Discussion on fixing the Open Data Index methodology wording has been added as a separate topic in this Forum.
The draft of Open Definition 2.1 has been updated to reflect discussion above.
Looping back to the start of this topic, a GTFS-RT feed without a bulk data download would not be classed as Open Data based on the draft Open Definition 2.1 (but please don’t let that stop you publishing because I really appreciate knowing if I’ve missed my bus or it’s just late.)