Movement Authority

MA. Movement authorization. It indicates the permission for a train to move from one point to another according to the characteristics of the infrastructure and the freedom of the street: line peculiarities, signaling, slopes, speed limitations, position of the downstream trains, etc. The MA can be given to a train from a Central Apparatus, from a blocking system, from a Radio Block Center (RBC), or from discontinuous (Balise) or continuous (Loop) information equipment. The MA can be limited in space, or in time and space. This means that after receiving an MA the train can continue in its direction up to the indicated point. The time limitation is used to automatically revoke the MA in the case of discontinuous information transmission systems. In the case of the ERTMS system, the MA can be given by radio, transmitted or upon request by the train or on changes in the status of the signaling system by the Central System; this variation can be cyclical or generated by an event, such as the formation of an itinerary. The MA allows the train to move up to an EOA (End Of Authority) stop point or to continue from a speed limitation point LOA (Limit Of Authority), with reduced speed, with a specific authorization to move