Heavy rail systems are a type of urban transit that operates on dedicated tracks, primarily designed for high-capacity passenger transport. These systems typically include trains that run on steel tracks and can carry a large number of passengers over long distances. They are often found in metropolitan areas and connect suburbs to city centers, providing an efficient alternative to road travel. Heavy rail systems are characterized by their ability to operate at high speeds and frequent intervals, making them a reliable choice for commuters. Examples of heavy rail systems include the New York City Subway and the London Underground, which serve millions of passengers daily and contribute significantly to urban mobility.