underground transportation

Underground transportation involves travel systems built below the Earth's surface, primarily to move people efficiently through densely populated areas. The most common form is the subway or metro, which consists of trains running on specially constructed tunnels, often using electric power for smooth operation. These systems help reduce surface congestion, enable quick travel across cities, and operate regardless of weather. They typically feature stations for boarding and arrivals, and are designed with safety and capacity in mind. Overall, underground transportation plays a crucial role in modern urban mobility, easing traffic and providing reliable transit options for millions daily.