[bydo]

Here's one for New York:

http://projects.newyorker.com/story/subway/

And Chicago:

http://youarehere.cc/j/subway/chicago.html

[qqrs]

A very cool sonification of income inequality along the New York subway: https://datadrivendj.com/tracks/subway

[bbarn]

Chicago's is heavily skewed by the loop stops - where almost nobody lives. Filtering those out would give a much clearer view.

[xivzgrev]

Wow that's interesting how for Brown line the median income is already high for Addison and stays relatively constant all the way downtown