A backup system based on a decentralized positioning system for managing the railway traffic in emergency situations

Railway traffic management is performed in an automatic way using centralized systems based on wired sensors and electronic elements fixed on the tracks. In spite of these systems, called Centralized Traffic Control systems (CTC), are robust and highly available, when they fail the traffic management must be done manually, increasing the probability of accidents due to the occurrence of human errors. We present a backup system for managing the railway traffic in emergency situations in which primary CTC systems do not work properly. The most innovative issue is that it is based on a decentralized positioning system in which each train is responsible of calculating its own position using an on board system based on wireless positioning technologies (GPS) and other on board devices and information sources (such as MEMS gyroscope, maps, ATP, odometer, etc.). Moreover, it combines train-side systems and terrestrial applications that exchange information via a hybrid mobile and radio wireless communications architecture. The system developed, a decentralized backup traffic management system, is the result of the work made during the last four years in collaboration with a railway company of Spain. This system is currently on real deployment phase.