diff --git a/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchState.cs b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchState.cs
new file mode 100644
index 0000000..caa87d7
--- /dev/null
+++ b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchState.cs
@@ -0,0 +1,11 @@
+namespace MultiWheelC.TrajectoryPlanning.EMPlanner;
+
+public enum GearSwitchState
+{
+    Following,
+    ApproachingGearSwitch,
+    HoldingZero,
+    RequestingDirectionChange,
+    AwaitingDirectionConfirmation,
+    Completed,
+}
diff --git a/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchStateMachine.cs b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchStateMachine.cs
new file mode 100644
index 0000000..f8d5e53
--- /dev/null
+++ b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/GearSwitchStateMachine.cs
@@ -0,0 +1,144 @@
+using System;
+using MultiWheelC.TrajectoryPlanning.CoarsePath;
+
+namespace MultiWheelC.TrajectoryPlanning.EMPlanner;
+
+/// <summary>Pure caller-clocked state machine for a zero-speed direction change.</summary>
+public sealed class GearSwitchStateMachine
+{
+    private readonly double stopSpeedToleranceMetersPerSecond;
+    private readonly TimeSpan zeroSpeedHoldDuration;
+    private DateTimeOffset? zeroSpeedSince;
+
+    public GearSwitchStateMachine(double stopSpeedToleranceMetersPerSecond, double zeroSpeedHoldSeconds)
+    {
+        if (!IsNonNegativeFinite(stopSpeedToleranceMetersPerSecond))
+            throw new ArgumentOutOfRangeException(nameof(stopSpeedToleranceMetersPerSecond));
+        if (!IsNonNegativeFinite(zeroSpeedHoldSeconds))
+            throw new ArgumentOutOfRangeException(nameof(zeroSpeedHoldSeconds));
+
+        this.stopSpeedToleranceMetersPerSecond = stopSpeedToleranceMetersPerSecond;
+        zeroSpeedHoldDuration = TimeSpan.FromSeconds(zeroSpeedHoldSeconds);
+    }
+
+    public GearSwitchState State { get; private set; } = GearSwitchState.Following;
+
+    public GearSwitchStateUpdate Update(DateTimeOffset now, double measuredSignedSpeed, TravelDirection desiredDirection,
+        TravelDirection currentDirection, bool directionConfirmed, bool atGearSwitchBoundary, bool atTerminal)
+    {
+        if (double.IsNaN(measuredSignedSpeed) || double.IsInfinity(measuredSignedSpeed))
+            throw new ArgumentOutOfRangeException(nameof(measuredSignedSpeed));
+        if (!Enum.IsDefined(typeof(TravelDirection), desiredDirection) ||
+            !Enum.IsDefined(typeof(TravelDirection), currentDirection))
+        {
+            throw new ArgumentOutOfRangeException(nameof(desiredDirection));
+        }
+
+        if (atTerminal)
+        {
+            State = GearSwitchState.Completed;
+            zeroSpeedSince = null;
+            return Held("terminal boundary reached", false, true);
+        }
+
+        switch (State)
+        {
+            case GearSwitchState.Following:
+                if (desiredDirection != currentDirection)
+                {
+                    State = GearSwitchState.ApproachingGearSwitch;
+                    return Moving("approaching gear-switch boundary");
+                }
+                return Moving("following current direction segment");
+
+            case GearSwitchState.ApproachingGearSwitch:
+                if (!atGearSwitchBoundary)
+                    return Moving("approaching gear-switch boundary");
+                State = GearSwitchState.HoldingZero;
+                zeroSpeedSince = IsStopped(measuredSignedSpeed) ? now : null;
+                return Held("holding at gear-switch boundary", false, false);
+
+            case GearSwitchState.HoldingZero:
+                if (!IsStopped(measuredSignedSpeed))
+                {
+                    zeroSpeedSince = null;
+                    return Held("measured speed remains above stop tolerance", false, false);
+                }
+                if (!zeroSpeedSince.HasValue)
+                {
+                    zeroSpeedSince = now;
+                    return Held("zero-speed dwell started", false, false);
+                }
+                if (now - zeroSpeedSince.Value < zeroSpeedHoldDuration)
+                    return Held("zero-speed dwell in progress", false, false);
+
+                State = GearSwitchState.RequestingDirectionChange;
+                return Held("requesting direction change", true, false);
+
+            case GearSwitchState.RequestingDirectionChange:
+                State = GearSwitchState.AwaitingDirectionConfirmation;
+                return Held("awaiting direction confirmation", false, false);
+
+            case GearSwitchState.AwaitingDirectionConfirmation:
+                if (directionConfirmed && desiredDirection == currentDirection)
+                {
+                    State = GearSwitchState.Following;
+                    zeroSpeedSince = null;
+                    return Moving("direction change confirmed");
+                }
+                return Held("awaiting direction confirmation", false, false);
+
+            case GearSwitchState.Completed:
+                return Held("trajectory already completed", false, true);
+
+            default:
+                throw new InvalidOperationException("Unsupported gear-switch state.");
+        }
+    }
+
+    private GearSwitchStateUpdate Moving(string reason)
+    {
+        return new GearSwitchStateUpdate(State, false, false, true, false, reason);
+    }
+
+    private GearSwitchStateUpdate Held(string reason, bool requestDirectionChange, bool isTrajectoryComplete)
+    {
+        return new GearSwitchStateUpdate(State, true, requestDirectionChange, false, isTrajectoryComplete, reason);
+    }
+
+    private bool IsStopped(double measuredSignedSpeed)
+    {
+        return Math.Abs(measuredSignedSpeed) < stopSpeedToleranceMetersPerSecond;
+    }
+
+    private static bool IsNonNegativeFinite(double value)
+    {
+        return !double.IsNaN(value) && !double.IsInfinity(value) && value >= 0d;
+    }
+}
+
+public sealed class GearSwitchStateUpdate
+{
+    internal GearSwitchStateUpdate(GearSwitchState state, bool holdZero, bool requestDirectionChange,
+        bool allowsTrajectoryMotion, bool isTrajectoryComplete, string reason)
+    {
+        State = state;
+        HoldZero = holdZero;
+        RequestDirectionChange = requestDirectionChange;
+        AllowsTrajectoryMotion = allowsTrajectoryMotion;
+        IsTrajectoryComplete = isTrajectoryComplete;
+        Reason = reason ?? string.Empty;
+    }
+
+    public GearSwitchState State { get; }
+
+    public bool HoldZero { get; }
+
+    public bool RequestDirectionChange { get; }
+
+    public bool AllowsTrajectoryMotion { get; }
+
+    public bool IsTrajectoryComplete { get; }
+
+    public string Reason { get; }
+}
diff --git a/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutionState.cs b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutionState.cs
new file mode 100644
index 0000000..d115fcb
--- /dev/null
+++ b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutionState.cs
@@ -0,0 +1,35 @@
+using System;
+
+namespace MultiWheelC.TrajectoryPlanning.EMPlanner;
+
+/// <summary>Immutable trajectory-execution outcome without controller or hardware coupling.</summary>
+public sealed class TrajectoryExecutionState
+{
+    internal TrajectoryExecutionState(EmTrajectoryPoint selectedPoint, GearSwitchStateUpdate gearSwitchUpdate)
+    {
+        SelectedPoint = selectedPoint ?? throw new ArgumentNullException(nameof(selectedPoint));
+        if (gearSwitchUpdate == null)
+            throw new ArgumentNullException(nameof(gearSwitchUpdate));
+
+        GearSwitchState = gearSwitchUpdate.State;
+        HoldZero = gearSwitchUpdate.HoldZero;
+        RequestDirectionChange = gearSwitchUpdate.RequestDirectionChange;
+        AllowsTrajectoryMotion = gearSwitchUpdate.AllowsTrajectoryMotion;
+        IsTrajectoryComplete = gearSwitchUpdate.IsTrajectoryComplete;
+        Reason = gearSwitchUpdate.Reason;
+    }
+
+    public EmTrajectoryPoint SelectedPoint { get; }
+
+    public GearSwitchState GearSwitchState { get; }
+
+    public bool HoldZero { get; }
+
+    public bool RequestDirectionChange { get; }
+
+    public bool AllowsTrajectoryMotion { get; }
+
+    public bool IsTrajectoryComplete { get; }
+
+    public string Reason { get; }
+}
diff --git a/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutor.cs b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutor.cs
new file mode 100644
index 0000000..49d6a08
--- /dev/null
+++ b/ClumsyPilot/ParkrobTrajplanner/TrajectoryExecution/TrajectoryExecutor.cs
@@ -0,0 +1,66 @@
+using System;
+using MultiWheelC.TrajectoryPlanning.CoarsePath;
+
+namespace MultiWheelC.TrajectoryPlanning.EMPlanner;
+
+/// <summary>Samples immutable EM trajectories and applies the pure zero-speed gear-switch state machine.</summary>
+public sealed class TrajectoryExecutor
+{
+    private readonly TrajectorySampler sampler = new TrajectorySampler();
+    private readonly GearSwitchStateMachine gearSwitchStateMachine;
+
+    public TrajectoryExecutor()
+        : this(EmPlannerConfiguration.CreateDefault())
+    {
+    }
+
+    public TrajectoryExecutor(EmPlannerConfiguration configuration)
+    {
+        if (configuration?.Longitudinal == null)
+            throw new ArgumentNullException(nameof(configuration));
+        gearSwitchStateMachine = new GearSwitchStateMachine(
+            configuration.Longitudinal.StopSpeedToleranceMetersPerSecond,
+            configuration.Longitudinal.ZeroSpeedHoldSeconds);
+    }
+
+    public TrajectoryExecutionState State { get; private set; }
+
+    public TrajectoryExecutionState Update(DateTimeOffset now, VehicleMotionState measuredState, EmTrajectory trajectory,
+        TravelDirection desiredDirection, TravelDirection currentDirection, bool directionConfirmed)
+    {
+        if (measuredState == null)
+            throw new ArgumentNullException(nameof(measuredState));
+        if (trajectory == null)
+            throw new ArgumentNullException(nameof(trajectory));
+
+        EmTrajectoryPoint selectedPoint = SelectPoint(trajectory, now);
+        bool atGearSwitchBoundary = selectedPoint.BoundaryType == EmBoundaryType.GearSwitchApproach;
+        bool atTerminal = selectedPoint.BoundaryType == EmBoundaryType.Goal ||
+            selectedPoint.BoundaryType == EmBoundaryType.RollingSafetyStop;
+        GearSwitchStateUpdate update = gearSwitchStateMachine.Update(now,
+            measuredState.SignedLongitudinalSpeedMetersPerSecond, desiredDirection, currentDirection,
+            directionConfirmed, atGearSwitchBoundary, atTerminal);
+        State = new TrajectoryExecutionState(selectedPoint, update);
+        return State;
+    }
+
+    private EmTrajectoryPoint SelectPoint(EmTrajectory trajectory, DateTimeOffset now)
+    {
+        double timeFromStart = (now - trajectory.Metadata.EffectiveAtUtc).TotalSeconds;
+        EmTrajectoryPoint first = trajectory.Points[0];
+        EmTrajectoryPoint last = trajectory.Points[trajectory.Points.Count - 1];
+        if (timeFromStart <= first.TimeFromStart)
+            return first;
+        if (timeFromStart >= last.TimeFromStart)
+            return last;
+        if (sampler.TrySample(trajectory, timeFromStart, out EmTrajectoryPoint sampled))
+            return sampled;
+
+        for (int index = trajectory.Points.Count - 1; index >= 0; index--)
+        {
+            if (trajectory.Points[index].TimeFromStart <= timeFromStart)
+                return trajectory.Points[index];
+        }
+        return first;
+    }
+}
diff --git a/ClumsyPilot/tests/EMPlannerVerificationHost/ExecutorChecks.cs b/ClumsyPilot/tests/EMPlannerVerificationHost/ExecutorChecks.cs
new file mode 100644
index 0000000..6a56ff0
--- /dev/null
+++ b/ClumsyPilot/tests/EMPlannerVerificationHost/ExecutorChecks.cs
@@ -0,0 +1,131 @@
+using System;
+using MultiWheelC.TrajectoryPlanning.CoarsePath;
+using MultiWheelC.TrajectoryPlanning.EMPlanner;
+
+namespace EMPlannerVerificationHost;
+
+internal static class ExecutorChecks
+{
+    public static void Run()
+    {
+        VerifiesGearSwitchSequence(TravelDirection.Forward, TravelDirection.Reverse, "forward-to-reverse");
+        VerifiesGearSwitchSequence(TravelDirection.Reverse, TravelDirection.Forward, "reverse-to-forward");
+        VerifiesExecutorSamplesBoundariesAndCompletesAtSafeTerminals();
+    }
+
+    private static void VerifiesGearSwitchSequence(TravelDirection currentDirection, TravelDirection desiredDirection,
+        string name)
+    {
+        var machine = new GearSwitchStateMachine(0.01d, 0.20d);
+        DateTimeOffset start = DateTimeOffset.UnixEpoch.AddSeconds(500d);
+
+        GearSwitchStateUpdate approaching = machine.Update(start, 0.10d, desiredDirection, currentDirection, false, false,
+            false);
+        Verification.Equal(GearSwitchState.ApproachingGearSwitch, approaching.State, name + " approaches switch");
+        Verification.True(approaching.AllowsTrajectoryMotion, name + " approach permits trajectory motion");
+
+        GearSwitchStateUpdate holding = machine.Update(start.AddMilliseconds(100), 0.005d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(holding, GearSwitchState.HoldingZero, name + " holds at boundary");
+
+        GearSwitchStateUpdate movingAgain = machine.Update(start.AddMilliseconds(110), 0.01d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(movingAgain, GearSwitchState.HoldingZero, name + " holds while measured speed is at tolerance");
+
+        GearSwitchStateUpdate dwellRestart = machine.Update(start.AddMilliseconds(120), 0d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(dwellRestart, GearSwitchState.HoldingZero, name + " starts zero-speed dwell");
+        GearSwitchStateUpdate dwellShort = machine.Update(start.AddMilliseconds(319), 0d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(dwellShort, GearSwitchState.HoldingZero, name + " does not request before full dwell");
+
+        GearSwitchStateUpdate requesting = machine.Update(start.AddMilliseconds(320), 0d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(requesting, GearSwitchState.RequestingDirectionChange, name + " requests after continuous dwell");
+        Verification.True(requesting.RequestDirectionChange, name + " emits exactly one direction request");
+
+        GearSwitchStateUpdate awaiting = machine.Update(start.AddMilliseconds(321), 0d, desiredDirection,
+            currentDirection, false, true, false);
+        AssertHeld(awaiting, GearSwitchState.AwaitingDirectionConfirmation, name + " awaits confirmation");
+        Verification.True(!awaiting.RequestDirectionChange, name + " does not repeat direction request");
+
+        GearSwitchStateUpdate following = machine.Update(start.AddMilliseconds(322), 0d, desiredDirection,
+            desiredDirection, true, false, false);
+        Verification.Equal(GearSwitchState.Following, following.State, name + " follows confirmed next segment");
+        Verification.True(!following.HoldZero && following.AllowsTrajectoryMotion,
+            name + " resumes only after confirmation");
+
+        GearSwitchStateUpdate completed = machine.Update(start.AddMilliseconds(323), 0d, desiredDirection,
+            desiredDirection, false, false, true);
+        AssertHeld(completed, GearSwitchState.Completed, name + " completes at terminal while holding zero");
+        Verification.True(completed.IsTrajectoryComplete, name + " marks terminal completion");
+    }
+
+    private static void VerifiesExecutorSamplesBoundariesAndCompletesAtSafeTerminals()
+    {
+        DateTimeOffset effectiveAt = DateTimeOffset.UnixEpoch.AddSeconds(600d);
+        var executor = new TrajectoryExecutor();
+        EmTrajectory gearTrajectory = CreateTrajectory(effectiveAt, TravelDirection.Forward,
+            EmBoundaryType.GearSwitchApproach, EmTerminalType.GearSwitch);
+
+        TrajectoryExecutionState approaching = executor.Update(effectiveAt.AddSeconds(0.10d),
+            CreateMeasuredState(0.10d, effectiveAt.AddSeconds(0.10d), 60L), gearTrajectory, TravelDirection.Reverse,
+            TravelDirection.Forward, false);
+        Verification.Equal(GearSwitchState.ApproachingGearSwitch, approaching.GearSwitchState,
+            "executor enters approach before exact gear boundary");
+        Verification.NearlyEqual(0.10d, approaching.SelectedPoint.SignedLongitudinalVelocity,
+            "executor samples moving approach point");
+
+        TrajectoryExecutionState holding = executor.Update(effectiveAt.AddSeconds(0.30d),
+            CreateMeasuredState(0.005d, effectiveAt.AddSeconds(0.30d), 61L), gearTrajectory, TravelDirection.Reverse,
+            TravelDirection.Forward, false);
+        AssertHeld(holding, GearSwitchState.HoldingZero, "executor holds at exact gear boundary");
+        Verification.Equal(EmBoundaryType.GearSwitchApproach, holding.SelectedPoint.BoundaryType,
+            "executor preserves exact gear boundary point");
+        Verification.NearlyEqual(0d, holding.SelectedPoint.SignedLongitudinalVelocity,
+            "executor does not release nonzero speed while holding");
+
+        foreach (EmBoundaryType terminalBoundary in new[] { EmBoundaryType.Goal, EmBoundaryType.RollingSafetyStop })
+        {
+            var terminalExecutor = new TrajectoryExecutor();
+            EmTrajectory terminal = CreateTrajectory(effectiveAt, TravelDirection.Forward, terminalBoundary,
+                terminalBoundary == EmBoundaryType.Goal ? EmTerminalType.Goal : EmTerminalType.RollingSafetyStop);
+            TrajectoryExecutionState completed = terminalExecutor.Update(effectiveAt.AddSeconds(0.30d),
+                CreateMeasuredState(0d, effectiveAt.AddSeconds(0.30d), 62L), terminal, TravelDirection.Forward,
+                TravelDirection.Forward, false);
+            AssertHeld(completed, GearSwitchState.Completed, "executor completes " + terminalBoundary);
+            Verification.True(completed.IsTrajectoryComplete, "executor marks " + terminalBoundary + " completion");
+        }
+    }
+
+    private static void AssertHeld(GearSwitchStateUpdate update, GearSwitchState expectedState, string name)
+    {
+        Verification.Equal(expectedState, update.State, name + " state");
+        Verification.True(update.HoldZero && !update.AllowsTrajectoryMotion, name + " forbids nonzero motion output");
+    }
+
+    private static void AssertHeld(TrajectoryExecutionState state, GearSwitchState expectedState, string name)
+    {
+        Verification.Equal(expectedState, state.GearSwitchState, name + " state");
+        Verification.True(state.HoldZero && !state.AllowsTrajectoryMotion, name + " forbids nonzero motion output");
+    }
+
+    private static VehicleMotionState CreateMeasuredState(double speed, DateTimeOffset capturedAt, long sequenceId)
+    {
+        return new VehicleMotionState(new Pose2D(0d, 0d, 0d), speed, 0d, capturedAt, sequenceId);
+    }
+
+    private static EmTrajectory CreateTrajectory(DateTimeOffset effectiveAt, TravelDirection direction,
+        EmBoundaryType terminalBoundary, EmTerminalType terminalType)
+    {
+        double signedSpeed = direction == TravelDirection.Forward ? 0.10d : -0.10d;
+        var metadata = new EmTrajectoryMetadata("executor-" + terminalBoundary, effectiveAt, effectiveAt, 70L,
+            "executor-reference", 60L, string.Empty, 4, direction, terminalType);
+        return new EmTrajectory(metadata, new[]
+        {
+            new EmTrajectoryPoint(0d, 0d, 0d, signedSpeed, 0d, 0d, 4, 0d, 0d, direction, EmBoundaryType.None, 0d, 0d),
+            new EmTrajectoryPoint(signedSpeed * 3d, 0d, 0d, 0d, 0.30d, 0d, 4, 0.03d, 0.03d, direction,
+                terminalBoundary, 0d, 0d),
+        });
+    }
+}
diff --git a/ClumsyPilot/tests/EMPlannerVerificationHost/Program.cs b/ClumsyPilot/tests/EMPlannerVerificationHost/Program.cs
index 87e5061..9fc64cb 100644
--- a/ClumsyPilot/tests/EMPlannerVerificationHost/Program.cs
+++ b/ClumsyPilot/tests/EMPlannerVerificationHost/Program.cs
@@ -12,7 +12,8 @@ internal static class Program
             args[0] != "lateral-real-osqp" && args[0] != "lateral-real-osqp-probe" && args[0] != "lateral-all" &&
             args[0] != "longitudinal-model" && args[0] != "longitudinal-integration" &&
             args[0] != "longitudinal-real-osqp-probe" && args[0] != "trajectory" &&
-            args[0] != "em-planning-service" && args[0] != "em-core-all" && args[0] != "coordinator"))
+            args[0] != "em-planning-service" && args[0] != "em-core-all" && args[0] != "coordinator" &&
+            args[0] != "executor"))
         {
             Console.Error.WriteLine("Usage: EMPlannerVerificationHost foundation|segmentation|frenet|corridor|optimization|osqp|osqp-loader|all-foundation|lateral-model|lateral-integration|lateral-real-osqp|lateral-all|longitudinal-model|longitudinal-integration");
             return 2;
@@ -113,6 +114,11 @@ internal static class Program
                 CoordinatorChecks.Run();
                 Console.WriteLine("PASS coordinator");
             }
+            if (args[0] == "executor")
+            {
+                ExecutorChecks.Run();
+                Console.WriteLine("PASS executor");
+            }
             return 0;
         }
         catch (Exception exception)