lightrail

Lightrail is a form of urban rail transit that uses light-weight electric vehicles to move passengers within cities. Vehicles run on rails and typically operate in dedicated rights-of-way, on street corridors, or a combination of both. Lightrail is distinct from heavy-rail metro systems, which use higher-capacity vehicles and extensive grade separation, and from conventional streetcars, which usually have lower capacity and speed. Modern lightrails aim to combine the flexibility of street-running service with the higher performance and reliability of rail.

Design and operations commonly feature light rail cars that can operate as single units or in short multiple-car configurations. Power is usually supplied by overhead electric lines at around 600–750 volts DC. Systems may be partially grade-separated to improve reliability, but many lines run in mixed traffic or along urban streets with signaling tailored to shared environments. Service frequency is often higher on exclusive or semi-exclusive segments, and speeds vary widely between urban street sections and dedicated alignments. Lightrail networks are typically integrated with buses and may use unified fare systems and transfer points.

History and scope: Modern light rail matured from mid-20th-century efforts to replace aging streetcar networks and to provide higher-capacity, lower-cost urban transit than heavy rail. The term covers a broad range of typologies, from streetcar-style lines to more modern, higher-capacity systems. Some operators employ tram-train concepts, where lines share tracks with other rail services or switch between street-running and heavy-rail operations.

Advantages and challenges: Lightrail often offers lower capital costs, shorter construction times, and better urban integration than heavy rail. However, at-grade sections can conflict with road traffic and pedestrians, and operating costs, maintenance, and political support influence project viability and expansion timelines.

Examples: Portland’s MAX, Calgary’s C-Train, Edmonton LRT, Manchester Metrolink, Sheffield Supertram, Nottingham Express Transit, and Los Angeles Expo Line are among well-known networks. Globally, many cities have ongoing lightrail programs as part of multi-modal transit strategies.