The table displays the date opened, number of kilometers and passengers each year in millions for subway systems in various cities. Looking from an overall perspective, it is readily apparent that the earlier underground railways tend to be longer and now serve more passengers per year relative to the more recent ones. Tokyo stands out for serving by far the most passengers and London for being both the oldest and largest.
London opened first (1863) and is nearly twice as expansive (394 kilometers) as the second largest subway, in Paris, which opened in 1900 and is 199 kilometers long. However, Paris now has more passengers compared to London (1,191,000,000 to 775,000,000). Tokyo was the next oldest having been constructed in 1927 with routes measuring a total of 155 kilometers and being made use of by 1,928,000,000 passengers annually.
The more modern subways are Washington D.C. (1976), Kyoto (1981), and Los Angeles (2001). Washington is the largest of the 3 at 126 kilometers with 144,000,000 yearly passengers. Kyoto is by far the smallest (11 kilometers) and serves relatively few individuals (45 million). Similarly, the Los Angeles subway is 18 kilometers in cumulative length and only 50,000,000 people travel on it each year.