Welcome to A.net
You used to be able to go to this page http://dms.dot.gov/cfreports/daily_rpt.cfm
and get a daily report of all filings into DOT dockets. If you knew the docket number you could find them easily. However the DMS (Docket Management System) has been deactivated and everything has been moved to a common site for all US government activites.
Look here: http://www.regulations.gov/fdmspublic/component/main
This new site is basically crap. Yesterday I failed to locate a DOT docket, even though I had the docket number. The search engine even failed using the title.
Being a conspiracy theorist I figure this is all a plot to keep you Americans (and us foreigners) in the dark.
Now if anyone has found an equivalent of the daily report, I'd certainly like to hear about it.