Brief Description
What is GTFS-Flex?
A detailed description of the superordinate General Transit Feed Specification (GTFS(-Static)) can be found HERE. GTFS basically describes the public transport timetables and associated geographical information, such as the locations of stops.
Over the course of time, various so-called extensions have been defined. One of the extensions is GTFS-Flex. GTFS-Flex should be used accordingly with GTFS-Static.
Who is behind it?
GTFS-Flex is designed to make it easier to find on-demand transport services.
With its acceptance on 18 March 2024, GTFS-Flex changed from a “proposal” to an official extension of GTFS-Static.
Why does the Open Data platform offer this?
On behalf of the Federal Office of Transport (FOT), the System Tasks Customer Information Plus (SKI+) office aims to provide as many of the current standards as possible.
In addition to GTFS-Flex, we also offer the on-demand services as NeTEx.
Access the Data
Functional Description
What information do we map with GTFS-Flex? Size:
GTFS-Flex extends GTFS as it allows the different forms of on-demand offers to be displayed. These include: on-demand scheduled transport, on-demand corridor transport and on-demand surface transport. More on this in the On-Demand technical concept (see further information).
In addition, the extension makes it possible to map the service areas (geographical areas) that are important for area transport and to map services as time windows (instead of fixed departure and arrival times).
How is the information structured? The model.
Like GTFS, GTFS-Flex is made up of several files. We have also adapted the standard to include some aspects relevant to Switzerland and summarised them in a Swiss profile (see further information).
Technical description
The following table is taken from the Swiss GTFS profile. The profile is considered a master’s degree.
| No | Filename | Required | Definition |
|---|---|---|---|
| 1 | agency.txt | Required | Transit agencies with service represented in this dataset |
| 2 | stops.txt | Required | Stops where vehicles pick up or drop off riders. Also defines stations and station entrances. |
| 3 | routes.txt | Required | Transit routes. A route is a group of trips that are displayed to riders as a single service |
| 4 | trips.txt | Required | Trips for each route. A trip is a sequence of two or more stops that occur during a specific time period. |
| 5 | stop_times.txt | Required | Extended and modified file to include time-windows that a vehicle picks up and drops off at stops or location groups/areas. |
| 6 | calendar.txt | Conditionally Required | Service dates specified using a weekly schedule with start and end dates. This file is required unless all dates of service are defined in calendar.txt |
| 7 | calendar_dates.txt | Conditionally Required | Exceptions for the services defined in the calendar.txt. If calendar.txt is omitted, then calendar_dates.txt is required and must contain all dates of service. |
| 8 | transfers.txt | Optional | When calculating an itinerary, GTFS-consuming applications interpolate transfers based on allowable time and stop proximity |
| 9 | feed_info.txt | Optional | This file contains information about the dataset itself, rather than the service the dataset describes |
| 10 | booking_rules.txt | Required | New file that defines the booking rules / requirements that must be met for a successful booking |
| 11 | locations.geojson | Required | New GeoJSON (and non-CSV) formatted file that allows defining Zones using Polygons and MultiPolygons (for Zones with “holes”). |
| 12 | location_groups | Required | New files to allow grouping of stops which allow predetermined groups of these features to be specified on individual rows of stop_times.txt.
This file specifically defines the group. |
| 13 | location_group_stops | Required | New files to allow grouping of stops which allow predetermined groups of these features to be specified on individual rows of stop_times.txt.
This file specifically defines the mapping of the groups from location_groups to stops. |
Further information
Restrictions
- GTFS-Flex does not cover all aspects of on-demand services, which is why an extension of GTFS-Flex (thus an extension of the extension) is currently being sought: https://share.mobilitydata.org/gtfs-ondemand
- GTFS-Flex, like the other GTFS-* standards, does not offer a booking mechanism, i.e. no price information
Further information
- Specialist concept on-demand: https://www.öv-info.ch/sites/default/files/2024-02/fachkonzept_on-demand_v2.0_en.pdf
- Swiss GTFS profile, incl. section on GTFS-Flex: https://www.öv-info.ch/sites/default/files/2024-04/gtfs_profil_switzerland_version_0_16.pdf