from Google's "What is GTFS-realtime?" guide:
GTFS-realtime is a feed specification that allows public transportation agencies to provide realtime updates about their fleet to application developers. It is an extension to GTFS (General Transit Feed Specification), an open data format for public transportation schedules and associated geographic information. GTFS-realtime was designed around ease of implementation, good GTFS interoperability and a focus on passenger information.
The specification was designed through a partnership of the initial Live Transit Updates partner agencies, a number of transit developers and Google. The specification is published under the Apache 2.0 License.
Components of GTFS-realtime
- Trip Updates - Predictions of when the vehicle will arrive
- Vehicle Positions - Locations of vehicles
- Service Alerts - Notifications to users that there is a disruption in the network
How to provide GTFS-realtime
This is a stub section that needs to be developed.
Applications that consume GTFS-realtime data
List is not comprehensive
As of March 2017, there is no official public validation tool either endorsed by the GTFS-realtime community or provided by Google that validates that a GTFS-realtime feed contents are correct.
However, a GTFS-realtime validation tool is currently under development at the Center for Urban Transportation Research at the University of South Florida as part of a National Institute for Transportation and Communities (NITC)-funded, based on early work from a 2015 Google Summer of Code project.