They are deriving a database from OpenStreetMap. Has anybody found where they share that data? It's likely that the OSM data license (the ODBL) requires them to publish the derived database.
Generated map tiles are "produced work" and don't have to be licensed under ODbL. If they make their (raw) data available as download would it have to be under ODbL.
IANAL, but that's not how I read the FAQ or the license:
4.6 Access to Derivative Databases. If You Publicly Use a Derivative
Database or a Produced Work from a Derivative Database, You must also
offer to recipients of the Derivative Database or Produced Work a copy
in a machine readable form of:
a. The entire Derivative Database; or
b. A file containing all of the alterations made to the Database or
the method of making the alterations to the Database (such as an
algorithm), including any additional Contents, that make up all the
differences between the Database and the Derivative Database.
The Derivative Database (under a.) or alteration file (under b.) must be
available at no more than a reasonable production cost for physical
distributions and free of charge if distributed over the internet.
I worded my comment softly because I don't think I have a strong opinion about this stuff, but I'm not sure it is a work produced strictly from the OpenStreetMap database. They take GTFS databases from transit systems and use them to build routes out of OpenStreetMap data. They then render something based on this combined data. So the correct characterization may be that the final work is produced from a derivative database (rather than produced from OpenStreetMap). If that is correct, then the ODBL would apply to that database (as is explained in 3b,3c,3d...).
Where you see a derivative, I am seeing cartography applied to unchanged source data. I don't see any requirement in the ODbL to publish cartography styles under the same license.
