Which city has the most extensive public transport system in the world?

With its vast network of subways, buses, and trains, Tokyo, Japan is considered to have the most extensive public transport system in the world.

One of the reasons why Tokyo has such a comprehensive public transport system is due to its high population density. More than 13 million people live in Tokyo's 23 wards, and the greater Tokyo area has a population of over 37 million. With so many people needing to get around, the city's public transport infrastructure has grown to meet their needs.

Another reason why Tokyo's public transport system is so impressive is its reliability. Trains and subways run like clockwork, with delays of just seconds being considered a major issue. Additionally, the system is clean, safe, and affordable, making it a popular choice for residents and tourists alike.