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Snap transit stops per access/egress mode (DMP-16462) #3

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Snap transit stops per access/egress mode (DMP-16462) #3

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19 changes: 15 additions & 4 deletions reader-gtfs/src/main/java/com/graphhopper/gtfs/GraphExplorer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@

package com.graphhopper.gtfs;

import com.carrotsearch.hppc.IntIntHashMap;
import com.conveyal.gtfs.GTFSFeed;
import com.google.common.collect.Iterators;
import com.google.transit.realtime.GtfsRealtime;
Expand Down Expand Up @@ -50,11 +51,21 @@ public final class GraphExplorer {
private final int blockedRouteTypes;
private final PtGraph ptGraph;
private final Graph graph;

public GraphExplorer(Graph graph, PtGraph ptGraph, Weighting accessEgressWeighting, GtfsStorage gtfsStorage, RealtimeFeed realtimeFeed, boolean reverse, boolean streetOnly, boolean ptOnly, double walkSpeedKmh, boolean ignoreValidities, int blockedRouteTypes) {
/**
* Street attachments for the mode this explorer routes, resolved once from {@code stopSnapProfile}.
* A search crossing between the street and transit graphs must use the attachments belonging to its
* own access/egress mode: walking onto the platform footway is not the same place as being dropped
* at the kerb.
*/
private final IntIntHashMap ptToStreet;
private final IntIntHashMap streetToPt;

public GraphExplorer(Graph graph, PtGraph ptGraph, Weighting accessEgressWeighting, GtfsStorage gtfsStorage, RealtimeFeed realtimeFeed, boolean reverse, boolean streetOnly, boolean ptOnly, double walkSpeedKmh, boolean ignoreValidities, int blockedRouteTypes, String stopSnapProfile) {
this.graph = graph;
this.ptGraph = ptGraph;
this.accessEgressWeighting = accessEgressWeighting;
this.ptToStreet = gtfsStorage.getPtToStreet(stopSnapProfile);
this.streetToPt = gtfsStorage.getStreetToPt(stopSnapProfile);
this.ignoreValidities = ignoreValidities;
this.blockedRouteTypes = blockedRouteTypes;
this.edgeExplorer = graph.createEdgeExplorer();
Expand Down Expand Up @@ -294,9 +305,9 @@ public int getId() {

public Label.NodeId getAdjNode() {
if (ptEdge != null) {
return new Label.NodeId(gtfsStorage.getPtToStreet().getOrDefault(ptEdge.getAdjNode(), -1), ptEdge.getAdjNode());
return new Label.NodeId(ptToStreet.getOrDefault(ptEdge.getAdjNode(), -1), ptEdge.getAdjNode());
} else {
return new Label.NodeId(adjNode, gtfsStorage.getStreetToPt().getOrDefault(adjNode, -1));
return new Label.NodeId(adjNode, streetToPt.getOrDefault(adjNode, -1));
}
}

Expand Down
63 changes: 51 additions & 12 deletions reader-gtfs/src/main/java/com/graphhopper/gtfs/GraphHopperGtfs.java
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Expand Up @@ -25,10 +25,12 @@
import com.google.common.collect.Multimaps;
import com.graphhopper.GraphHopper;
import com.graphhopper.GraphHopperConfig;
import com.graphhopper.config.Profile;
import com.graphhopper.gtfs.analysis.Trips;
import com.graphhopper.routing.ev.Subnetwork;
import com.graphhopper.routing.querygraph.QueryGraph;
import com.graphhopper.routing.util.DefaultSnapFilter;
import com.graphhopper.routing.util.EdgeFilter;
import com.graphhopper.routing.weighting.Weighting;
import com.graphhopper.storage.index.InMemConstructionIndex;
import com.graphhopper.storage.index.IndexStructureInfo;
Expand Down Expand Up @@ -90,8 +92,12 @@ protected void importPublicTransit() {
}
}
} else {
// Resolved before any store is created: a bad profile name is a config error, and reporting it
// from inside the block below would blame the GTFS feed for it.
List<String> stopSnapProfiles = readStopSnapProfiles();
ensureWriteAccess();
getGtfsStorage().create();
getGtfsStorage().setStopSnapProfiles(stopSnapProfiles);
ptGraph.create(100);
InMemConstructionIndex indexBuilder = new InMemConstructionIndex(IndexStructureInfo.create(
new BBox(-180.0, 180.0, -90.0, 90.0), 300));
Expand All @@ -102,22 +108,22 @@ protected void importPublicTransit() {
getGtfsStorage().loadGtfsFromZipFileOrDirectory("gtfs_" + idx++, new File(gtfsFile));
}
getGtfsStorage().postInit();
LOGGER.info("Snapping stops to the street network once per profile: {} (primary: {})",
stopSnapProfiles, stopSnapProfiles.get(0));
Map<String, Transfers> allTransfers = new HashMap<>();
HashMap<String, GtfsReader> allReaders = new HashMap<>();
getGtfsStorage().getGtfsFeeds().forEach((id, gtfsFeed) -> {
Transfers transfers = new Transfers(gtfsFeed);
allTransfers.put(id, transfers);
GtfsReader gtfsReader = new GtfsReader(id, ptGraph, ptGraph, getGtfsStorage(), getLocationIndex(), transfers, indexBuilder);
// Stops must be connected to the networks of all the modes
List<DefaultSnapFilter> snapFilters = getProfiles().stream().map(p ->
new DefaultSnapFilter(createWeighting(p, new PMap()), getEncodingManager().getBooleanEncodedValue(Subnetwork.key(p.getName())))).collect(Collectors.toList());
gtfsReader.connectStopsToStreetNetwork(e -> {
for (DefaultSnapFilter snapFilter : snapFilters) {
if (!snapFilter.accept(e))
return false;
}
return true;
});
// One attachment per mode, rather than one attachment that every mode must accept.
Map<String, EdgeFilter> snapFilters = new LinkedHashMap<>();
for (String profileName : stopSnapProfiles) {
Profile profile = getProfile(profileName);
snapFilters.put(profileName, new DefaultSnapFilter(createWeighting(profile, new PMap()),
getEncodingManager().getBooleanEncodedValue(Subnetwork.key(profileName))));
}
gtfsReader.connectStopsToStreetNetwork(snapFilters, stopSnapProfiles.get(0));
LOGGER.info("Building transit graph for feed {}", gtfsFeed.feedId);
gtfsReader.buildPtNetwork();
allReaders.put(id, gtfsReader);
Expand Down Expand Up @@ -145,13 +151,46 @@ protected void importPublicTransit() {
gtfsStorage.setStopIndex(stopIndex);
}

/**
* Profiles to snap stops for, from {@code gtfs.stop_snap_profiles} (comma-separated, first entry is
* primary). Defaults to {@link GtfsStorage#DEFAULT_STOP_SNAP_PROFILE} alone: riders reach transit on
* foot, and requiring an attachment that cars and trucks can also use strands stops whose only
* nearby street is a footway (DMP-16462). List additional profiles to support non-walk access legs.
*/
private List<String> readStopSnapProfiles() {
String configured = ghConfig.getString("gtfs.stop_snap_profiles", GtfsStorage.DEFAULT_STOP_SNAP_PROFILE);
List<String> profiles = new ArrayList<>();
for (String name : configured.split(",")) {
String profileName = name.trim();
if (profileName.isEmpty()) {
continue;
}
// getProfile returns null for an unknown name, which would otherwise NPE inside createWeighting.
if (getProfile(profileName) == null) {
throw new IllegalArgumentException("gtfs.stop_snap_profiles names profile '" + profileName
+ "', which is not configured. Available profiles: "
+ getProfiles().stream().map(Profile::getName).collect(Collectors.toList()));
}
if (!profiles.contains(profileName)) {
profiles.add(profileName);
}
}
if (profiles.isEmpty()) {
throw new IllegalArgumentException("gtfs.stop_snap_profiles is set but names no usable profile: '"
+ configured + "'");
}
return profiles;
}

private void interpolateTransfers(HashMap<String, GtfsReader> readers, Map<String, Transfers> allTransfers) {
LOGGER.info("Looking for transfers");
final int maxTransferWalkTimeSeconds = ghConfig.getInt("gtfs.max_transfer_interpolation_walk_time_seconds", 120);
QueryGraph queryGraph = QueryGraph.create(getBaseGraph(), Collections.emptyList());
Weighting transferWeighting = createWeighting(getProfile("foot"), new PMap());
final GraphExplorer graphExplorer = new GraphExplorer(queryGraph, ptGraph, transferWeighting, getGtfsStorage(), RealtimeFeed.empty(), true, true, false, 5.0, false, 0);
getGtfsStorage().getStationNodes().values().stream().distinct().map(n -> new Label.NodeId(gtfsStorage.getPtToStreet().getOrDefault(n, -1), n)).forEach(stationNode -> {
// Transfer walking always uses the primary profile's attachments, matching the foot weighting above.
String transferSnapProfile = getGtfsStorage().getPrimaryStopSnapProfile();
final GraphExplorer graphExplorer = new GraphExplorer(queryGraph, ptGraph, transferWeighting, getGtfsStorage(), RealtimeFeed.empty(), true, true, false, 5.0, false, 0, transferSnapProfile);
getGtfsStorage().getStationNodes().values().stream().distinct().map(n -> new Label.NodeId(gtfsStorage.getPtToStreet(transferSnapProfile).getOrDefault(n, -1), n)).forEach(stationNode -> {
MultiCriteriaLabelSetting router = new MultiCriteriaLabelSetting(graphExplorer, true, false, false, 0, new ArrayList<>());
router.setLimitStreetTime(Duration.ofSeconds(maxTransferWalkTimeSeconds).toMillis());
for (Label label : router.calcLabels(stationNode, Instant.ofEpochMilli(0))) {
Expand Down
76 changes: 65 additions & 11 deletions reader-gtfs/src/main/java/com/graphhopper/gtfs/GtfsReader.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@

package com.graphhopper.gtfs;

import com.carrotsearch.hppc.IntIntHashMap;
import com.conveyal.gtfs.GTFSFeed;
import com.conveyal.gtfs.model.*;
import com.google.common.collect.HashMultimap;
Expand Down Expand Up @@ -93,26 +94,79 @@ static class TripWithStopTimes {
this.indexBuilder = indexBuilder;
}

void connectStopsToStreetNetwork(EdgeFilter filter) {
/**
* Attaches every stop to the street network once per mode.
*
* Each stop gets a single stop node in the transit graph, but one street attachment per profile in
* {@code snapFiltersByProfile}, so a rail platform can be reached over the adjacent footway on foot
* and over the nearest kerb by car. Previously a stop had one attachment, found with a filter every
* profile had to accept at once; nothing near an airport platform satisfies that, which pushed the
* attachment hundreds of metres away or dropped it entirely (DMP-16462).
*
* {@code primaryProfile} decides stop node identity, including which co-located stops collapse onto
* a shared stop node. Identity must come from exactly one profile, otherwise the set of stop nodes
* -- and hence the transit graph -- would depend on which modes happen to be configured.
*
* @param snapFiltersByProfile snap filter per profile
* @param primaryProfile key in {@code snapFiltersByProfile} that governs stop node identity
*/
void connectStopsToStreetNetwork(Map<String, EdgeFilter> snapFiltersByProfile, String primaryProfile) {
if (!snapFiltersByProfile.containsKey(primaryProfile)) {
throw new IllegalArgumentException("Primary stop snap profile '" + primaryProfile
+ "' is not among the snapped profiles " + snapFiltersByProfile.keySet());
}
int unattachedStops = 0;
int sharedAttachments = 0;
for (Stop stop : feed.stops.values()) {
if (stop.location_type == 0) { // Only stops. Not interested in parent stations for now.
Snap locationSnap = streetNetworkIndex.findClosest(stop.stop_lat, stop.stop_lon, filter);
int stopNode;
if (locationSnap.isValid()) {
stopNode = gtfsStorage.getStreetToPt().getOrDefault(locationSnap.getClosestNode(), -1);
if (stopNode == -1) {
stopNode = out.createNode();
indexBuilder.addToAllTilesOnLine(stopNode, stop.stop_lat, stop.stop_lon, stop.stop_lat, stop.stop_lon);
gtfsStorage.getPtToStreet().put(stopNode, locationSnap.getClosestNode());
gtfsStorage.getStreetToPt().put(locationSnap.getClosestNode(), stopNode);
Map<String, Integer> streetNodeByProfile = new LinkedHashMap<>();
for (Map.Entry<String, EdgeFilter> e : snapFiltersByProfile.entrySet()) {
Snap snap = streetNetworkIndex.findClosest(stop.stop_lat, stop.stop_lon, e.getValue());
if (snap.isValid()) {
streetNodeByProfile.put(e.getKey(), snap.getClosestNode());
}
} else {
}

Integer primaryStreetNode = streetNodeByProfile.get(primaryProfile);
int stopNode = -1;
if (primaryStreetNode != null) {
// Reuse the stop node of an earlier stop sharing this street node, so co-located stops
// (including across feeds) stay a single boarding point as they did before.
stopNode = gtfsStorage.getStreetToPt(primaryProfile).getOrDefault(primaryStreetNode, -1);
}
if (stopNode == -1) {
stopNode = out.createNode();
indexBuilder.addToAllTilesOnLine(stopNode, stop.stop_lat, stop.stop_lon, stop.stop_lat, stop.stop_lon);
}
if (streetNodeByProfile.isEmpty()) {
unattachedStops++;
}

for (Map.Entry<String, Integer> e : streetNodeByProfile.entrySet()) {
IntIntHashMap ptToStreet = gtfsStorage.getPtToStreet(e.getKey());
IntIntHashMap streetToPt = gtfsStorage.getStreetToPt(e.getKey());
if (!ptToStreet.containsKey(stopNode)) {
ptToStreet.put(stopNode, e.getValue());
}
// This direction is one-to-one: if another stop already claimed this street node for
// this profile, it stays reachable from the street side and this one does not.
if (streetToPt.containsKey(e.getValue())) {
sharedAttachments++;
} else {
streetToPt.put(e.getValue(), stopNode);
}
}
gtfsStorage.getStationNodes().put(new GtfsStorage.FeedIdWithStopId(id, stop.stop_id), stopNode);
}
}
if (unattachedStops > 0) {
LOGGER.warn("Feed {}: {} stops could not be attached to the street network for any of the profiles"
+ " {}, so they are reachable only by stop id.", id, unattachedStops, snapFiltersByProfile.keySet());
}
if (sharedAttachments > 0) {

@BNewborn BNewborn Aug 19, 2026 •
edited
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is this true? Does a stop/profile sharing a node mean one of the stop/profile points becomes unroutable? Claude suggests this is only for car / access, but we dont use that ATM. Maybe its worth just removing this warning if I'm understanding this all correctly?

LOGGER.info("Feed {}: {} stop/profile attachments landed on a street node already claimed by another"
+ " stop; those are not discoverable from the street side for that profile.", id, sharedAttachments);
}
}

void buildPtNetwork() {
Expand Down
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