[presentation]

What they mean is that you have many different train operators who run different portions on the track as independent lines, but seamlessly, without connections, your train will become another line’s train when you reach the border stations.

For example, let’s say you are going from Motomachi Chukagai to Kawagoe, try plugging this into Google Maps - you board the Minatomirai line, then once you reach Yokohama, without getting off your seat you are now on the Tokyu Toyoko line, then again at Shibuya it becomes the Tokyo Metro Fukutoshin line, then again at Wakoshi it becomes the Tobu Tojo line.

4 different train operators maintained and run by 4 different companies with their own rolling stock and drivers, but they share access to the track and trains, they interoperate, and it just feels like one train with no dip in service quality. Many lines here do this.

[anileated]

That is not what they wrote, but what you describe sure sounds like an interesting design that I don't recall in countries other than Japan.