GTFS feeds let public transit agencies publish their transit data and developers write applications that consume that data in an interoperable way. Many of these feeds are openly available at the Open Mobility Data website.
But let’s face it, if you ever worked with a GTFS dataset you know there will always be a missing field or skipped stop, making it hard to put it to actual use.
For that very reason, there are many modules in various programming languages available for us to correct errors, fill in gaps and generate missing files for that broken GTFS dataset from your local transit authority.