The Stockholm Metro has a mix of underground and above-ground stations. Photo by Kicki.

What is Metro?

Metro goes by a number of different names in English alone. Whether called the subway, the elevated, rail rapid transit, heavy rail, or the underground, a metro system is a rapid transit system powered by electricity (usually by a third rail or an overhead wire), with high capacity due to multiple car trains, and entirely grade separated from other traffic. Usually, metro systems are either in underground tunnels or on elevated tracks rather than at street level.

Why Metro?

Although metro systems are the most expensive form of urban rapid transit, their high capacity and speed make them invaluable parts of highly-developed transit systems. For example, to move all the passengers that the New York City subway system takes into its CBD during just one hour of the morning commute would take a 228-lane Brooklyn Bridge. The Tokyo metro system made a staggering 3.174 billion passenger trips per year. The density of business districts like downtown Manhattan or Tokyo simply would not be possible without their metro systems.

As with light rail, metro systems draw from the electric grid, meaning that there is no pollution emitted by the train itself. In this sense, metro rail can be better for the environment than vehicles running on carbon-intensive fuels only if the grid is powered by clean and renewable sources.

Additionally, all rail systems have the benefit of permanence, enabling residents and businesses to invest confidently around transit stations. That helps build denser, more sustainable cities.

Today, most new metro systems are being built in Latin America and Asia. In North America and Europe, most cities that can afford metro systems already have them; these cities are instead investing in filling in their networks with light rail, buses, and cycling infrastructure.

Metro: The Cadillac of Transit

The Komsomolskaya Metro Station in Moscow. Photo by GoGoJingo.

Metro systems are not only high-capacity, they are iconic. The Moscow Metro is adorned with some of the best examples of socialist realist art in the world and even has stations decorated with chandeliers.

The London Underground, a.k.a. the "tube," is the oldest metro system in the world. Photo by Sibotk (Holiday).

Both the logo and the original map of the London Underground—the world’s oldest metro system—are universally recognizable, partly as a result of their sophisticated graphic design.

One of the biggest benefits of metro systems is the incredibly good brand that they have developed. Metros are not only trusted to be high-quality transportation modes, they are also held up as the symbol of world cities. Compared to other modes of urban transport, selling to both the public and decision-makers is relatively easier with metro systems.