A Subway System is an underground or elevated train network designed to transport passengers quickly across urban areas. It typically consists of multiple lines, each identified by a unique color or number, connecting various neighborhoods and key locations. Subways are known for their efficiency, as they can bypass road traffic and reduce travel time. Subway systems are found in many major cities worldwide, including New York City, London, and Tokyo. They usually operate on a fixed schedule and have designated stations where passengers can board and disembark. This public transportation option helps alleviate congestion and promotes environmentally friendly travel.