diff --git a/src/pbs.cpp b/src/pbs.cpp
index dea262268e..2e937d926a 100644
--- a/src/pbs.cpp
+++ b/src/pbs.cpp
@@ -478,7 +478,7 @@ static PBSTileInfo FollowReservation(Owner o, RailTypes rts, TileIndex tile, Tra
 			if (_settings_game.vehicle.train_braking_model == TBM_REALISTIC && IsTunnelBridgeSignalSimulationEntrance(tile)) {
 				TileIndex end = GetOtherTunnelBridgeEnd(tile);
 				if (HasAcrossTunnelBridgeReservation(end) && GetTunnelBridgeExitSignalState(end) == SIGNAL_STATE_GREEN &&
-						((flags & FRF_TB_EXIT_FREE) || TunnelBridgeIsFree(tile, end, nullptr, true).Succeeded())) {
+						((flags & FRF_TB_EXIT_FREE) || TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY).Succeeded())) {
 					/* skip far end */
 					if (lookahead != nullptr) {
 						lookahead->reservation_end_position += (DistanceManhattan(tile, end) - 1) * TILE_SIZE;
@@ -501,7 +501,7 @@ static PBSTileInfo FollowReservation(Owner o, RailTypes rts, TileIndex tile, Tra
 			if ((flags & FRF_IGNORE_ONEWAY) && _settings_game.vehicle.train_braking_model == TBM_REALISTIC && IsTunnelBridgeSignalSimulationExit(tile) &&
 					GetTunnelBridgeExitSignalState(tile) == SIGNAL_STATE_GREEN) {
 				TileIndex end = GetOtherTunnelBridgeEnd(tile);
-				if (HasAcrossTunnelBridgeReservation(end) && TunnelBridgeIsFree(tile, end, nullptr, true).Succeeded()) {
+				if (HasAcrossTunnelBridgeReservation(end) && TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY).Succeeded()) {
 					/* skip far end */
 					tile = end;
 					trackdir = GetTunnelBridgeExitTrackdir(tile);
@@ -729,7 +729,7 @@ static void FollowReservationEnumerate(Owner o, RailTypes rts, TileIndex tile, T
 			if (_settings_game.vehicle.train_braking_model == TBM_REALISTIC && IsTunnelBridgeSignalSimulationEntrance(tile)) {
 				TileIndex end = GetOtherTunnelBridgeEnd(tile);
 				if (HasAcrossTunnelBridgeReservation(end) && GetTunnelBridgeExitSignalState(end) == SIGNAL_STATE_GREEN &&
-						((flags & FRF_TB_EXIT_FREE) || TunnelBridgeIsFree(tile, end, nullptr, true).Succeeded())) {
+						((flags & FRF_TB_EXIT_FREE) || TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY).Succeeded())) {
 					/* skip far end */
 					Trackdir end_trackdir = GetTunnelBridgeExitTrackdir(end);
 					tile = end;
@@ -741,7 +741,7 @@ static void FollowReservationEnumerate(Owner o, RailTypes rts, TileIndex tile, T
 			if ((flags & FRF_IGNORE_ONEWAY) && _settings_game.vehicle.train_braking_model == TBM_REALISTIC && IsTunnelBridgeSignalSimulationExit(tile) &&
 					GetTunnelBridgeExitSignalState(tile) == SIGNAL_STATE_GREEN) {
 				TileIndex end = GetOtherTunnelBridgeEnd(tile);
-				if (HasAcrossTunnelBridgeReservation(end) && TunnelBridgeIsFree(tile, end, nullptr, true).Succeeded()) {
+				if (HasAcrossTunnelBridgeReservation(end) && TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY).Succeeded()) {
 					/* skip far end */
 					tile = end;
 					trackdir = GetTunnelBridgeExitTrackdir(tile);
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index bca6e79893..8d2604914f 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -1496,7 +1496,7 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 		if (!ValParamTrackOrientation(track) || !IsTrackAcrossTunnelBridge(tile, track)) {
 			return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
 		}
-		CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile), nullptr, true);
+		CommandCost ret = TunnelBridgeIsFree(tile, GetOtherTunnelBridgeEnd(tile), nullptr, TBIFM_ACROSS_ONLY);
 		if (ret.Failed()) return ret;
 	} else if (!ValParamTrackOrientation(track) || !IsPlainRailTile(tile) || !HasTrack(tile, track)) {
 		return_cmd_error(STR_ERROR_THERE_IS_NO_RAILROAD_TRACK);
@@ -2185,7 +2185,7 @@ CommandCost CmdRemoveSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1
 		}
 		if (!IsTunnelBridgeWithSignalSimulation(tile)) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
 		TileIndex end = GetOtherTunnelBridgeEnd(tile);
-		CommandCost ret = TunnelBridgeIsFree(tile, end, nullptr, true);
+		CommandCost ret = TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY);
 		if (ret.Failed()) return ret;
 
 		cost *= GetTunnelBridgeSignalSimulationSignalCount(tile, end);
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index 5342545da6..06696e0a21 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -3593,7 +3593,7 @@ static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_
 				/* Are we just leaving a tunnel/bridge? */
 				if (TrackdirExitsTunnelBridge(tile, track_dir)) {
 					TileIndex end = GetOtherTunnelBridgeEnd(tile);
-					bool free = TunnelBridgeIsFree(tile, end, v, true).Succeeded();
+					bool free = TunnelBridgeIsFree(tile, end, v, TBIFM_ACROSS_ONLY).Succeeded();
 					HandleLastTunnelBridgeSignals(tile, end, ReverseDiagDir(GetTunnelBridgeDirection(tile)), free);
 				}
 			} else if (tunbridge_clear_unsignaled_other_end) {
@@ -3720,7 +3720,7 @@ void FreeTrainTrackReservation(Train *v, TileIndex origin, Trackdir orig_td)
 			}
 		} else if (IsTunnelBridgeWithSignalSimulation(tile) && TrackdirExitsTunnelBridge(tile, td)) {
 			TileIndex end = GetOtherTunnelBridgeEnd(tile);
-			bool free = TunnelBridgeIsFree(tile, end, v, true).Succeeded();
+			bool free = TunnelBridgeIsFree(tile, end, v, TBIFM_ACROSS_ONLY).Succeeded();
 			if (!free) break;
 		}
 
@@ -6107,7 +6107,7 @@ static Vehicle *CollectTrackbitsFromCrashedVehiclesEnum(Vehicle *v, void *data)
 
 static void SetSignalledBridgeTunnelGreenIfClear(TileIndex tile, TileIndex end)
 {
-	if (TunnelBridgeIsFree(tile, end, nullptr, true).Succeeded()) {
+	if (TunnelBridgeIsFree(tile, end, nullptr, TBIFM_ACROSS_ONLY).Succeeded()) {
 		auto process_tile = [](TileIndex t) {
 			if (IsTunnelBridgeSignalSimulationEntrance(t)) {
 				if (IsBridge(t)) {
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 02837bb6a8..5410af5918 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -619,7 +619,7 @@ bool IsTrainCollidableRoadVehicleOnGround(TileIndex tile)
 struct GetVehicleTunnelBridgeProcData {
 	const Vehicle *v;
 	TileIndex t;
-	bool across_only;
+	TunnelBridgeIsFreeMode mode;
 };
 
 /** Procedure called for every vehicle found in tunnel/bridge in the hash map */
@@ -628,9 +628,11 @@ static Vehicle *GetVehicleTunnelBridgeProc(Vehicle *v, void *data)
 	const GetVehicleTunnelBridgeProcData *info = (GetVehicleTunnelBridgeProcData*) data;
 	if (v == info->v) return nullptr;
 
-	if (v->type == VEH_TRAIN && info->across_only && IsBridge(info->t)) {
+	if (v->type == VEH_TRAIN && info->mode != TBIFM_ALL && IsBridge(info->t)) {
 		TrackBits vehicle_track = Train::From(v)->track;
-		if (!(vehicle_track & TRACK_BIT_WORMHOLE) && !(GetAcrossBridgePossibleTrackBits(info->t) & vehicle_track)) return nullptr;
+		if (!(vehicle_track & TRACK_BIT_WORMHOLE)) {
+			if (info->mode == TBIFM_ACROSS_ONLY && !(GetAcrossBridgePossibleTrackBits(info->t) & vehicle_track)) return nullptr;
+		}
 	}
 
 	return v;
@@ -641,10 +643,10 @@ static Vehicle *GetVehicleTunnelBridgeProc(Vehicle *v, void *data)
  * @param tile first end
  * @param endtile second end
  * @param ignore Ignore this vehicle when searching
- * @param across_only Only find vehicles which are passing across the bridge/tunnel or on connecting bridge head track pieces
+ * @param mode Whether to only find vehicles which are passing across the bridge/tunnel or on connecting bridge head track pieces
  * @return Succeeded command (if tunnel/bridge is free) or failed command (if a vehicle is using the tunnel/bridge).
  */
-CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle *ignore, bool across_only)
+CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle *ignore, TunnelBridgeIsFreeMode mode)
 {
 	/* Value v is not safe in MP games, however, it is used to generate a local
 	 * error message only (which may be different for different machines).
@@ -653,7 +655,7 @@ CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle
 	GetVehicleTunnelBridgeProcData data;
 	data.v = ignore;
 	data.t = tile;
-	data.across_only = across_only;
+	data.mode = mode;
 	VehicleType type = static_cast<VehicleType>(GetTunnelBridgeTransportType(tile));
 	Vehicle *v = VehicleFromPos(tile, type, &data, &GetVehicleTunnelBridgeProc, true);
 	if (v == nullptr) {
diff --git a/src/vehicle_func.h b/src/vehicle_func.h
index 5b8b3f24c8..ce88600116 100644
--- a/src/vehicle_func.h
+++ b/src/vehicle_func.h
@@ -132,7 +132,12 @@ void ViewportAddVehicles(DrawPixelInfo *dpi, bool update_vehicles);
 void ViewportMapDrawVehicles(DrawPixelInfo *dpi, Viewport *vp);
 
 void ShowNewGrfVehicleError(EngineID engine, StringID part1, StringID part2, GRFBugs bug_type, bool critical);
-CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle *ignore = nullptr, bool across_only = false);
+
+enum TunnelBridgeIsFreeMode {
+	TBIFM_ALL,
+	TBIFM_ACROSS_ONLY,
+};
+CommandCost TunnelBridgeIsFree(TileIndex tile, TileIndex endtile, const Vehicle *ignore = nullptr, TunnelBridgeIsFreeMode mode = TBIFM_ALL);
 Train *GetTrainClosestToTunnelBridgeEnd(TileIndex tile, TileIndex other_tile);
 int GetAvailableFreeTilesInSignalledTunnelBridge(TileIndex entrance, TileIndex exit, TileIndex tile);
 int GetAvailableFreeTilesInSignalledTunnelBridgeWithStartOffset(TileIndex entrance, TileIndex exit, int offset);