When a GTFS feed contains critical errors, we short-circuit in the loader and don't bother looking for patterns, since the feed shouldn't be usable for routing anyhow. However, loadFromGtfs assumes that patterns are created.
The code for creating TripPatterns from GTFS patterns starts out like this.
String patternId = gtfs.patternForTrip.get(tripId);
TripPattern tripPattern = tripPatternForPatternId.get(patternId);
if (tripPattern == null) {
tripPattern = new TripPattern(String.format("%s:%s", gtfs.feedId, route.route_id), stopTimes, indexForUnscopedStopId);If there are no patterns in the GTFS feed at all due to critical errors, gtfs.patternForTrip.get(tripId) will return null for all trips. null is allowed as a key in a Java HashMap, so the next few lines of code will create a trip pattern with the ID null and then add every last trip in the feed to that pattern. The first sign of any trouble won't show up until you do routing, when the overtakes function will report an array-out-of-bounds error because there are trips in the pattern that do not have the same number of stops.
I suspect in the Conveyal UI these critical feed errors are reported, but in other applications if using e.g. TransportNetwork.fromFiles the only sign that anything is wrong is that warning (not even an error) that the feed is unusable, and the network will build successfully.
First discovered by @c-voulgaris - @c-voulgaris is it ok to link to the GTFS you have that causes the issue here?
When a GTFS feed contains critical errors, we short-circuit in the loader and don't bother looking for patterns, since the feed shouldn't be usable for routing anyhow. However,
loadFromGtfsassumes that patterns are created.The code for creating TripPatterns from GTFS patterns starts out like this.
If there are no patterns in the GTFS feed at all due to critical errors,
gtfs.patternForTrip.get(tripId)will returnnullfor all trips.nullis allowed as a key in a Java HashMap, so the next few lines of code will create a trip pattern with the IDnulland then add every last trip in the feed to that pattern. The first sign of any trouble won't show up until you do routing, when theovertakesfunction will report an array-out-of-bounds error because there are trips in the pattern that do not have the same number of stops.I suspect in the Conveyal UI these critical feed errors are reported, but in other applications if using e.g.
TransportNetwork.fromFilesthe only sign that anything is wrong is that warning (not even an error) that the feed is unusable, and the network will build successfully.First discovered by @c-voulgaris - @c-voulgaris is it ok to link to the GTFS you have that causes the issue here?