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.
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.
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.
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.
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.
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.