Expected behavior

OpenTripPlanner loads my GTFS with a reasonable amount of memory

Observed behavior

OpenTripPlanner runs out of heap space when loading my GTFS file, even if I use 16 GB

Version of OTP used (exact commit hash or JAR name)

2.9.0-SNAPSHOT

Data sets in use (links to GTFS and OSM PBF files)

A GTFS file which can be downloaded at https://storage.miklcct.com/national_rail_gtfs.zip

Command line used to start OTP

Router config and graph build config JSON

Transfer constraints are on. If it is switched off, it starts up normally with a normal amount of memory usage.

The map size isn't relevant. Even if I only use a small geographical area it still runs out of the memory.

Steps to reproduce the problem

Build and serve the graph with the above GTFS file and with transfer constraints on.