Rapid transit system

Modal tradeoffs and interconnections

Suburban commuter rail is a heavy rail system that operates at a lower frequency than urban rapid transit, with higher average speeds, often only serving one station in each village and town. Commuter rail systems of some cities (such as German S-Bahns, Jakarta's KRL Commuterline, Mumbai Suburban Railway, Australian suburban networks, Danish S-tog etc.) can be seen as the substitute for the city's rapid transit system providing frequent mass transit within city. In contrast, the mainly urban rapid transit systems in some cities (such as the Dubai Metro, Shanghai Metro, MetroSur of the Madrid Metro, Taipei Metro, Kuala Lumpur Rapid Transit etc.) have lines that fan out to reach the outer suburbs. With some other urban or "near urban" rapid transit systems (Guangfo Metro, Bay Area Rapid Transit, Los Teques Metro and Seoul Subway Line 7, etc.) serving bi- and multi-nucleus agglomerations.