Fix missing transfers

application/src/ext-test/java/org/opentripplanner/ext/flex/FlexIntegrationTest.java

@@ -20,8 +20,8 @@
 import org.opentripplanner.TestServerContext;
 import org.opentripplanner.framework.application.OTPFeature;
 import org.opentripplanner.graph_builder.issue.api.DataImportIssueStore;
-import org.opentripplanner.graph_builder.module.DirectTransferGenerator;
 import org.opentripplanner.graph_builder.module.TestStreetLinkerModule;
+import org.opentripplanner.graph_builder.module.transfer.DirectTransferGenerator;
 import org.opentripplanner.gtfs.graphbuilder.GtfsBundleTestFactory;
 import org.opentripplanner.gtfs.graphbuilder.GtfsModule;
 import org.opentripplanner.model.GenericLocation;

application/src/main/java/org/opentripplanner/framework/application/OTPFeature.java

@@ -22,17 +22,6 @@ public enum OTPFeature {
   ),
   APIServerInfo(true, false, "Enable the server info endpoint."),
   APIUpdaterStatus(true, false, "Enable endpoint for graph updaters status."),
-  IncludeEmptyRailStopsInTransfers(
-    false,
-    false,
-    """
-    Turning this on guarantees that Rail stops without scheduled departures still get included
-    when generating transfers using `ConsiderPatternsForDirectTransfers`. It is common for stops
-    to be assign at real-time for Rail. Turning this on will help to avoid dropping transfers which
-    are needed, when the stop is in use later. Turning this on, if
-    ConsiderPatternsForDirectTransfers is off has no effect.
-    """
-  ),
   ConsiderPatternsForDirectTransfers(
     true,
     false,
@@ -54,6 +43,20 @@ public enum OTPFeature {
   ),
   FloatingBike(true, false, "Enable floating bike routing."),
   GtfsGraphQlApi(true, false, "Enable the [GTFS GraphQL API](apis/GTFS-GraphQL-API.md)."),
+  IncludeStopsUsedRealTimeInTransfers(
+    false,
+    false,
+    """
+    When generating transfers, stops without any patterns are excluded to improve performance if
+    `ConsiderPatternsForDirectTransfers` is enabled. However, some stops are only used by trips
+    changed or added by real-time updates. Since transfer generation happens before real-time
+    updates are applied, OTP cannot know which stops will be needed. Instead, OTP will attempt to
+    identify stops likely to be used by real-time updates at import time. Common cases include rail
+    stops (which often have late platform assignments) and stops reserved for replacement services.
+    This is detected examining the stop `subMode`(NeTEx) and `vehicleType`(GTFS). This feature has
+    no effect if `ConsiderPatternsForDirectTransfers` is disabled.
+    """
+  ),
   /**
    * If this feature flag is switched on, then the minimum transfer time is not the minimum transfer
    * time, but the definitive transfer time. Use this to override what we think the transfer will

application/src/main/java/org/opentripplanner/graph_builder/module/configure/GraphBuilderFactory.java

@@ -21,7 +21,6 @@
 import org.opentripplanner.graph_builder.GraphBuilderDataSources;
 import org.opentripplanner.graph_builder.configure.GraphBuilderModule;
 import org.opentripplanner.graph_builder.issue.report.DataImportIssueReporter;
-import org.opentripplanner.graph_builder.module.DirectTransferGenerator;
 import org.opentripplanner.graph_builder.module.GraphCoherencyCheckerModule;
 import org.opentripplanner.graph_builder.module.OsmBoardingLocationsModule;
 import org.opentripplanner.graph_builder.module.RouteToCentroidStationIdsValidator;
@@ -33,6 +32,7 @@
 import org.opentripplanner.graph_builder.module.islandpruning.PruneIslands;
 import org.opentripplanner.graph_builder.module.ned.ElevationModule;
 import org.opentripplanner.graph_builder.module.osm.OsmModule;
+import org.opentripplanner.graph_builder.module.transfer.DirectTransferGenerator;
 import org.opentripplanner.gtfs.graphbuilder.GtfsModule;
 import org.opentripplanner.netex.NetexModule;
 import org.opentripplanner.routing.fares.FareServiceFactory;

application/src/main/java/org/opentripplanner/graph_builder/module/configure/GraphBuilderModules.java

@@ -21,7 +21,6 @@
 import org.opentripplanner.graph_builder.issue.report.DataImportIssueReporter;
 import org.opentripplanner.graph_builder.issue.service.DefaultDataImportIssueStore;
 import org.opentripplanner.graph_builder.model.ConfiguredDataSource;
-import org.opentripplanner.graph_builder.module.DirectTransferGenerator;
 import org.opentripplanner.graph_builder.module.RouteToCentroidStationIdsValidator;
 import org.opentripplanner.graph_builder.module.StreetLinkerModule;
 import org.opentripplanner.graph_builder.module.TurnRestrictionModule;
@@ -33,6 +32,7 @@
 import org.opentripplanner.graph_builder.module.ned.parameter.DemExtractParameters;
 import org.opentripplanner.graph_builder.module.osm.OsmModule;
 import org.opentripplanner.graph_builder.module.osm.parameters.OsmExtractParameters;
+import org.opentripplanner.graph_builder.module.transfer.DirectTransferGenerator;
 import org.opentripplanner.graph_builder.services.ned.ElevationGridCoverageFactory;
 import org.opentripplanner.gtfs.graphbuilder.GtfsBundle;
 import org.opentripplanner.gtfs.graphbuilder.GtfsModule;

application/src/main/java/org/opentripplanner/graph_builder/module/DirectTransferGenerator.java → application/src/main/java/org/opentripplanner/graph_builder/module/transfer/DirectTransferGenerator.java

@@ -1,4 +1,4 @@
-package org.opentripplanner.graph_builder.module;
+package org.opentripplanner.graph_builder.module.transfer;
 
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimaps;
@@ -15,12 +15,13 @@
 import org.opentripplanner.graph_builder.issue.api.DataImportIssueStore;
 import org.opentripplanner.graph_builder.issues.StopNotLinkedForTransfers;
 import org.opentripplanner.graph_builder.model.GraphBuilderModule;
+import org.opentripplanner.graph_builder.module.TransferParameters;
 import org.opentripplanner.graph_builder.module.nearbystops.NearbyStopFinder;
-import org.opentripplanner.graph_builder.module.nearbystops.PatternConsideringNearbyStopFinder;
 import org.opentripplanner.graph_builder.module.nearbystops.SiteRepositoryResolver;
 import org.opentripplanner.graph_builder.module.nearbystops.StopResolver;
 import org.opentripplanner.graph_builder.module.nearbystops.StraightLineNearbyStopFinder;
 import org.opentripplanner.graph_builder.module.nearbystops.StreetNearbyStopFinder;
+import org.opentripplanner.graph_builder.module.transfer.filter.PatternConsideringNearbyStopFinder;
 import org.opentripplanner.model.PathTransfer;
 import org.opentripplanner.routing.api.request.RouteRequest;
 import org.opentripplanner.routing.api.request.StreetMode;
@@ -388,9 +389,6 @@ private void calculateDefaultTransfers(
         if (sd.stop == stop) {
           continue;
         }
-        if (sd.stop.transfersNotAllowed()) {
-          continue;
-        }
         createPathTransfer(stop, sd.stop, sd, distinctTransfers, mode);
       }
     }

application/src/main/java/org/opentripplanner/graph_builder/module/transfer/filter/CompositeNearbyStopFilter.java

@@ -0,0 +1,69 @@
+package org.opentripplanner.graph_builder.module.transfer.filter;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import org.opentripplanner.routing.graphfinder.NearbyStop;
+import org.opentripplanner.transit.model.framework.FeedScopedId;
+
+/**
+ * Combines multiple {@link NearbyStopFilter}s into a single filter.
+ * <p>
+ * This filter applies all configured filters and returns the union of their results. A stop is
+ * included if ANY of the component filters include it (OR logic for from-stops, union for
+ * to-stops).
+ */
+class CompositeNearbyStopFilter implements NearbyStopFilter {
+
+  private final List<NearbyStopFilter> filters;
+
+  private CompositeNearbyStopFilter(List<NearbyStopFilter> filters) {
+    this.filters = filters;
+  }
+
+  static Builder of() {
+    return new Builder();
+  }
+
+  @Override
+  public boolean includeFromStop(FeedScopedId id, boolean reverseDirection) {
+    for (NearbyStopFilter filter : filters) {
+      if (filter.includeFromStop(id, reverseDirection)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  @Override
+  public Collection<NearbyStop> filterToStops(
+    Collection<NearbyStop> nearbyStops,
+    boolean reverseDirection
+  ) {
+    Set<NearbyStop> result = new HashSet<>();
+
+    for (NearbyStopFilter it : filters) {
+      result.addAll(it.filterToStops(nearbyStops, reverseDirection));
+    }
+    return result;
+  }
+
+  static class Builder {
+
+    List<NearbyStopFilter> filters = new ArrayList<>();
+
+    Builder add(NearbyStopFilter filter) {
+      filters.add(filter);
+      return this;
+    }
+
+    NearbyStopFilter build() {
+      if (filters.size() == 1) {
+        return filters.getFirst();
+      }
+      return new CompositeNearbyStopFilter(filters);
+    }
+  }
+}

application/src/main/java/org/opentripplanner/graph_builder/module/transfer/filter/FlexTripNearbyStopFilter.java

@@ -0,0 +1,48 @@
+package org.opentripplanner.graph_builder.module.transfer.filter;
+
+import java.util.Collection;
+import org.opentripplanner.ext.flex.trip.FlexTrip;
+import org.opentripplanner.routing.graphfinder.NearbyStop;
+import org.opentripplanner.transit.model.framework.FeedScopedId;
+import org.opentripplanner.transit.service.TransitService;
+
+/**
+ * Filters nearby stops based on flex trip availability.
+ * <p>
+ * This filter ensures that transfers are generated for stops used by flex trips. For each flex
+ * trip, it keeps only the closest stop where the flex trip can board or alight (depending on
+ * direction).
+ */
+class FlexTripNearbyStopFilter implements NearbyStopFilter {
+
+  private final TransitService transitService;
+
+  FlexTripNearbyStopFilter(TransitService transitService) {
+    this.transitService = transitService;
+  }
+
+  @Override
+  public boolean includeFromStop(FeedScopedId id, boolean reverseDirection) {
+    var stop = transitService.getStopLocation(id);
+    return !transitService.getFlexIndex().getFlexTripsByStop(stop).isEmpty();
+  }
+
+  @Override
+  public Collection<NearbyStop> filterToStops(
+    Collection<NearbyStop> nearbyStops,
+    boolean reverseDirection
+  ) {
+    MinMap<FlexTrip<?, ?>, NearbyStop> closestStopForFlexTrip = new MinMap<>();
+    for (var it : nearbyStops) {
+      var stop = it.stop;
+      var flexTrips = transitService.getFlexIndex().getFlexTripsByStop(stop);
+
+      for (FlexTrip<?, ?> trip : flexTrips) {
+        if (reverseDirection ? trip.isAlightingPossible(stop) : trip.isBoardingPossible(stop)) {
+          closestStopForFlexTrip.putMin(trip, it);
+        }
+      }
+    }
+    return closestStopForFlexTrip.values();
+  }
+}