/// <summary>
        /// Plan a lane change
        /// </summary>
        /// <param name="cls"></param>
        /// <param name="initialManeuver"></param>
        /// <param name="targetManeuver"></param>
        /// <returns></returns>
        public Maneuver PlanLaneChange(ChangeLanesState cls, VehicleState vehicleState, RoadPlan roadPlan, 
            List<ITacticalBlockage> blockages, List<ArbiterWaypoint> ignorable)
        {
            // check blockages
            if (blockages != null && blockages.Count > 0 && blockages[0] is LaneChangeBlockage)
            {
                // create the blockage state
                EncounteredBlockageState ebs = new EncounteredBlockageState(blockages[0], CoreCommon.CorePlanningState);

                // go to a blockage handling tactical
                return new Maneuver(new NullBehavior(), ebs, TurnDecorators.NoDecorators, vehicleState.Timestamp);
            }

            // lanes of the lane change
            ArbiterLane initial = cls.Parameters.Initial;
            ArbiterLane target = cls.Parameters.Target;

            #region Initial Forwards

            if (!cls.Parameters.InitialOncoming)
            {
                ForwardReasoning initialReasoning = new ForwardReasoning(new LateralReasoning(null, SideObstacleSide.Driver), new LateralReasoning(null, SideObstacleSide.Driver), initial);

                #region Target Forwards

                if (!cls.Parameters.TargetOncoming)
                {
                    // target reasoning
                    ForwardReasoning targetReasoning = new ForwardReasoning(new LateralReasoning(null, SideObstacleSide.Driver), new LateralReasoning(null, SideObstacleSide.Driver), target);

                    #region Navigation

                    if (cls.Parameters.Reason == LaneChangeReason.Navigation)
                    {
                        // parameters to follow
                        List<TravelingParameters> tps = new List<TravelingParameters>();

                        // vehicles to ignore
                        List<int> ignorableVehicles = new List<int>();

                        // params for forward lane
                        initialReasoning.ForwardManeuver(initial, vehicleState, roadPlan, blockages, ignorable);
                        TravelingParameters initialParams = initialReasoning.ForwardMonitor.ParameterizationHelper(initial, initial,
                            CoreCommon.Mission.MissionCheckpoints.Peek().WaypointId.Equals(roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.WaypointId) ?
                            initial.WaypointList[initial.WaypointList.Count - 1].Position : roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.Position,
                            vehicleState.Front, CoreCommon.CorePlanningState, vehicleState, initialReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle);

                        ArbiterOutput.Output("initial dist to go: " + initialParams.DistanceToGo.ToString("f3"));

                        if (initialParams.Type == TravellingType.Vehicle && !initialReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle.IsStopped)
                        {
                            tps.Add(initialParams);
                        }
                        else
                            tps.Add(initialReasoning.ForwardMonitor.NavigationParameters);

                        ignorableVehicles.AddRange(initialParams.VehiclesToIgnore);

                        // get params for the final lane
                        targetReasoning.ForwardManeuver(target, vehicleState, roadPlan, blockages, new List<ArbiterWaypoint>());
                        TravelingParameters targetParams = targetReasoning.ForwardMonitor.CurrentParameters;
                        tps.Add(targetParams);
                        ignorableVehicles.AddRange(targetParams.VehiclesToIgnore);

                        try
                        {
                            if (CoreCommon.Communications.GetVehicleSpeed().Value < 0.1 &&
                                targetParams.Type == TravellingType.Vehicle &&
                                targetReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle != null &&
                                targetReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle.QueuingState.Queuing == QueuingState.Failed)
                            {
                                return new Maneuver(new HoldBrakeBehavior(), new StayInLaneState(target, CoreCommon.CorePlanningState), TurnDecorators.NoDecorators, vehicleState.Timestamp);
                            }
                        }
                        catch (Exception) { }

                        ArbiterOutput.Output("target dist to go: " + targetParams.DistanceToGo.ToString("f3"));

                        // decorators
                        List<BehaviorDecorator> decorators = initial.LaneOnLeft != null && initial.LaneOnLeft.Equals(target) ? TurnDecorators.LeftTurnDecorator : TurnDecorators.RightTurnDecorator;

                        // distance
                        double distanceToGo = initial.DistanceBetween(vehicleState.Front, cls.Parameters.DepartUpperBound);
                        cls.Parameters.DistanceToDepartUpperBound = distanceToGo;

                        // check if need to modify distance to go
                        if (initialParams.Type == TravellingType.Vehicle && initialReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle.IsStopped)
                        {
                            double curDistToUpper = cls.Parameters.DistanceToDepartUpperBound;
                            double newVhcDistToUpper = initial.DistanceBetween(vehicleState.Front, initialReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle.ClosestPosition) - 2.0;

                            if (curDistToUpper > newVhcDistToUpper)
                            {
                                distanceToGo = newVhcDistToUpper;
                            }
                        }

                        // get final
                        tps.Sort();

                        // get the proper speed command
                        ScalarSpeedCommand sc = new ScalarSpeedCommand(tps[0].RecommendedSpeed);
                        if (sc.Speed < 8.84)
                            sc = new ScalarSpeedCommand(Math.Min(targetParams.RecommendedSpeed, 8.84));

                        // continue the lane change with the proper speed command
                        ChangeLaneBehavior clb = new ChangeLaneBehavior(initial.LaneId, target.LaneId, initial.LaneOnLeft != null && initial.LaneOnLeft.Equals(target), distanceToGo,
                            sc, targetParams.VehiclesToIgnore, initial.LanePath(), target.LanePath(), initial.Width, target.Width, initial.NumberOfLanesLeft(vehicleState.Front, true),
                            initial.NumberOfLanesRight(vehicleState.Front, true));

                        // standard maneuver
                        return new Maneuver(clb, CoreCommon.CorePlanningState, decorators, vehicleState.Timestamp);
                    }

                    #endregion

                    #region Failed Forwards

                    else if (cls.Parameters.Reason == LaneChangeReason.FailedForwardVehicle)
                    {
                        // parameters to follow
                        List<TravelingParameters> tps = new List<TravelingParameters>();

                        // vehicles to ignore
                        List<int> ignorableVehicles = new List<int>();

                        // params for forward lane
                        initialReasoning.ForwardManeuver(initial, vehicleState, roadPlan, blockages, ignorable);
                        TravelingParameters initialParams = initialReasoning.ForwardMonitor.ParameterizationHelper(initial, initial,
                            CoreCommon.Mission.MissionCheckpoints.Peek().WaypointId.Equals(roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.WaypointId) ?
                            initial.WaypointList[initial.WaypointList.Count - 1].Position : roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.Position,
                            vehicleState.Front, CoreCommon.CorePlanningState, vehicleState, null);
                        tps.Add(initialParams);
                        ignorableVehicles.AddRange(initialParams.VehiclesToIgnore);

                        // get params for the final lane
                        targetReasoning.ForwardManeuver(target, vehicleState, roadPlan, blockages, new List<ArbiterWaypoint>());
                        TravelingParameters targetParams = targetReasoning.ForwardMonitor.CurrentParameters;
                        tps.Add(targetParams);
                        ignorableVehicles.AddRange(targetParams.VehiclesToIgnore);

                        // decorators
                        List<BehaviorDecorator> decorators = initial.LaneOnLeft != null && initial.LaneOnLeft.Equals(target) ? TurnDecorators.LeftTurnDecorator : TurnDecorators.RightTurnDecorator;

                        // distance
                        double distanceToGo = initial.DistanceBetween(vehicleState.Front, cls.Parameters.DepartUpperBound);
                        cls.Parameters.DistanceToDepartUpperBound = distanceToGo;

                        // get final
                        tps.Sort();

                        // get the proper speed command
                        SpeedCommand sc = new ScalarSpeedCommand(tps[0].RecommendedSpeed);

                        // continue the lane change with the proper speed command
                        ChangeLaneBehavior clb = new ChangeLaneBehavior(initial.LaneId, target.LaneId, initial.LaneOnLeft != null && initial.LaneOnLeft.Equals(target), distanceToGo,
                            sc, targetParams.VehiclesToIgnore, initial.LanePath(), target.LanePath(), initial.Width, target.Width, initial.NumberOfLanesLeft(vehicleState.Front, true),
                            initial.NumberOfLanesRight(vehicleState.Front, true));

                        // standard maneuver
                        return new Maneuver(clb, CoreCommon.CorePlanningState, decorators, vehicleState.Timestamp);
                    }

                    #endregion

                    #region Slow

                    else if (cls.Parameters.Reason == LaneChangeReason.SlowForwardVehicle)
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }

                    #endregion

                    else
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }
                }

                #endregion

                #region Target Oncoming

                else
                {
                    OpposingReasoning targetReasoning = new OpposingReasoning(new OpposingLateralReasoning(null, SideObstacleSide.Driver), new OpposingLateralReasoning(null, SideObstacleSide.Driver), target);

                    #region Failed Forward

                    if (cls.Parameters.Reason == LaneChangeReason.FailedForwardVehicle)
                    {
                        // parameters to follow
                        List<TravelingParameters> tps = new List<TravelingParameters>();

                        // ignore the forward vehicle but keep params for forward lane
                        initialReasoning.ForwardManeuver(initial, vehicleState, roadPlan, blockages, ignorable);
                        TravelingParameters initialParams = initialReasoning.ForwardMonitor.ParameterizationHelper(initial, initial,
                            CoreCommon.Mission.MissionCheckpoints.Peek().WaypointId.Equals(roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.WaypointId) ?
                            initial.WaypointList[initial.WaypointList.Count-1].Position : roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.Position, vehicleState.Front, CoreCommon.CorePlanningState, vehicleState, null);
                        tps.Add(initialParams);

                        // get params for the final lane
                        targetReasoning.ForwardManeuver(target, initial, vehicleState, roadPlan, blockages);
                        TravelingParameters targetParams = targetReasoning.OpposingForwardMonitor.CurrentParamters.Value;
                        tps.Add(targetParams);

                        // decorators
                        List<BehaviorDecorator> decorators = cls.Parameters.ToLeft ? TurnDecorators.LeftTurnDecorator : TurnDecorators.RightTurnDecorator;

                        // distance
                        double distanceToGo = initial.DistanceBetween(vehicleState.Front, cls.Parameters.DepartUpperBound);
                        cls.Parameters.DistanceToDepartUpperBound = distanceToGo;

                        // get final
                        tps.Sort();

                        // get the proper speed command
                        SpeedCommand sc = new ScalarSpeedCommand(Math.Min(tps[0].RecommendedSpeed, 2.24));

                        // check final for stopped failed opposing
                        VehicleAgent forwardVa = targetReasoning.OpposingForwardMonitor.ForwardVehicle.CurrentVehicle;
                        if (forwardVa != null)
                        {
                            // dist between
                            double distToFV = -targetReasoning.Lane.DistanceBetween(vehicleState.Front, forwardVa.ClosestPosition);

                            // check stopped
                            bool stopped = Math.Abs(CoreCommon.Communications.GetVehicleSpeed().Value) < 0.5;

                            // check distance
                            bool distOk = distToFV < 2.5 * TahoeParams.VL;

                            // check failed
                            bool failed = forwardVa.QueuingState.Queuing == QueuingState.Failed;

                            // notify
                            ArbiterOutput.Output("Forward Vehicle: Stopped: " + stopped.ToString() + ", DistOk: " + distOk.ToString() + ", Failed: " + failed.ToString());

                            // check all for failed
                            if (stopped && distOk && failed)
                            {
                                // check inside target
                                if (target.LanePolygon.IsInside(vehicleState.Front))
                                {
                                    // blockage recovery
                                    StayInLaneState sils = new StayInLaneState(initial, CoreCommon.CorePlanningState);
                                    StayInLaneBehavior silb = new StayInLaneBehavior(initial.LaneId, new StopAtDistSpeedCommand(TahoeParams.VL * 2.0, true), new List<int>(), initial.LanePath(), initial.Width, initial.NumberOfLanesLeft(vehicleState.Front, false), initial.NumberOfLanesRight(vehicleState.Front, false));
                                    BlockageRecoveryState brs = new BlockageRecoveryState(silb, sils, sils, BlockageRecoveryDEFCON.REVERSE,
                                        new EncounteredBlockageState(new LaneBlockage(new TrajectoryBlockedReport(CompletionResult.Stopped, 4.0, BlockageType.Static, -1, true, silb.GetType())), sils, BlockageRecoveryDEFCON.INITIAL, SAUDILevel.None),
                                        BlockageRecoverySTATUS.EXECUTING);
                                    return new Maneuver(silb, brs, TurnDecorators.HazardDecorator, vehicleState.Timestamp);
                                }
                                // check which lane we are in
                                else
                                {
                                    // return to forward lane
                                    return new Maneuver(new HoldBrakeBehavior(), new StayInLaneState(initial, CoreCommon.CorePlanningState), TurnDecorators.NoDecorators, vehicleState.Timestamp);
                                }
                            }
                        }

                        // continue the lane change with the proper speed command
                        ChangeLaneBehavior clb = new ChangeLaneBehavior(initial.LaneId, target.LaneId, cls.Parameters.ToLeft, distanceToGo,
                            sc, targetParams.VehiclesToIgnore, initial.LanePath(), target.ReversePath, initial.Width, target.Width, initial.NumberOfLanesLeft(vehicleState.Front, true),
                            initial.NumberOfLanesRight(vehicleState.Front, true));

                        // standard maneuver
                        return new Maneuver(clb, CoreCommon.CorePlanningState, decorators, vehicleState.Timestamp);
                    }

                    #endregion

                    #region Other

                    else if (cls.Parameters.Reason == LaneChangeReason.Navigation)
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }
                    else if (cls.Parameters.Reason == LaneChangeReason.SlowForwardVehicle)
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }
                    else
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }

                    #endregion
                }

                #endregion
            }

            #endregion

            #region Initial Oncoming

            else
            {
                OpposingReasoning initialReasoning = new OpposingReasoning(new OpposingLateralReasoning(null, SideObstacleSide.Driver), new OpposingLateralReasoning(null, SideObstacleSide.Driver), initial);

                #region Target Forwards

                if (!cls.Parameters.TargetOncoming)
                {
                    ForwardReasoning targetReasoning = new ForwardReasoning(new LateralReasoning(null, SideObstacleSide.Driver), new LateralReasoning(null, SideObstacleSide.Driver), target);

                    if (cls.Parameters.Reason == LaneChangeReason.FailedForwardVehicle)
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }

                    #region Navigation

                    else if (cls.Parameters.Reason == LaneChangeReason.Navigation)
                    {
                        // parameters to follow
                        List<TravelingParameters> tps = new List<TravelingParameters>();

                        // distance to the upper bound of the change
                        double distanceToGo = target.DistanceBetween(vehicleState.Front, cls.Parameters.DepartUpperBound);
                        cls.Parameters.DistanceToDepartUpperBound = distanceToGo;

                        // get params for the initial lane
                        initialReasoning.ForwardManeuver(initial, target, vehicleState, roadPlan, blockages);

                        // current params of the fqm
                        TravelingParameters initialParams = initialReasoning.OpposingForwardMonitor.CurrentParamters.Value;

                        if (initialParams.Type == TravellingType.Vehicle)
                        {
                            if(!initialReasoning.OpposingForwardMonitor.ForwardVehicle.CurrentVehicle.IsStopped)
                                tps.Add(initialParams);
                            else
                            {
                                tps.Add(initialReasoning.OpposingForwardMonitor.NaviationParameters);
                                distanceToGo = initial.DistanceBetween(initialReasoning.OpposingForwardMonitor.ForwardVehicle.CurrentVehicle.ClosestPosition, vehicleState.Front) - TahoeParams.VL;
                            }
                        }
                        else
                            tps.Add(initialReasoning.OpposingForwardMonitor.NaviationParameters);

                        // get params for forward lane
                        targetReasoning.ForwardManeuver(target, vehicleState, roadPlan, blockages, ignorable);
                        TravelingParameters targetParams = targetReasoning.ForwardMonitor.ParameterizationHelper(target, target,
                            CoreCommon.Mission.MissionCheckpoints.Peek().WaypointId.Equals(roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.WaypointId) ?
                            target.WaypointList[target.WaypointList.Count-1].Position : roadPlan.BestPlan.laneWaypointOfInterest.PointOfInterest.Position,
                            vehicleState.Front, CoreCommon.CorePlanningState, vehicleState, targetReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle);
                        tps.Add(targetParams);

                        // ignoring vehicles add
                        List<int> ignoreVehicles = initialParams.VehiclesToIgnore;
                        ignoreVehicles.AddRange(targetParams.VehiclesToIgnore);

                        // decorators
                        List<BehaviorDecorator> decorators = !cls.Parameters.ToLeft ? TurnDecorators.RightTurnDecorator : TurnDecorators.LeftTurnDecorator;

                        // get final
                        tps.Sort();

                        // get the proper speed command
                        SpeedCommand sc = tps[0].SpeedCommand;

                        if (sc is StopAtDistSpeedCommand)
                        {
                            sc = new ScalarSpeedCommand(0.0);
                        }

                        // check final for stopped failed opposing
                        VehicleAgent forwardVa = targetReasoning.ForwardMonitor.ForwardVehicle.CurrentVehicle;
                        if (forwardVa != null)
                        {
                            // dist between
                            double distToFV = targetReasoning.Lane.DistanceBetween(vehicleState.Front, forwardVa.ClosestPosition);

                            // check stopped
                            bool stopped = Math.Abs(CoreCommon.Communications.GetVehicleSpeed().Value) < 0.5;

                            // check distance
                            bool distOk = distToFV < 2.5 * TahoeParams.VL;

                            // check failed
                            bool failed = forwardVa.QueuingState.Queuing == QueuingState.Failed;

                            // notify
                            ArbiterOutput.Output("Forward Vehicle: Stopped: " + stopped.ToString() + ", DistOk: " + distOk.ToString() + ", Failed: " + failed.ToString());

                            // check all for failed
                            if (stopped && distOk && failed)
                            {
                                // check which lane we are in
                                if (initial.LanePolygon.IsInside(vehicleState.Front))
                                {
                                    // return to opposing lane
                                    return new Maneuver(new HoldBrakeBehavior(), new OpposingLanesState(initial, true, CoreCommon.CorePlanningState, vehicleState), TurnDecorators.NoDecorators, vehicleState.Timestamp);
                                }
                                else
                                {
                                    // lane state
                                    return new Maneuver(new HoldBrakeBehavior(), new StayInLaneState(target, CoreCommon.CorePlanningState), TurnDecorators.NoDecorators, vehicleState.Timestamp);
                                }
                            }
                        }

                        // continue the lane change with the proper speed command
                        ChangeLaneBehavior clb = new ChangeLaneBehavior(initial.LaneId, target.LaneId, cls.Parameters.ToLeft, distanceToGo,
                            sc, ignoreVehicles, initial.ReversePath, target.LanePath(), initial.Width, target.Width, initial.NumberOfLanesLeft(vehicleState.Front, false),
                            initial.NumberOfLanesRight(vehicleState.Front, false));

                        // standard maneuver
                        return new Maneuver(clb, CoreCommon.CorePlanningState, decorators, vehicleState.Timestamp);
                    }

                    #endregion

                    else if (cls.Parameters.Reason == LaneChangeReason.SlowForwardVehicle)
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }
                    else
                    {
                        // fallout exception
                        throw new Exception("currently unsupported lane change type");
                    }
                }

                #endregion

                else
                {
                    // fallout exception
                    throw new Exception("currently unsupported lane change type");
                }
            }

            #endregion
        }