Compare it to Lisbon (where I live): some five or six different systems to serve less than 2 million people. Disheveled, impossible to coordinate. Dense coverage in the city centre and sparse where people actually live, so masses of cars go into the centre every day. Gridlock and pollution everywhere. And the systems we have are considered good!
I'll gladly join the chorus calling Tokyo the future. Can't come soon enough.
A classmate of mine who visited Amsterdam in the 80's described his experience like this: People seemed to hang out in different neighborhoods based on what "type" they appeared to be. The police might spot you being "out of place" and guide you back to where you were "supposed" to be. Essentially, they would do a friendly "deportation" of you to the right neighborhood.
I think all cities have something like this going on, to one extent or another: subdivision into different sub-cities.