This page provides a list of realtime transit terms and definitions to help transit partners and data aggregators use the terms consistently across multiple documents or user interfaces.
Terms | |
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Carriage | A separate section of a train that carries passengers. |
Entity | A distinguishable object that represents a real-world existence, such as a vehicle, trip, or stop. Entities are identifiable with a unique ID, and each entity type has a set of fields that describe it. |
Header | A record that provides metadata about a feed, such as its version and timestamp. |
Message | A record that contains data about a particular entity. Messages are included in feed messages, and they provide information about the entities in the feed. |
Realtime feed | A file that complies with the GTFS-realtime format and provides current information about the transit service. The file's contents cover trip updates, service alerts, or vehicle positions |
Service alerts | Alerts that provide passengers with updates when there’s a disruption on the transit network. |
Trip updates | Updates about the delays or cancellations of individual trips. |
Vehicle positions | Information about the current location of a particular vehicle. |