I have 2 questions about those data:
Is there any way to determine if a service_id such as "TA+b04vz" correspond to a "standard schedule" or to a "special schedule" (for example a schedule used during holiday only). I've found no information about that in the GTFS documentation.
I noticed that some agency (for example the agence_id = 801 (PostAuto Schweiz)) have a direction_id always equal to "1". For this agency there is no way to determine the direction of the trip. Is that a mistake or the agency simply don't provide those informations ?