Before trains & subways came along urban travel was a bit of a mess. People traveled on foot or by horse and cart and for long distances or crossing water they used ferries or airplanes. When elevated train lines began to pop up it drastically improved efficiency in cities by getting people to their destinations quickly and safely. They also minimized road traffic and reduced the need for horses reducing air pollution.
The first elevated line opened in 1878 on Greenwich Street and Ninth Avenue. Initially it was not a huge success and the merchants along Broadway fought any encroachment into their retail space. But once it became more reliable, the lines grew in popularity and business boomed. The train’s emergence as a practical form of public transit ushered in the modern mass transportation age.
By the 1920s the el was not only running around the city but into the Bronx and other boroughs. But when the IND subway came in 1940 the elevated’s death was sealed and the last lines were demolished in 1955.
While they may look outdated today elevated trains (not to be confused with light rail) can still be a great option for cities that have the space. They are often cheaper to build than subways and can be used in conjunction with existing underground lines to increase capacity. Plus they are a great option for getting people out of their cars and into a more environmentally friendly mode of transport.