Skip to content

General Transit Feed Specification (GTFS)

The General Transit Feed Specification (GTFS) is an Open Standard used to distribute relevant information about transit systems to riders. It allows public transit agencies to publish their transit data in a format that can be consumed by a wide variety of software applications.

GTFS consists of two main parts: GTFS Schedule and GTFS Realtime.

GTFS Schedule

GTFS Schedule is a feed specification that defines a common format for static public transportation information. It is composed of a collection of simple files, mostly text files (.txt) that are contained in a single ZIP file.

Each file describes a particular aspect of transit information such as stops, routes, trips, etc. At its most basic form, a GTFS Schedule dataset is composed of 7 files: agency.txt, routes.txt, trips.txt, stops.txt, stop_times.txt, calendar.txt and calendar_dates.txt.

Along with this basic set of files, additional (optional) files can also be grouped to provide information of other service elements, such as fares, translations, transfers, in-station pathways, etc. Currently there are more than 15 optional files that extend the basic elements of GTFS, including locations.geojson which introduced a new format besides text files (.txt) which can be used to represent geographical areas.

The source of truth for all GTFS Schedule files is the official GTFS Schedule Reference, which provides detailed information on the requirements for all information elements in each file that composes a GTFS Schedule dataset.

GTFS Realtime

GTFS Realtime is a feed specification that allows public transportation agencies to provide up-to-date information about current arrival and departure times, service alerts, and vehicle position, allowing users to smoothly plan their trips.

The specification currently supports the following types of information:

  • Trip updates - delays, cancellations, changed routes
  • Service alerts - stop moved, unforeseen events affecting a station, route or the entire network
  • Vehicle positions - information about the vehicles including location and congestion level

To learn more about them visit the Feed Entities section.

GTFS Realtime was designed around ease of implementation, good GTFS interoperability and a focus on passenger information. This was possible 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.

The GTFS Realtime data exchange format is based on Protocol Buffers which is a language- and platform-neutral mechanism for serializing structured data (think XML, but smaller, faster, and simpler).

Similarly to GTFS Schedule, the GTFS Realtime Reference is the source of truth that establishes the rules and requirements for any GTFS Realtime feed, while the gtfs-realtime.proto file defines the hierarchy of elements and their type definitions that are used.