diff --git a/src/newgrf_newsignals.cpp b/src/newgrf_newsignals.cpp
index dd37a112c5..1e8865b550 100644
--- a/src/newgrf_newsignals.cpp
+++ b/src/newgrf_newsignals.cpp
@@ -89,7 +89,7 @@ NewSignalsResolverObject::NewSignalsResolverObject(const GRFFile *grffile, TileI
 uint GetNewSignalsRestrictedSignalsInfo(const TraceRestrictProgram *prog, TileIndex tile, uint8 signal_style)
 {
 	uint result = 0;
-	if (signal_style != 0 && HasBit(_always_reserve_through_style_mask, signal_style)) result |= 2;
+	if (signal_style != 0 && HasBit(_signal_style_masks.always_reserve_through, signal_style)) result |= 2;
 	if (prog != nullptr) {
 		result |= 1;
 		if ((prog->actions_used_flags & TRPAUF_RESERVE_THROUGH_ALWAYS) && !IsTileType(tile, MP_TUNNELBRIDGE)) result |= 2;
diff --git a/src/pbs.cpp b/src/pbs.cpp
index 078ea30016..3f66f3ab30 100644
--- a/src/pbs.cpp
+++ b/src/pbs.cpp
@@ -661,10 +661,10 @@ static PBSTileInfo FollowReservation(Owner o, RailTypes rts, TileIndex tile, Tra
 					if (signal_speed == 0 || (speed_restriction != 0 && speed_restriction < signal_speed)) signal_speed = speed_restriction;
 					uint8 signal_style = GetSignalStyle(tile, TrackdirToTrack(trackdir));
 					uint16 signal_flags = signal_style << 8;
-					if (HasBit(_non_aspect_inc_style_mask, signal_style)) {
+					if (HasBit(_signal_style_masks.non_aspect_inc, signal_style)) {
 						SetBit(signal_flags, TRSLAI_NO_ASPECT_INC);
 					}
-					if (HasBit(_next_only_style_mask, signal_style)) {
+					if (HasBit(_signal_style_masks.next_only, signal_style)) {
 						SetBit(signal_flags, TRSLAI_NEXT_ONLY);
 					}
 					lookahead->AddSignal(signal_speed, 0, z, signal_flags);
diff --git a/src/rail_cmd.cpp b/src/rail_cmd.cpp
index c3a89444e5..68f6890729 100644
--- a/src/rail_cmd.cpp
+++ b/src/rail_cmd.cpp
@@ -1531,7 +1531,7 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 			if (convert_signal) return_cmd_error(STR_ERROR_THERE_ARE_NO_SIGNALS);
 			if (!(p2_signal_in && p2_signal_out)) {
 				cost = CommandCost(EXPENSES_CONSTRUCTION, _price[PR_BUILD_SIGNALS] * ((GetTunnelBridgeLength(tile, tile_exit) + 4) >> 2) * (bidirectional ? 2 : 1)); // minimal 1
-				if (HasBit(_no_tunnel_bridge_style_mask, signal_style)) return_cmd_error(STR_ERROR_UNSUITABLE_SIGNAL_TYPE);
+				if (HasBit(_signal_style_masks.no_tunnel_bridge, signal_style)) return_cmd_error(STR_ERROR_UNSUITABLE_SIGNAL_TYPE);
 				if (!is_style_usable(sigvar, signal_style, bidirectional ? 0x11 : (is_pbs ? 0x21 : 0x1))) return_cmd_error(STR_ERROR_UNSUITABLE_SIGNAL_TYPE);
 			}
 		} else {
@@ -1550,7 +1550,7 @@ CommandCost CmdBuildSingleSignal(TileIndex tile, DoCommandFlag flags, uint32 p1,
 					will_be_style = signal_style;
 					will_be_pbs = is_pbs;
 					will_be_semaphore = (sigvar == SIG_SEMAPHORE);
-					if (HasBit(_no_tunnel_bridge_style_mask, signal_style)) return_cmd_error(STR_ERROR_UNSUITABLE_SIGNAL_TYPE);
+					if (HasBit(_signal_style_masks.no_tunnel_bridge, signal_style)) return_cmd_error(STR_ERROR_UNSUITABLE_SIGNAL_TYPE);
 				} else if (ctrl_pressed) {
 					will_be_bidi = false;
 					will_be_pbs = !will_be_pbs;
@@ -2815,7 +2815,7 @@ void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track track, Sign
 	}
 
 	uint x, y;
-	GetSignalXY(tile, pos, HasBit(_signal_opposite_side_style_mask, style), x, y);
+	GetSignalXY(tile, pos, HasBit(_signal_style_masks.signal_opposite_side, style), x, y);
 
 	uint8 aspect;
 	if (condition == SIGNAL_STATE_GREEN) {
@@ -2967,8 +2967,8 @@ void MarkSingleSignalDirty(TileIndex tile, Trackdir td)
 		return;
 	}
 	bool opposite = false;
-	if (_signal_opposite_side_style_mask != 0) {
-		opposite = HasBit(_signal_opposite_side_style_mask, GetSignalStyleGeneric(tile, TrackdirToTrack(td)));
+	if (_signal_style_masks.signal_opposite_side != 0) {
+		opposite = HasBit(_signal_style_masks.signal_opposite_side, GetSignalStyleGeneric(tile, TrackdirToTrack(td)));
 	}
 	MarkSingleSignalDirtyIntl(tile, td, opposite, [td](uint x, uint y) -> uint {
 		return GetSaveSlopeZ(x, y, TrackdirToTrack(td));
diff --git a/src/signal.cpp b/src/signal.cpp
index 33f55b7797..43bfebda73 100644
--- a/src/signal.cpp
+++ b/src/signal.cpp
@@ -30,11 +30,7 @@
 
 uint8 _extra_aspects = 0;
 uint64 _aspect_cfg_hash = 0;
-uint16 _non_aspect_inc_style_mask = 0;
-uint16 _next_only_style_mask = 0;
-uint16 _always_reserve_through_style_mask = 0;
-uint16 _no_tunnel_bridge_style_mask = 0;
-uint16 _signal_opposite_side_style_mask = 0;
+SignalStyleMasks _signal_style_masks = {};
 bool _signal_sprite_oversized = false;
 
 /// List of signals dependent upon this one
@@ -1267,7 +1263,7 @@ uint8 GetSignalAspectGeneric(TileIndex tile, Trackdir trackdir, bool check_non_i
 
 void AdjustSignalAspectIfNonIncStyleIntl(TileIndex tile, Track track, uint8 &aspect)
 {
-	if (IsTileType(tile, MP_RAILWAY) && HasBit(_non_aspect_inc_style_mask, GetSignalStyle(tile, track))) aspect--;
+	if (IsTileType(tile, MP_RAILWAY) && HasBit(_signal_style_masks.non_aspect_inc, GetSignalStyle(tile, track))) aspect--;
 }
 
 static void RefreshBridgeOnExitAspectChange(TileIndex entrance, TileIndex exit)
@@ -1512,11 +1508,7 @@ static bool DetermineExtraAspectsVariable()
 	bool changed = false;
 	uint8 new_extra_aspects = 0;
 
-	_non_aspect_inc_style_mask = 0;
-	_next_only_style_mask = 0;
-	_no_tunnel_bridge_style_mask = 0;
-	_always_reserve_through_style_mask = 0;
-	_signal_opposite_side_style_mask = 0;
+	_signal_style_masks = {};
 
 	if (_settings_game.vehicle.train_braking_model == TBM_REALISTIC) {
 		for (RailType r = RAILTYPE_BEGIN; r != RAILTYPE_END; r++) {
@@ -1528,23 +1520,23 @@ static bool DetermineExtraAspectsVariable()
 		}
 		for (uint i = 0; i < _num_new_signal_styles; i++) {
 			if (HasBit(_new_signal_styles[i].style_flags, NSSF_NO_ASPECT_INC)) {
-				SetBit(_non_aspect_inc_style_mask, i + 1);
-				SetBit(_no_tunnel_bridge_style_mask, i + 1);
+				SetBit(_signal_style_masks.non_aspect_inc, i + 1);
+				SetBit(_signal_style_masks.no_tunnel_bridge, i + 1);
 			}
 			if (HasBit(_new_signal_styles[i].style_flags, NSSF_ALWAYS_RESERVE_THROUGH)) {
-				SetBit(_always_reserve_through_style_mask, i + 1);
-				SetBit(_no_tunnel_bridge_style_mask, i + 1);
+				SetBit(_signal_style_masks.always_reserve_through, i + 1);
+				SetBit(_signal_style_masks.no_tunnel_bridge, i + 1);
 			}
 			if (HasBit(_new_signal_styles[i].style_flags, NSSF_LOOKAHEAD_SINGLE_SIGNAL)) {
 				_new_signal_styles[i].lookahead_extra_aspects = 0;
-				SetBit(_next_only_style_mask, i + 1);
+				SetBit(_signal_style_masks.next_only, i + 1);
 			} else if (HasBit(_new_signal_styles[i].style_flags, NSSF_LOOKAHEAD_ASPECTS_SET)) {
 				_new_signal_styles[i].lookahead_extra_aspects = std::min<uint8>(_new_signal_styles[i].lookahead_extra_aspects, _new_signal_styles[i].grffile->new_signal_extra_aspects);
 			} else {
 				_new_signal_styles[i].lookahead_extra_aspects = _new_signal_styles[i].grffile->new_signal_extra_aspects;
 			}
 			if (HasBit(_new_signal_styles[i].style_flags, NSSF_OPPOSITE_SIDE)) {
-				SetBit(_signal_opposite_side_style_mask, i + 1);
+				SetBit(_signal_style_masks.signal_opposite_side, i + 1);
 			}
 		}
 		for (uint i = _num_new_signal_styles; i < MAX_NEW_SIGNAL_STYLES; i++) {
@@ -1556,8 +1548,8 @@ static bool DetermineExtraAspectsVariable()
 
 	SimpleChecksum64 checksum;
 	checksum.Update(SimpleHash32(_extra_aspects));
-	checksum.Update(SimpleHash32(_non_aspect_inc_style_mask));
-	checksum.Update(SimpleHash32(_always_reserve_through_style_mask));
+	checksum.Update(SimpleHash32(_signal_style_masks.non_aspect_inc));
+	checksum.Update(SimpleHash32(_signal_style_masks.always_reserve_through));
 
 	if (checksum.state != _aspect_cfg_hash) {
 		_aspect_cfg_hash = checksum.state;
@@ -1587,8 +1579,8 @@ void InitialiseExtraAspectsVariable()
 void UpdateSignalReserveThroughBit(TileIndex tile, Track track, bool update_signal)
 {
 	bool reserve_through = false;
-	if (NonZeroSignalStylePossiblyOnTile(tile) && _always_reserve_through_style_mask != 0 &&
-			HasBit(_always_reserve_through_style_mask, GetSignalStyle(tile, track))) {
+	if (NonZeroSignalStylePossiblyOnTile(tile) && _signal_style_masks.always_reserve_through != 0 &&
+			HasBit(_signal_style_masks.always_reserve_through, GetSignalStyle(tile, track))) {
 		reserve_through = true;
 	} else {
 		if (IsRestrictedSignal(tile)) {
diff --git a/src/signal_func.h b/src/signal_func.h
index 5cb7e6846f..e70cadea19 100644
--- a/src/signal_func.h
+++ b/src/signal_func.h
@@ -21,11 +21,16 @@
 
 extern uint8 _extra_aspects;
 extern uint64 _aspect_cfg_hash;
-extern uint16 _non_aspect_inc_style_mask;
-extern uint16 _next_only_style_mask;
-extern uint16 _always_reserve_through_style_mask;
-extern uint16 _no_tunnel_bridge_style_mask;
-extern uint16 _signal_opposite_side_style_mask;
+
+struct SignalStyleMasks {
+	uint16 non_aspect_inc = 0;
+	uint16 next_only = 0;
+	uint16 always_reserve_through = 0;
+	uint16 no_tunnel_bridge = 0;
+	uint16 signal_opposite_side = 0;
+};
+extern SignalStyleMasks _signal_style_masks;
+
 extern bool _signal_sprite_oversized;
 
 /**
@@ -187,7 +192,7 @@ void InitialiseExtraAspectsVariable();
 inline void AdjustSignalAspectIfNonIncStyle(TileIndex tile, Track track, uint8 &aspect)
 {
 	extern void AdjustSignalAspectIfNonIncStyleIntl(TileIndex tile, Track track, uint8 &aspect);
-	if (aspect > 0 && _non_aspect_inc_style_mask != 0) AdjustSignalAspectIfNonIncStyleIntl(tile, track, aspect);
+	if (aspect > 0 && _signal_style_masks.non_aspect_inc != 0) AdjustSignalAspectIfNonIncStyleIntl(tile, track, aspect);
 }
 
 inline uint8 GetForwardAspectFollowingTrackAndIncrement(TileIndex tile, Trackdir trackdir)
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 2eecbb7ed2..75095f60b8 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -1733,7 +1733,7 @@ static void DrawTunnelBridgeRampSingleSignal(const TileInfo *ti, bool is_green,
 	DiagDirection dir = GetTunnelBridgeDirection(ti->tile);
 
 	uint8 style = GetTunnelBridgeSignalStyle(ti->tile);
-	side ^= HasBit(_signal_opposite_side_style_mask, style);
+	side ^= HasBit(_signal_style_masks.signal_opposite_side, style);
 
 	static const Point SignalPositions[2][4] = {
 		{   /*  X         X         Y         Y     Signals on the left side */
@@ -1870,7 +1870,7 @@ static void DrawBridgeSignalOnMiddlePart(const TileInfo *ti, TileIndex bridge_st
 			uint8 style = GetBridgeSignalStyle(bridge_start_tile);
 
 			uint position, x, y;
-			GetBridgeSignalXY(ti->tile, GetTunnelBridgeDirection(bridge_start_tile), HasBit(_signal_opposite_side_style_mask, style), position, x, y);
+			GetBridgeSignalXY(ti->tile, GetTunnelBridgeDirection(bridge_start_tile), HasBit(_signal_style_masks.signal_opposite_side, style), position, x, y);
 
 			SignalVariant variant = IsTunnelBridgeSemaphore(bridge_start_tile) ? SIG_SEMAPHORE : SIG_ELECTRIC;
 			SignalState state = GetBridgeEntranceSimulatedSignalState(bridge_start_tile, m2_position);
@@ -1926,8 +1926,8 @@ void MarkSingleBridgeSignalDirty(TileIndex tile, TileIndex bridge_start_tile)
 	}
 
 	bool opposite_side = false;
-	if (_signal_opposite_side_style_mask != 0) {
-		opposite_side = HasBit(_signal_opposite_side_style_mask, GetTunnelBridgeSignalStyle(bridge_start_tile));
+	if (_signal_style_masks.signal_opposite_side != 0) {
+		opposite_side = HasBit(_signal_style_masks.signal_opposite_side, GetTunnelBridgeSignalStyle(bridge_start_tile));
 	}
 
 	uint position, x, y;
@@ -1950,8 +1950,8 @@ void MarkTunnelBridgeSignalDirty(TileIndex tile, bool exit)
 	}
 
 	bool opposite_side = false;
-	if (_signal_opposite_side_style_mask != 0) {
-		opposite_side = HasBit(_signal_opposite_side_style_mask, GetTunnelBridgeSignalStyle(tile));
+	if (_signal_style_masks.signal_opposite_side != 0) {
+		opposite_side = HasBit(_signal_style_masks.signal_opposite_side, GetTunnelBridgeSignalStyle(tile));
 	}
 
 	if (IsRailCustomBridgeHeadTile(tile)) {