I found the gtfs2pgrouting project from pgRoutings' GitHub page. But it's three years old and doesn't work with the (current) full GTFS specification as it looks.
First of all I would like to know if there is a simple way to route GTFS data (preferably inside PostgreSQL). I think OpenTripPlanner is too full blown for me. And it has problems with huge/multiple graphs as it looks.
Otherwise I would write my own solution, connected to my already imported OSM/pgRouting instances.
So part two: Are there any fully functional import tools to get GTFS data into PostgreSQL 9.3+ that employ PostGIS 2+?