The GTFS specification defines the following files along with their associated content:
| Filename | Required | Defines |
|---|---|---|
| agency.txt | Required | One or more transit agencies that provide the data in this feed. |
| stops.txt | Required | Individual locations where vehicles pick up or drop off passengers. |
| routes.txt | Required | Transit routes. A route is a group of trips that are displayed to riders as a single service. |
| trips.txt | Required | Trips for each route. A trip is a sequence of two or more stops that occurs at specific time. |
| stop_times.txt | Required | Times that a vehicle arrives at and departs from individual stops for each trip. |
| calendar.txt | Required | Dates for service IDs using a weekly schedule. Specify when service starts and ends, as well as days of the week where service is available. |
| calendar_dates.txt | Optional | Exceptions for the service IDs defined in the calendar.txt file. If calendar_dates.txt includes ALL dates of service, this file may be specified instead of calendar.txt. |
| fare_attributes.txt | Optional | Fare information for a transit organization's routes. |
| fare_rules.txt | Optional | Rules for applying fare information for a transit organization's routes. |
| shapes.txt | Optional | Rules for drawing lines on a map to represent a transit organization's routes. |
| frequencies.txt | Optional | Headway (time between trips) for routes with variable frequency of service. |
| transfers.txt | Optional | Rules for making connections at transfer points between routes. |
| feed_info.txt | Optional | Additional information about the feed itself, including publisher, version, and expiration information. |
The following image shows the relationships among the various files:
