A tram is an enclosed carriage intended for public transportation, powered by electricity, and designed to run on rails located in the street. Trams are also known as streetcars, trolleycars, or trolleys, and they were once abundant in metropolitan areas around the world. After a decline in the middle of the 20th century, trams were revived in some communities in the early 21st century, thanks to a growing interest in environmentally-friendly transportation options.
The defining features of a tram are the rails, and the fact that it runs in the street. This distinguishes it from light and heavy rail, which run on dedicated tracks, and cable cars, which run in the street, but operate by clasping onto a constantly moving cable. Trams may be attached to overhead electric wires, or they may connect with an electrified rail, depending on the design and the region, with an operator seated in the front of the tram to steer and stop.
Trams provide a number of advantages over buses. For example, they tend to command more respect than buses, ensuring that they move smoothly through traffic, and they are less polluting than buses. Trams can also be better than light rail in some circumstances; light rail is usually speedy, with minimal stops, which is great for basic commutes, but not always so ideal for riders. A tram is slower, but it can stop any time, allowing people to get off close to work, home, or entertainment, rather than having to transfer to another method of public transit to reach an end destination.
Early trams were developed in the 1800s, and pulled by horses. They were probably inspired by the mule and horse-drawn rail cars used to take coal and other products out of mines. The rails made transport easier by reducing friction, making less work for the animals, and the applications for city streets could clearly be seen. A tram could hold a high number of passengers as a group in a relatively small space, making it a marked improvement over a multitude of carriages and wagons used to transport individuals.
With the development of electricity, the tram grew to be a feature in many cities. Trams were cheap for riders, since lots of people could pack on, sharing the cost, and they are also convenient for cities, since they helped keep the streets clear of private vehicles, and they could be used to carry cargo. In periods of peak demand, cars could easily be added without having to add staff, making trams efficient and versatile. Buses began to be more popular in the 20th century, for a variety of reasons, and many cities unfortunately tore out their tram rails to make smooth paved streets.
Cities with trams today often mix them with light rail for longer commutes, and sometimes bus routes will be used to supplement the tram's network of rails. Tram rails are also specially designed to be minimally obtrusive, ensuring that drivers, pedestrians, and cyclists are not disrupted by the rails.