ConflictUtil.java
package org.opentrafficsim.road.gtu.tactical.util;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.UUID;
import java.util.function.Function;
import java.util.function.Supplier;
import org.djunits.unit.AccelerationUnit;
import org.djunits.unit.DurationUnit;
import org.djunits.unit.LengthUnit;
import org.djunits.value.vdouble.scalar.Acceleration;
import org.djunits.value.vdouble.scalar.Duration;
import org.djunits.value.vdouble.scalar.Length;
import org.djunits.value.vdouble.scalar.Speed;
import org.djunits.value.vdouble.scalar.Time;
import org.djutils.exceptions.Throw;
import org.opentrafficsim.base.OtsRuntimeException;
import org.opentrafficsim.base.logger.Logger;
import org.opentrafficsim.base.parameters.ParameterException;
import org.opentrafficsim.base.parameters.ParameterTypeAcceleration;
import org.opentrafficsim.base.parameters.ParameterTypeBoolean;
import org.opentrafficsim.base.parameters.ParameterTypeDouble;
import org.opentrafficsim.base.parameters.ParameterTypeDuration;
import org.opentrafficsim.base.parameters.ParameterTypeLength;
import org.opentrafficsim.base.parameters.ParameterTypes;
import org.opentrafficsim.base.parameters.Parameters;
import org.opentrafficsim.base.parameters.constraint.ConstraintInterface;
import org.opentrafficsim.core.definitions.DefaultsNl;
import org.opentrafficsim.core.gtu.GtuException;
import org.opentrafficsim.core.gtu.TurnIndicatorStatus;
import org.opentrafficsim.core.network.Node;
import org.opentrafficsim.core.network.route.Route;
import org.opentrafficsim.road.gtu.LaneBasedGtu;
import org.opentrafficsim.road.gtu.perception.PerceptionCollectable;
import org.opentrafficsim.road.gtu.perception.PerceptionCollectable.PerceptionAccumulator;
import org.opentrafficsim.road.gtu.perception.PerceptionCollectable.PerceptionCollector;
import org.opentrafficsim.road.gtu.perception.PerceptionIterable;
import org.opentrafficsim.road.gtu.perception.RelativeLane;
import org.opentrafficsim.road.gtu.perception.categories.IntersectionPerception;
import org.opentrafficsim.road.gtu.perception.categories.neighbors.NeighborsPerception;
import org.opentrafficsim.road.gtu.perception.object.PerceivedConflict;
import org.opentrafficsim.road.gtu.perception.object.PerceivedGtu;
import org.opentrafficsim.road.gtu.perception.object.PerceivedGtu.Maneuver;
import org.opentrafficsim.road.gtu.perception.object.PerceivedGtu.Signals;
import org.opentrafficsim.road.gtu.perception.object.PerceivedGtuBase;
import org.opentrafficsim.road.gtu.perception.object.PerceivedGtuSimple;
import org.opentrafficsim.road.gtu.perception.object.PerceivedObject;
import org.opentrafficsim.road.gtu.perception.object.PerceivedObject.Kinematics;
import org.opentrafficsim.road.gtu.tactical.Blockable;
import org.opentrafficsim.road.gtu.tactical.TacticalContext;
import org.opentrafficsim.road.gtu.tactical.TacticalContextEgo;
import org.opentrafficsim.road.gtu.tactical.lmrs.AccelerationIncentive;
import org.opentrafficsim.road.gtu.tactical.pt.BusSchedule;
import org.opentrafficsim.road.network.CrossSectionLink;
import org.opentrafficsim.road.network.conflict.BusStopConflictRule;
import org.opentrafficsim.road.network.conflict.ConflictRule;
/**
* This class implements default behavior for intersection conflicts for use in tactical planners.
* <p>
* Copyright (c) 2013-2026 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
* BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
* </p>
* @author Alexander Verbraeck
* @author Peter Knoppers
* @author Wouter Schakel
* @see <a href="https://rstrail.nl/wp-content/uploads/2015/02/schakel_2012.pdf">Schakel, W.J., B. van Arem (2012) “An Urban
* Traffic Extension of a Freeway Driver Model for use in the OpenTraffic® Open Source Traffic Simulation”, presented at
* TRAIL Congress 2012.</a>
*/
// TODO do not ignore vehicles upstream of conflict if they have green
// TODO conflict over multiple lanes (longitudinal in own direction)
// TODO a) yielding while having priority happens only when leaders is standing still on conflict (then its useless...)
// b) two vehicles can remain upstream of merge if vehicle stands on merge but leaves some space to move
// probably 1 is yielding, and 1 is courtesy yielding as the other stands still
// c) they might start moving together and collide further down (no response to negative headway on merge)
public final class ConflictUtil
{
/** Minimum time gap between events. */
public static final ParameterTypeDuration MIN_GAP = new ParameterTypeDuration("minGap", "Minimum gap for conflicts",
new Duration(0.000001, DurationUnit.SECOND), ConstraintInterface.POSITIVE);
/** Comfortable deceleration. */
public static final ParameterTypeAcceleration B = ParameterTypes.B;
/** Critical deceleration. */
public static final ParameterTypeAcceleration BCRIT = ParameterTypes.BCRIT;
/** Stopping distance. */
public static final ParameterTypeLength S0 = ParameterTypes.S0;
/** Stopping distance at conflicts. */
public static final ParameterTypeLength S0_CONF = new ParameterTypeLength("s0conf", "Stopping distance at conflicts",
new Length(1.5, LengthUnit.METER), ConstraintInterface.POSITIVE);
/** Multiplication factor on time for conservative assessment. */
public static final ParameterTypeDouble TIME_FACTOR =
new ParameterTypeDouble("timeFactor", "Safety factor on estimated time", 1.25, ConstraintInterface.ATLEASTONE);
/** Area before stop line where one is considered arrived at the intersection. */
public static final ParameterTypeLength STOP_AREA =
new ParameterTypeLength("stopArea", "Area before stop line where one is considered arrived at the intersection",
new Length(4, LengthUnit.METER), ConstraintInterface.POSITIVE);
/** Parameter of how much time before departure a bus indicates its departure to get priority. */
public static final ParameterTypeDuration TI = new ParameterTypeDuration("ti", "Indicator time before bus departure",
Duration.ofSI(3.0), ConstraintInterface.POSITIVE);
/** Parameter to deviate laterally at splits. */
public static final ParameterTypeBoolean DEV_SPLIT =
new ParameterTypeBoolean("dev_split", "Deviate laterally at splits.", false);
/** Time step for free acceleration anticipation. */
private static final Duration TIME_STEP = Duration.ofSI(0.5);
/** Cross standing vehicles on crossings. We allow this to prevent dead-locks. A better model should render this useless. */
private static final boolean CROSSSTANDING = true;
/** Registry of crossing events as one GTU, is crossing some stand-still other GTU. */
private static final ThreadLocal<Map<String, Set<String>>> CROSSEVENTS =
ThreadLocal.withInitial(() -> new LinkedHashMap<>());
/**
* Do not instantiate.
*/
private ConflictUtil()
{
//
}
/**
* Approach conflicts by applying appropriate acceleration (or deceleration). The model may yield for a vehicle even while
* having priority. Such a plan is remembered in {@link ConflictPlans}. By forwarding the same {@code ConflictPlans} for a
* GTU consistency of such plans is provided. If any conflict is not accepted to pass, stopping before a more upstream
* conflict is applied if there is not sufficient stopping length in between conflicts.
* @param context tactical information such as parameters and car-following model
* @param conflictPlans set of plans for conflict
* @param lane lane
* @param mergeDistance distance along which no lane changes can be performed towards the lane
* @param onRoute filter conflicts to only include conflict on the route
* @return acceleration appropriate for approaching the conflicts
* @throws GtuException in case of an unsupported conflict rule
* @throws ParameterException if a parameter is not defined or out of bounds
*/
@SuppressWarnings("checkstyle:methodlength")
// @docs/06-behavior/tactical-planner/#modular-utilities (..., final ConflictPlans conflictPlans, ...)
public static Acceleration approachConflicts(final TacticalContextEgo context, final ConflictPlans conflictPlans,
final RelativeLane lane, final Length mergeDistance, final boolean onRoute) throws GtuException, ParameterException
{
Iterable<PerceivedConflict> conflicts =
context.getPerception().getPerceptionCategory(IntersectionPerception.class).getConflicts(lane);
conflicts = AccelerationIncentive.onRoad(conflicts, lane, mergeDistance);
if (onRoute)
{
conflicts = AccelerationIncentive.onRoute(conflicts, context.getRoute().orElse(null));
}
PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders =
context.getPerception().getPerceptionCategory(NeighborsPerception.class).getLeaders(lane);
boolean blocking = false;
// Ignore conflicts if we are beyond a stopping distance
Acceleration a = Acceleration.POS_MAXVALUE;
Length stoppingDistance = Length.ofSI(context.getParameters().getParameter(S0).si + context.getLength().si
+ .5 * context.getSpeed().si * context.getSpeed().si / context.getParameters().getParameter(B).si);
Iterator<PerceivedConflict> it = conflicts.iterator();
if (it.hasNext() && it.next().getDistance().gt(stoppingDistance))
{
conflictPlans.setBlocking(blocking);
return a;
}
// Maintain lists of info per conflict required for consistency in a plan to cross (part of) an intersection
List<Length> prevStarts = new ArrayList<>();
List<Length> prevEnds = new ArrayList<>();
List<Class<? extends ConflictRule>> conflictRuleTypes = new ArrayList<>();
// Distance until first stationary leader, minus spaces required for stationary intermediate vehicle and minus ego
Space space = leaders.collect(new AvailableSpace());
Length availableSpace = space.availableSpace().minus(passableDistance(context.getLength(), context.getParameters()));
/*
* We subtract any space that is likely not to be used by a queue ahead. This is the length of all crossing and merge
* conflicts between the first leader, and the first stand-still leader. If the rear of the first stand-still leader is
* on a conflict, only the length of that conflict up to the rear is subtracted. If the first non-split conflict is a
* merge, it's length is never subtracted. That would prevent taking priority when its given for zip-merging.
*/
Length firstLeader = leaders.isEmpty() ? Length.POS_MAXVALUE : leaders.first().getDistance();
boolean first = true;
for (PerceivedConflict conflict : conflicts)
{
if (conflict.getDistance().gt(space.firstStationary()))
{
break;
}
if (!conflict.isSplit())
{
Length conflictEnd = conflict.getDistance().plus(conflict.getLength());
if ((!first || conflict.isCrossing()) && conflictEnd.gt(firstLeader))
{
Length effectiveEnd = Length.min(space.firstStationary(), conflictEnd);
Length effectiveLength = effectiveEnd.minus(conflict.getDistance());
availableSpace = availableSpace.minus(effectiveLength);
}
first = false;
}
}
for (PerceivedConflict conflict : conflicts)
{
// adjust acceleration for situations where stopping might not be required
if (conflict.isCrossing())
{
// avoid collision if crossing is occupied
a = Acceleration.min(a, avoidCrossingCollision(context, conflict));
}
else
{
if (conflict.isMerge() && !lane.isCurrent() && conflict.getConflictPriority().isPriority())
{
// this is probably evaluation for a lane-change as this it not on the current lane
a = Acceleration.min(a, avoidMergeCollision(context, conflict));
}
// lateral deviation intent on split
lateralDeviationAtSplit(context, conflict, leaders, availableSpace);
// follow leading GTUs on merge or split
a = Acceleration.min(a, followConflictingLeaderOnMergeOrSplit(context, conflict));
}
// indicator if bus
if (lane.isCurrent())
{
// TODO priority rules of busses should be handled differently
// This also makes a GTU type and -Ego- context unnecessary here
Optional<Route> route = context.getRoute();
if (route.isPresent() && route.get() instanceof BusSchedule busSchedule
&& context.getGtuType().isOfType(DefaultsNl.BUS)
&& conflict.getConflictRuleType().equals(BusStopConflictRule.class))
{
Optional<Duration> actualDeparture = busSchedule.getActualDepartureConflict(conflict.getId());
if (actualDeparture.isPresent()
&& actualDeparture.get().si < context.getTime().si + context.getParameters().getParameter(TI).si)
{
// TODO depending on left/right-hand traffic
context.addIntent(TurnIndicatorStatus.LEFT, conflict.getDistance());
}
}
}
// blocking and ignoring
if (conflict.getDistance().lt0() && lane.isCurrent())
{
if (conflict.getConflictType().isCrossing() && !conflict.getConflictPriority().isPriority())
{
// note that we are blocking a conflict
blocking = true;
}
// ignore conflicts we are on (i.e. negative distance to start of conflict)
continue;
}
// zip-merging
boolean stop = false;
if (conflict.isMerge() && conflict.getConflictPriority().isPriority())
{
if (conflict.getUpstreamConflictingGtus().isEmpty()
|| !conflictPlans.isZipGtu(conflict.getUpstreamConflictingGtus().first().getId()))
{
conflictPlans.clearZipGtu();
}
else
{
stop = true;
}
}
// determine if we need to stop by available space downstream
if (!stop)
{
Length d = conflict.isCrossing() ? conflict.getDistance().plus(conflict.getLength()) : conflict.getDistance();
stop = !conflict.getConflictType().isSplit() && d.lt(space.firstStationary()) && availableSpace.lt(d);
// trigger zip-merging
/*
* Note that when a vehicle is fully on a merge, only vehicles from the same direction consider it regarding
* available space. Vehicles from the other direction do not have the vehicle as one of their regular leaders.
* One vehicle from the other direction will thus put the nose on the merge or close to it. If this is on the
* merge, zip behavior automatically results. If it is close to the merge, and the vehicle on the conflict was
* from the priority direction, the priority vehicle upstream of the conflict needs to remember to let the other
* vehicle go. Otherwise, as soon as traffic starts to move and the available space heuristic is lifted, regular
* priority behavior results. This may cause the non-priority direction to never flow.
*/
if (stop && conflict.isMerge() && conflict.getConflictPriority().isPriority() && conflict.getDistance().gt0()
&& !conflict.getUpstreamConflictingGtus().isEmpty() && conflict.getUpstreamConflictingGtus().first()
.getDistance().lt(context.getParameters().getParameter(STOP_AREA)))
{
conflictPlans.setZipGtu(conflict.getUpstreamConflictingGtus().first().getId());
}
}
if (!stop)
{
switch (conflict.getConflictPriority())
{
case PRIORITY:
{
// available space consideration and zip-merging allow no further action
break;
}
case YIELD:
{
Length prevEnd = prevEnds.isEmpty() ? null : prevEnds.get(prevEnds.size() - 1);
stop = stopForGiveWayConflict(context, conflict, leaders, blocking ? BCRIT : B, prevEnd);
break;
}
case STOP:
{
Length prevEnd = prevEnds.isEmpty() ? null : prevEnds.get(prevEnds.size() - 1);
stop = stopForStopConflict(context, conflict, leaders, blocking ? BCRIT : B, prevEnd);
break;
}
case ALL_STOP:
{
stop = stopForAllStopConflict(conflict, conflictPlans);
break;
}
case SPLIT:
{
continue;
}
default:
{
throw new GtuException("Unsupported conflict rule encountered while approaching conflicts.");
}
}
}
// stop if required, account for upstream conflicts to keep clear
if (stop)
{
prevStarts.add(conflict.getDistance());
conflictRuleTypes.add(conflict.getConflictRuleType());
// stop for first conflict looking upstream of this blocked conflict that allows sufficient space
int j = 0; // most upstream conflict if not in between conflicts
for (int i = prevEnds.size() - 1; i >= 0; i--) // downstream to upstream
{
// note, at this point prevStarts contains one more conflict than prevEnds
if (prevStarts.get(i + 1).minus(prevEnds.get(i))
.gt(passableDistance(context.getLength(), context.getParameters())))
{
j = i + 1;
break;
}
}
if (blocking && j == 0)
{
// we are blocking a conflict, let's not stop more upstream than the conflict that forces our stop
j = prevStarts.size() - 1;
}
// stop for j'th conflict, if deceleration is too strong, for next one
context.getParameters().setParameterResettable(S0, context.getParameters().getParameter(S0_CONF));
Acceleration bCrit = context.getParameters().getParameter(ParameterTypes.BCRIT).neg();
Acceleration aConflict = Acceleration.ofSI(-Double.MAX_VALUE);
while (aConflict.si < bCrit.si && j < prevStarts.size())
{
if (prevStarts.get(j).lt(context.getParameters().getParameter(S0_CONF)))
{
// critical deceleration once GTU is within s0_conf
// otherwise car-following model may generate unreasonably large decelerations
aConflict = Acceleration.max(aConflict, bCrit);
}
else
{
Acceleration aStop = CarFollowingUtil.stop(context, prevStarts.get(j));
if (conflictRuleTypes.get(j).equals(BusStopConflictRule.class) && aStop.lt(bCrit))
{
// as it may suddenly switch state, i.e. ignore like a yellow traffic light
aStop = Acceleration.POS_MAXVALUE;
}
aConflict = Acceleration.max(aConflict, aStop);
}
j++;
}
context.getParameters().resetParameter(S0);
a = Acceleration.min(a, aConflict);
break;
}
// remember info to keep conflict clear (when stopping for another conflict)
if (conflict.isCrossing())
{
prevStarts.add(conflict.getDistance());
conflictRuleTypes.add(conflict.getConflictRuleType());
prevEnds.add(conflict.getDistance().plus(conflict.getLength()));
}
}
conflictPlans.setBlocking(blocking);
if (a.si < -6.0 && context.getSpeed().si > 5.0 / 3.6)
{
Logger.ots().info("Deceleration from conflict util stronger than 6m/s^2.");
// return Acceleration.POSITIVE_INFINITY;
}
return a;
}
/**
* Determines acceleration for following conflicting vehicles <i>on</i> a merge or split conflict.
* @param context tactical information such as parameters and car-following model
* @param conflict merge or split conflict
* @return acceleration for following conflicting vehicles <i>on</i> a merge or split conflict
* @throws ParameterException if a parameter is not given or out of bounds
*/
private static Acceleration followConflictingLeaderOnMergeOrSplit(final TacticalContext context,
final PerceivedConflict conflict) throws ParameterException
{
// ignore if no conflicting GTU's, or if first is downstream of conflict
PerceptionIterable<PerceivedGtu> downstreamGTUs = conflict.getDownstreamConflictingGtus();
if (downstreamGTUs.isEmpty() || downstreamGTUs.first().getKinematics().getOverlap().isAhead())
{
return Acceleration.POS_MAXVALUE;
}
// get the most upstream GTU to consider
PerceivedGtu c = null;
Length virtualDistance = null;
if (conflict.getDistance().gt0())
{
c = downstreamGTUs.first();
virtualDistance = getVirtualDistance(c, conflict);
}
else
{
for (PerceivedGtu con : downstreamGTUs)
{
if (con.getKinematics().getOverlap().isAhead())
{
// conflict GTU completely downstream of conflict (i.e. regular car-following, ignore here)
return Acceleration.POS_MAXVALUE;
}
// conflict GTU (partially) on the conflict
virtualDistance = getVirtualDistance(con, conflict);
if (virtualDistance.gt0())
{
// on split, ignore leader if combined vehicle widths fit within the width of the conflict
if (conflict.isSplit())
{
double conflictWidth = conflict.getWidthAtFraction(
(-conflict.getDistance().si + virtualDistance.si) / conflict.getConflictingLength().si).si;
double gtuWidth = con.getWidth().si + context.getWidth().si;
if (conflictWidth > gtuWidth)
{
continue;
}
}
// found first downstream GTU on conflict
c = con;
break;
}
}
}
if (c == null)
{
// conflict GTU downstream of start of conflict, but upstream of us
return Acceleration.POS_MAXVALUE;
}
// follow leader
Acceleration a = CarFollowingUtil.followSingleLeader(context, virtualDistance, c.getSpeed());
// if conflicting GTU is partially upstream of the conflict and at (near) stand-still, stop for the conflict rather than
// following the tail of the conflicting GTU
if (conflict.isMerge() && virtualDistance.lt(conflict.getDistance()))
{
/*-
* ______________________________________________
* ___ stop for conflict | |
* |___|(--------------------)| ___ |
* _____________________________|__/ /_|________
* / /__/ /
* / /
*/
context.getParameters().setParameterResettable(S0, context.getParameters().getParameter(S0_CONF));
Acceleration aStop = CarFollowingUtil.stop(context, conflict.getDistance());
context.getParameters().resetParameter(S0);
a = Acceleration.max(a, aStop); // max, which ever allows the largest acceleration
}
return a;
}
/**
* Set lateral deviation intent when appropriate.
* @param context tactical information such as parameters and car-following model
* @param conflict conflict (need not be a split, this is checked)
* @param leaders leaders
* @param availableSpace distance over which movement is expected to be possible
*/
private static void lateralDeviationAtSplit(final TacticalContextEgo context, final PerceivedConflict conflict,
final PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders, final Length availableSpace)
{
// 1) This only concerns splits
// 2) In rare cases it might be geometrically ambiguous which side to move to, so skip then
// 3) Only if DEV_SPLIT enabled
// 4) Upstream of conflict-pair on same link it would arbitrarily result in deviating left or right, so skip then
// (this is due to both conflicts being perceived as they are both on the current lane and on the route)
if (conflict.isSplit() && !conflict.getTurn().isNone()
&& context.getParameters().getOptionalParameter(DEV_SPLIT).orElse(false)
&& (!conflict.getLane().getLink().equals(conflict.getConflictingLink()) || conflict.getDistance().lt0()))
{
// distance at which the deviation should be achieved
Length relevantDistance = null;
// first leader in ego-direction (but beyond start of the conflict)
if (!leaders.isEmpty() && leaders.first().getDistance().gt(conflict.getDistance()))
{
relevantDistance = leaders.first().getDistance();
}
// or first conflicting vehicle
var conflictingLeaders = conflict.getDownstreamConflictingGtus();
if (!conflictingLeaders.isEmpty())
{
Length virtualDistance = getVirtualDistance(conflictingLeaders.first(), conflict);
relevantDistance = relevantDistance == null ? virtualDistance : Length.min(relevantDistance, virtualDistance);
}
// 1) there must be at least some leading vehicle somewhere
// 2a) standstill on the conflict is likely, or
// 2b) for the case the other direction might cause a vehicle to stand still (which we know nothing about), deviate
// if the relevant distance (distance to some leading vehicle)
if (relevantDistance != null && (conflict.getDistance().plus(conflict.getLength()).gt(availableSpace)
|| (relevantDistance.lt(availableSpace) && !conflictingLeaders.isEmpty()
&& conflictingLeaders.first().getSpeed().eq0())))
{
// deviation based on lane and vehicle width
Length positionAtWidthToConsider = Length.max(Length.ZERO, conflict.getDistance().neg());
Length laneWidth = conflict.getLane().getWidth(positionAtWidthToConsider);
Length deviation = laneWidth.times(0.5).minus(context.getWidth().times(0.5));
if (conflict.getTurn().isRight())
{
deviation = deviation.neg();
}
// never before conflict itself
context.addIntent(deviation, Length.max(Length.ZERO, relevantDistance));
}
}
}
/**
* Returns the virtual distance towards a conflicting vehicle on a merge or split conflict. Results on a crossing conflict
* make no sense and this method should not be called on such conflicts.
* @param conflictingVehicle conflicting vehicle
* @param conflict conflict
* @return virtual distance towards a conflicting vehicle on a merge or split conflict
*/
private static Length getVirtualDistance(final PerceivedGtu conflictingVehicle, final PerceivedConflict conflict)
{
if (conflictingVehicle.getKinematics().getOverlap().isAhead())
{
return conflict.getDistance().plus(conflict.getLength()).plus(conflictingVehicle.getDistance());
}
if (conflictingVehicle.getKinematics().getOverlap().isBehind())
{
return conflict.getDistance().minus(conflictingVehicle.getDistance()).minus(conflictingVehicle.getLength());
}
/*-
* ______________________________________________
* ___ virtual headway | ___ |
* |___|(-----------------------)|___|(vehicle from south, on lane from south, but virtually on lane from west)
* _____________________________|_______|________
* / /
* / /
*/
return conflict.getDistance().plus(conflictingVehicle.getKinematics().getOverlap().getOverlapRear().get());
}
/**
* Determines an acceleration required to avoid a collision with GTUs <i>on</i> a crossing conflict.
* @param context tactical information such as parameters and car-following model
* @param conflict conflict
* @return acceleration required to avoid a collision
* @throws ParameterException if parameter is not defined
*/
private static Acceleration avoidCrossingCollision(final TacticalContext context, final PerceivedConflict conflict)
throws ParameterException
{
// gather relevant GTUs (first up, and downstream on)
List<PerceivedGtu> conflictingGTUs = new ArrayList<>();
for (PerceivedGtu gtu : conflict.getUpstreamConflictingGtus())
{
if (conflict.getConflictingVisibility().lt(gtu.getDistance()))
{
break;
}
if (isOnRoute(conflict.getConflictingLink(), gtu))
{
// first upstream vehicle on route to this conflict
conflictingGTUs.add(gtu);
break;
}
}
for (PerceivedGtu gtu : conflict.getDownstreamConflictingGtus())
{
if (gtu.getKinematics().getOverlap().isParallel())
{
conflictingGTUs.add(gtu);
}
else
{
// vehicles beyond conflict are not a thread
break;
}
}
if (conflictingGTUs.isEmpty())
{
return Acceleration.POS_MAXVALUE;
}
Acceleration a = Acceleration.POS_MAXVALUE;
for (PerceivedGtu conflictingGTU : conflictingGTUs)
{
// time till enter, conflicting vehicle, no acceleration
AnticipationInfo tteCz;
Length distance;
if (conflictingGTU.getKinematics().getOverlap().isParallel())
{
tteCz = new AnticipationInfo(Duration.ZERO, conflictingGTU.getSpeed());
distance = conflictingGTU.getKinematics().getOverlap().getOverlapRear().get().abs()
.plus(conflictingGTU.getKinematics().getOverlap().getOverlap().get()).plus(Length.max(Length.ZERO,
conflictingGTU.getKinematics().getOverlap().getOverlapFront().get().neg()));
}
else
{
tteCz = AnticipationInfo.anticipateMovement(conflictingGTU.getDistance(), conflictingGTU.getSpeed(),
Acceleration.ZERO);
distance = conflictingGTU.getDistance().plus(conflict.getLength()).plus(conflictingGTU.getLength());
}
// time till clear (rear past conflict), conflicting vehicle, no acceleration
AnticipationInfo ttcCz =
AnticipationInfo.anticipateMovement(distance, conflictingGTU.getSpeed(), Acceleration.ZERO);
// time till enter, own vehicle, free acceleration
AnticipationInfo tteOa =
AnticipationInfo.anticipateMovementFreeAcceleration(context, conflict.getDistance(), TIME_STEP);
// enter before cleared (tteCz < tteOa < ttcCz)
// TODO safety factor?
if (tteCz.duration().lt(tteOa.duration()) && tteOa.duration().lt(ttcCz.duration()))
{
if (!conflictingGTU.getSpeed().eq0() || !CROSSSTANDING)
{
double t = ttcCz.duration().si;
// solve parabolic speed profile s = v*t + .5*a*t*t, a =
double acc = 2.0 * (conflict.getDistance().si - context.getSpeed().si * t) / (t * t);
// time till zero speed > time to avoid conflict?
if (context.getSpeed().si / -acc > ttcCz.duration().si)
{
a = Acceleration.min(a, new Acceleration(acc, AccelerationUnit.SI));
}
else
{
// will reach zero speed ourselves
a = Acceleration.min(a, CarFollowingUtil.stop(context, conflict.getDistance()));
}
}
else
{
// conflicting vehicle stand-still, ignore even at conflict
if (tteOa.duration()
.lt(context.getParameters().getOptionalParameter(ParameterTypes.DT).orElse(Duration.ofSI(0.5))))
{
// report only if the GTU is likely to enter the conflict in the next time step
Map<String, Set<String>> map = CROSSEVENTS.get();
if (map.computeIfAbsent(context.getId(), (id) -> new LinkedHashSet<>()).add(conflictingGTU.getId()))
{
int count = map.values().stream().reduce(0, (c, s) -> Integer.valueOf(c + s.size()),
(c1, c2) -> Integer.valueOf(c1 + c2));
Logger.ots().info("GTU {} passes through GTU {} at crossing [{}].", context.getId(),
conflictingGTU.getId(), count);
}
}
}
}
}
return a;
}
/**
* Avoid collision at merge. This method assumes the GTU has priority.
* @param context tactical information such as parameters and car-following model
* @param conflict conflict
* @return acceleration required to avoid a collision
* @throws ParameterException if parameter is not defined
*/
private static Acceleration avoidMergeCollision(final TacticalContext context, final PerceivedConflict conflict)
throws ParameterException
{
PerceptionCollectable<PerceivedGtu, LaneBasedGtu> conflicting = conflict.getUpstreamConflictingGtus();
// parallel, followConflictingLeaderOnMergeOrSplit?
if (conflicting.isEmpty() || conflicting.first().getKinematics().getOverlap().isParallel())
{
return Acceleration.POS_MAXVALUE;
}
// TODO: this check is simplistic, designed quick and dirty, it just adds 3s as a safe gap
PerceivedGtu conflictingGtu = conflicting.first();
double tteC = conflictingGtu.getDistance().si / conflictingGtu.getSpeed().si;
if (tteC < conflict.getDistance().si / context.getSpeed().si + 3.0)
{
return CarFollowingUtil.stop(context, conflict.getDistance());
}
return Acceleration.POS_MAXVALUE;
}
/**
* Approach a give-way conflict.
* @param context tactical information such as parameters and car-following model
* @param conflict conflict
* @param leaders leaders
* @param bType parameter type for considered deceleration
* @param prevEnd distance to end of previous conflict that should not be blocked, {@code null} if none
* @return whether to stop for this conflict
* @throws ParameterException if a parameter is not defined
*/
@SuppressWarnings({"checkstyle:parameternumber", "checkstyle:methodlength"})
public static boolean stopForGiveWayConflict(final TacticalContext context, final PerceivedConflict conflict,
final PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders, final ParameterTypeAcceleration bType,
final Length prevEnd) throws ParameterException
{
// Account for limited visibility and traffic light
PerceptionCollectable<PerceivedGtu, LaneBasedGtu> conflictingVehiclesCollectable =
conflict.getUpstreamConflictingGtus();
Iterable<PerceivedGtu> conflictingVehicles;
if (conflictingVehiclesCollectable.isEmpty())
{
if (conflict.getConflictingTrafficLightDistance().isEmpty())
{
// none within visibility, assume a conflicting vehicle just outside of visibility driving at speed limit
Length length = Length.ofSI(4.0);
PerceivedGtuSimple conflictGtu = new PerceivedGtuSimple("virtual " + UUID.randomUUID().toString(),
DefaultsNl.CAR, length, Length.ofSI(2.0),
Kinematics.dynamicBehind(conflict.getConflictingVisibility(),
conflict.getConflictingSpeedLimit().speed(), Acceleration.ZERO, true, length,
conflict.getLength()),
Signals.NONE, Maneuver.NONE);
conflictingVehicles = Set.of(conflictGtu);
}
else
{
// no conflicting vehicles
return false;
}
}
else
{
PerceivedGtu conflicting = conflictingVehiclesCollectable.first();
Optional<Length> tlDistance = conflict.getConflictingTrafficLightDistance();
if (tlDistance.isPresent() && conflicting.getKinematics().getOverlap().isAhead()
&& tlDistance.get().lt(conflicting.getDistance())
&& (conflicting.getSpeed().eq0() || conflicting.getAcceleration().lt0()))
{
// conflicting traffic upstream of traffic light
return false;
}
conflictingVehicles = conflictingVehiclesCollectable;
}
// Get data independent of conflicting vehicle
Acceleration b = context.getParameters().getParameter(bType).neg();
double f = context.getParameters().getParameter(TIME_FACTOR);
Duration gap = context.getParameters().getParameter(MIN_GAP);
Length passable = passableDistance(context.getLength(), context.getParameters());
Length distance = conflict.getDistance().plus(context.getLength());
if (conflict.isCrossing())
{
distance = distance.plus(conflict.getLength()); // merge is cleared at start, crossing at end
}
// time till clear (i.e. rear leaves conflict), own vehicle, free acceleration
AnticipationInfo ttcOa = AnticipationInfo.anticipateMovementFreeAcceleration(context, distance, TIME_STEP);
// Loop over conflicting vehicles
boolean first = true;
for (PerceivedGtu conflictingVehicle : conflictingVehicles)
{
// skip if not on route
if (!isOnRoute(conflict.getConflictingLink(), conflictingVehicle))
{
continue;
}
// do not stop if first conflicting vehicle is standing still
if (first && conflictingVehicle.getSpeed().eq0() && conflictingVehicle.getKinematics().getOverlap().isAhead())
{
return false;
}
// time till enter, conflict vehicle, free acceleration
AnticipationInfo tteCa;
if (conflictingVehicle instanceof PerceivedGtuSimple)
{
// fixed acceleration for simple as it provides no behavioral information
tteCa = AnticipationInfo.anticipateMovement(conflictingVehicle.getDistance(), conflictingVehicle.getSpeed(),
conflictingVehicle.getAcceleration());
}
else
{
// Constant acceleration creates inf at stand still, triggering passing trough a congested stream
if (conflictingVehicle.getKinematics().getOverlap().isAhead())
{
tteCa = AnticipationInfo.anticipateMovementFreeAcceleration(conflictingVehicle,
conflictingVehicle.getDistance(), TIME_STEP);
}
else
{
tteCa = new AnticipationInfo(Duration.ZERO, conflictingVehicle.getSpeed());
}
}
// check gap
if (conflict.isMerge())
{
/*
* At a merge the conflicting vehicle will become ego's follower. Hence time might be needed to overcome a speed
* difference. We assume that the speed difference at the moment the ego vehicle clears the conflict, relative
* to the current speed of the conflicting vehicle, must be removed by deceleration b. This will require
* additional time, within which we need to have moved sufficiently assuming the speed we have when we clear the
* conflict. Sufficient space is when the follower can perform the deceleration over that space. Then, also
* space for a car-following headway and the gap time is required. Note that tteCa assumes free acceleration of
* the conflicting vehicle until it enters the conflict. The ego vehicle however clears the conflict earlier, so
* the resulting speed of that acceleration is not the right speed to consider for the speed difference after
* the conflict. The conflicting vehicle's speed at the moment ego clear the conflict is not known. Hence, the
* current conflicting vehicle's speed is used. This is compensated by not assuming further acceleration of ego
* after clearing the conflict.
*/
double vSelf = ttcOa.endSpeed().si;
double speedDiff = conflictingVehicle.getSpeed().si - vSelf;
speedDiff = speedDiff > 0 ? speedDiff : 0;
Duration additionalTime = Duration.ofSI(speedDiff / -b.si);
double followerFront = conflictingVehicle.getSpeed().si * (ttcOa.duration().si + additionalTime.si)
- conflictingVehicle.getDistance().si + 0.5 * b.si * additionalTime.si * additionalTime.si;
double ownRear = vSelf * additionalTime.si;
Duration tMax = context.getParameters().getParameter(ParameterTypes.TMAX);
Length s0 = context.getParameters().getParameter(S0);
// 1) will clear the conflict after the conflict vehicle enters
// 2) conflict vehicle will be too near after adjusting speed
if (ttcOa.duration().times(f).plus(gap).gt(tteCa.duration()) || (!Double.isInfinite(tteCa.duration().si)
&& tteCa.duration().si > 0.0 && ownRear < (followerFront + (tMax.si + gap.si) * vSelf + s0.si) * f))
{
return true;
}
}
else if (conflict.isCrossing())
{
// time till passible, downstream, zero acceleration
AnticipationInfo ttpDz = null;
if (!leaders.isEmpty())
{
distance = conflict.getDistance().minus(leaders.first().getDistance()).plus(conflict.getLength())
.plus(passable);
ttpDz = AnticipationInfo.anticipateMovement(distance, leaders.first().getSpeed(), Acceleration.ZERO);
}
else
{
// no leader so conflict is passable within a duration of 0
ttpDz = new AnticipationInfo(Duration.ZERO, Speed.ZERO);
}
// 1) downstream vehicle must supply sufficient space before conflict vehicle will enter
// 2) must clear the conflict before the conflict vehicle will enter
if (ttpDz.duration().times(f).plus(gap).gt(tteCa.duration())
|| ttcOa.duration().times(f).plus(gap).gt(tteCa.duration()))
{
return true;
}
}
else
{
throw new RuntimeException(
"Conflict is of unknown type " + conflict.getConflictType() + ", which is not merge nor a crossing.");
}
first = false;
}
// No conflict vehicle triggered stopping
return false;
}
/**
* Approach a stop conflict. Currently this is equal to approaching a give-way conflict.
* @param context tactical information such as parameters and car-following model
* @param conflict conflict
* @param leaders leaders
* @param bType parameter type for considered deceleration
* @param prevEnd distance to end of previous conflict that should not be blocked, {@code null} if none
* @return whether to stop for this conflict
* @throws ParameterException if a parameter is not defined
*/
@SuppressWarnings("checkstyle:parameternumber")
public static boolean stopForStopConflict(final TacticalContext context, final PerceivedConflict conflict,
final PerceptionCollectable<PerceivedGtu, LaneBasedGtu> leaders, final ParameterTypeAcceleration bType,
final Length prevEnd) throws ParameterException
{
// TODO stopping
return stopForGiveWayConflict(context, conflict, leaders, bType, prevEnd);
}
/**
* Approach an all-stop conflict.
* @param conflict conflict to approach
* @param conflictPlans set of plans for conflict
* @return whether to stop for this conflict
*/
public static boolean stopForAllStopConflict(final PerceivedConflict conflict, final ConflictPlans conflictPlans)
{
// TODO all-stop behavior
if (conflictPlans.isStopPhaseRun(conflict.getStopLine()))
{
return false;
}
return false;
}
/**
* Returns whether the conflicting link is on the route of the given gtu.
* @param conflictingLink conflicting link
* @param gtu gtu
* @return whether the conflict is on the route of the given gtu
*/
private static boolean isOnRoute(final CrossSectionLink conflictingLink, final PerceivedGtu gtu)
{
try
{
Optional<Route> route = gtu.getBehavior().getRoute();
if (route.isEmpty())
{
// conservative assumption: it's on the route (gtu should be upstream of the conflict)
return true;
}
Node startNode = conflictingLink.getStartNode();
Node endNode = conflictingLink.getEndNode();
return route.get().contains(startNode) && route.get().contains(endNode)
&& Math.abs(route.get().indexOf(endNode) - route.get().indexOf(startNode)) == 1;
}
catch (UnsupportedOperationException uoe)
{
// conservative assumption: it's on the route (gtu should be upstream of the conflict)
return true;
}
}
/**
* Returns distance needed behind the leader to completely pass the conflict.
* @param vehicleLength vehicle length
* @param parameters parameters
* @return distance needed behind the leader to completely pass the conflict
* @throws ParameterException if parameter is not available
*/
private static Length passableDistance(final Length vehicleLength, final Parameters parameters) throws ParameterException
{
return parameters.getParameter(S0).plus(vehicleLength);
}
/**
* Holds the tactical plans of a driver considering conflicts. These are remembered for consistency. For instance, if the
* decision is made to yield as current deceleration suggests it's safe to do so, but the trajectory for stopping in front
* of the conflict results in deceleration slightly above what is considered safe deceleration, the plan should not be
* abandoned. Decelerations above what is considered safe deceleration may result due to numerical overshoot or other
* factors coming into play in car-following models. Many other examples exist where a driver sticks to a certain plan.
*/
public static final class ConflictPlans implements Blockable
{
/** Phases of navigating an all-stop intersection per intersection. */
private final LinkedHashMap<String, StopPhase> stopPhases = new LinkedHashMap<>();
/** Estimated arrival times of vehicles at all-stop intersection. */
private final LinkedHashMap<String, Time> arrivalTimes = new LinkedHashMap<>();
/** Whether the GTU is blocking conflicts. */
private boolean blocking;
/** Id of GTU that we allow priority (although it has not) for zip-merging at congested merge conflict. */
private String zipGtuId;
/**
* Constructor.
*/
public ConflictPlans()
{
//
}
/**
* Sets the estimated arrival time of a GTU.
* @param gtu GTU
* @param time estimated arrival time
*/
void setArrivalTime(final PerceivedGtuBase gtu, final Time time)
{
this.arrivalTimes.put(gtu.getId(), time);
}
/**
* Returns the estimated arrival time of given GTU.
* @param gtu GTU
* @return estimated arrival time of given GTU
*/
Time getArrivalTime(final PerceivedGtuBase gtu)
{
return this.arrivalTimes.get(gtu.getId());
}
/**
* Sets the current phase to 'approach' for the given stop line.
* @param stopLine stop line
*/
void setStopPhaseApproach(final PerceivedObject stopLine)
{
this.stopPhases.put(stopLine.getId(), StopPhase.APPROACH);
}
/**
* Sets the current phase to 'yield' for the given stop line.
* @param stopLine stop line
* @throws OtsRuntimeException if the phase was not set to approach before
*/
void setStopPhaseYield(final PerceivedObject stopLine)
{
Throw.when(
!this.stopPhases.containsKey(stopLine.getId())
|| !this.stopPhases.get(stopLine.getId()).equals(StopPhase.APPROACH),
OtsRuntimeException.class, "Yield stop phase is set for stop line that was not approached.");
this.stopPhases.put(stopLine.getId(), StopPhase.YIELD);
}
/**
* Sets the current phase to 'run' for the given stop line.
* @param stopLine stop line
* @throws OtsRuntimeException if the phase was not set to approach before
*/
void setStopPhaseRun(final PerceivedObject stopLine)
{
Throw.when(!this.stopPhases.containsKey(stopLine.getId()), OtsRuntimeException.class,
"Run stop phase is set for stop line that was not approached.");
this.stopPhases.put(stopLine.getId(), StopPhase.YIELD);
}
/**
* Return whether plan is in approach stop line phase.
* @param stopLine stop line
* @return whether the current phase is 'approach' for the given stop line
*/
boolean isStopPhaseApproach(final PerceivedObject stopLine)
{
return this.stopPhases.containsKey(stopLine.getId())
&& this.stopPhases.get(stopLine.getId()).equals(StopPhase.APPROACH);
}
/**
* Returns whether yielding was planned for the stop line.
* @param stopLine stop line
* @return whether the current phase is 'yield' for the given stop line
*/
boolean isStopPhaseYield(final PerceivedObject stopLine)
{
return this.stopPhases.containsKey(stopLine.getId())
&& this.stopPhases.get(stopLine.getId()).equals(StopPhase.YIELD);
}
/**
* Returns whether running was planned for the stop line.
* @param stopLine stop line
* @return whether the current phase is 'run' for the given stop line
*/
boolean isStopPhaseRun(final PerceivedObject stopLine)
{
return this.stopPhases.containsKey(stopLine.getId()) && this.stopPhases.get(stopLine.getId()).equals(StopPhase.RUN);
}
@Override
public boolean isBlocking()
{
return this.blocking;
}
/**
* Sets the GTU as blocking conflicts or not.
* @param blocking whether the GTU is blocking conflicts
*/
public void setBlocking(final boolean blocking)
{
this.blocking = blocking;
}
/**
* Sets the id of GTU that we allow priority (although it has not) for zip-merging at congested merge conflict.
* @param zipGtuId id of GTU that we allow priority
*/
void setZipGtu(final String zipGtuId)
{
this.zipGtuId = zipGtuId;
}
/**
* Clear the id of GTU that we allow priority (although it has not) for zip-merging at congested merge conflict.
*/
void clearZipGtu()
{
this.zipGtuId = null;
}
/**
* Check whether the given id is of the GTU for which we allow priority.
* @param id GTU id
* @return whether the given id is of the GTU for which we allow priority
*/
boolean isZipGtu(final String id)
{
return id.equals(this.zipGtuId);
}
@Override
public String toString()
{
return "ConflictPlans";
}
}
/**
* Phases of navigating an all-stop intersection.
* <p>
* Copyright (c) 2013-2026 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved.
* <br>
* BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
* </p>
* @author Alexander Verbraeck
* @author Peter Knoppers
* @author Wouter Schakel
*/
private enum StopPhase
{
/** Approaching stop intersection. */
APPROACH,
/** Yielding for stop intersection. */
YIELD,
/** Running over stop intersection. */
RUN;
}
/**
* Returns the net available space when all moving GTUs will become stationary behind the first stationary GTU.
*/
private static final class AvailableSpace implements PerceptionCollector<Space, LaneBasedGtu, Space>
{
@Override
public Supplier<Space> getIdentity()
{
return () -> new Space();
}
@Override
public PerceptionAccumulator<LaneBasedGtu, Space> getAccumulator()
{
return (i, u, h) ->
{
if (i.getObject().addVehicle(u, h))
{
i.stop();
}
return i;
};
}
@Override
public Function<Space, Space> getFinalizer()
{
return (l) -> l;
}
}
/**
* Intermediate result for {@link AvailableSpace} collector.
*/
private static final class Space
{
/** Accumulated required space for vehicles up to stationary leader. */
private Length cumulativeRequiredSpace = Length.ZERO;
/** Distance to first stationary leader. */
private Length firstStationary;
/**
* Adds a vehicle.
* @param gtu GTU
* @param h distance to GTU
* @return whether the accumulator can stop as the vehicles is stationary
*/
public boolean addVehicle(final LaneBasedGtu gtu, final Length h)
{
if (gtu.getSpeed().si < 5.0 / 3.6 && gtu.getAcceleration().le0())
{
this.firstStationary = h;
return true;
}
Length s0;
try
{
s0 = gtu.getParameters().getParameter(ParameterTypes.S0);
}
catch (ParameterException ex)
{
s0 = Length.ofSI(3.0);
}
this.cumulativeRequiredSpace = this.cumulativeRequiredSpace.plus(gtu.getLength()).plus(s0);
return false;
}
/**
* Returns the available space up to first stationary leader.
* @return available space up to first stationary leader
*/
public Length availableSpace()
{
return this.firstStationary == null ? Length.POSITIVE_INFINITY
: this.firstStationary.minus(this.cumulativeRequiredSpace);
}
/**
* Returns the distance to first stationary leader.
* @return distance to first stationary leader
*/
public Length firstStationary()
{
return this.firstStationary == null ? Length.POSITIVE_INFINITY : this.firstStationary;
}
}
}