Nathan Johnson archives MTA data, including elevator/escalator status, Bus Time data, and an archive of GTFS files starting Aug 2014.
For more info, go here -
https://talk.beta.nyc/t/workgroup-introductions/522/4
For more info about Nathan's Bus Performance project, go here-
http://transitcenter.org/2015/08/11/big-data-opportunity-to-rethink-nycs-buses/
To use of the archive, you must agree to the terms and conditions of MTA data usage detailed at http://web.mta.info/developers/developer-data-terms.html