Trip arrival times are computed using machine learning models that analyse historical positional data and timetables.

In 2022, CalTrans' Integrated Travel Project began validating GTFS Schedule and Realtime feeds published by municipality and county public transport agencies within California.

[7] Monthly reports are published on the errors in agency data, along with analysis of typical street speeds and traffic.

In September 2023, Swiftly and the app Transit proposed 2 additional feed entity types: Stop and Trip Modifications.

Unlike GTFS Schedule zip files, many agencies may require developers to request an API key via email or a web form.

Developers then write programs to periodically fetch an agency's web API over HTTP, typically every few seconds to minutes.

There is no standard for streaming GTFS Realtime data, also support is built in to allow for deletion of items from previous iterations.

Each Alert stores the cause (such as labour strike or a mechanical fault) of an incident, along with its effect (reduced service, detour, stop cancellation, etc.).

Alerts also contain detailed headers, descriptions, urls, images, and a list of routes or stops affected (known as the Informed Entity).