Rapid transit

Rapid transit is a high-capacity public transport system designed for urban areas.

It is often called a metro, subway, or mass rapid transit (MRT). These systems are essential for moving large numbers of people through crowded cities. Unlike buses or trams, rapid transit operates on an exclusive right-of-way. This means the tracks are separated from pedestrians and other vehicles. This separation allows trains to move quickly and maintain strict schedules.

Most modern rapid transit systems function as electric railways. They typically use electric multiple units, which are trains where the power is distributed among several cars.

To make boarding easy, stations often feature high platforms. These platforms are level with the train floor to minimize gaps. This design allows passengers to step directly onto the train without using steps. While most systems use standard railway tracks, some use different technologies. These include guided rubber tires, monorails, or magnetic levitation, known as maglev.

Rapid transit lines can be built in several different ways. A grade-separated line built through tunnels below the surface is often called a subway or underground. In Germany, this is known as the U-Bahn.

Other lines are built on elevated railways, which are raised above the ground. These are sometimes called skytrains or "L" trains, short for elevated.

Some systems also have at-grade intersections, where the line crosses a road or another transit line at ground level. Some systems are even hybrid, using concepts like tram-trains or premetros.

The history of rapid transit began in the 19th century. The world's first system was the Metropolitan Railway in London, which opened in 1863.

This early system used steam locomotives, which could be unpleasant for passengers due to ventilation issues. In 1868, New York opened the West Side and Yonkers Patent Railway. This was an elevated line that used stationary steam engines and cables to move. A major technological shift occurred in 1890 with the City & South London Railway. This was the first fully underground rapid transit railway to use electric traction.

As electric technology spread, cities like Budapest, Chicago, and Buenos Aires converted to electric service. The Buenos Aires underground opened in 1913 with Line A.

In the 21st century, the focus of expansion has shifted to Asia. China is now the global leader in metro expansion. The country operates almost 60 cities with rapid transit systems.

The Shanghai Metro holds the record for the longest single-operator system by route length. Meanwhile, the New York City Subway is the largest provider by station count, with 472 stations.

Rapid transit serves different purposes depending on the city's layout. In many areas, the system handles local transport within the inner city or inner suburbs. For longer trips, a separate commuter rail network might take over. These commuter trains have stations that are spaced further apart to allow for higher speeds. Rapid transit is also frequently integrated with other transport modes. For instance, buses or trams often act as feeder systems. They carry passengers from residential areas to the major rapid transit stations.

Terminology for these systems varies widely by region and language. In Southeast Asia and Taiwan, the acronym MRT is the standard term. In many European countries, the word "metro" is common. In Germany and Austria, the term U-Bahn is used. Even in North America, names change based on local identity. Boston calls its system "The T," while Atlanta uses the acronym "MARTA." These diverse names all describe the same goal: moving people efficiently through the complex systems of a modern city.