Here is a list of subway projects in the last 15-20 years, in both developed and developing countries. It’s in addition to my initial lists for developed and developing countries, but includes projects mentioned in past blog posts not on those two lists. This is still not an exhaustive list, due to some cities for which I couldn’t find any information (Moscow), cities for which the information from different sources contradicts itself (Bucharest), and cities for which I couldn’t source numbers beyond Wikipedia (Osaka). My rule is that Wikipedia is an acceptable source for construction timelines and route length but not cost.

While the list is meant to be for urban subways, urban rail projects that are predominantly elevated are also included. As far as possible I have tried using PPP dollars adjusted for inflation to give 2010 dollars (2010 and not 2013, because when I started comparing costs that’s what I used). For core developed countries, because inflation rates are similar, I use American inflation rates, using the CPI (not GDP deflator: the two measures have disagreed for a while, and the CPI points to higher inflation). For other ones, I’ve tried focusing on more recent projects, including even some that are under construction, but I use actual inflation rates.

Bear in mind the data is only as accurate as my sources for it and my PPP conversions. Errors of 10-20% in each direction are to be expected: sources disagree on conversion rates, sometimes the years of construction are not made clear so deflating to the midpoint is not reliable, etc. Even larger errors sometimes crop up, for example if old cost figures are not updated after a cost overrun.

Explicitly, the rates I use today are C$1.25 = S$1 = US$1 = 3.8 yuan = 100 yen = 800 won; £1 = $1.50; €1 = $1.25; CHF1 = $1.65.

Singapore Thomson MRT Line: not yet under construction, expected to open 2019-21, S$18 billion for 30 km. This is $600 million/km, all underground. Included only as a lower bound of costs; costs can rise beyond budget but rarely come significantly under it.

Hong Kong Sha Tin to Central Link: a 1-km segment underground (not underwater) is £270 million, under construction with opening expected in 2018. After converting to PPP using Hong Kong’s conversion rate this is $586 million/km.

Singapore Downtown MRT Line: under construction since around 2008, to be completed in 2017; S$20.7 billion for 42 km: $493 million/km. This line is fully underground. This represents a 70% cost overrun already, announced after I previously reported the original budget of S$12 billion.

Budapest Metro Line 4: under construction since 2006, completion expected in 2014, 400 billion forint for 7.4 km. This is $358 million per km. The line is fully underground.

Fukuoka, Nanakuma Line extension to Hakata: construction expected to begin 2014 with line opening expected in 2020, ¥45 billion for 1.4 km: $321 million/km. I do not know for certain that the extension is fully underground, but this is likely, as the preexisting line is underground and the extension follows busy CBD streets.

Cairo Metro Line 3, Phase 1: opened 2012 with construction since 2006, LE4.2 billion for 4.3 km. This is $310 million/km. The phase is fully underground.

Kawasaki Subway: under construction, opening expected in 2018, ¥433.6 billion for 16.7 km: $260 million/km. The line is fully underground. Update: people in comments explain that the line was actually canceled; the link in this paragraph is just a plan.

Stockholm City Line: to open in 2017, 16.8 billion kronor (2007 prices) for 6 km of tunnel and 1.4 km of bridge: $259 million/km.

Sao Paulo Metro Line 6: construction due to begin in 2014; 7.8 billion reais for 15.9 km: $250 million/km. The line is 84% underground.

Sao Paulo Metro Line 4: construction began in 2004, first phase opened in 2010, completion expected in 2014; 5.6 billion reais for 12.8 km: $223 million/km. The line is fully underground.

Dnipropetrovsk Metro extension: under construction since about 2008, opening expected in 2015, €367 million for 4 km. After PPP conversion this is $214 million/km. It appears to be fully underground.

Malmö City Tunnel: built 2005-10, 9 billion kronor for 4.65 km: $212 million/km. This is a fully underground project.

Bangalore Metro Phase 2: to be opened by 2017, 264 billion rupees for 72.1 km. This is $164 million/km. I do not know what proportion of the project is underground; it does not seem to be large, as the extension of the phase 1 lines are all outbound, and only line 4 seems to have significant tunneling, about 14 km by pure Wikipedia eyeballing.

San Juan Tren Urbano: built 1996-2004, $2.28 billion (2001 figures, see PDF-p. 145) for 17.2 km: $163 million/km. The line is only 7.5% underground by direct inspection on Google Earth.

Lucern Zentralbahn: built 2008-13, CHF250 million for 1.32 km of tunnel: $151 million/km.

Hangzhou: I can’t find any ex post numbers, but in both 2005 and this year (Chinese) officials pegged the cost of future construction as ¥550 million/km: $145 million/km.

Sofia Metro Line 2: built 2008-12, €952 million for 17 km. After PPP conversion, this is $148 million/km. The line appears to be almost fully underground: the numbers here do not fully add up but point to 1.3-2.9 km above ground (7.6-13% of total line length) in one segment while Wikipedia’s line map shows only that segment with above-ground segments.

Thessaloniki: I can’t find any ex post numbers, but in 2005 the budget for the first phase, under construction to be opened in 2016, was €798 million for 9.6 km: $104 million/km. The second phase received bids last year and is expected to open in 2017, with an estimated cost of €518 million for 4.78 km: $135 million/km. Both phases are fully underground.

Vancouver Evergreen Line: under construction since 2012, completion expected 2016; C$1.4 billion for 11 km: $103 million/km. Only 2 km of the system, 18%, is underground, but Vancouver seems to have an unusually low underground construction cost premium.

Dubai Metro (lines 1 and 2): built 2005-11, Dh28 billion ($6.9 billion in PPP2010US$) for 75 km: $92 million/km. Only 13 km of the system, 17%, is underground.

Mexico City Metro Line 12: built 2007-2012, $1.8 billion for 26.4 km. After PPP conversion, this is $90 million/km. From a Google Earth overlay map, this line is 49% underground.

Seoul Sin-Bundang Line: built 2005-11, 1,169 billion won for about 18 km (sources disagree on whether it’s 17.3 or 18.5): $87 million/km. The line is 100% underground according to YouTube videos.

Bangalore Metro, Phase 1: built 2006-11, 8,158 crore rupees for 42.3 km: $93 million/km. Only 8.82 km, or 21% of the project, is underground. See above for Indian construction costs in a heavier-tunneling setting.

Helsinki Westmetro: under construction since 2009 with completion expected in 2015, €714 million for 13.5 kilometers: $66 million/km. The line is fully underground.

Seoul Subway Line 9: opened 2009, 900 billion won for 27 km: $43 million/km. The line is almost fully underground by direct inspection on Google Maps.

Barcelona Sants-La Sagrera tunnel: built 2008-11, €179.3 million for 5.8 km: $39 million/km. This project is intercity but fully underground.

Just from eyeballing the data, spliced together with the two older lists, the biggest correlation of each country’s construction costs is with the construction costs of other lines in the same country. When there is more than one project listed separately in a city – e.g. Seoul, Singapore, Sao Paulo – the projects have similar costs. This persists across different cities in the same country, judging by the similarity between Bangalore Metro’s Phase 2 cost and the Delhi Metro’s cost from a previous list and by the similarity between Hangzhou and Beijing’s costs.

While looking for South Korean cost data for a major update of my construction costs posts, I stumbled upon a newspaper article excoriating Seoul’s extravagant construction, comparing it unfavorably with the US. Per Joong-Ang, the US neglect of infrastructure is a form of frugality that South Korea should imitate; the National Mall’s poorly maintained, weedy lawns are treated as something to admire. Moreover, Seoul subway construction is more extravagant than in the Washington Metro:

I got on a train at the Smithsonian Metro station. All the stations there have the same architectural styles. They are the 1976 creation of American architect Harry Weese. High ceilings and open spaces are their trademarks. They are known for their practicality. But they are very modest compared to the subway stations of Seoul. The platforms are dimly lighted. It’s hard to read a book there. The walls are concrete, with none of Korea’s flashing signboards. The architecture is very quiet.

After I returned to Seoul, I got on the subway at Guryong Station in Gangnam District, southern Seoul. Marble proliferates at the entrance. A public table is covered with glass. Every day, about 3,600 people use the station, which cost 55 billion won ($51.2 million) to build.

Of course, in reality, Korean construction costs are a fraction of American ones. Guryong Station is an infill subway station in a dense urban neighborhood, opening about a year after the rest of the Bundang Line; it cost about $75 million in 2010 PPP dollars. The US sometimes builds at-grade infill commuter stations for more than that, and those do not have marble entrances or glass tables (update: New York Avenue in Washington is another example of more expensive US infill, this time an elevated station). Building just the shell of an infill subway station on the 7 extension simultaneously with the rest of the extension was estimated at $500 million. Similarly, the Sin-Bundang Line, a driverless rapid transit line, cost 1,169 billion won, about $1.4 billion, for about 18 km; the line is described as “largely underground,” fully underground, and its city terminus is under a dense secondary CBD. In contrast, in Washington, the suburban Silver Line, with very little tunneling, is $6.8 billion (in 2009-2018 dollars) for 37 km. $183 million per km versus about $80.

There are two takeaway lessons from this. The first is that to gauge whether something is cheap or extravagant we need to know the normal range of costs and compare, rather than looking at the quality of construction. Seoul may build very extravagant-looking stations, but it builds them cheaply for some reason.

The second, more important lesson is that people perceive costs the way they perceive local corruption. The US is indeed the world’s most expensive country to build transit in, which Americans can easily believe since they do not trust their government very much. At the opposite corner, Switzerland is quite cheap: a rejected mountain tunneling project in Neuchatel was CHF 850 million for 17 km, and a recently completed urban tunnel in Lucern was CHF 250 million for 1.32 km; accounting for the Swiss franc’s 87% overvaluation relative to PPP, these are $28 and $121 million per km respectively. And as far as I hear from Swiss commenters, the Swiss are proud of the success of their public transportation system. Indeed, Swiss levels of trust in government and institutions are very high.

In contrast, in cheap countries where people do not trust the government, people do not readily accept that construction costs are low. When I talk to Spaniards who are not railfans, they talk about corrupt and extravagant infrastructure projects, and do not believe that both high-speed rail and subway construction costs in Spain are so low. (It doesn’t help that Barcelona’s L9/10, despite still being about average-cost, went over budget by a factor of over 3.) This is no different from the Joong-Ang attitude toward Korean costs: the government self-evidently doesn’t work, and so a $75 million infill subway station is self-evidently a boondoggle.

The situation in the opposite corner – high trust/low perceptions of corruption, high costs – exists as well, in Singapore. The sixth MRT line, soon to begin construction, is S$18 billion for 30 km; the PPP exchange rate between Singapore and US dollars is about 1:1. The line is automated and fully underground, but about half of it is under very wide arterial roads and portions of it are in undeveloped rather than built-up land; it shouldn’t cost this much. The fifth line, currently under construction, is cheaper, S$12 billion for 40-42 km, but still much more expensive than the non-Anglophone average.

And yet, although Singapore’s not far behind Japan in its construction costs, I doubt Singaporeans are as willing to consider their construction practices expensive as Americans, Britons, and Japanese are. I know for a fact that international commentators who hold Singapore in high regard for its efficient government would not be willing to think of it as an expensive-construction country.

All this makes good transit activism somewhat frustrating, in that people will not usually recognize efficient government in absolute numbers. Percentages, certainly – people understand cost overruns and (much less common) cost underruns, and as we’ve seen in Canada people can compare different technologies. But absolute numbers are not as well-understood, and neither are international comparisons of the same technology, where cost differences revolve around questions of project management, contracting practices, labor rules, and details of geology and surrounding infrastructure; people have only recently begun to think in terms of per-km costs in New York, and in the rest of the US I have not seen such thinking. When a transit agency proposes a project, people automatically think it’s expensive, and some will also say it’s necessary, regardless of whether it actually is either. I don’t think reactions to Second Avenue Subway at $5 billion would be materially different from what they were when Phase 1 alone grew to $5 billion.

The upside is that in budget negotiations, the amounts given to transportation are based on absolute shares of the budget rather than on the needs of specific megaprojects, which means that lower costs would translate to more projects built for the same budget. People might not notice that costs have gone down, and might still complain that every subway line is a boondoggle, but more lines would be built and more people would ride those lines. Just the perception of government competence would not change.