What Is the Difference Between a Subway, Metro, and Underground?

What is the difference between a subway, metro, and underground?

The difference is mostly in the name rather than the thing itself: subway, metro, and underground are all regional terms for a city's rapid transit rail system, the high-frequency, usually electric urban railway that moves large numbers of people around a metropolitan area, often running underground. In other words, they refer to the same basic concept, and which word is used depends largely on the country or city. Subway is the common term in much of the United States, metro is widely used internationally, and underground is the British term, especially in London. So when you travel and encounter these different words, they generally point to the same kind of system: the local rapid transit network. The naming differences can be confusing, but understanding that they describe the same concept helps you navigate public transit in any city.

What is a subway?

Subway is the term used in many American cities, and some others, for the urban rapid transit rail system, particularly where it runs underground, as in New York City and Boston. The word literally suggests a way that goes under, reflecting the underground portions of these networks, though subway systems often include elevated or surface sections too. A subway provides frequent service along fixed routes with numerous stations throughout the city, allowing riders to travel quickly around the metropolitan area while avoiding street traffic. In the US, subway is the everyday word for this kind of system. Interestingly, in British English, subway can instead mean a pedestrian underpass, which is a source of confusion for travelers, so context matters. When an American city refers to its subway, it means the rapid transit rail network locals use to get around.

What is a metro?

Metro is the most widely used international term for a city's rapid transit rail system, employed in cities around the world, from Paris to Washington to countless others. The word comes from metropolitan, as in metropolitan railway, and it has become the generic global label for urban rapid transit. A metro system typically features frequent electric trains running on dedicated tracks, often underground in city centers and sometimes elevated or at surface level elsewhere, with many stations across the urban area. Because metro is so broadly understood, it is often the term travelers will see on signs and maps in non-English-speaking countries and beyond. If you are trying to find a city's rapid transit while traveling internationally, looking for the metro is usually the safest bet, as it is the term most consistently used across different countries and languages.

What do they all have in common?

What subway, metro, underground, and other local names such as the Tube in London or U-Bahn in Germany all have in common is the underlying system they describe: an urban rapid transit railway designed to move many passengers quickly and frequently around a city. These systems share key features, including trains running on fixed routes with regular, high-frequency service, numerous stations spaced throughout the metropolitan area, dedicated tracks separated from road traffic for speed and reliability, and typically electric power. Whether it runs underground, elevated, or at street level in places, the purpose is the same: efficient mass transit within a city. So rather than getting caught up in the different names, travelers can recognize that any of these terms points them to the local rapid transit network. Learning the local name for your destination's system is simply part of navigating a new city.