Just ran across this on Reddit:
(http://i.imgur.com/dUTdadv.png)
http://i.imgur.com/dUTdadv.png
and
(http://urbanchange.eu/arquivos/downloads/tokyocorridors.gif)
http://urbanchange.eu/arquivos/downloads/tokyocorridors.gif
Someone may find this useful :)
Reddit thread: https://www.reddit.com/r/MapPorn/comments/53yuxd/heres_a_full_railway_map_of_tokyo_and_suburbs/
Reminds me of a diagram I made at work today. It had fewer nodes, but was a similar chaos of crossing lines.
I don't think a combined map of railway lines in Scandinavia would have that many lines. Maybe if closed lines were included. Then again, the population is just half, assuming "greater Tokyo" is the same as "metro" on Wikipedia.
Those are incredible. That top one is surely completely unusable. And I thought Southern Rail's map (http://www.southernrailway.com/images/network_map_accessibility_20120502.pdf) was bad (it's worse in the trains - it's squashed further on the vertical axis. It mostly annoys me because of how poor a geographical representation it is)
Having to navigate quite a few time on this net, I must say the second map is mildly useful, while the first map is a complete disaster area, as location and even train directions appear completely wrong in many cases.