This repo was a brief attempt at building a dataset of historical transit arrival times in New York City using gtfs-tripify and the MTA's GTFS-RT archive. This project ended in failure when I discovered that there were large swatches of data missing from the archives provided by the MTA. Namely, the {1, 2, 3, 4, 5, 6} were completely missing from the two samples I took from the dataset, on Febuary 1, 2019 and on June 1, 2019.
Unfortunately, until a more reliable archival service comes into being, the NYT Upshot Subway Variability Calculator is the best we can have (the calculator has some fundamental flaws, but whatever).
As an aside, the ultimate useful expression of this data would be a user-queryable API. I did some design work on this. Not only would it require solving the archival problem, it would also require solving other structural problems that amount to a full-time job.
See also gtfs-tripify and nyc-transit-archive-old.