diff --git a/src/newgrf_callbacks.h b/src/newgrf_callbacks.h
index 482031cec0..056461c006 100644
--- a/src/newgrf_callbacks.h
+++ b/src/newgrf_callbacks.h
@@ -282,6 +282,9 @@ enum CallbackID {
 
 	/** Called to determine the engine name to show. */
 	CBID_VEHICLE_NAME                    = 0x161, // 15 bit callback
+
+	/** Called to determine probability during build. */
+	CBID_VEHICLE_BUILD_PROBABILITY       = 0x162, // 15 bit callback
 };
 
 /**
diff --git a/src/newgrf_engine.cpp b/src/newgrf_engine.cpp
index df3be19561..bea6c1d2e8 100644
--- a/src/newgrf_engine.cpp
+++ b/src/newgrf_engine.cpp
@@ -1192,6 +1192,20 @@ int GetEngineProperty(EngineID engine, PropertyID property, int orig_value, cons
 	return orig_value;
 }
 
+/**
+ * Test for vehicle build probablity type.
+ * @param v Vehicle whose build probability to test.
+ * @param type Build probability type to test for.
+ * @returns True iff the probability result says so.
+ */
+bool TestVehicleBuildProbability(Vehicle *v, EngineID engine, BuildProbabilityType type)
+{
+	uint16_t p = GetVehicleCallback(CBID_VEHICLE_BUILD_PROBABILITY, std::underlying_type<BuildProbabilityType>::type(type), 0, engine, v);
+	if (p == CALLBACK_FAILED) return false;
+
+	const uint16_t PROBABILITY_RANGE = 100;
+	return p + RandomRange(PROBABILITY_RANGE) >= PROBABILITY_RANGE;
+}
 
 static void DoTriggerVehicle(Vehicle *v, VehicleTrigger trigger, uint16_t base_random_bits, bool first)
 {
diff --git a/src/newgrf_engine.h b/src/newgrf_engine.h
index 4452ad9caf..da37602b81 100644
--- a/src/newgrf_engine.h
+++ b/src/newgrf_engine.h
@@ -103,6 +103,12 @@ bool UsesWagonOverride(const Vehicle *v);
 int GetVehicleProperty(const Vehicle *v, PropertyID property, int orig_value, bool is_signed = false);
 int GetEngineProperty(EngineID engine, PropertyID property, int orig_value, const Vehicle *v = nullptr, bool is_signed = false);
 
+enum class BuildProbabilityType {
+	Reversed = 0,
+};
+
+bool TestVehicleBuildProbability(Vehicle *v, EngineID engine, BuildProbabilityType type);
+
 enum VehicleTrigger {
 	VEHICLE_TRIGGER_NEW_CARGO     = 0x01,
 	/* Externally triggered only for the first vehicle in chain */
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 67e233f9d7..848a1bad4e 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -661,6 +661,7 @@ static CommandCost CmdBuildRailWagon(DoCommandFlag flags, TileIndex tile, const
 
 		v->group_id = DEFAULT_GROUP;
 
+		if (TestVehicleBuildProbability(v, v->engine_type, BuildProbabilityType::Reversed)) SetBit(v->flags, VRF_REVERSE_DIRECTION);
 		AddArticulatedParts(v);
 
 		v->UpdatePosition();
@@ -728,6 +729,7 @@ static void AddRearEngineToMultiheadedTrain(Train *v)
 	v->SetMultiheaded();
 	u->SetMultiheaded();
 	v->SetNext(u);
+	if (TestVehicleBuildProbability(u, u->engine_type, BuildProbabilityType::Reversed)) SetBit(u->flags, VRF_REVERSE_DIRECTION);
 	u->UpdatePosition();
 
 	/* Now we need to link the front and rear engines together */
@@ -799,6 +801,7 @@ CommandCost CmdBuildRailVehicle(DoCommandFlag flags, TileIndex tile, const Engin
 		v->SetFrontEngine();
 		v->SetEngine();
 
+		if (TestVehicleBuildProbability(v, v->engine_type, BuildProbabilityType::Reversed)) SetBit(v->flags, VRF_REVERSE_DIRECTION);
 		v->UpdatePosition();
 
 		if (rvi->railveh_type == RAILVEH_MULTIHEAD) {