consider creating a merge gtfs feed script

[carocad]

There are several cases where you might want to combine the data provided by two different parties. Of course the ids used must follow the same rules but in general this should be possible for gtfs feeds.

One case that comes to mind is: we create a gtfs feed with o2g, work with it and update its data, then later on we realize that we missed some routes/agencies/etc which by then are present in osm, so we would like to combine the two feeds to get a better one ....