I will of course mention the predominance of els. Moreover, these Indian els are spread across many items – there are 29 Indian items, since individual lines in Mumbai and phases in other cities each get their own lines, which matters for unweighted correlation estimates. Similarly, Thailand is 20% underground, Vietnam 50%, Pakistan’s single line 6%, Bangladesh 48%, the Philippines 55%, Malaysia 22%, Indonesia’s single line 38%, Panama 12%, Saudi Arabia 14%, the UAE 22% – and all of these are high-cost. In the developed world, the el-happiest country is Taiwan, only 40% underground in our database, and it’s on the expensive side, its average cost at 40% underground still amounting to $240 million/km, and its three all-underground lines averaging $375 million/km.
It makes sense when you think about it. If construction costs in a country are higher, then it will look for ways to cut costs by building less visually desirable els (typically in developing countries) or slower light rail lines (as in the United States). If we included at-grade light rail lines, then our table would also have a wealth of high-cost American lines; as it is, we’re likely to add some at-grade heavy rail lines like the Silver Line in Washington and, if it actually begins construction, the planned PATH extension to Newark Airport.
So instead of averaging in the entire database, let’s look internally to countries, chosen to be big enough to have a mix of projects with different underground proportions. I’m also going to ignore some cases where I worry about comparability – for example, in France, above-ground lines are represented mostly by a metro extension in Toulouse and by the most outlying parts of Grand Paris Express, and I worry about comparing those with Parisian and inner-suburban tunnels. The worst exclusion has to be that of China: while there is a wealth of data there, China built more els 15-20 years ago than it does now, so comparing subways to els in (say) Shanghai is to some extent a comparison of costs in the 2010s to costs in the late 1990s and early 2000s. In that, China is hardly different from the United States – New York built many els from the 19th century until the mid-1920s, but subsequently built an almost 100% underground system.
In Japan, we go back to the 1990s, so using dollar amounts does have inflation artifacts. Thankfully, the yen has had no inflation, so we can just plug in raw yen numbers and convert at the 2020 rate of 100:1. The 100% underground lines in Japan have averaged $382 million per km, the elevated ones $123 million/km; the ratio is 3.1. The regression estimate, again using ¥100 = $1 throughout, is cost = 149.8978 + 255.9496*tunnel-proportion; the ratio using this method is 2.7.
India has a single 100% underground line in the database, Line 3 in Mumbai, built for $449 million/km. The pure els in India cost $158 million/km, for a subway : el ratio of 2.8. Looking only at els in Mumbai, the average inches up to $167 million/km, a ratio of 2.7. Inflation adjustment would have marginal impact as all of these lines are recent, the earliest priced in 2011 terms. The regression estimate (for all of India, not just Mumbai) is cost = 151.6146 + 222.2716*tunnel-proportion, which yields a ratio of 2.5.
As mentioned above, Taiwan’s three pure subways average $375 million/km. But as a note of caution, they are all regional rail tunnels, and we know from evidence in countries that build 100% underground metros and regional rail tunnels (Finland, Sweden, France, Britain, Germany…) that the latter are more expensive.
With that caveat, the four pure above-ground lines in Taiwan average $170 million/km, a ratio of 2.2. The regression estimate is cost = 183.3252 + 163.0895*tunnel-proportion, a ratio of 1.9. This is a lower ratio than in India and Japan, despite the caveat; the reason could be that the underground lines in the dataset are in Kaohsiung, Taoyuan, and Tainan, whereas the lines in Taipei and New Taipei are elevated, as the database so far does not include the older Taipei MRT lines with their city-center tunnels.
There are no pure subways in Thailand; even the underground MRT’s extension is only 20% underground. However, the under-construction Orange Line is 75% underground, and costs $531 million/km. Overall, the regression estimate is 155.9491 + 350.2821*tunnel-proportion, which includes a number of lines in Bangkok and a cheaper half-underground line in Chiang Mai. This is a ratio of 3.2; excluding the one Chiang Mai line, this rises to 3.9.
Our database is consistent with the observation in the literature that the subway : el cost ratio is about 2-2.5. But a crude averaging of global costs would lead to an underestimate, since higher-cost countries are more likely to be building els. This is partly coincidence – former colonies in the developing world tend to have high costs and also wide throughfares where els are more politically acceptable – and partly the use of els to reduce costs where the country’s ability to afford subways is limited.
This reinforces the need to look at other treatments for reducing costs more carefully. It’s plausible that some policy treatments are not found in low-cost countries because those treatments are undesirable for some reason but do reduce costs. Thus, it is critical to look at both the best industry practices and the variation in practices within the parts of the world one considers best.