With nearly 300 stations, Tokyo has one of the world's busiest and most sprawling subway networks at work today — not to mention globally notorious rush hours.

A quick glance at a transit map shows a spider web of colorful lines representing each route — the product of more than 80 years of digging and constructing to provide an efficient system reaching virtually every part of the metropolis.

Tokyo's environmentally friendly rapid transit system has been copied to a lesser extent by most cities of significant size nationwide, from Sapporo to Fukuoka.