A Highly Available GTFS-RT Positions System

We develop a system for real-time public transportation data, deciding to use the data standard GTFS-RT (GTFS Realtime), an open data format for public transit data. We give an overview of the design of a physical GPS sensor device, its firmware, and processes. Next, we give the algorithms used to translate raw sensor data into a public GTFS-RT data feed. We deploy this feed over a highly available cluster across multiple regions to maintain high availability.