> Yes the Second Ave Subway is expensive, but how many cities are building new subway lines underground through incredibly dense existing infrastructure?
Tokyo for one. E.g. the very recently built Fukutoshin line, deep tunneled subway underneath some of the busiest areas of the city (the tunneling is complicated in part because it had to dodge myriad existing subway lines), including very elaborate and expensive stations, had a cost-per-km about 1/4 that of the SAS. The Fukutoshin line is also overbuilt in various ways because it will be interlined in the future with the Tokyu Toyoko line (an extremely high-ridership suburban line).
A number of recently built subway lines in the Tokyo area had many problems, and were considered extremely expensive—but they were still much cheaper than the SAS...
So it isn't "complexity," it isn't "density," and it isn't high wages (Japan is not a low-wage country!). It's not fares—Tokyo transit fares are roughly on par with NYC; they're distance-based, so sometimes higher, sometimes lower, but it works out to roughly the same thing. Arguably it isn't even unionization, as Japanese industry is heavily unionized, although of course Japanese unions are rather different than U.S. unions.
One difference may be that Tokyo actually keeps building subway (and other rail) lines, and thus has has kept around the necessary in-house organization and knowledge for doing so, and has a wide selection of competent contractors available. U.S. cities typically have none of these things, and end up relying on consultants (and may not even have the competence or freedom to choose the consultants well), and a limited selection of contractors. [The NYC contracting situation is reportedly pretty dire, with a very few contractors having figured out how to game the system.]
Tokyo for one. E.g. the very recently built Fukutoshin line, deep tunneled subway underneath some of the busiest areas of the city (the tunneling is complicated in part because it had to dodge myriad existing subway lines), including very elaborate and expensive stations, had a cost-per-km about 1/4 that of the SAS. The Fukutoshin line is also overbuilt in various ways because it will be interlined in the future with the Tokyu Toyoko line (an extremely high-ridership suburban line).
A number of recently built subway lines in the Tokyo area had many problems, and were considered extremely expensive—but they were still much cheaper than the SAS...
So it isn't "complexity," it isn't "density," and it isn't high wages (Japan is not a low-wage country!). It's not fares—Tokyo transit fares are roughly on par with NYC; they're distance-based, so sometimes higher, sometimes lower, but it works out to roughly the same thing. Arguably it isn't even unionization, as Japanese industry is heavily unionized, although of course Japanese unions are rather different than U.S. unions.
One difference may be that Tokyo actually keeps building subway (and other rail) lines, and thus has has kept around the necessary in-house organization and knowledge for doing so, and has a wide selection of competent contractors available. U.S. cities typically have none of these things, and end up relying on consultants (and may not even have the competence or freedom to choose the consultants well), and a limited selection of contractors. [The NYC contracting situation is reportedly pretty dire, with a very few contractors having figured out how to game the system.]