Train Crash

Sometimes extreme congestion of commuter trains becomes a problem. For example, an estimated 3.5 million passengers ride every day on Yamanote Line in Tokyo, Japan, with its 29 stations. For comparison, the New York City Subway carries 4.8 million passengers per day on 24 services serving 468 stations. To cope with large traffic, special cars in which the bench seats fold up to provide standing room only during the morning rush hour (until 10 a.m.) are operated in Tokyo (E231 series train). This train has as many as six sets of doors on each side to shorten the time for passengers to get on and off at station.
Passenger trains usually have emergency brake handles (or a "communication cord") that the public can operate. Misuse is punished by a heavy fine.
• Rapid transit
Large cities often have a metro system, also called underground, subway or tube. The trains are electrically powered, usually by third rail, and their railroads are separate from other traffic, usually without level crossings. Usually they run in tunnels in the city center and sometimes on elevated structures in the outer parts of the city. They can accelerate and decelerate faster than heavier, long-distance trains.