[sho]

> some closely timed transfer from another source

Often when different lines meet the tracks are organised such that the trains pull up together on either side of a platform: a so-called cross-platform interchange[1]. The passengers on either train then have 30 seconds or so to board the other train if they wish to change. Obviously this has to be precisely timed - if one train is late or the other departs early, the transfer can't take place.

It really is an amazing system, a wonder of the world. There's one part of the yamanote line that runs parallel to the keihin-touhoku line. In this section, the K-T line acts as an express, whereas the yamanote generally stops all stations. So as the lines meet, you'll have a bunch of people get off the yamanote onto the "express" keihin-touhoko - they arrive synchronously, then the keihin speeds past a few slow poke yamanotes, before arriving in sync again with a yamanote a few trains ahead of the original one, so people can switch back before the keihin diverges and goes off on its route. It's unbelievable, choreographed like a steel ballet. The best train system in the world bar none.

[1] https://en.wikipedia.org/wiki/Cross-platform_interchange#Tok...

[megy]

I mean, what? There are often different companies running different train systems in the same city, and you will have a fair walk.

[phinnaeus]

Are the trains all automated or manually run? Or some mix of the two?

[kevmo314]

It's not fully automated. The drivers are very disciplined (https://youtu.be/xzkU6tmdImY?t=639) although I don't know to what extent they have automation helping them.

[oliv__]

Wow that's fascinating. Thanks for sharing!