Abstract
<jats:p>This entry explores the history, structure, applications, and challenges of both the General Transit Feed Specification (GTFS) and GTFS Realtime (GTFS‐RT), and illustrates their impact on transit systems and their role in shaping future transportation analytics. The GTFS is the de facto open data standard for the representation, communication, and analysis of public transportation systems. As well as providing a foundation for trip planning, transit mapping, and analytics applications, the GTFS includes several text‐based files that describe key transit elements, such as routes, trips, stops, and operating schedules. It is highly standardized, accessible, and flexible, which makes it a valuable resource of transit schedule for developers, transit agencies, and researchers. Beyond the schedule, the GTFS‐RT has been introduced to provide updates on vehicle positions, trip changes, and service disruptions. By supporting better‐informed travel decisions in real‐time trip planning apps, the GTFS‐RT has become a critical tool for performance monitoring and system optimization.</jats:p>