003118: One or more of the trip_id values in the GTFS trips.txt file are not used by any stops in the stop_times.txt file. No shapes will be created for these trip_ids, and the trips will be removed from the output trips.txt file.

Description

This indicates an error in your input GTFS dataset. The trips.txt file contains entries for trips that are never used. Because no stop sequence is associated with these trips, it is not possible to generate a shape representing the trip.

Solution

The tool automatically removes the extra trips when generating the output trips.txt file.