Communication-Based Train Control (CBTC): The Backbone of Metro Systems
CBTC is the gold standard for modern urban metro and subway systems. It uses continuous, high-capacity radio communication (like Wi-Fi) between trains and a central control computer. This allows for real-time, precise tracking of every train's location. The result is moving blocks: the safe zone around each train moves with it, enabling much shorter headways (time/distance between trains), increased line capacity, and fully automated (driverless) operation.
FAQ:
Q: How does CBTC increase capacity?
A: By knowing each train's exact position and speed in real-time, the system can safely reduce the distance between trains compared to fixed-block systems, allowing more trains to run on the same line.
Q: Can CBTC and traditional signals work together?
A: Yes, during a phased implementation, systems often operate in a "mixed mode" where some trains use CBTC and others rely on traditional fixed-block signals, managed by interoperable wayside equipment.