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:
- 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.
- 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.
- 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 proportion||Median US cost||Median non-US cost|
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.
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.
Three examples of public-private partnerships screwing up urban transit are on my mind. The Canada Line in Vancouver is not new to me – I was poking around a few years ago. But the other two in this post are. The Maryland Purple Line in the suburbs of Washington was supposed to be the smooth PPP offering low-risk orbital light rail connecting suburbs to other suburbs without having to go through Downtown Washington, and now it is in shambles because the contractor walked away. Milan is not a new example either, but it is new to me, as we’ve discovered it during the construction costs project comparing high American (and British) costs to low Southern European ones; even there, the PPP bug bit, leading not so much to high capital costs but to high future operating charges. In no case is such a PPP program good government; the bulk of construction and risk must always lie in the public sector, and if your public sector is too incompetent to build things itself, as in the United States, then it’s equally incompetent at overseeing a PPP, as we’re seeing in Maryland. Don’t do this.
Washington: the Purple Line
Maryland planned on building two major urban rail projects last decade, stretching into the current one: the Red Line and the Purple Line. The Red Line was to be a conventional public project to build a subway in Baltimore, mostly serving low-income West Baltimore neighborhoods. The Purple Line, a light rail project in the DC suburbs acting as an orbital for Metro, was designed as a PPP. Governor Larry Hogan canceled the Red Line, most likely for racist reasons. The physical construction costs per rider were higher on the Red Line, but the overall disbursement including very high operating charges made the Purple Line more expensive, and yet Hogan kept the more expensive system and tossed the cheaper one.
One might expect that the PPP structure of the Maryland Purple Line would allow it to at least resist cost escalation – the risk was put entirely on the private contractor. And yet, the opposite happened. Costs turned out to be higher than expected, so the contractor just quit. Once the contract is signed, no matter what it says, the risk is in practice public, and this is no exception. The contractor stopped all work and left the region with a linear swath of ripped up roads; eventually the concessionaire and the state came into a settlement in which the state would pay $250 million extra and the concessionaire would hire a new contractor. The cost overrun was $800 million and the state said that the deal was going to save taxpayers $500 million, but what it signals is that even with very high public-sector payouts over decades that intend to put the entirety of the risk on the private concession, the public sector shares a high proportion of the risk, and the private bidders know this. This is a lose-lose situation and under no circumstances should countries put themselves in it.
Vancouver provides another good example of PPPs and operating costs. SkyTrain operates driverless equipment throughout the system, which means that operating costs should be low, and, moreover, should not depend on train size much. The Expo and Millennium Lines, built and operated publicly, cost C$3.20 to run per car-km, cheaper than on any system for which I have data (mostly very large ones plus Oslo) and less than half as expensive as the major European systems. But the Canada Line, operated by a concessionaire as part of a PPP scheme, costs $17.90/car-km, which is considerably worse than any system for which I have data except PATH. Even taking into account that the Canada Line cars are somewhat bigger, this is a difference of a factor of more than 3.
This is not a matter of economies of scale. The Canada Line’s trunk runs every 3.5 minutes most of the day, which is better than the vast majority of non-driverless systems I am familiar with off-peak, so the high costs there cannot be ascribed to poor utilization. In fact, before the Evergreen extension of the Millennium Line opened in 2016, the two systems’ total operating costs were almost identical but the operating costs per car-km were about 3.5 times worse on the Canada Line – economies of scale predict that unit costs should be degressive, not almost flat.
Marco Chitti is busy collecting information and conducting interviews regarding subway construction in Italy as part of our construction costs report. Italian costs are low, which makes it feasible to build metros even in very small cities like Brescia, where per Wikipedia the cost of the metro was around €65 million per km and €15,000 per weekday rider. However, the use of PPPs has not been good in the places where it happened, due to fiscal austerity following the Great Recession.
- What is the impact on the cost of the PPP? The impact on costs of the potential transfer of risk from the Public to the Private is hard to calculate, but it appears to have an impact more on higher gross operational costs (the fee that the Municipality will pay in the 26 years of the concession for the operation and pay back a return to the private operators) than on the actual construction cost. But that is unclear yet. A bit of detail: the municipality will pay to the concessionaire a 1.09 €/passenger as a minimum granted fee up to 84 million passengers/year, 0.45€/passenger for each additional user up to a maximum determined as an increase of the IRR of 2 percentage points more than the “base IRR” of 5.93%. That means that this is basically the rate at which the private investors are de facto borrowing the money to the municipality, with most of the risk from low ridership transferred to the municipality. What makes calculations complicate is that the city is directly a majority stakeholder of the concessionaire Metro M4 S.p.A. and also, indirectly, as the owner of ATM, which will be the “private” operator. It’s very blurred compared to other PPP schemes where the concessionaire is 100% private (like M5).
- PPP emerges as a stratagem to finance the project without increasing the municipal public debt. The PPP schemes is used to compensate for the lack of local public funds matching the national ones, limited due to the debt cap imposed by the so-called “internal Stability Compact”, an austerity measure implemented after the 2011 debt crisis, which strongly limits the capacity of local governments to borrow money for infrastructure projects. It was suspended in 2016.
Note that contra the plan to build the system without public debt, the PPP does in fact include borrowing. It’s opaque, but the payment per rider is a form of borrowing. Driverless metro operating costs are lower than €1.09 per unlinked trip. The Expo and Millennium Lines cost C$1.55, which in PPP terms is about €0.90, and feature much longer trips, as the Expo Line is 36 km long and one-tailed, which means many people ride end-to-end, whereas Milan M4 is to be 15 km and two-tailed, which means few trips are longer than half the total. In effect, this is high-interest borrowing, kept off the books in an atmosphere of strict budgetary austerity
Don’t do this
PPP-built lines do not have to have high construction costs. The Canada Line was cheap to build – it was Canada’s last reasonable-cost subway, and since then costs have exploded around the country. M4 in Milan is inexpensive as well, around €110 million per kilometer at current estimates even while going underneath older subways in city center. The current annual ridership projection of M4, 87 million, means that the current projected cost per weekday trip is €6,000, which represents an enormous social surplus in a region that builds up to around €30,000-40,000 before even pro-transit activists demand cancellation.
But in those cases, the structure of the contract keeps the operating costs artificially high, privatizing what should be public-sector profit from building a very inexpensive-to-operate system. This is especially bad if it is bundled into construction costs as an up-front payment, as in Maryland. In Maryland, the extra operating costs raised the construction cost well above the maximum level that is acceptable to the public transportation community over here, and in the United States too, such lines tend to be under threat of cancellation from fiscally conservative governors if they are not portrayed as pro-market PPPs. But those PPPs then have higher costs and, through poor risk allocation, lead to the worst of both worlds: the private concessionaire increases costs in order to deal with the risk of escalation, but if the risk exceeds prior estimates, then the state remains on the hook.
Don’t do this. One can to some extent understand why Italy was forced into this position at the bottom of the financial crisis. This isn’t such a situation – all countries in Europe are engaging in large discretionary deficit spending nowadays, as the market appears to believe that not only will corona pass, but also the new vaccines developed will help prevent the common cold and the flu in the near future, increasing future health outcomes and improving productivity through less lost sick time. In the United States, a $2 trillion stimulus is sold as just the first of two steps, because there’s fiscal room. You, even as a state or local government, can find money in the budget for more spending – raise taxes or sell bonds, and do so transparently. Don’t take opaque high-interest loans just to tell the public that you haven’t borrowed on the open market. It’s not worth it.
A bunch of Americans who should know better tell me that nobody really cares about construction costs – what matters is getting projects built. This post is dedicated to them; if you already believe that efficiency and social return on investment matter then you may find these examples interesting but you probably are not looking for the main argument.
Exhibit 1: North America
I wrote a post focusing on some North American West Coast examples 5 years ago, but costs have since run over and this matters from the point of view of building more in the future. In the 2000s and 10s, Vancouver had the lowest construction costs in North America. The cost estimate for the Broadway subway in the 2010s was C$250 million per kilometer, which is below world median; subsequently, after I wrote the original post, an overrun by a factor of about two was announced, in line with real increases in costs throughout Canada in the same period.
Metro Vancouver has always had to contend with small, finite amounts of money, especially with obligatory political waste. The Broadway subway serves the two largest non-CBD job centers in the region, the City Hall/Central Broadway area and the UBC, but in regional politics it is viewed as a Vancouver project that must be balanced with a suburban project, namely the lower-performing Surrey light rail. Thus, the amount of money that was ever made available was about in line with the original budget, which is currently only enough to build half the line. Owing to the geography of the West Side, half a line is a lot less than half as good as the full line, so Vancouver’s inability to control costs has led to worse public transportation investment.
Like Vancouver, Toronto has gone from having pretty good cost control 20 years ago to having terrible cost control today. Toronto’s situation is in fact worse – its urban rail program today is a contender for the second most expensive per kilometer in the world, next to New York. The question of whether it beats Singapore, Hong Kong, London, Melbourne, Manila, Qatar, and Los Angeles depends on project details, essentially on scoring which of these is geologically and geographically the hardest to build in assuming competent leadership, which is in short supply in all of these cities. I am even tempted to specifically blame the most recent political interference for the rising costs, just as the adoption of design-build in the 2000s as an in-vogue reform must be blamed for the beginning of the cost blowouts.
The result is that Toronto is building less stuff. It’s been planning a U-shaped Downtown Relief Line for decades, since only the Yonge-University-Spadina (“YUS”) line serves downtown proper and is therefore overcrowded. However, it’s not really able to afford the full line, and hence it keeps downgrading it with various iterations, right now to an inverted L for the Ontario Line project.
Los Angeles’s costs, uniquely in the United States, seemed reasonable 15 years ago, and no longer are. This, as in Canada, can be seen in building less stuff. High-ranking officials at Los Angeles Metro explained to me and Eric that the money for capital expansion is bound by formulas decided by referendum; there is a schedule for how to spend the money as far as 2060, which means that anything that is not in the current plan is not planned to be built in the next 40 years. Shifting priorities is not really possible, not with how Metro has to buy off every regional interest group to ensure the tax increases win referendums by the required 2/3 supermajority. And even then, the taxes imposed are rising to become a noticeable fraction of consumer spending – even if California went to majority vote, its tax capacity would remain very finite.
The history of Second Avenue Subway screams “we would have built more had costs been lower.” People with deeper historic grounding than I do have written at length about the problems of the Independent Subway System (“IND”) built in the 1920s and 30s; in short, construction costs were in today’s terms around $140 million per km, which at the time was a lot (London and Paris were building subways for $30-35 million/km), and this doomed the Second System. But the same impact of high costs, scaled to the modern economy, is seen for the current SAS project.
The history of SAS is that it was planned as a single system from 125th Street to Hanover Square. The politician most responsible for funding it, Sheldon Silver, represented the Lower East Side. But spending capacity was limited, and in particular Silver had to trade that horse for East Side Access serving Long Island, which was Governor George Pataki’s base. The package was such that SAS could only get a few billion dollars, whereas at the time the cost estimate for the entire 13-km line was $17 billion. That’s why SAS was chopped into four phases, starting on the Upper East Side. Silver himself signed off on this in the early 2000s even though his district would only be served in phase four: he and the MTA assumed that there would be further statewide infrastructure packages and the entire line would be complete by 2020.
Exhibit 2: Israel
Israel is discussing extending the Tel Aviv Metro. It sounds weird to speak of extensions when the first line is yet to open, but that line, the Red Line, is under construction and close enough to the end that people are believing it will happen; Israelis’ faith that there would ever be a subway in Tel Aviv was until recently comparable to New Yorkers’ faith until the early 2010s that Second Avenue Subway would ever open. The Red Line is a subway-surface Stadtbahn, as is the under-construction Green Line and the planned Purple Line. But metropolitan Tel Aviv keeps growing and is at this point an economic conurbation of about 3-4 million people, with a contiguous urban core of 1.5 million. It needs more. Hence, people keep discussing additions. The Ministry of Finance, having soured on the Stadtbahn idea, bypassed the Ministry of Transport and introduced a complementary three-line underground driverless metro system.
The cost of the system is estimated at 130-150 billion shekels, which is around $39 billion. This is not a sum Israelis are used to seeing for a government project. It’s about two years’ worth of IDF spending, and Israeli is a militarized society. It’s about 10% of annual GDP, which in American or EU-wide terms would be $2 trillion. The state has many competing budget priorities, and there are so many other valid claims on the state coffers. It is therefore likely that the metro project’s construction will stretch over many years, not out of planning latency but out of real resource limits. People in Israel understand that Gush Dan has severe traffic congestion and needs better transportation – this is not a point of political controversy in a society that has many. But this means the public is willing to spend this amount of money over 15-20 years at the shortest. Were costs to double, in line with the costs in most of th Anglosphere, it would take twice as long; were they to fall in half, in line with Mediterranean Europe, it would take half as long.
Exhibit 3: Spain
As the country with the world’s lowest construction costs for infrastructure, Spain builds a lot of it, everywhere. This includes places where nobody else would think to build a metro tunnel or an airport or a high-speed rail line; Spain has the world’s second longest high-speed rail network, behind China. Many of these lines probably don’t even make sense within a Spanish context – RENFE at best operationally breaks even, and the airports were often white elephants built at the peak of the Spanish bubble before the 2008 financial crisis.
One can see this in urban rail length just as in high-speed rail. Madrid Metro is 293 km long, the third longest in Europe behind London and Moscow. This is the result of aggressive expansion in the 1990s and 2000s; new readers are invited to read Manuel Melis Maynar’s writeup of how when he was Madrid Metro’s CEO he built tunnels so cheaply. Expansion slowed down dramatically after the financial crisis, but is starting up again; the Spanish economy is not good, but when one can build subways for €100 million per kilometer, one can build subways that other cities would not. In addition to regular metros, Madrid also has regional rail tunnels – two of them in operation, going north-south, with a third under construction going east-west and a separate mainline rail tunnel for cross-city high-speed rail.
Exhibit 4: Japan
Japan practices economic austerity. It wants to privatize Tokyo Metro, and to get the best price, it needs to keep debt service low. When the Fukutoshin Line opened in 2008, Tokyo Metro said it would be the system’s last line, to limit depreciation and interest costs. The line amounted to around $280 million/km in today’s money, but Tokyo Metro warned that the next line would have to cost $500 million/km, which was too high. The rule in Japan has recently been that the state will fund a subway if it is profitable enough to pay back construction costs within 30 years.
Now, as a matter of politics, on can and should point out that a 30-year payback, or 3.3% annual interest, is ridiculously high. For one, Japan’s natural interest rate is far lower, and corporations borrow at a fraction of that interest; JR Central is expecting to be paying down Chuo Shinkansen debt until the 2090s, for a project that is slated to open in full in the 2040s. However, if the state changes its rule to something else, say 1% interest, all that will change is the frontier of what it will fund; lines will continue to be built up to a budgetary limit, so that the lower the construction costs, the more stuff can be built.
Conclusion: the frontier of construction
In a functioning state, infrastructure is built as it becomes cost-effective based on economic growth, demographic projections, public need, and advances in technology. There can be political or cultural influences on the decisionmaking process, but they don’t lead to huge swings. What this means is that as time goes by, more infrastructure becomes viable – and infrastructure is generally built shortly after it becomes economically beneficial, so that it looks right on the edge of viability.
This is why megaprojects are so controversial. Taiwan High-Speed Rail and Korea Train Express are both very strong systems nowadays. Total KTX ridership stood at 89 million in 2019 and was rising on the eve of corona, thanks to Korea’s ability to build more and more lines, for example the $69 million/km, 82% underground SRT reverse-branch. THSR, which has financial data on Wikipedia, has 67 million annual riders and is financially profitable, returning about 4% on capital after depreciation, before interest. But when KTX and THSR opened, they both came far below ridership projections, which were made in the 1990s when they had much faster economic convergence before the 1997 crisis. They were viewed as white elephants, and THSR could not pay interest and had to refinance at a lower rate. Taiwan and South Korea could have waited 15 years and only opened HSR now that they have almost fully converged to first-world Western incomes. But why would they? In the 2000s, HSR in both countries was a positive value proposition; why skip on 15 years of good infrastructure just because it was controversially good then and only uncontroversially good now?
In a functioning state, there is always a frontier of technology. The more cost-effective construction is, the further away the frontier is and the more infrastructure can be built. It’s likely that a Japan that can build subways for Korean costs is a Japan that keeps expanding the Tokyo rail network, because Japan is not incompetent, just austerian and somewhat high-cost. The way one gets more stuff built is by ensuring costs look like those of Spain and Korea and not like those of Japan and Israel, let alone those of the United States and Canada.
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.
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.