Passengers line up for a bullet train at a platform in Tokyo Station.
Credit: Yuya Shino/Reuters

It is a scene that plays out each weekday morning across Tokyo. Suit-clad office workers, gaggles of schoolchildren, and other travelers gamely wend their way through the city’s sprawling rail stations.

To the casual observer, it is chaos; commuters packed shoulder-to-shoulder amid the constant clatter of arriving and departing trains. But a closer look reveals something more beneath the surface: A station may be packed, yet commuters move smoothly along concourses and platforms. Platforms are a whirl of noisy activity, yet trains maintain remarkable on-time performance. Indeed, the staggering punctuality of the Japanese rail system occasionally becomes the focus of international headlines—as on May 11, when West Japan Railways issued a florid apology after one of its commuter trains left the station 25 seconds early.

Tokyo is home to the world’s busiest train stations, with the capital’s rail operators handling a combined 13 billion passenger trips annually. Ridership of that volume requires a deft blend of engineering, planning, and psychology. […]