Lille metro: Description of the VAL control system

The VAL System is designed to operate in a fully automatic mode. The primary objectives of this design were: - safety : the fail-safe concept is one of the major VAL principles; - dependability : an effective combination of redundancies and alternative operating modes is used to achieve a high system dependability; -high level of performance : the headway can be as low as 60 seconds including a 30- second dwell time; -a low cost of operation : minimum operating and maintenance personnel is required for service and trains are unmanned. The VAL control system design provides all automatic functions necessary to perform safe and reliable transportation of people over a wide range of operating conditions.