In this essay I am going to mention some cities which have the underground train systems.
London has underground train systems. It was opened in 1863. It is the longest with 394 kilometers. It carried a large number of people, 77 million in 2010. On the other hand also Paris has an underground train system. It was opened in 1900 with 199 kilometers of length. These trains carried 192 million people in 2010. Tokyo also opened underground train system in 1927 with 155 kilometers of length. It carried 192 million passengers in 2010. Kyoto as well has established an underground train system in 1981 with the shortest distance of 11 kilometers. In addition it carried 45 million passengers in 2010. The last city is Boston which was opened an underground train system in 2001. The distance is 28 kilometers. It carried 50 million passengers in 2010.
London has the oldest and longest system at all. Tokyo carried the most passengers.