heavyrail

Heavy rail, or heavy-rail transit, is a designation used in transit planning to describe high-capacity passenger rail systems that typically operate on dedicated, grade-separated rights-of-way and use heavy rolling stock. The term is often contrasted with light rail, trams, or street-running systems, as well as with some forms of commuter or intercity rail. Heavy-rail networks are designed to move large numbers of people quickly within urban centers and along suburban corridors.

Key characteristics include high capacity and frequent service, long and heavy rolling stock, and electrified traction power. Electrification is commonly provided by overhead catenary or a third rail, with voltages and configurations varying by region. Infrastructure often features fully segregated tracks, extensive signaling and control systems, and modern stations with high platforms and integrated interchanges. Safety, accessibility, and reliability are prioritized, and many systems employ advanced signaling such as CBTC or ETCS to improve headway and safety.

Operations on heavy-rail networks typically involve all-day service with high peak frequencies, rapid acceleration, and long trains to accommodate peak demand. They may be operated by public transit agencies or private concessions and can include automated or semi-automated operations on some lines. Rolling stock generally consists of electric multiple units or locomotives pulling heavy passenger cars, maintained at centralized depots.

Examples of heavy-rail networks include major urban systems such as the New York City Subway, London Underground, Paris Métro, Tokyo and Moscow Metro systems, and other large metropolitan networks around the world. Heavy rail is distinguished by its emphasis on high capacity, speed, and grade-separated operation compared with lighter rail modes.