- Service Interface for Real Time Information (SIRI)
In order to make real-time transport information compatible between different systems, several European countries joined efforts to create a standard protocol known as Service Interface for Real Time Information (SIRI). This protocol describes (at length!) how different systems can share real-time passenger information, allowing different suppliers, operators and local authorities to work together without costly development bills every time one of the party is swapped out.
SIRI-SM (Stop Monitoring) is a feed for the estimated time of arrival of a vehicle to a particular stop. SM can also include further information about vehicles such as the vehicle’s location.
SIRI-VM (Vehicle Monitoring). Providing a map with live tracking of vehicles is also possible thanks to the SIRI-VM feed. SIRI-VM can also include further information about upcoming stops, such as the vehicle’s ETA.