package org.opentrafficsim.road.gtu.lane;
   
   import java.util.ArrayList;
   import java.util.HashMap;
   import java.util.HashSet;
   import java.util.Iterator;
   import java.util.LinkedHashMap;
   import java.util.List;
   import java.util.Map;
  import java.util.Set;
  
  import javax.media.j3d.Bounds;
  import javax.vecmath.Point3d;
  
  import org.djunits.unit.LengthUnit;
  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.opentrafficsim.core.dsol.OTSDEVSSimulatorInterface;
  import org.opentrafficsim.core.dsol.OTSSimTimeDouble;
  import org.opentrafficsim.core.geometry.OTSGeometryException;
  import org.opentrafficsim.core.gtu.AbstractGTU;
  import org.opentrafficsim.core.gtu.GTUDirectionality;
  import org.opentrafficsim.core.gtu.GTUException;
  import org.opentrafficsim.core.gtu.GTUType;
  import org.opentrafficsim.core.gtu.RelativePosition;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.BehavioralCharacteristics;
  import org.opentrafficsim.core.gtu.behavioralcharacteristics.ParameterException;
  import org.opentrafficsim.core.gtu.plan.operational.OperationalPlanException;
  import org.opentrafficsim.core.network.LateralDirectionality;
  import org.opentrafficsim.core.network.Link;
  import org.opentrafficsim.core.network.NetworkException;
  import org.opentrafficsim.core.network.Node;
  import org.opentrafficsim.core.network.OTSNetwork;
  import org.opentrafficsim.road.gtu.lane.tactical.LaneBasedTacticalPlanner;
  import org.opentrafficsim.road.gtu.strategical.LaneBasedStrategicalPlanner;
  import org.opentrafficsim.road.gtu.strategical.route.LaneBasedStrategicalRoutePlanner;
  import org.opentrafficsim.road.network.lane.CrossSectionElement;
  import org.opentrafficsim.road.network.lane.CrossSectionLink;
  import org.opentrafficsim.road.network.lane.DirectedLanePosition;
  import org.opentrafficsim.road.network.lane.Lane;
  
  import nl.tudelft.simulation.dsol.SimRuntimeException;
  import nl.tudelft.simulation.dsol.formalisms.eventscheduling.SimEvent;
  import nl.tudelft.simulation.language.Throw;
  import nl.tudelft.simulation.language.d3.BoundingBox;
  import nl.tudelft.simulation.language.d3.DirectedPoint;
  
  /**
   * This class contains most of the code that is needed to run a lane based GTU. <br>
   * The starting point of a LaneBasedTU is that it can be in <b>multiple lanes</b> at the same time. This can be due to a lane
   * change (lateral), or due to crossing a link (front of the GTU is on another Lane than rear of the GTU). If a Lane is shorter
   * than the length of the GTU (e.g. when we do node expansion on a crossing, this is very well possible), a GTU could occupy
   * dozens of Lanes at the same time.
   * <p>
   * When calculating a headway, the GTU has to look in successive lanes. When Lanes (or underlying CrossSectionLinks) diverge,
   * the headway algorithms have to look at multiple Lanes and return the minimum headway in each of the Lanes. When the Lanes (or
   * underlying CrossSectionLinks) converge, "parallel" traffic is not taken into account in the headway calculation. Instead, gap
   * acceptance algorithms or their equivalent should guide the merging behavior.
   * <p>
   * To decide its movement, an AbstractLaneBasedGTU applies its car following algorithm and lane change algorithm to set the
   * acceleration and any lane change operation to perform. It then schedules the triggers that will add it to subsequent lanes
   * and remove it from current lanes as needed during the time step that is has committed to. Finally, it re-schedules its next
   * movement evaluation with the simulator.
   * <p>
   * Copyright (c) 2013-2016 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * <p>
   * @version $Revision: 1408 $, $LastChangedDate: 2015-09-24 15:17:25 +0200 (Thu, 24 Sep 2015) $, by $Author: pknoppers $,
   *          initial version Oct 22, 2014 <br>
   * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public abstract class AbstractLaneBasedGTU extends AbstractGTU implements LaneBasedGTU
  {
      /** */
      private static final long serialVersionUID = 20140822L;
  
      /**
       * Fractional longitudinal positions of the reference point of the GTU on one or more links at the start of the current
       * operational plan. Because the reference point of the GTU might not be on all the links the GTU is registered on, the
       * fractional longitudinal positions can be more than one, or less than zero.
       */
      private Map<Link, Double> fractionalLinkPositions = new LinkedHashMap<>();
  
      /**
       * The lanes the GTU is registered on. Each lane has to have its link registered in the fractionalLinkPositions as well to
       * keep consistency. Each link from the fractionalLinkPositions can have one or more Lanes on which the vehicle is
       * registered. This is a list to improve reproducibility: The 'oldest' lanes on which the vehicle is registered are at the
       * front of the list, the later ones more to the back.
       */
      private final Map<Lane, GTUDirectionality> lanesCurrentOperationalPlan = new HashMap<>();
  
      /** Pending triggers for each lane. */
      private Map<Lane, List<SimEvent<OTSSimTimeDouble>>> pendingTriggers = new HashMap<>();
  
      /** The object to lock to make the GTU thread safe. */
      private Object lock = new Object();
 
     /**
      * Construct a Lane Based GTU.
      * @param id the id of the GTU
      * @param gtuType the type of GTU, e.g. TruckType, CarType, BusType
      * @param simulator to initialize the move method and to get the current time
      * @param network the network that the GTU is initially registered in
      * @throws GTUException when initial values are not correct
      */
     @SuppressWarnings("checkstyle:parameternumber")
     public AbstractLaneBasedGTU(final String id, final GTUType gtuType, final OTSDEVSSimulatorInterface simulator,
             final OTSNetwork network) throws GTUException
     {
         super(id, gtuType, simulator, network);
     }
 
     /**
      * @param strategicalPlanner the strategical planner (e.g., route determination) to use
      * @param initialLongitudinalPositions the initial positions of the car on one or more lanes with their directions
      * @param initialSpeed the initial speed of the car on the lane
      * @throws NetworkException when the GTU cannot be placed on the given lane
      * @throws SimRuntimeException when the move method cannot be scheduled
      * @throws GTUException when initial values are not correct
      * @throws OTSGeometryException when the initial path is wrong
      */
     public final void init(final LaneBasedStrategicalPlanner strategicalPlanner,
             final Set<DirectedLanePosition> initialLongitudinalPositions, final Speed initialSpeed)
             throws NetworkException, SimRuntimeException, GTUException, OTSGeometryException
     {
         Throw.when(null == initialLongitudinalPositions, GTUException.class, "InitialLongitudinalPositions is null");
         Throw.when(0 == initialLongitudinalPositions.size(), GTUException.class, "InitialLongitudinalPositions is empty set");
 
         DirectedPoint lastPoint = null;
         for (DirectedLanePosition pos : initialLongitudinalPositions)
         {
             Throw.when(lastPoint != null && pos.getLocation().distance(lastPoint) > 1E-6, GTUException.class,
                     "initial locations for GTU have distance > 1 mm");
             lastPoint = pos.getLocation();
         }
         DirectedPoint initialLocation = lastPoint;
 
         // register the GTU on the lanes
         for (DirectedLanePosition directedLanePosition : initialLongitudinalPositions)
         {
             Lane lane = directedLanePosition.getLane();
             enterLane(lane, directedLanePosition.getPosition(), directedLanePosition.getGtuDirection());
         }
 
         // initiate the actual move
         super.init(strategicalPlanner, initialLocation, initialSpeed);
 
         Lane referenceLane = getReferencePosition().getLane();
         fireTimedEvent(LaneBasedGTU.LANEBASED_INIT_EVENT,
                 new Object[] { getId(), initialLocation, getLength(), getWidth(), getBaseColor(), referenceLane,
                         position(referenceLane, getReference()), this.lanesCurrentOperationalPlan.get(referenceLane) },
                 getSimulator().getSimulatorTime());
     }
 
     /** {@inheritDoc} */
     @Override
     public final void enterLane(final Lane lane, final Length position, final GTUDirectionality gtuDirection)
             throws GTUException
     {
         if (lane == null || gtuDirection == null || position == null)
         {
             throw new GTUException("enterLane - one of the arguments is null");
         }
         if (this.lanesCurrentOperationalPlan.containsKey(lane))
         {
             System.err.println(this + " is already registered on lane: " + lane + " at fractional position "
                     + this.fractionalPosition(lane, RelativePosition.REFERENCE_POSITION) + " intended position is " + position
                     + " length of lane is " + lane.getLength());
             return;
         }
 
         // if the GTU is already registered on a lane of the same link, do not change its fractional position, as
         // this might lead to a "jump".
         if (!this.fractionalLinkPositions.containsKey(lane.getParentLink()))
         {
             this.fractionalLinkPositions.put(lane.getParentLink(), lane.fraction(position));
         }
         this.lanesCurrentOperationalPlan.put(lane, gtuDirection);
         lane.addGTU(this, position);
     }
 
     /** {@inheritDoc} */
     @Override
     public final void leaveLane(final Lane lane) throws GTUException
     {
         leaveLane(lane, false);
     }
 
     /**
      * Leave a lane but do not complain about having no lanes left when beingDestroyed is true.
      * @param lane the lane to leave
      * @param beingDestroyed if true, no complaints about having no lanes left
      * @throws GTUException in case leaveLane should not be called
      */
     public final void leaveLane(final Lane lane, final boolean beingDestroyed) throws GTUException
     {
         this.lanesCurrentOperationalPlan.remove(lane);
         List<SimEvent<OTSSimTimeDouble>> pending = this.pendingTriggers.get(lane);
         if (null != pending)
         {
             for (SimEvent<OTSSimTimeDouble> event : pending)
             {
                 if (event.getAbsoluteExecutionTime().get().ge(getSimulator().getSimulatorTime().get()))
                 {
                     boolean result = getSimulator().cancelEvent(event);
                     if (!result && event.getAbsoluteExecutionTime().get().ne(getSimulator().getSimulatorTime().get()))
                     {
                         System.err.println("leaveLane, trying to remove event: NOTHING REMOVED");
                     }
                 }
             }
             this.pendingTriggers.remove(lane);
         }
         // check of there are any lanes for this link left. If not, remove the link.
         boolean found = false;
         for (Lane l : this.lanesCurrentOperationalPlan.keySet())
         {
             if (l.getParentLink().equals(lane.getParentLink()))
             {
                 found = true;
             }
         }
         if (!found)
         {
             this.fractionalLinkPositions.remove(lane.getParentLink());
         }
         lane.removeGTU(this, !found);
         if (this.lanesCurrentOperationalPlan.size() == 0 && !beingDestroyed)
         {
             System.err.println("leaveLane: lanes.size() = 0 for GTU " + getId());
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final void changeLaneInstantaneously(final LateralDirectionality laneChangeDirection) throws GTUException
     {
         // keep a copy of the lanes and directions (!)
         Map<Lane, GTUDirectionality> lanesCopy = new HashMap<>(this.lanesCurrentOperationalPlan);
         Set<Lane> lanesToBeRemoved = new HashSet<>(lanesCopy.keySet());
         Map<Lane, Double> fractionalLanePositions = new HashMap<>();
 
         for (Lane lane : lanesCopy.keySet())
         {
             fractionalLanePositions.put(lane, fractionalPosition(lane, getReference()));
             lanesToBeRemoved.add(lane);
         }
 
         for (Lane lane : lanesCopy.keySet())
         {
             Set<Lane> laneSet = lane.accessibleAdjacentLanes(laneChangeDirection, getGTUType());
             if (laneSet.size() > 0)
             {
                 Lane adjacentLane = laneSet.iterator().next();
                 enterLane(adjacentLane, adjacentLane.getLength().multiplyBy(fractionalLanePositions.get(lane)),
                         lanesCopy.get(lane));
                 lanesToBeRemoved.remove(adjacentLane); // don't remove lanes we might end up
             }
 
         }
         for (Lane lane : lanesToBeRemoved)
         {
             leaveLane(lane);
         }
     }
 
     /**
      * Register on lanes in target lane.
      * @param laneChangeDirection direction of lane change
      * @throws GTUException exception
      */
     public final void initLaneChange(final LateralDirectionality laneChangeDirection) throws GTUException
     {
         Map<Lane, GTUDirectionality> lanesCopy = new HashMap<>(this.lanesCurrentOperationalPlan);
         Map<Lane, Double> fractionalLanePositions = new HashMap<>();
         for (Lane lane : lanesCopy.keySet())
         {
             fractionalLanePositions.put(lane, fractionalPosition(lane, getReference()));
         }
         int numRegistered = 0;
         for (Lane lane : lanesCopy.keySet())
         {
             Set<Lane> laneSet = lane.accessibleAdjacentLanes(laneChangeDirection, getGTUType());
             if (laneSet.size() > 0)
             {
                 numRegistered++;
                 Lane adjacentLane = laneSet.iterator().next();
                 enterLane(adjacentLane, adjacentLane.getLength().multiplyBy(fractionalLanePositions.get(lane)),
                         lanesCopy.get(lane));
             }
         }
         Throw.when(numRegistered == 0, GTUException.class, "Gtu %s starting %s lane change, but no adjacent lane found.",
                 getId(), laneChangeDirection);
     }
 
     /**
      * Unregister on lanes in source lane.
      * @param laneChangeDirection direction of lane change
      * @param time time to leave lanes
      * @throws GTUException exception
      */
     public final void finalizeLaneChange(final LateralDirectionality laneChangeDirection, final Time time) throws GTUException
     {
         try
         {
             getSimulator().scheduleEventAbs(time, this, this, "executeLaneChangeFinalization",
                     new Object[] { laneChangeDirection });
         }
         catch (SimRuntimeException exception)
         {
             throw new RuntimeException("Error when finalizing lane change.", exception);
         }
     }
 
     /**
      * Performs the finalization of a lane change by leaving the from lanes.
      * @param laneChangeDirection direction of lane change
      */
     protected final void executeLaneChangeFinalization(final LateralDirectionality laneChangeDirection)
     {
         Map<Lane, GTUDirectionality> lanesCopy = new HashMap<>(this.lanesCurrentOperationalPlan);
         Set<Lane> lanesToBeRemoved = new HashSet<>();
         Map<Lane, Double> fractionalLanePositions = new HashMap<>();
         try
         {
             for (Lane lane : lanesCopy.keySet())
             {
 
                 fractionalLanePositions.put(lane, fractionalPosition(lane, getReference()));
             }
             for (Lane lane : lanesCopy.keySet())
             {
                 Iterator<Lane> iterator = lane.accessibleAdjacentLanes(laneChangeDirection, getGTUType()).iterator();
                 if (iterator.hasNext() && lanesCopy.keySet().contains(iterator.next()))
                 {
                     lanesToBeRemoved.add(lane);
                 }
             }
             for (Lane lane : lanesToBeRemoved)
             {
                 leaveLane(lane);
             }
         }
         catch (GTUException exception)
         {
             // should not happen, lane was obtained from GTU
             throw new RuntimeException("fractionalPosition on lane not possible", exception);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final GTUDirectionality getDirection(final Lane lane) throws GTUException
     {
         Throw.when(!this.lanesCurrentOperationalPlan.containsKey(lane), GTUException.class,
                 "getDirection: Lanes %s does not contain %s", this.lanesCurrentOperationalPlan.keySet(), lane);
         return this.lanesCurrentOperationalPlan.get(lane);
     }
 
     /** {@inheritDoc} */
     @Override
     protected final void move(final DirectedPoint fromLocation)
             throws SimRuntimeException, GTUException, OperationalPlanException, NetworkException, ParameterException
     {
         // Only carry out move() if we still have lane(s) to drive on.
         // Note: a (Sink) trigger can have 'destroyed' us between the previous evaluation step and this one.
         if (this.lanesCurrentOperationalPlan.isEmpty())
         {
             destroy();
             return; // Done; do not re-schedule execution of this move method.
         }
 
         // store the new positions, and sample statistics
         Map<Link, Double> newLinkPositions = new HashMap<>();
         for (Lane lane : this.lanesCurrentOperationalPlan.keySet())
         {
             newLinkPositions.put(lane.getParentLink(), lane.fraction(position(lane, getReference())));
         }
 
         // generate the next operational plan and carry it out
         super.move(fromLocation);
 
         // update the positions on the lanes we are registered on
         this.fractionalLinkPositions = newLinkPositions;
 
         DirectedLanePosition dlp = getReferencePosition();
         fireTimedEvent(
                 LaneBasedGTU.LANEBASED_MOVE_EVENT, new Object[] { getId(), fromLocation, getSpeed(), getAcceleration(),
                         getTurnIndicatorStatus(), getOdometer(), dlp.getLane(), dlp.getPosition(), dlp.getGtuDirection() },
                 getSimulator().getSimulatorTime());
 
         if (getOperationalPlan().getAcceleration(Duration.ZERO).si < -10
                 && getOperationalPlan().getSpeed(Duration.ZERO).si > 2.5)
         {
             System.err.println("(getOperationalPlan().getAcceleration(Duration.ZERO).si < -10)");
         }
 
         // schedule triggers and determine when to enter lanes with front and leave lanes with rear
         scheduleEnterLeaveTriggers();
     }
 
     /** {@inheritDoc} */
     @Override
     public final Map<Lane, Length> positions(final RelativePosition relativePosition) throws GTUException
     {
         return positions(relativePosition, getSimulator().getSimulatorTime().getTime());
     }
 
     /** {@inheritDoc} */
     @Override
     public final Map<Lane, Length> positions(final RelativePosition relativePosition, final Time when) throws GTUException
     {
         Map<Lane, Length> positions = new LinkedHashMap<>();
         for (Lane lane : this.lanesCurrentOperationalPlan.keySet())
         {
             positions.put(lane, position(lane, relativePosition, when));
         }
         return positions;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Length position(final Lane lane, final RelativePosition relativePosition) throws GTUException
     {
         return position(lane, relativePosition, getSimulator().getSimulatorTime().getTime());
     }
 
     /** {@inheritDoc} */
     @Override
     public final Length projectedPosition(final Lane projectionLane, final RelativePosition relativePosition, final Time when)
             throws GTUException
     {
         // do not make a wedge in a curve of the projected position!
         CrossSectionLink link = projectionLane.getParentLink();
         for (CrossSectionElement cse : link.getCrossSectionElementList())
         {
             if (cse instanceof Lane)
             {
                 Lane cseLane = (Lane) cse;
                 if (null != this.lanesCurrentOperationalPlan.get(cseLane))
                 {
                     double fractionalPosition = fractionalPosition(cseLane, RelativePosition.REFERENCE_POSITION, when);
                     Length pos = new Length(projectionLane.getLength().getSI() * fractionalPosition, LengthUnit.SI);
                     if (this.lanesCurrentOperationalPlan.get(cseLane).isPlus())
                     {
                         return pos.plus(relativePosition.getDx());
                     }
                     return pos.minus(relativePosition.getDx());
                 }
             }
         }
         throw new GTUException(this + " is not on any lane of Link " + link);
     }
 
     /** {@inheritDoc} */
     @Override
     public final Length position(final Lane lane, final RelativePosition relativePosition, final Time when) throws GTUException
     {
         if (null == lane)
         {
             throw new GTUException("lane is null");
         }
         synchronized (this.lock)
         {
             if (!this.lanesCurrentOperationalPlan.containsKey(lane))
             {
                 throw new GTUException("position() : GTU " + toString() + " is not on lane " + lane);
             }
             if (!this.fractionalLinkPositions.containsKey(lane.getParentLink()))
             {
                 // DO NOT USE toString() here, as it will cause an endless loop...
                 throw new GTUException(this + " does not have a fractional position on " + lane.toString());
             }
             double longitudinalPosition = lane.positionSI(this.fractionalLinkPositions.get(lane.getParentLink()));
             if (getOperationalPlan() == null)
             {
                 // no valid operational plan, e.g. during generation of a new plan
                 return new Length(longitudinalPosition + relativePosition.getDx().si, LengthUnit.SI);
             }
             double loc;
             try
             {
                 if (this.lanesCurrentOperationalPlan.get(lane).isPlus())
                 {
                     loc = longitudinalPosition + getOperationalPlan().getTraveledDistanceSI(when) + relativePosition.getDx().si;
                 }
                 else
                 {
                     loc = longitudinalPosition - getOperationalPlan().getTraveledDistanceSI(when) - relativePosition.getDx().si;
                 }
             }
             catch (Exception e)
             {
                 System.err.println(toString());
                 System.err.println(this.lanesCurrentOperationalPlan);
                 System.err.println(this.fractionalLinkPositions);
                 throw new GTUException(e);
             }
             if (Double.isNaN(loc))
             {
                 System.out.println("loc is NaN");
             }
             return new Length(loc, LengthUnit.SI);
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final DirectedLanePosition getReferencePosition() throws GTUException
     {
         for (Lane lane : this.lanesCurrentOperationalPlan.keySet())
         {
             double fraction = fractionalPosition(lane, getReference());
             if (fraction >= 0.0 && fraction <= 1.0)
             {
                 // TODO widest lane in case we are registered on more than one lane with the reference point
                 // TODO lane that leads to our location or not if we are registered on parallel lanes?
                 return new DirectedLanePosition(lane, position(lane, getReference()), this.getDirection(lane));
             }
         }
         throw new GTUException("The reference point of GTU " + this + " is not on any of the lanes on which it is registered");
     }
 
     /**
      * Schedule the triggers for this GTU that are going to happen until the next evaluation time. Also schedule the
      * registration and deregistration of lanes when the vehicle enters or leaves them, at the exact right time. <br>
      * Note: when the GTU makes a lane change, the vehicle will be registered for both lanes during the entire maneuver.
      * @throws NetworkException on network inconsistency
      * @throws SimRuntimeException should never happen
      * @throws GTUException when a branch is reached where the GTU does not know where to go next
      */
     private void scheduleEnterLeaveTriggers() throws NetworkException, SimRuntimeException, GTUException
     {
         /*
          * Move the vehicle into any new lanes with the front, and schedule entrance during this time step and calculate the
          * current position based on the fractional position, because THE POSITION METHOD DOES NOT WORK FOR THIS. IT CALCULATES
          * THE POSITION BASED ON THE NEWLY CALCULATED ACCELERATION AND SPEED AND CAN THEREFORE MAKE AN ERROR.
          */
         double moveSI = getOperationalPlan().getTotalLength().si;
         Map<Lane, GTUDirectionality> lanesCopy = new LinkedHashMap<>(this.lanesCurrentOperationalPlan);
         for (Lane lane : lanesCopy.keySet()) // use a copy because this.lanes can change
         {
             // schedule triggers on this lane
             double referenceStartSI = this.fractionalLinkPositions.get(lane.getParentLink()) * lane.getLength().getSI();
             double sign = lanesCopy.get(lane).equals(GTUDirectionality.DIR_PLUS) ? 1.0 : -1.0;
             if (lanesCopy.get(lane).equals(GTUDirectionality.DIR_PLUS))
             {
                 lane.scheduleSensorTriggers(this, referenceStartSI, moveSI);
             }
             else
             {
                 // TODO extra argument for DIR_MINUS driving direction?
                 lane.scheduleSensorTriggers(this, referenceStartSI - moveSI, moveSI);
             }
 
             // determine when our FRONT will pass the end of this registered lane in case of driving DIR_PLUS or
             // the start of this registered lane when driving DIR_MINUS.
             // if the time is earlier than the end of the timestep: schedule the enterLane method.
             double frontPosSI = referenceStartSI + sign * getFront().getDx().getSI();
             double nextFrontPosSI = frontPosSI + sign * moveSI;
 
             // LANE WE COME FROM IS IN PLUS DIRECTION
             if (lanesCopy.get(lane).equals(GTUDirectionality.DIR_PLUS))
             {
                 while (frontPosSI <= lane.getLength().si && nextFrontPosSI > lane.getLength().si)
                 {
                     // TODO PK: this goes very wrong for networks with short lanes with alternating GTUDireationality
                     Lane nextLane = determineNextLane(lane);
                     GTUDirectionality direction = lane.nextLanes(getGTUType()).get(nextLane);
                     /*
                      * We have to register the position at the previous timestep to keep calculations consistent. And we have to
                      * correct for the position of the reference point. The idea is that we register the vehicle 'before' the
                      * entrance of the new lane at the time of the last timestep, so for a DIR_PLUS on a negative position, and
                      * for a DIR_MINUS on a position beyond the length of the next lane.
                      */
                     if (direction.equals(GTUDirectionality.DIR_PLUS))
                     {
                         Length refPosAtLastTimestep =
                                 new Length(-(lane.getLength().si - frontPosSI) - getFront().getDx().si, LengthUnit.SI);
                         enterLane(nextLane, refPosAtLastTimestep, direction);
                         // schedule any sensor triggers on this lane for the remainder time
                         nextLane.scheduleSensorTriggers(this, refPosAtLastTimestep.getSI(), moveSI);
                     }
                     else if (direction.equals(GTUDirectionality.DIR_MINUS))
                     {
                         Length refPosAtLastTimestep =
                                 new Length(nextLane.getLength().si + (lane.getLength().si - frontPosSI) + getFront().getDx().si,
                                         LengthUnit.SI);
                         enterLane(nextLane, refPosAtLastTimestep, direction);
                         // schedule any sensor triggers on this lane for the remainder time
                         // TODO extra argument for DIR_MINUS driving direction?
                         nextLane.scheduleSensorTriggers(this, refPosAtLastTimestep.getSI() - moveSI, moveSI);
                     }
                     else
                     {
                         throw new NetworkException("scheduleTriggers DIR_PLUS for GTU " + toString() + ", nextLane " + nextLane
                                 + ", direction not DIR_PLUS or DIR_MINUS");
                     }
 
                     // TODO this does not account for the GTUDirectionality
                     // next lane
                     frontPosSI -= lane.getLength().si;
                     nextFrontPosSI -= lane.getLength().si;
                     lane = nextLane;
                 }
             }
 
             // LANE WE COME FROM IS IN MINUS DIRECTION
             else if (lanesCopy.get(lane).equals(GTUDirectionality.DIR_MINUS))
             {
                 if (frontPosSI >= 0.0 && nextFrontPosSI < 0.0)
                 {
                     Lane prevLane = determinePrevLane(lane);
                     GTUDirectionality direction = lane.prevLanes(getGTUType()).get(prevLane);
                     /*
                      * We have to register the position at the previous timestep to keep calculations consistent. And we have to
                      * correct for the position of the reference point. The idea is that we register the vehicle 'before' the
                      * entrance of the new lane at the time of the last timestep, so for a DIR_MINUS on a negative position, and
                      * for a DIR_PLUS on a position beyond the length of the next lane.
                      */
                     if (direction.equals(GTUDirectionality.DIR_MINUS))
                     {
                         // TODO do this at the right time, scheduled with triggers. 4x
                         Length refPosAtLastTimestep =
                                 new Length(prevLane.getLength().si + frontPosSI + getFront().getDx().si, LengthUnit.SI);
                         enterLane(prevLane, refPosAtLastTimestep, direction);
                         // schedule any sensor triggers on this lane for the remainder time
                         prevLane.scheduleSensorTriggers(this, refPosAtLastTimestep.getSI() - moveSI, moveSI);
                     }
                     else if (direction.equals(GTUDirectionality.DIR_PLUS))
                     {
                         Length refPosAtLastTimestep = new Length(-frontPosSI - getFront().getDx().si, LengthUnit.SI);
                         enterLane(prevLane, refPosAtLastTimestep, direction);
                         // schedule any sensor triggers on this lane for the remainder time
                         // TODO extra argument for DIR_MINUS driving direction?
                         prevLane.scheduleSensorTriggers(this, refPosAtLastTimestep.getSI(), moveSI);
                     }
                     else
                     {
                         throw new NetworkException("scheduleTriggers DIR_MINUS for GTU " + toString() + ", prevLane " + prevLane
                                 + ", direction not DIR_PLUS or DIR_MINUS");
                     }
                 }
             }
 
             else
             {
                 throw new NetworkException(
                         "scheduleTriggers for GTU " + toString() + ", lane " + lane + ", direction not DIR_PLUS or DIR_MINUS");
             }
         }
 
         // move the vehicle out of any lanes with the BACK, and schedule exit during this time step
         for (Lane lane : this.lanesCurrentOperationalPlan.keySet())
         {
             // Determine when our REAR will pass the end of this registered lane.
             // TODO look if more lanes are exited in one timestep, and continue the algorithm with the remainder of the time...
             double referenceStartSI = this.fractionalLinkPositions.get(lane.getParentLink()) * lane.getLength().getSI();
             double sign = this.lanesCurrentOperationalPlan.get(lane).equals(GTUDirectionality.DIR_PLUS) ? 1.0 : -1.0;
             double rearPosSI = referenceStartSI + sign * getRear().getDx().getSI();
 
             if (this.lanesCurrentOperationalPlan.get(lane).equals(GTUDirectionality.DIR_PLUS))
             {
                 if (rearPosSI <= lane.getLength().si && rearPosSI + moveSI > lane.getLength().si)
                 {
                     double distanceToLeave = lane.getLength().si - rearPosSI;
                     Time exitTime = getOperationalPlan().timeAtDistance(new Length(distanceToLeave, LengthUnit.SI));
                     SimEvent<OTSSimTimeDouble> event = new SimEvent<>(new OTSSimTimeDouble(exitTime), this, this, "leaveLane",
                             new Object[] { lane, new Boolean(false) });
                     getSimulator().scheduleEvent(event);
                     addTrigger(lane, event);
                     // XXXXXXXXXXXXXXXXXX Minus one ULP is not safe if you want to add the current time
                     // XXXXXXXXXXXXXXXXXX Should compute the time time at which the rear of the GTU exits the lane???
                     // getSimulator().scheduleEventRel(new Duration(timestep - Math.ulp(timestep), TimeUnit.SI), this, this,
                     // "leaveLane", new Object[] { lane, new Boolean(true) }); // TODO should be false?
                 }
             }
             else
             {
                 if (rearPosSI >= 0.0 && rearPosSI - moveSI < 0.0)
                 {
                     double distanceToLeave = rearPosSI;
                     Time exitTime = getOperationalPlan().timeAtDistance(new Length(distanceToLeave, LengthUnit.SI));
                     SimEvent<OTSSimTimeDouble> event = new SimEvent<>(new OTSSimTimeDouble(exitTime), this, this, "leaveLane",
                             new Object[] { lane, new Boolean(false) });
                     getSimulator().scheduleEvent(event);
                     addTrigger(lane, event);
 
                     // getSimulator().scheduleEventRel(new Duration(timestep - Math.ulp(timestep), TimeUnit.SI), this, this,
                     // "leaveLane", new Object[] { lane, new Boolean(true) }); // XXX: should be false?
                 }
             }
         }
     }
 
     /**
      * XXX: direction dependent... <br>
      * @param lane the lane to find the successor for
      * @return the next lane for this GTU
      * @throws NetworkException when no next lane exists or the route branches into multiple next lanes
      * @throws GTUException when no route could be found or the routeNavigator returns null
      */
     private Lane determineNextLane(final Lane lane) throws NetworkException, GTUException
     {
         Lane nextLane = null;
         if (lane.nextLanes(getGTUType()).size() == 0)
         {
             throw new NetworkException(this + " - lane " + lane + " does not have a successor");
         }
         if (lane.nextLanes(getGTUType()).size() == 1)
         {
             nextLane = lane.nextLanes(getGTUType()).keySet().iterator().next();
         }
         else
         {
             if (!(getStrategicalPlanner() instanceof LaneBasedStrategicalRoutePlanner))
             {
                 throw new GTUException(this + " reaches branch but has no route navigator");
             }
             Node nextNode = ((LaneBasedStrategicalRoutePlanner) getStrategicalPlanner()).nextNode(lane.getParentLink(),
                     GTUDirectionality.DIR_PLUS, getGTUType());
             if (null == nextNode)
             {
                 throw new GTUException(this + " reaches branch and the route returns null as nextNodeToVisit");
             }
             int continuingLaneCount = 0;
             for (Lane candidateLane : lane.nextLanes(getGTUType()).keySet())
             {
                 if (null != this.lanesCurrentOperationalPlan.get(candidateLane))
                 {
                     continue; // Already on this lane
                 }
                 // XXX Hack - this should be done more considerate -- fails at loops...
                 if (nextNode == candidateLane.getParentLink().getEndNode()
                         || nextNode == candidateLane.getParentLink().getStartNode())
                 {
                     nextLane = candidateLane;
                     continuingLaneCount++;
                 }
             }
             if (continuingLaneCount == 0)
             {
                 throw new NetworkException(this + " reached branch and the route specifies a nextNodeToVisit (" + nextNode
                         + ") that is not a next node " + "at this branch at (" + lane.getParentLink().getEndNode() + ")");
             }
             if (continuingLaneCount > 1)
             {
                 throw new NetworkException(
                         this + " reached branch and the route specifies multiple lanes to continue on at this branch ("
                                 + lane.getParentLink().getEndNode() + "). This is not yet supported");
             }
         }
         return nextLane;
     }
 
     /**
      * XXX: direction dependent... <br>
      * @param lane the lane to find the predecessor for
      * @return the next lane for this GTU
      * @throws NetworkException when no next lane exists or the route branches into multiple next lanes
      * @throws GTUException when no route could be found or the routeNavigator returns null
      */
     private Lane determinePrevLane(final Lane lane) throws NetworkException, GTUException
     {
         Lane prevLane = null;
         if (lane.prevLanes(getGTUType()).size() == 0)
         {
             throw new NetworkException(this + " - lane " + lane + " does not have a predecessor");
         }
         if (lane.prevLanes(getGTUType()).size() == 1)
         {
             prevLane = lane.prevLanes(getGTUType()).keySet().iterator().next();
         }
         else
         {
             if (!(getStrategicalPlanner() instanceof LaneBasedStrategicalRoutePlanner))
             {
                 throw new GTUException(this + " reaches branch but has no route navigator");
             }
             Node prevNode = ((LaneBasedStrategicalRoutePlanner) getStrategicalPlanner()).nextNode(lane.getParentLink(),
                     GTUDirectionality.DIR_MINUS, getGTUType());
             if (null == prevNode)
             {
                 throw new GTUException(this + " reaches branch and the route returns null as nextNodeToVisit");
             }
             int continuingLaneCount = 0;
             for (Lane candidateLane : lane.prevLanes(getGTUType()).keySet())
             {
                 if (null != this.lanesCurrentOperationalPlan.get(candidateLane))
                 {
                     continue; // Already on this lane
                 }
                 // XXX Hack - this should be done more considerate -- fails at loops...
                 if (prevNode == candidateLane.getParentLink().getEndNode()
                         || prevNode == candidateLane.getParentLink().getStartNode())
                 {
                     prevLane = candidateLane;
                     continuingLaneCount++;
                 }
             }
             if (continuingLaneCount == 0)
             {
                 throw new NetworkException(this + " reached branch and the route specifies a nextNodeToVisit (" + prevNode
                         + ") that is not a next node " + "at this branch at (" + lane.getParentLink().getStartNode() + ")");
             }
             if (continuingLaneCount > 1)
             {
                 throw new NetworkException(
                         this + " reached branch and the route specifies multiple lanes to continue on at this branch ("
                                 + lane.getParentLink().getStartNode() + "). This is not yet supported");
             }
         }
         return prevLane;
     }
 
     /** {@inheritDoc} */
     @Override
     public final Map<Lane, Double> fractionalPositions(final RelativePosition relativePosition) throws GTUException
     {
         return fractionalPositions(relativePosition, getSimulator().getSimulatorTime().getTime());
     }
 
     /** {@inheritDoc} */
     @Override
     public final Map<Lane, Double> fractionalPositions(final RelativePosition relativePosition, final Time when)
             throws GTUException
     {
         Map<Lane, Double> positions = new LinkedHashMap<>();
         for (Lane lane : this.lanesCurrentOperationalPlan.keySet())
         {
             positions.put(lane, fractionalPosition(lane, relativePosition, when));
         }
         return positions;
     }
 
     /** {@inheritDoc} */
     @Override
     public final double fractionalPosition(final Lane lane, final RelativePosition relativePosition, final Time when)
             throws GTUException
     {
         return position(lane, relativePosition, when).getSI() / lane.getLength().getSI();
     }
 
     /** {@inheritDoc} */
     @Override
     public final double fractionalPosition(final Lane lane, final RelativePosition relativePosition) throws GTUException
     {
         return position(lane, relativePosition).getSI() / lane.getLength().getSI();
     }
 
     /** {@inheritDoc} */
     @Override
     public final LaneBasedStrategicalPlanner getStrategicalPlanner()
     {
         return (LaneBasedStrategicalPlanner) super.getStrategicalPlanner();
     }
 
     /** {@inheritDoc} */
     @Override
     public final BehavioralCharacteristics getBehavioralCharacteristics()
     {
         return getStrategicalPlanner().getBehavioralCharacteristics();
     }
 
     /** {@inheritDoc} */
     @Override
     public final LaneBasedTacticalPlanner getTacticalPlanner()
     {
         return (LaneBasedTacticalPlanner) super.getTacticalPlanner();
     }
 
     /** {@inheritDoc} */
     public final void addTrigger(final Lane lane, final SimEvent<OTSSimTimeDouble> event)
     {
         List<SimEvent<OTSSimTimeDouble>> list = this.pendingTriggers.get(lane);
         if (null == list)
         {
             list = new ArrayList<>();
         }
         list.add(event);
         this.pendingTriggers.put(lane, list);
     }
 
     /** {@inheritDoc} */
     @Override
     @SuppressWarnings("checkstyle:designforextension")
     public void destroy()
     {
         DirectedLanePosition dlp = null;
         try
         {
             dlp = getReferencePosition();
         }
         catch (GTUException e)
         {
             // ignore. not important at destroy
         }
         DirectedPoint location = this.getOperationalPlan() == null ? new DirectedPoint(0.0, 0.0, 0.0) : getLocation();
 
         synchronized (this.lock)
         {
             Set<Lane> laneSet = new HashSet<>(this.lanesCurrentOperationalPlan.keySet()); // Operate on a copy of the key set
             for (Lane lane : laneSet)
             {
                 try
                 {
                     leaveLane(lane, true);
                 }
                 catch (GTUException e)
                 {
                     // ignore. not important at destroy
                 }
             }
         }
 
         if (dlp != null && dlp.getLane() != null)
         {
             Lane referenceLane = dlp.getLane();
             fireTimedEvent(LaneBasedGTU.LANEBASED_DESTROY_EVENT,
                     new Object[] { getId(), location, getOdometer(), referenceLane, dlp.getPosition(), dlp.getGtuDirection() },
                     getSimulator().getSimulatorTime());
         }
         else
         {
             fireTimedEvent(LaneBasedGTU.LANEBASED_DESTROY_EVENT,
                     new Object[] { getId(), location, getOdometer(), null, Length.ZERO, null },
                     getSimulator().getSimulatorTime());
         }
 
         super.destroy();
     }
 
     /** {@inheritDoc} */
     @Override
     public final Bounds getBounds()
     {
         double dx = 0.5 * getLength().doubleValue();
         double dy = 0.5 * getWidth().doubleValue();
         return new BoundingBox(new Point3d(-dx, -dy, 0.0), new Point3d(dx, dy, 0.0));
     }
 
     /** {@inheritDoc} */
     @SuppressWarnings("checkstyle:designforextension")
     public String toString()
     {
         return String.format("GTU " + getId());
     }
 }