Static GTFS feed Versions

Feed versions represent a specific static GTFS archive that was published at a particular point in time by a source feed.

Transitland calculates metadata about each feed version's contents, as well as importing the GTFS entities within the feed version. Metadata includes service levels over the duration of the feed, summaries of included CSV files, a convex hull geometry that contains all stops, etc.

Each feed version is accessed and referenced using the SHA1 checksum of the GTFS archive.

New feed versions

The static GTFS URL for each feed is checked approximately once per hour, and a new feed version is created any time new data is observed. New feed versions are given the SHA1 checksum value of the entire GTFS Zip archive.

Data is considered new if the total checksum of the individual GTFS CSV files, processed in alphabetical order, has not been observed previously. Checking for uniqueness in individual file content avoids the common situation where timestamps or other non-GTFS files inside the archive change but the GTFS CSV data itself has not been updated.

For a small number of GTFS source feeds, Transitland staff have manually throttled the fetch process to only check for new feed versions once per week. These feeds may come from servers that modify the feed contents on each request (which confuses Transitland's SHA1 checksum comparison process) or from agencies that produce very large feeds with many new feed versions per week. Users on the Transitland Professional or Enterprise tiers may contact Interline to request that these rate limits be increased if they happen to require more up-to-date data for one of these feeds.

Active feed version

Each feed has at most one active feed version, selected as the best feed version for the current day. In most cases it will be the most recently fetched feed version, unless that feed version only contains service for dates in the future. Requests to other endpoints, such as map tiles, routes, stops, etc., will use data from this feed version unless another version is explicitly specified using the feed_version_sha1 parameter.

Downloading static GTFS feed versions

Users may download static GTFS feed versions from the Transitland archives under the following conditions:

  1. The feed's license metadata cannot explicitly disallow redistribution.
  2. If the feed version is the most recent version, all users may download it from the REST API feed endpoint.
  3. If the feed version is a historic version (not the most recent version), users must be on a paid Transitland Professional plan, a paid Transitland Enterprise plan, or a complementary Hobbyist/Academic plan to download it using the REST API feed versions endpoint.