Metro lines are rapid transit systems that operate in urban areas, providing efficient transportation for commuters. They consist of underground, elevated, or surface tracks and are designed to connect various neighborhoods and key locations within a city. Metro lines typically feature multiple stations, allowing passengers to board and disembark easily. These systems are often part of a larger public transportation network, which may include buses and trams. Cities like New York, London, and Tokyo have extensive metro lines that help reduce traffic congestion and promote sustainable travel options. Metro lines are crucial for enhancing urban mobility and accessibility.