Many major transit municipalities in the United States public realtime information about the state of their systems using a common format known as a GTFS-Realtime feed. This is the information that the Metropolitan Transit Authority, for example, uses to power its arrival countdown clocks on station platforms.

gtfs-tripify is a Python package for turning streams of GTFS-Realtime messages into a "trip log" of train arrival and departure times. The result is the ground truth history of arrivals and departures of all trains included in the inputted GTFS-RT feeds:

To learn more about gtfs_tripify check out the docs.