[polymath21]

If you think London is good, wait til you try the subway in big Asian cities like Taipei, Tokyo, or Seoul.

[beisner]

Don’t forget the subway lines in basically every Chinese city! Beijing has overcrowding issues, but Shanghai, Chengdu, Guangzhou all have phenomenal metros.

[leroy_masochist]

As a native New Yorker I was blown away by the Shenzhen subway when I visited last year.

It's spotless, easy to navigate (lots of language-free signs with really clear intuitive diagrams of where to go), and almost eerily fast and smooth-riding. And 5 bars of LTE the whole time.

[dagw]

A thing built 6-10 years ago will always be more modern and less run down than a thing built 60-100 years ago. Time will tell how well the Chinese systems age.

[jpatokal]

Tokyo's subway turns 90 this year, and while the older stations aren't as flashy as new ones, it remains remarkably efficient & functional.