(svn r5155) - Remove the bridge branch merge (revision r5070)

33 files changed, 992 insertions, 766 deletions

diff --git a/BUGS b/BUGS
index 12b059cc6..bcdcee6f2 100644
--- a/BUGS
+++ b/BUGS
@@ -1,12 +1,7 @@
-/* $Id$ */
+/* $Id */
 
 KNOWN BUGS / PROBLEMS:
 
-bridges:
-Graphical problems, especially in conjunction with signals and catenary
-
-electrified rails:
 Normal and elrail depots look the same. Use 'X' (transparent buildings)
    to distinguish between them
 Missing curors / icons for construction (currently using the conventional ones)
-
diff --git a/ai/default/default.c b/ai/default/default.c
index c71b0b1cd..dd682581c 100644
--- a/ai/default/default.c
+++ b/ai/default/default.c
@@ -2165,7 +2165,9 @@ static bool AiRemoveTileAndGoForward(Player *p)
 				return false;
 			p->ai.cur_tile_a = TILE_MASK(_build_tunnel_endtile - TileOffsByDir(p->ai.cur_dir_a));
 			return true;
-		} else {
+		}
+
+		if (IsBridgeRamp(tile)) {
 			// Check if the bridge points in the right direction.
 			// This is not really needed the first place AiRemoveTileAndGoForward is called.
 			if (DiagDirToAxis(GetBridgeRampDirection(tile)) != (p->ai.cur_dir_a & 1U)) return false;
@@ -3697,6 +3699,7 @@ pos_3:
 	} else if (IsTileType(tile, MP_TUNNELBRIDGE)) {
 		if (!IsTileOwner(tile, _current_player) ||
 				!IsBridge(tile) ||
+				!IsBridgeRamp(tile) ||
 				GetBridgeTransportType(tile) != TRANSPORT_RAIL) {
 			return;
 		}
diff --git a/bridge.h b/bridge.h
index efeba7dba..95c6b2004 100644
--- a/bridge.h
+++ b/bridge.h
@@ -27,6 +27,5 @@ extern const Bridge orig_bridge[MAX_BRIDGES];
 extern Bridge _bridge[MAX_BRIDGES];
 
 uint GetBridgeFoundation(Slope tileh, Axis axis);
-uint SetSpeedLimitOnBridge(Vehicle *);
 
 #endif /* BRIDGE_H */
diff --git a/bridge_map.c b/bridge_map.c
index e21c5928c..cbb955c37 100644
--- a/bridge_map.c
+++ b/bridge_map.c
@@ -3,22 +3,19 @@
 #include "stdafx.h"
 #include "openttd.h"
 #include "bridge_map.h"
-#include "variables.h"
 
 
 TileIndex GetBridgeEnd(TileIndex tile, DiagDirection dir)
 {
 	TileIndexDiff delta = TileOffsByDir(dir);
 
-	do { tile += delta; } while (IsBridgeAbove(tile) && IsBridgeOfAxis(tile, DiagDirToAxis(dir)));
-
-	return tile;
-}
+	assert(DiagDirToAxis(dir) == GetBridgeAxis(tile));
 
+	do {
+		tile += delta;
+	} while (!IsBridgeRamp(tile));
 
-TileIndex GetNorthernBridgeEnd(TileIndex t)
-{
-	return GetBridgeEnd(t, ReverseDiagDir(AxisToDiagDir(GetBridgeAxis(t))));
+	return tile;
 }
 
 
@@ -30,25 +27,11 @@ TileIndex GetSouthernBridgeEnd(TileIndex t)
 
 TileIndex GetOtherBridgeEnd(TileIndex tile)
 {
-	assert(IsBridgeTile(tile));
-	return GetBridgeEnd(tile, GetBridgeRampDirection(tile));
-}
-
-uint GetBridgeHeight(TileIndex tile, Axis a)
-{
-	uint h, f;
-	uint tileh = GetTileSlope(tile, &h);
+	TileIndexDiff delta = TileOffsByDir(GetBridgeRampDirection(tile));
 
-	f = GetBridgeFoundation(tileh, a);
+	do {
+		tile += delta;
+	} while (!IsBridgeRamp(tile));
 
-	if (f) {
-		if (f < 15) {
-			h += TILE_HEIGHT;
-			tileh = SLOPE_FLAT;
-		} else {
-			tileh = _inclined_tileh[f - 15];
-		}
-	}
-
-	return h + TILE_HEIGHT;
+	return tile;
 }
diff --git a/bridge_map.h b/bridge_map.h
index 40113471b..525547e0f 100644
--- a/bridge_map.h
+++ b/bridge_map.h
@@ -11,9 +11,6 @@
 #include "tile.h"
 
 
-void DrawBridgeMiddle(const TileInfo* ti); // XXX
-
-
 static inline bool IsBridge(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
@@ -26,38 +23,28 @@ static inline bool IsBridgeTile(TileIndex t)
 }
 
 
-static inline bool MayHaveBridgeAbove(TileIndex t)
+static inline bool IsBridgeRamp(TileIndex t)
 {
-	return
-		IsTileType(t, MP_CLEAR) ||
-		IsTileType(t, MP_RAILWAY) ||
-		IsTileType(t, MP_STREET) ||
-		IsTileType(t, MP_WATER) ||
-		IsTileType(t, MP_TUNNELBRIDGE);
+	assert(IsBridgeTile(t));
+	return !HASBIT(_m[t].m5, 6);
 }
 
-
-static inline bool IsXBridgeAbove(TileIndex t)
+static inline bool IsBridgeMiddle(TileIndex t)
 {
-	assert(MayHaveBridgeAbove(t));
-	return GB(_m[t].extra, 6, 1) != 0;
+	assert(IsBridgeTile(t));
+	return HASBIT(_m[t].m5, 6);
 }
 
-static inline bool IsYBridgeAbove(TileIndex t)
-{
-	assert(MayHaveBridgeAbove(t));
-	return GB(_m[t].extra, 7, 1) != 0;
-}
 
-static inline bool IsBridgeOfAxis(TileIndex t, Axis a)
-{
-	if (a == AXIS_X) return IsXBridgeAbove(t);
-	return IsYBridgeAbove(t);
-}
-
-static inline bool IsBridgeAbove(TileIndex t)
+/**
+ * Determines which piece of a bridge is contained in the current tile
+ * @param tile The tile to analyze
+ * @return the piece
+ */
+static inline uint GetBridgePiece(TileIndex t)
 {
-	return (IsXBridgeAbove(t) || IsYBridgeAbove(t));
+	assert(IsBridgeMiddle(t));
+	return GB(_m[t].m2, 0, 4);
 }
 
 
@@ -78,15 +65,15 @@ static inline uint GetBridgeType(TileIndex t)
  */
 static inline DiagDirection GetBridgeRampDirection(TileIndex t)
 {
+	assert(IsBridgeRamp(t));
 	return ReverseDiagDir(XYNSToDiagDir((Axis)GB(_m[t].m5, 0, 1), GB(_m[t].m5, 5, 1)));
 }
 
 
 static inline Axis GetBridgeAxis(TileIndex t)
 {
-	static const Axis BridgeAxis[] = {AXIS_END, AXIS_X, AXIS_Y, AXIS_END};
-	assert(IsBridgeAbove(t));
-	return BridgeAxis[GB(_m[t].extra, 6, 2)];
+	assert(IsBridgeMiddle(t));
+	return (Axis)GB(_m[t].m5, 0, 1);
 }
 
 
@@ -97,17 +84,50 @@ static inline TransportType GetBridgeTransportType(TileIndex t)
 }
 
 
+static inline bool IsClearUnderBridge(TileIndex t)
+{
+	assert(IsBridgeMiddle(t));
+	return GB(_m[t].m5, 3, 3) == 0;
+}
+
+static inline bool IsWaterUnderBridge(TileIndex t)
+{
+	assert(IsBridgeMiddle(t));
+	return GB(_m[t].m5, 3, 3) == 1;
+}
+
+
+static inline bool IsTransportUnderBridge(TileIndex t)
+{
+	assert(IsBridgeMiddle(t));
+	return HASBIT(_m[t].m5, 5);
+}
+
+static inline TransportType GetTransportTypeUnderBridge(TileIndex t)
+{
+	assert(IsTransportUnderBridge(t));
+	return (TransportType)GB(_m[t].m5, 3, 2);
+}
+
+static inline RoadBits GetRoadBitsUnderBridge(TileIndex t)
+{
+	assert(GetTransportTypeUnderBridge(t) == TRANSPORT_ROAD);
+	return GetBridgeAxis(t) == AXIS_X ? ROAD_Y : ROAD_X;
+}
+
+static inline TrackBits GetRailBitsUnderBridge(TileIndex t)
+{
+	assert(GetTransportTypeUnderBridge(t) == TRANSPORT_RAIL);
+	return GetBridgeAxis(t) == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X;
+}
+
+
 /**
  * Finds the end of a bridge in the specified direction starting at a middle tile
  */
 TileIndex GetBridgeEnd(TileIndex, DiagDirection);
 
 /**
- * Finds the northern end of a bridge starting at a middle tile
- */
-TileIndex GetNorthernBridgeEnd(TileIndex t);
-
-/**
  * Finds the southern end of a bridge starting at a middle tile
  */
 TileIndex GetSouthernBridgeEnd(TileIndex t);
@@ -118,26 +138,46 @@ TileIndex GetSouthernBridgeEnd(TileIndex t);
  */
 TileIndex GetOtherBridgeEnd(TileIndex);
 
-uint GetBridgeHeight(TileIndex tile, Axis a);
-uint GetBridgeFoundation(Slope tileh, Axis axis);
+uint GetBridgeHeight(TileIndex t);
 
-static inline void ClearSingleBridgeMiddle(TileIndex t, Axis a)
+static inline void SetClearUnderBridge(TileIndex t)
 {
-	assert(MayHaveBridgeAbove(t));
-	CLRBIT(_m[t].extra, 6 + a);
+	assert(IsBridgeMiddle(t));
+	SetTileOwner(t, OWNER_NONE);
+	SB(_m[t].m5, 3, 3, 0 << 2 | 0);
+	SB(_m[t].m3, 0, 4, 0);
 }
 
+static inline void SetWaterUnderBridge(TileIndex t)
+{
+	assert(IsBridgeMiddle(t));
+	SetTileOwner(t, OWNER_WATER);
+	SB(_m[t].m5, 3, 3, 0 << 2 | 1);
+	SB(_m[t].m3, 0, 4, 0);
+}
 
-static inline void ClearBridgeMiddle(TileIndex t)
+static inline void SetCanalUnderBridge(TileIndex t, Owner o)
 {
-	ClearSingleBridgeMiddle(t, AXIS_X);
-	ClearSingleBridgeMiddle(t, AXIS_Y);
+	assert(IsBridgeMiddle(t));
+	SetTileOwner(t, o);
+	SB(_m[t].m5, 3, 3, 0 << 2 | 1);
+	SB(_m[t].m3, 0, 4, 0);
+}
+
+static inline void SetRailUnderBridge(TileIndex t, Owner o, RailType r)
+{
+	assert(IsBridgeMiddle(t));
+	SetTileOwner(t, o);
+	SB(_m[t].m5, 3, 3, 1 << 2 | TRANSPORT_RAIL);
+	SB(_m[t].m3, 0, 4, r);
 }
 
-static inline void SetBridgeMiddle(TileIndex t, Axis a)
+static inline void SetRoadUnderBridge(TileIndex t, Owner o)
 {
-	assert(MayHaveBridgeAbove(t));
-	SETBIT(_m[t].extra, 6 + a);
+	assert(IsBridgeMiddle(t));
+	SetTileOwner(t, o);
+	SB(_m[t].m5, 3, 3, 1 << 2 | TRANSPORT_ROAD);
+	SB(_m[t].m3, 0, 4, 0);
 }
 
 
@@ -165,4 +205,26 @@ static inline void MakeRailBridgeRamp(TileIndex t, Owner o, uint bridgetype, Dia
 }
 
 
+static inline void MakeBridgeMiddle(TileIndex t, uint bridgetype, uint piece, Axis a, TransportType tt)
+{
+	SetTileType(t, MP_TUNNELBRIDGE);
+	SetTileOwner(t, OWNER_NONE);
+	_m[t].m2 = bridgetype << 4 | piece;
+	_m[t].m3 = 0;
+	_m[t].m4 = 0;
+	_m[t].m5 = 1 << 7 | 1 << 6 | 0 << 5 | 0 << 3 | tt << 1 | a;
+}
+
+static inline void MakeRoadBridgeMiddle(TileIndex t, uint bridgetype, uint piece, Axis a)
+{
+	MakeBridgeMiddle(t, bridgetype, piece, a, TRANSPORT_ROAD);
+}
+
+static inline void MakeRailBridgeMiddle(TileIndex t, uint bridgetype, uint piece, Axis a, RailType r)
+{
+	MakeBridgeMiddle(t, bridgetype, piece, a, TRANSPORT_RAIL);
+	SB(_m[t].m3, 4, 4, r);
+}
+
+
 #endif
diff --git a/clear_cmd.c b/clear_cmd.c
index ca4cfa24b..259146965 100644
--- a/clear_cmd.c
+++ b/clear_cmd.c
@@ -11,7 +11,6 @@
 #include "viewport.h"
 #include "command.h"
 #include "tunnel_map.h"
-#include "bridge_map.h"
 #include "variables.h"
 #include "table/sprites.h"
 #include "unmovable_map.h"
@@ -260,14 +259,6 @@ int32 CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 				} else return_cmd_error(STR_5800_OBJECT_IN_THE_WAY);
 			}
 
-			if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
-				byte height = GetBridgeHeight(GetNorthernBridgeEnd(tile), GetBridgeAxis(tile));
-
-				height /= TILE_HEIGHT;
-
-				if (a >= height || b >= height || c >= height || d >= height) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-			}
-
 			if (direction == -1 && IsTunnelInWay(tile, min)) return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
 
 			_terraform_err_tile = 0;
@@ -510,7 +501,6 @@ static void DrawTile_Clear(TileInfo *ti)
 	}
 
 	DrawClearLandFence(ti);
-	DrawBridgeMiddle(ti);
 }
 
 static uint GetSlopeZ_Clear(const TileInfo* ti)
diff --git a/elrail.c b/elrail.c
index d3a7e8180..14fd85049 100644
--- a/elrail.c
+++ b/elrail.c
@@ -91,10 +91,18 @@ static TrackBits GetRailTrackBitsUniversal(TileIndex t, byte *override)
 				return DiagDirToAxis(GetTunnelDirection(t)) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y;
 			} else {
 				if (GetRailType(t) != RAILTYPE_ELECTRIC) return 0;
-				if (override != NULL && DistanceMax(t, GetOtherBridgeEnd(t)) > 1) {
-					*override = 1 << GetBridgeRampDirection(t);
+				if (IsBridgeMiddle(t)) {
+					if (IsTransportUnderBridge(t) &&
+						GetTransportTypeUnderBridge(t) == TRANSPORT_RAIL) {
+						return GetRailBitsUnderBridge(t);
+					} else {
+						return 0;
+					}
+				} else {
+					if (override != NULL && DistanceMax(t, GetOtherBridgeEnd(t)) > 1) *override = 1 << GetBridgeRampDirection(t);
+
+					return DiagDirToAxis(GetBridgeRampDirection(t)) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y;
 				}
-				return DiagDirToAxis(GetBridgeRampDirection(t)) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y;
 			}
 		case MP_STREET:
 			if (GetRoadTileType(t) != ROAD_TILE_CROSSING) return 0;
@@ -117,7 +125,7 @@ static TrackBits GetRailTrackBitsUniversal(TileIndex t, byte *override)
 static void AdjustTileh(TileIndex tile, Slope* tileh)
 {
 	if (IsTunnelTile(tile)) *tileh = SLOPE_FLAT;
-	if (IsBridgeTile(tile)) {
+	if (IsBridgeTile(tile) && IsBridgeRamp(tile)) {
 		if (*tileh != SLOPE_FLAT) {
 			*tileh = SLOPE_FLAT;
 		} else {
@@ -185,10 +193,9 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 		for (k = 0; k < NUM_TRACKS_AT_PCP; k++) {
 			/* Next to us, we have a bridge head, don't worry about that one, if it shows away from us */
 			if (TrackSourceTile[i][k] == TS_NEIGHBOUR &&
-			    IsBridgeTile(neighbour) &&
-			    GetBridgeRampDirection(neighbour) == ReverseDiagDir(i)) {
-				continue;
-			}
+			    IsBridgeTile(neighbour) && IsBridgeRamp(neighbour) &&
+			    GetBridgeRampDirection(neighbour) == ReverseDiagDir(i)
+			   ) continue;
 
 			/* We check whether the track in question (k) is present in the tile
 			   (TrackSourceTile) */
@@ -212,7 +219,7 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 
 		/* Read the foundataions if they are present, and adjust the tileh */
 		if (IsTileType(neighbour, MP_RAILWAY)) foundation = GetRailFoundation(tileh[TS_NEIGHBOUR], trackconfig[TS_NEIGHBOUR]);
-		if (IsBridgeTile(neighbour)) {
+		if (IsBridgeTile(neighbour) && IsBridgeRamp(neighbour)) {
 			foundation = GetBridgeFoundation(tileh[TS_NEIGHBOUR], DiagDirToAxis(GetBridgeRampDirection(neighbour)));
 		}
 
@@ -240,14 +247,6 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 		   Remove those (simply by ANDing with allowed, since these markers are never allowed) */
 		if ( (PPPallowed[i] & PPPpreferred[i]) != 0) PPPallowed[i] &= PPPpreferred[i];
 
-		if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile)) {
-			Track bridgetrack = GetBridgeAxis(ti->tile) == AXIS_X ? TRACK_X : TRACK_Y;
-			uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile), GetBridgeAxis(ti->tile));
-
-			if ((height <= TilePixelHeight(ti->tile) + TILE_HEIGHT) &&
-			(i == PCPpositions[bridgetrack][0] || i == PCPpositions[bridgetrack][1])) SETBIT(OverridePCP, i);
-		}
-
 		if (PPPallowed[i] != 0 && HASBIT(PCPstatus, i) && !HASBIT(OverridePCP, i)) {
 			for (k = 0; k < DIR_END; k++) {
 				byte temp = PPPorder[i][GetTLG(ti->tile)][k];
@@ -280,11 +279,12 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 			const SortableSpriteStruct *sss;
 			int tileh_selector = !(tileh[TS_HOME] % 3) * tileh[TS_HOME] / 3; /* tileh for the slopes, 0 otherwise */
 
-			if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !(_display_opt & DO_TRANS_BUILDINGS)) {
-				uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile), GetBridgeAxis(ti->tile));
-
-				if (height <= TilePixelHeight(ti->tile) + TILE_HEIGHT) return;
-			}
+			if ( /* We are not drawing a wire under a low bridge */
+					IsBridgeTile(ti->tile) &&
+					IsBridgeMiddle(ti->tile) &&
+					!(_display_opt & DO_TRANS_BUILDINGS) &&
+					GetBridgeHeight(ti->tile) <= TilePixelHeight(ti->tile)
+			   ) return;
 
 			assert(PCPconfig != 0); /* We have a pylon on neither end of the wire, that doesn't work (since we have no sprites for that) */
 			assert(!IsSteepSlope(tileh[TS_HOME]));
@@ -320,37 +320,30 @@ static void DrawCatenaryOnBridge(const TileInfo *ti)
 	}
 
 	AddSortableSpriteToDraw( sss->image, ti->x + sss->x_offset, ti->y + sss->y_offset,
-			sss->x_size, sss->y_size, sss->z_size, GetBridgeHeight(end, axis) + sss->z_offset);
+			sss->x_size, sss->y_size, sss->z_size, GetBridgeHeight(ti->tile) + sss->z_offset + 8);
 
 	/* Finished with wires, draw pylons */
 	/* every other tile needs a pylon on the northern end */
 	if (num % 2) {
 		if (axis == AXIS_X) {
-			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(end, axis));
+			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		} else {
-			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y, 1, 1, 10, GetBridgeHeight(end, axis));
+			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y, 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		}
 	}
 
 	/* need a pylon on the southern end of the bridge */
 	if (DistanceMax(ti->tile, start) == length) {
 		if (axis == AXIS_X) {
-			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x + 16, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(end, axis));
+			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x + 16, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		} else {
-			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y + 16, 1, 1, 10, GetBridgeHeight(end, axis));
+			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y + 16, 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		}
 	}
 }
 
 void DrawCatenary(const TileInfo *ti)
 {
-	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile)) {
-		TileIndex head = GetNorthernBridgeEnd(ti->tile);
-
-		if (GetBridgeTransportType(head) == TRANSPORT_RAIL && GetRailType(head) == RAILTYPE_ELECTRIC) {
-			DrawCatenaryOnBridge(ti);
-		}
-	}
 	switch (GetTileType(ti->tile)) {
 		case MP_RAILWAY:
 			if (GetRailTileType(ti->tile) == RAIL_TILE_DEPOT_WAYPOINT && GetRailTileSubtype(ti->tile) == RAIL_SUBTYPE_DEPOT) {
@@ -361,8 +354,9 @@ void DrawCatenary(const TileInfo *ti)
 			}
 			/* Fall through */
 		case MP_TUNNELBRIDGE:
-		case MP_STREET:
-		case MP_STATION:
+			if (IsBridgeTile(ti->tile) && IsBridgeMiddle(ti->tile) && GetRailTypeOnBridge(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenaryOnBridge(ti);
+			/* Fall further */
+		case MP_STREET: case MP_STATION:
 			DrawCatenaryRailway(ti);
 			break;
 		default:
diff --git a/landscape.c b/landscape.c
index 1209940f2..cc044eab2 100644
--- a/landscape.c
+++ b/landscape.c
@@ -2,7 +2,6 @@
 
 #include "stdafx.h"
 #include "openttd.h"
-#include "bridge_map.h"
 #include "clear_map.h"
 #include "functions.h"
 #include "map.h"
@@ -388,8 +387,6 @@ void InitializeLandscape(void)
 		for (x = 0; x < maxx; x++) {
 			MakeClear(sizex * y + x, CLEAR_GRASS, 3);
 			SetTileHeight(sizex * y + x, 0);
-			_m[sizex * y + x].extra = 0;
-			ClearBridgeMiddle(sizex * y + x);
 		}
 		MakeVoid(sizex * y + x);
 	}
diff --git a/misc.c b/misc.c
index 689340d3d..71e9e25fa 100644
--- a/misc.c
+++ b/misc.c
@@ -859,26 +859,16 @@ static void Load_MAPE(void)
 	uint size = MapSize();
 	uint i;
 
-	if (CheckSavegameVersion(29)) {
-		for (i = 0; i != size;) {
-			uint8 buf[1024];
-			uint j;
-
-			SlArray(buf, lengthof(buf), SLE_UINT8);
-			for (j = 0; j != lengthof(buf); j++) {
-				_m[i++].extra = GB(buf[j], 0, 2);
-				_m[i++].extra = GB(buf[j], 2, 2);
-				_m[i++].extra = GB(buf[j], 4, 2);
-				_m[i++].extra = GB(buf[j], 6, 2);
-			}
-		}
-	} else {
-		for (i = 0; i != size;) {
-			byte buf[4096];
-			uint j;
+	for (i = 0; i != size;) {
+		uint8 buf[1024];
+		uint j;
 
-			SlArray(buf, lengthof(buf), SLE_UINT8);
-			for (j = 0; j != lengthof(buf); j++) _m[i++].extra = buf[j];
+		SlArray(buf, lengthof(buf), SLE_UINT8);
+		for (j = 0; j != lengthof(buf); j++) {
+			_m[i++].extra = GB(buf[j], 0, 2);
+			_m[i++].extra = GB(buf[j], 2, 2);
+			_m[i++].extra = GB(buf[j], 4, 2);
+			_m[i++].extra = GB(buf[j], 6, 2);
 		}
 	}
 }
@@ -888,12 +878,17 @@ static void Save_MAPE(void)
 	uint size = MapSize();
 	uint i;
 
-	SlSetLength(size);
+	SlSetLength(size / 4);
 	for (i = 0; i != size;) {
-		uint8 buf[4096];
+		uint8 buf[1024];
 		uint j;
 
-		for (j = 0; j != lengthof(buf); j++) buf[j] = _m[i++].extra;
+		for (j = 0; j != lengthof(buf); j++) {
+			buf[j]  = _m[i++].extra << 0;
+			buf[j] |= _m[i++].extra << 2;
+			buf[j] |= _m[i++].extra << 4;
+			buf[j] |= _m[i++].extra << 6;
+		}
 		SlArray(buf, lengthof(buf), SLE_UINT8);
 	}
 }
diff --git a/npf.c b/npf.c
index 9e41f76f7..f3cf1f1fc 100644
--- a/npf.c
+++ b/npf.c
@@ -480,7 +480,17 @@ static bool VehicleMayEnterTile(Owner owner, TileIndex tile, DiagDirection enter
 
 		case MP_TUNNELBRIDGE:
 			if ((IsTunnel(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) ||
-					(IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL)) {
+					(IsBridge(tile) && (
+						(
+							IsBridgeRamp(tile) &&
+							GetBridgeTransportType(tile) == TRANSPORT_RAIL
+						) || (
+							IsBridgeMiddle(tile) &&
+							IsTransportUnderBridge(tile) &&
+							GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL &&
+							GetBridgeAxis(tile) != DiagDirToAxis(enterdir)
+						)
+					))) {
 				return IsTileOwner(tile, owner);
 			}
 			break;
@@ -524,7 +534,6 @@ static void NPFFollowTrack(AyStar* aystar, OpenListNode* current)
 	int i;
 	TrackdirBits trackdirbits, ts;
 	TransportType type = aystar->user_data[NPF_TYPE];
-	bool override_dst_check = false;
 	/* Initialize to 0, so we can jump out (return) somewhere an have no neighbours */
 	aystar->num_neighbours = 0;
 	DEBUG(npf, 4)("Expanding: (%d, %d, %d) [%d]", TileX(src_tile), TileY(src_tile), src_trackdir, src_tile);
@@ -535,10 +544,6 @@ static void NPFFollowTrack(AyStar* aystar, OpenListNode* current)
 		 * otherwise we wouldn't have got here. It is also facing us,
 		 * so we should skip it's body */
 		dst_tile = GetOtherTunnelEnd(src_tile);
-		override_dst_check = true;
-	} else if (IsBridgeTile(src_tile) && GetBridgeRampDirection(src_tile) == src_exitdir) {
-		dst_tile = GetOtherBridgeEnd(src_tile);
-		override_dst_check = true;
 	} else if (type != TRANSPORT_WATER && (IsRoadStopTile(src_tile) || IsTileDepotType(src_tile, type))) {
 		/* This is a road station or a train or road depot. We can enter and exit
 		 * those from one side only. Trackdirs don't support that (yet), so we'll
@@ -586,14 +591,8 @@ static void NPFFollowTrack(AyStar* aystar, OpenListNode* current)
 	/* I can't enter a tunnel entry/exit tile from a tile above the tunnel. Note
 	 * that I can enter the tunnel from a tile below the tunnel entrance. This
 	 * solves the problem of vehicles wanting to drive off a tunnel entrance */
-	if (!override_dst_check) {
-		if (IsTileType(dst_tile, MP_TUNNELBRIDGE)) {
-			if (IsTunnel(dst_tile)) {
-				if (GetTunnelDirection(dst_tile) != src_exitdir) return;
-			} else {
-				if (GetBridgeRampDirection(dst_tile) != src_exitdir) return;
-			}
-		}
+	if (IsTunnelTile(dst_tile) && GetTileZ(dst_tile) < GetTileZ(src_tile)) {
+		return;
 	}
 
 	/* check correct rail type (mono, maglev, etc) */
diff --git a/openttd.c b/openttd.c
index 7cef648e3..0589f84b7 100644
--- a/openttd.c
+++ b/openttd.c
@@ -49,12 +49,6 @@
 #include "yapf/yapf.h"
 #include "settings.h"
 
-#include "bridge_map.h"
-#include "clear_map.h"
-#include "rail_map.h"
-#include "road_map.h"
-#include "water_map.h"
-
 #include <stdarg.h>
 
 void GenerateWorld(int mode, uint size_x, uint size_y);
@@ -1262,72 +1256,6 @@ bool AfterLoadGame(void)
 		}
 	}
 
-	if (CheckSavegameVersion(29)) {
-		TileIndex map_end = MapSize();
-		TileIndex tile;
-		Vehicle* v;
-
-		for (tile = 0; tile != map_end; tile++) {
-			if (MayHaveBridgeAbove(tile)) ClearBridgeMiddle(tile);
-			if (IsTileType(tile, MP_TUNNELBRIDGE) &&
-					_m[tile].m5 & 0x80 && // bridge
-					_m[tile].m5 & 0x40) { // middle part
-				Axis axis = (Axis)GB(_m[tile].m5, 0, 1);
-
-				if (_m[tile].m5 & 0x20) { // transport route under bridge?
-					if (GB(_m[tile].m5, 3, 2) == TRANSPORT_RAIL) {
-						MakeRailNormal(
-							tile,
-							GetTileOwner(tile),
-							axis == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X,
-							GetRailType(tile)
-						);
-					} else {
-						uint town = IsTileOwner(tile, OWNER_TOWN) ? ClosestTownFromTile(tile, (uint)-1)->index : 0;
-
-						MakeRoadNormal(
-							tile,
-							GetTileOwner(tile),
-							axis == AXIS_X ? ROAD_Y : ROAD_X,
-							town
-						);
-					}
-				} else {
-					if (GB(_m[tile].m5, 3, 2) == 0) {
-						MakeClear(tile, CLEAR_GRASS, 3);
-					} else {
-						MakeWater(tile);
-					}
-				}
-				SetBridgeMiddle(tile, axis);
-			}
-		}
-
-		FOR_ALL_VEHICLES(v) {
-			if (v->type != VEH_Train && v->type != VEH_Road) continue;
-			if (IsBridgeTile(v->tile)) {
-				DiagDirection dir = GetBridgeRampDirection(v->tile);
-
-				if (dir != DirToDiagDir(v->direction)) continue;
-				switch (dir) {
-					default:
-					case DIAGDIR_NE: if ((v->x_pos & 0xF) !=  0) continue;
-					case DIAGDIR_SE: if ((v->y_pos & 0xF) != 15) continue;
-					case DIAGDIR_SW: if ((v->x_pos & 0xF) != 15) continue;
-					case DIAGDIR_NW: if ((v->y_pos & 0xF) !=  0) continue;
-				}
-			} else if (v->z_pos <= GetSlopeZ(v->x_pos, v->y_pos)) {
-				continue;
-			}
-			if (!IsBridgeTile(v->tile)) v->tile = GetNorthernBridgeEnd(v->tile);
-			if (v->type == VEH_Train) {
-				v->u.rail.track = 0x40;
-			} else {
-				v->u.road.state = 0xFF;
-			}
-		}
-	}
-
 	/* Elrails got added in rev 24 */
 	if (CheckSavegameVersion(24)) {
 		Vehicle* v;
@@ -1378,6 +1306,15 @@ bool AfterLoadGame(void)
 						}
 					} else {
 						if (GetBridgeTransportType(t) == TRANSPORT_RAIL) {
+							if (IsBridgeRamp(t)) {
+								SetRailType(t, UpdateRailType(GetRailType(t), min_rail));
+							} else {
+								SetRailTypeOnBridge(t, UpdateRailType(GetRailTypeOnBridge(t), min_rail));
+							}
+						}
+						if (IsBridgeMiddle(t) &&
+								IsTransportUnderBridge(t) &&
+								GetTransportTypeUnderBridge(t) == TRANSPORT_RAIL) {
 							SetRailType(t, UpdateRailType(GetRailType(t), min_rail));
 						}
 					}
diff --git a/pathfind.c b/pathfind.c
index 77bc9804a..622b820f0 100644
--- a/pathfind.c
+++ b/pathfind.c
@@ -256,27 +256,21 @@ static void TPFMode1(TrackPathFinder* tpf, TileIndex tile, DiagDirection directi
 	RememberData rd;
 	TileIndex tile_org = tile;
 
-	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
-		if (IsTunnel(tile)) {
-			if (GetTunnelDirection(tile) != direction ||
-					GetTunnelTransportType(tile) != tpf->tracktype) {
-				return;
-			}
-			tile = SkipToEndOfTunnel(tpf, tile, direction);
-		} else {
-			TileIndex tile_end;
-			if (GetBridgeRampDirection(tile) != direction ||
-					GetBridgeTransportType(tile) != tpf->tracktype) {
-				return;
-			}
-			//fprintf(stderr, "%s: Planning over bridge\n", __func__);
-			// TODO doesn't work - WHAT doesn't work?
-			TPFSetTileBit(tpf, tile, 14);
-			tile_end = GetOtherBridgeEnd(tile);
-			tpf->rd.cur_length += DistanceManhattan(tile, tile_end);
-			tile = tile_end;
-			TPFSetTileBit(tpf, tile, 14);
+	// check if the old tile can be left at that direction
+	if (tpf->tracktype == TRANSPORT_ROAD) {
+		// road stops and depots now have a track (r4419)
+		// don't enter road stop from the back
+		if (IsRoadStopTile(tile) && GetRoadStopDir(tile) != direction) return;
+		// don't enter road depot from the back
+		if (IsTileDepotType(tile, TRANSPORT_ROAD) && GetRoadDepotDirection(tile) != direction) return;
+	}
+
+	if (IsTunnelTile(tile)) {
+		if (GetTunnelDirection(tile) != direction ||
+				GetTunnelTransportType(tile) != tpf->tracktype) {
+			return;
 		}
+		tile = SkipToEndOfTunnel(tpf, tile, direction);
 	}
 	tile += TileOffsByDir(direction);
 
@@ -287,7 +281,11 @@ static void TPFMode1(TrackPathFinder* tpf, TileIndex tile, DiagDirection directi
 
 		if (IsTileType(tile_org, MP_RAILWAY) || IsTileType(tile_org, MP_STATION) || IsTileType(tile_org, MP_TUNNELBRIDGE))
 			if (IsTileType(tile, MP_RAILWAY) || IsTileType(tile, MP_STATION) || IsTileType(tile, MP_TUNNELBRIDGE))
-				if (GetTileOwner(tile_org) != GetTileOwner(tile)) return;
+				/* Check if we are on a bridge (middle parts don't have an owner */
+				if (!IsBridgeTile(tile) || !IsBridgeMiddle(tile))
+					if (!IsBridgeTile(tile_org) || !IsBridgeMiddle(tile_org))
+						if (GetTileOwner(tile_org) != GetTileOwner(tile))
+							return;
 	}
 
 	// check if the new tile can be entered from that direction
@@ -675,6 +673,7 @@ static void NTPEnum(NewTrackPathFinder* tpf, TileIndex tile, DiagDirection direc
 	uint track;
 	TileIndex tile_org;
 	StackedItem si;
+	FindLengthOfTunnelResult flotr;
 	int estimation;
 
 
@@ -712,40 +711,22 @@ callback_and_continue:
 start_at:
 		// If the tile is the entry tile of a tunnel, and we're not going out of the tunnel,
 		//   need to find the exit of the tunnel.
-		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
-			if (IsTunnel(tile)) {
-				if (GetTunnelDirection(tile) != ReverseDiagDir(direction)) {
-					FindLengthOfTunnelResult flotr;
-
-					/* We are not just driving out of the tunnel */
-					if (GetTunnelDirection(tile) != direction ||
-							GetTunnelTransportType(tile) != tpf->tracktype) {
-						// We are not driving into the tunnel, or it is an invalid tunnel
-						continue;
-					}
-					if (!HASBIT(tpf->railtypes, GetRailType(tile))) {
-						bits = 0;
-						break;
-					}
-					flotr = FindLengthOfTunnel(tile, direction);
-					si.cur_length += flotr.length * DIAG_FACTOR;
-					tile = flotr.tile;
-					// tile now points to the exit tile of the tunnel
-				}
-			} else {
-				TileIndex tile_end;
-				if (GetBridgeRampDirection(tile) != ReverseDiagDir(direction)) {
-					// We are not just leaving the bridge
-					if (GetBridgeRampDirection(tile) != direction ||
-							GetBridgeTransportType(tile) != tpf->tracktype) {
-						// Not entering the bridge or not compatible
-						continue;
-					}
-				}
-				tile_end = GetOtherBridgeEnd(tile);
-				si.cur_length += DistanceManhattan(tile, tile_end) * DIAG_FACTOR;
-				tile = tile_end;
+		if (IsTunnelTile(tile) &&
+				GetTunnelDirection(tile) != ReverseDiagDir(direction)) {
+			/* We are not just driving out of the tunnel */
+			if (GetTunnelDirection(tile) != direction ||
+					GetTunnelTransportType(tile) != tpf->tracktype) {
+				// We are not driving into the tunnel, or it is an invalid tunnel
+				continue;
 			}
+			if (!HASBIT(tpf->railtypes, GetRailType(tile))) {
+				bits = 0;
+				break;
+			}
+			flotr = FindLengthOfTunnel(tile, direction);
+			si.cur_length += flotr.length * DIAG_FACTOR;
+			tile = flotr.tile;
+			// tile now points to the exit tile of the tunnel
 		}
 
 		// This is a special loop used to go through
@@ -773,9 +754,13 @@ start_at:
 				// Check that the tile contains exactly one track
 				if (bits == 0 || KILL_FIRST_BIT(bits) != 0) break;
 
-				if (IsTileType(tile, MP_STREET) ? !HASBIT(tpf->railtypes, GetRailTypeCrossing(tile)) : !HASBIT(tpf->railtypes, GetRailType(tile))) {
-					bits = 0;
-					break;
+				/* Check the rail type only if the train is *NOT* on top of
+				 * a bridge. */
+				if (!(IsBridgeTile(tile) && IsBridgeMiddle(tile) && GetBridgeAxis(tile) == DiagDirToAxis(direction))) {
+					if (IsTileType(tile, MP_STREET) ? !HASBIT(tpf->railtypes, GetRailTypeCrossing(tile)) : !HASBIT(tpf->railtypes, GetRailType(tile))) {
+						bits = 0;
+						break;
+					}
 				}
 
 				///////////////////
diff --git a/rail.c b/rail.c
index aa2865cb3..5b6650667 100644
--- a/rail.c
+++ b/rail.c
@@ -104,6 +104,7 @@ const Trackdir _dir_to_diag_trackdir[] = {
 
 RailType GetTileRailType(TileIndex tile, Trackdir trackdir)
 {
+	DiagDirection exitdir = TrackdirToExitdir(trackdir);
 	switch (GetTileType(tile)) {
 		case MP_RAILWAY:
 			return GetRailType(tile);
@@ -123,8 +124,21 @@ RailType GetTileRailType(TileIndex tile, Trackdir trackdir)
 					return GetRailType(tile);
 				}
 			} else {
-				if (GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
-					return GetRailType(tile);
+				if (IsBridgeRamp(tile)) {
+					if (GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+						return GetRailType(tile);
+					}
+				} else {
+					if (GetBridgeAxis(tile) == DiagDirToAxis(exitdir)) {
+						if (GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+							return GetRailTypeOnBridge(tile);
+						}
+					} else {
+						if (IsTransportUnderBridge(tile) &&
+								GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL) {
+							return GetRailType(tile);
+						}
+					}
 				}
 			}
 			break;
diff --git a/rail_cmd.c b/rail_cmd.c
index 61e316af2..8e7792601 100644
--- a/rail_cmd.c
+++ b/rail_cmd.c
@@ -231,6 +231,29 @@ int32 CmdBuildSingleRail(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
 	switch (GetTileType(tile)) {
+		case MP_TUNNELBRIDGE:
+			if (!IsBridge(tile) ||
+					!IsBridgeMiddle(tile) ||
+					(GetBridgeAxis(tile) == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X) != trackbit) {
+				// Get detailed error message
+				return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+			}
+
+			if (IsClearUnderBridge(tile)) {
+				ret = CheckRailSlope(tileh, trackbit, 0, tile);
+				if (CmdFailed(ret)) return ret;
+				cost += ret;
+
+				if (flags & DC_EXEC) SetRailUnderBridge(tile, _current_player, p1);
+			} else if (IsTransportUnderBridge(tile) &&
+					GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL) {
+				return_cmd_error(STR_1007_ALREADY_BUILT);
+			} else {
+				// Get detailed error message
+				return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+			}
+			break;
+
 		case MP_RAILWAY:
 			if (!CheckTrackCombination(tile, trackbit, flags) ||
 					!EnsureNoVehicle(tile)) {
@@ -318,6 +341,20 @@ int32 CmdRemoveSingleRail(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
 	switch (GetTileType(tile)) {
+		case MP_TUNNELBRIDGE:
+			if (!IsBridge(tile) ||
+					!IsBridgeMiddle(tile) ||
+					!IsTransportUnderBridge(tile) ||
+					GetTransportTypeUnderBridge(tile) != TRANSPORT_RAIL ||
+					GetRailBitsUnderBridge(tile) != trackbit ||
+					(_current_player != OWNER_WATER && !CheckTileOwnership(tile)) ||
+					!EnsureNoVehicleOnGround(tile)) {
+				return CMD_ERROR;
+			}
+
+			if (flags & DC_EXEC) SetClearUnderBridge(tile);
+			break;
+
 		case MP_STREET: {
 			if (!IsLevelCrossing(tile) ||
 					GetCrossingRailBits(tile) != trackbit ||
@@ -554,8 +591,6 @@ int32 CmdBuildTrainDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	if (CmdFailed(ret)) return CMD_ERROR;
 	cost = ret;
 
-	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
 	d = AllocateDepot();
 	if (d == NULL) return CMD_ERROR;
 
@@ -1381,7 +1416,6 @@ static void DrawTile_Track(TileInfo *ti)
 			);
 		}
 	}
-	DrawBridgeMiddle(ti);
 }
 
 void DrawTrainDepotSprite(int x, int y, int image, RailType railtype)
@@ -1491,11 +1525,19 @@ typedef struct SignalVehicleCheckStruct {
 static void *SignalVehicleCheckProc(Vehicle *v, void *data)
 {
 	const SignalVehicleCheckStruct* dest = data;
+	TileIndex tile;
 
 	if (v->type != VEH_Train) return NULL;
 
+	/* Find the tile outside the tunnel, for signalling */
+	if (v->u.rail.track == 0x40) {
+		tile = GetVehicleOutOfTunnelTile(v);
+	} else {
+		tile = v->tile;
+	}
+
 	/* Wrong tile, or no train? Not a match */
-	if (v->tile != dest->tile) return NULL;
+	if (tile != dest->tile) return NULL;
 
 	/* Are we on the same piece of track? */
 	if (dest->track & (v->u.rail.track + (v->u.rail.track << 8))) return v;
@@ -1511,18 +1553,15 @@ static bool SignalVehicleCheck(TileIndex tile, uint track)
 	dest.tile = tile;
 	dest.track = track;
 
-	/* Locate vehicles in tunnels or on bridges */
-	if (IsTunnelTile(tile) || IsBridgeTile(tile)) {
-		TileIndex end;
-		DiagDirection direction;
-
-		if (IsTunnelTile(tile)) {
-			end = GetOtherTunnelEnd(tile);
-			direction = GetTunnelDirection(tile);
-		} else {
-			end = GetOtherBridgeEnd(tile);
-			direction = GetBridgeRampDirection(tile);
-		}
+	/** @todo "Hackish" fix for the tunnel problems. This is needed because a tunnel
+	 * is some kind of invisible black hole, and there is some special magic going
+	 * on in there. This 'workaround' can be removed once the maprewrite is done.
+	 */
+	if (IsTunnelTile(tile)) {
+		// It is a tunnel we're checking, we need to do some special stuff
+		// because VehicleFromPos will not find the vihicle otherwise
+		TileIndex end = GetOtherTunnelEnd(tile);
+		DiagDirection direction = GetTunnelDirection(tile);
 
 		dest.track = 1 << (direction & 1); // get the trackbit the vehicle would have if it has not entered the tunnel yet (ie is still visible)
 
@@ -1532,9 +1571,9 @@ static bool SignalVehicleCheck(TileIndex tile, uint track)
 		// check for a vehicle with that trackdir on the end tile of the tunnel
 		if (VehicleFromPos(end, &dest, SignalVehicleCheckProc) != NULL) return true;
 
-		// now check all tiles from start to end for a warping vehicle
+		// now check all tiles from start to end for a "hidden" vehicle
 		// NOTE: the hashes for tiles may overlap, so this could maybe be optimised a bit by not checking every tile?
-		dest.track = 0x40;
+		dest.track = 0x40; // trackbit for vehicles "hidden" inside a tunnel
 		for (; tile != end; tile += TileOffsByDir(direction)) {
 			if (VehicleFromPos(tile, &dest, SignalVehicleCheckProc) != NULL)
 				return true;
diff --git a/rail_map.h b/rail_map.h
index 43166d671..44a42f9aa 100644
--- a/rail_map.h
+++ b/rail_map.h
@@ -81,6 +81,11 @@ static inline RailType GetRailTypeCrossing(TileIndex t)
 	return (RailType)GB(_m[t].m4, 0, 4);
 }
 
+static inline RailType GetRailTypeOnBridge(TileIndex t)
+{
+	return (RailType)GB(_m[t].m3, 4, 4);
+}
+
 static inline void SetRailType(TileIndex t, RailType r)
 {
 	SB(_m[t].m3, 0, 4, r);
@@ -92,6 +97,11 @@ static inline void SetRailTypeCrossing(TileIndex t, RailType r)
 	SB(_m[t].m4, 0, 4, r);
 }
 
+static inline void SetRailTypeOnBridge(TileIndex t, RailType r)
+{
+	SB(_m[t].m3, 4, 4, r);
+}
+
 
 /** These are used to specify a single track.
  * Can be translated to a trackbit with TrackToTrackbit */
diff --git a/road_cmd.c b/road_cmd.c
index 30f683b41..832ca7a24 100644
--- a/road_cmd.c
+++ b/road_cmd.c
@@ -108,70 +108,97 @@ int32 CmdRemoveRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	if (p1 >> 4) return CMD_ERROR;
 	pieces = p1;
 
-	if (!IsTileType(tile, MP_STREET)) return CMD_ERROR;
+	if (!IsTileType(tile, MP_STREET) && !IsTileType(tile, MP_TUNNELBRIDGE)) return CMD_ERROR;
 
 	owner = IsLevelCrossingTile(tile) ? GetCrossingRoadOwner(tile) : GetTileOwner(tile);
 
 	if (owner == OWNER_TOWN && _game_mode != GM_EDITOR) {
-		t = GetTownByTile(tile);
+		if (IsTileType(tile, MP_TUNNELBRIDGE)) { // index of town is not saved for bridge (no space)
+			t = ClosestTownFromTile(tile, _patches.dist_local_authority);
+		} else {
+			t = GetTownByTile(tile);
+		}
 	} else {
 		t = NULL;
 	}
 
 	if (!CheckAllowRemoveRoad(tile, pieces, &edge_road)) return CMD_ERROR;
 
-	if (!EnsureNoVehicle(tile)) return CMD_ERROR;
+	switch (GetTileType(tile)) {
+		case MP_TUNNELBRIDGE:
+			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
+
+			if (!IsBridge(tile) ||
+					!IsBridgeMiddle(tile) ||
+					!IsTransportUnderBridge(tile) ||
+					GetTransportTypeUnderBridge(tile) != TRANSPORT_ROAD ||
+					(pieces & ComplementRoadBits(GetRoadBitsUnderBridge(tile))) != 0) {
+				return CMD_ERROR;
+			}
 
-	// check if you're allowed to remove the street owned by a town
-	// removal allowance depends on difficulty setting
-	if (!CheckforTownRating(flags, t, ROAD_REMOVE)) return CMD_ERROR;
+			if (flags & DC_EXEC) {
+				ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
+				SetClearUnderBridge(tile);
+				MarkTileDirtyByTile(tile);
+			}
+			return _price.remove_road * 2;
 
-	switch (GetRoadTileType(tile)) {
-		case ROAD_TILE_NORMAL: {
-			RoadBits present = GetRoadBits(tile);
-			RoadBits c = pieces;
+		case MP_STREET:
+			if (!EnsureNoVehicle(tile)) return CMD_ERROR;
 
-			if (GetTileSlope(tile, NULL) != SLOPE_FLAT  &&
-					(present == ROAD_Y || present == ROAD_X)) {
-				c |= (c & 0xC) >> 2;
-				c |= (c & 0x3) << 2;
-			}
+			// check if you're allowed to remove the street owned by a town
+			// removal allowance depends on difficulty setting
+			if (!CheckforTownRating(flags, t, ROAD_REMOVE)) return CMD_ERROR;
 
-			// limit the bits to delete to the existing bits.
-			c &= present;
-			if (c == 0) return CMD_ERROR;
+			switch (GetRoadTileType(tile)) {
+				case ROAD_TILE_NORMAL: {
+					RoadBits present = GetRoadBits(tile);
+					RoadBits c = pieces;
+
+					if (GetTileSlope(tile, NULL) != SLOPE_FLAT &&
+							(present == ROAD_Y || present == ROAD_X)) {
+						c |= (c & 0xC) >> 2;
+						c |= (c & 0x3) << 2;
+					}
 
-			if (flags & DC_EXEC) {
-				ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
+					// limit the bits to delete to the existing bits.
+					c &= present;
+					if (c == 0) return CMD_ERROR;
 
-				present ^= c;
-				if (present == 0) {
-					DoClearSquare(tile);
-				} else {
-					SetRoadBits(tile, present);
-					MarkTileDirtyByTile(tile);
+					if (flags & DC_EXEC) {
+						ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
+
+						present ^= c;
+						if (present == 0) {
+							DoClearSquare(tile);
+						} else {
+							SetRoadBits(tile, present);
+							MarkTileDirtyByTile(tile);
+						}
+					}
+					return CountRoadBits(c) * _price.remove_road;
 				}
-			}
-			return CountRoadBits(c) * _price.remove_road;
-		}
 
-		case ROAD_TILE_CROSSING: {
-			if (pieces & ComplementRoadBits(GetCrossingRoadBits(tile))) {
-				return CMD_ERROR;
-			}
+				case ROAD_TILE_CROSSING: {
+					if (pieces & ComplementRoadBits(GetCrossingRoadBits(tile))) {
+						return CMD_ERROR;
+					}
 
-			if (flags & DC_EXEC) {
-				ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
+					if (flags & DC_EXEC) {
+						ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
 
-				MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailTypeCrossing(tile));
-				MarkTileDirtyByTile(tile);
+						MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailTypeCrossing(tile));
+						MarkTileDirtyByTile(tile);
+					}
+					return _price.remove_road * 2;
+				}
+
+				default:
+				case ROAD_TILE_DEPOT:
+					return CMD_ERROR;
 			}
-			return _price.remove_road * 2;
-		}
 
-		case ROAD_TILE_DEPOT:
-		default:
-			return CMD_ERROR;
+		default: return CMD_ERROR;
 	}
 }
 
@@ -321,6 +348,37 @@ int32 CmdBuildRoad(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 			return _price.build_road * 2;
 		}
 
+		case MP_TUNNELBRIDGE:
+			/* check for flat land */
+			if (IsSteepSlope(tileh)) {
+				return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+			}
+
+			if (!IsBridge(tile) || !IsBridgeMiddle(tile)) goto do_clear;
+
+			/* only allow roads pertendicular to bridge */
+			if ((pieces & (GetBridgeAxis(tile) == AXIS_X ? ROAD_X : ROAD_Y)) != 0) {
+				goto do_clear;
+			}
+
+			/* check if clear land under bridge */
+			if (IsTransportUnderBridge(tile)) {
+				switch (GetTransportTypeUnderBridge(tile)) {
+					case TRANSPORT_ROAD: return_cmd_error(STR_1007_ALREADY_BUILT);
+					default: return_cmd_error(STR_1008_MUST_REMOVE_RAILROAD_TRACK);
+				}
+			} else {
+				if (IsWaterUnderBridge(tile)) {
+					return_cmd_error(STR_3807_CAN_T_BUILD_ON_WATER);
+				}
+			}
+
+			if (flags & DC_EXEC) {
+				SetRoadUnderBridge(tile, _current_player);
+				MarkTileDirtyByTile(tile);
+			}
+			return _price.build_road * 2;
+
 		default:
 do_clear:;
 			ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
@@ -517,8 +575,6 @@ int32 CmdBuildRoadDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	cost = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 	if (CmdFailed(cost)) return CMD_ERROR;
 
-	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
 	dep = AllocateDepot();
 	if (dep == NULL) return CMD_ERROR;
 
@@ -742,7 +798,6 @@ static void DrawTile_Road(TileInfo *ti)
 			break;
 		}
 	}
-	DrawBridgeMiddle(ti);
 }
 
 void DrawRoadDepotSprite(int x, int y, int image)
diff --git a/road_map.c b/road_map.c
index 1c1040476..8702f7692 100644
--- a/road_map.c
+++ b/road_map.c
@@ -27,12 +27,22 @@ RoadBits GetAnyRoadBits(TileIndex tile)
 			return DiagDirToRoadBits(GetRoadStopDir(tile));
 
 		case MP_TUNNELBRIDGE:
-			if (IsTunnel(tile)) {
+			if (IsBridge(tile)) {
+				if (IsBridgeMiddle(tile)) {
+					if (!IsTransportUnderBridge(tile) ||
+							GetBridgeTransportType(tile) != TRANSPORT_ROAD) {
+						return 0;
+					}
+					return GetRoadBitsUnderBridge(tile);
+				} else {
+					// ending
+					if (GetBridgeTransportType(tile) != TRANSPORT_ROAD) return 0;
+					return DiagDirToRoadBits(ReverseDiagDir(GetBridgeRampDirection(tile)));
+				}
+			} else {
+				// tunnel
 				if (GetTunnelTransportType(tile) != TRANSPORT_ROAD) return 0;
 				return DiagDirToRoadBits(ReverseDiagDir(GetTunnelDirection(tile)));
-			} else {
-				if (GetBridgeTransportType(tile) != TRANSPORT_ROAD) return 0;
-				return DiagDirToRoadBits(ReverseDiagDir(GetBridgeRampDirection(tile)));
 			}
 
 		default: return 0;
diff --git a/roadveh_cmd.c b/roadveh_cmd.c
index e46666066..bd99fd227 100644
--- a/roadveh_cmd.c
+++ b/roadveh_cmd.c
@@ -21,9 +21,7 @@
 #include "player.h"
 #include "sound.h"
 #include "depot.h"
-#include "bridge.h"
 #include "tunnel_map.h"
-#include "bridge_map.h"
 #include "vehicle_gui.h"
 #include "newgrf_engine.h"
 #include "yapf/yapf.h"
@@ -309,6 +307,8 @@ static const Depot* FindClosestRoadDepot(const Vehicle* v)
 {
 	TileIndex tile = v->tile;
 
+	if (v->u.road.state == 255) tile = GetVehicleOutOfTunnelTile(v);
+
 	if (_patches.yapf.road_use_yapf) {
 		Depot* ret = YapfFindNearestRoadDepot(v);
 		return ret;
@@ -405,19 +405,14 @@ int32 CmdTurnRoadVeh(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 
 	if (v->type != VEH_Road || !CheckOwnership(v->owner)) return CMD_ERROR;
 
-	if (v->vehstatus & VS_STOPPED ||
+	if (v->vehstatus & (VS_HIDDEN | VS_STOPPED) ||
 			v->u.road.crashed_ctr != 0 ||
 			v->breakdown_ctr != 0 ||
 			v->u.road.overtaking != 0 ||
-			v->u.road.state == 255 ||
-			IsRoadVehInDepot(v) ||
 			v->cur_speed < 5) {
 		return CMD_ERROR;
 	}
 
-	if (IsTunnelTile(v->tile) && DirToDiagDir(v->direction) == GetTunnelDirection(v->tile)) return CMD_ERROR;
-	if (IsBridgeTile(v->tile) && DirToDiagDir(v->direction) == GetBridgeRampDirection(v->tile)) return CMD_ERROR;
-
 	if (flags & DC_EXEC) v->u.road.reverse_ctr = 180;
 
 	return 0;
@@ -484,9 +479,11 @@ static byte SetRoadVehPosition(Vehicle *v, int x, int y)
 	byte new_z, old_z;
 
 	// need this hint so it returns the right z coordinate on bridges.
+	_get_z_hint = v->z_pos;
 	v->x_pos = x;
 	v->y_pos = y;
 	new_z = GetSlopeZ(x, y);
+	_get_z_hint = 0;
 
 	old_z = v->z_pos;
 	v->z_pos = new_z;
@@ -821,7 +818,6 @@ static bool RoadVehAccelerate(Vehicle *v)
 
 	// Clamp
 	spd = min(spd, v->max_speed);
-	if (v->u.road.state == 255) spd = min(spd, SetSpeedLimitOnBridge(v));
 
 	//updates statusbar only if speed have changed to save CPU time
 	if (spd != v->cur_speed) {
@@ -1290,7 +1286,8 @@ static void RoadVehController(Vehicle *v)
 			return;
 		}
 
-		if ((IsTunnelTile(gp.new_tile) || IsBridgeTile(gp.new_tile)) && VehicleEnterTile(v, gp.new_tile, gp.x, gp.y) & 4) {
+		if (IsTunnelTile(gp.new_tile) &&
+				VehicleEnterTile(v, gp.new_tile, gp.x, gp.y) & 4) {
 			//new_dir = RoadGetNewDirection(v, gp.x, gp.y)
 			v->cur_image = GetRoadVehImage(v, v->direction);
 			UpdateRoadVehDeltaXY(v);
@@ -1301,7 +1298,6 @@ static void RoadVehController(Vehicle *v)
 		v->x_pos = gp.x;
 		v->y_pos = gp.y;
 		VehiclePositionChanged(v);
-		if (!(v->vehstatus & VS_HIDDEN)) EndVehicleMove(v);
 		return;
 	}
 
diff --git a/saveload.c b/saveload.c
index 48535b18b..4f6854a96 100644
--- a/saveload.c
+++ b/saveload.c
@@ -30,7 +30,7 @@
 #include "variables.h"
 #include <setjmp.h>
 
-const uint16 SAVEGAME_VERSION = 29;
+const uint16 SAVEGAME_VERSION = 28;
 uint16 _sl_version;       /// the major savegame version identifier
 byte   _sl_minor_version; /// the minor savegame version, DO NOT USE!
 
diff --git a/station_cmd.c b/station_cmd.c
index dfd8df362..0339ec0a6 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -5,7 +5,6 @@
 
 #include "stdafx.h"
 #include "openttd.h"
-#include "bridge_map.h"
 #include "debug.h"
 #include "functions.h"
 #include "station_map.h"
@@ -783,10 +782,6 @@ int32 CheckFlatLandBelow(TileIndex tile, uint w, uint h, uint flags, uint invali
 	int flat_z;
 
 	BEGIN_TILE_LOOP(tile_cur, w, h, tile)
-		if (MayHaveBridgeAbove(tile_cur) && IsBridgeAbove(tile_cur)) {
-			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-		}
-
 		if (!EnsureNoVehicle(tile_cur)) return CMD_ERROR;
 
 		tileh = GetTileSlope(tile_cur, &z);
diff --git a/table/sprites.h b/table/sprites.h
index 1af230eca..c74239e35 100644
--- a/table/sprites.h
+++ b/table/sprites.h
@@ -708,27 +708,6 @@ enum Sprites {
 	SPR_BTTUB_X_RAIL_REAR_BEG   = 2569,
 	SPR_BTTUB_X_RAIL_REAR_MID   = 2570,
 	SPR_BTTUB_X_RAIL_REAR_END   = 2571,
-	SPR_BTTUB_Y_RAIL_REAR_BEG   = 2572,
-	SPR_BTTUB_Y_RAIL_REAR_MID   = 2573,
-	SPR_BTTUB_Y_RAIL_REAR_END   = 2574,
-	SPR_BTTUB_X_ROAD_REAR_BEG   = 2575,
-	SPR_BTTUB_X_ROAD_REAR_MID   = 2576,
-	SPR_BTTUB_X_ROAD_REAR_END   = 2577,
-	SPR_BTTUB_Y_ROAD_REAR_BEG   = 2578,
-	SPR_BTTUB_Y_ROAD_REAR_MID   = 2579,
-	SPR_BTTUB_Y_ROAD_REAR_END   = 2580,
-	SPR_BTTUB_X_MONO_REAR_BEG   = 2581,
-	SPR_BTTUB_X_MONO_REAR_MID   = 2582,
-	SPR_BTTUB_X_MONO_REAR_END   = 2583,
-	SPR_BTTUB_Y_MONO_REAR_BEG   = 2584,
-	SPR_BTTUB_Y_MONO_REAR_MID   = 2585,
-	SPR_BTTUB_Y_MONO_REAR_END   = 2586,
-	SPR_BTTUB_X_MGLV_REAR_BEG   = 2587,
-	SPR_BTTUB_X_MGLV_REAR_MID   = 2588,
-	SPR_BTTUB_X_MGLV_REAR_END   = 2589,
-	SPR_BTTUB_Y_MGLV_REAR_BEG   = 2590,
-	SPR_BTTUB_Y_MGLV_REAR_MID   = 2591,
-	SPR_BTTUB_Y_MGLV_REAR_END   = 2592,
 
 
 	/* ramps (for all bridges except wood and tubular?)*/
diff --git a/terraform_gui.c b/terraform_gui.c
index 571f1298e..72b2a53a7 100644
--- a/terraform_gui.c
+++ b/terraform_gui.c
@@ -2,7 +2,6 @@
 
 #include "stdafx.h"
 #include "openttd.h"
-#include "bridge_map.h"
 #include "clear_map.h"
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -82,20 +81,11 @@ static void GenerateRockyArea(TileIndex end, TileIndex start)
 	size_y = (ey - sy) + 1;
 
 	BEGIN_TILE_LOOP(tile, size_x, size_y, TileXY(sx, sy)) {
-		switch (GetTileType(tile)) {
-			case MP_CLEAR:
-				MakeClear(tile, CLEAR_ROCKS, 3);
-				break;
-
-			case MP_TREES:
-				MakeClear(tile, CLEAR_ROCKS, 3);
-				ClearBridgeMiddle(tile);
-				break;
-
-			default: continue;
+		if (IsTileType(tile, MP_CLEAR) || IsTileType(tile, MP_TREES)) {
+			MakeClear(tile, CLEAR_ROCKS, 3);
+			MarkTileDirtyByTile(tile);
+			success = true;
 		}
-		MarkTileDirtyByTile(tile);
-		success = true;
 	} END_TILE_LOOP(tile, size_x, size_y, 0);
 
 	if (success) SndPlayTileFx(SND_1F_SPLAT, end);
diff --git a/town_cmd.c b/town_cmd.c
index 590641406..2c7a8653c 100644
--- a/town_cmd.c
+++ b/town_cmd.c
@@ -26,7 +26,6 @@
 #include "water_map.h"
 #include "variables.h"
 #include "bridge.h"
-#include "bridge_map.h"
 #include "table/town_land.h"
 
 enum {
@@ -1094,8 +1093,6 @@ static bool CheckBuildHouseMode(TileIndex tile, Slope tileh, int mode)
 	slope = GetTileSlope(tile, NULL);
 	if (IsSteepSlope(slope)) return false;
 
-	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return false;
-
 	b = 0;
 	if ((slope != SLOPE_FLAT && ~slope & _masks[mode])) b = ~b;
 	if ((tileh != SLOPE_FLAT && ~tileh & _masks[mode+4])) b = ~b;
@@ -1139,8 +1136,6 @@ static bool CheckFree2x2Area(TileIndex tile)
 
 		if (GetTileSlope(tile, NULL) != SLOPE_FLAT) return false;
 
-		if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return false;
-
 		if (CmdFailed(DoCommand(tile, 0, 0, DC_EXEC | DC_AUTO | DC_NO_WATER | DC_FORCETEST, CMD_LANDSCAPE_CLEAR)))
 			return false;
 	}
@@ -1275,7 +1270,6 @@ static bool BuildTownHouse(Town *t, TileIndex tile)
 	// make sure it's possible
 	if (!EnsureNoVehicle(tile)) return false;
 	if (IsSteepSlope(GetTileSlope(tile, NULL))) return false;
-	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return false;
 
 	r = DoCommand(tile, 0, 0, DC_EXEC | DC_AUTO | DC_NO_WATER, CMD_LANDSCAPE_CLEAR);
 	if (CmdFailed(r)) return false;
diff --git a/train_cmd.c b/train_cmd.c
index 3a5300adc..582aa0530 100644
--- a/train_cmd.c
+++ b/train_cmd.c
@@ -25,7 +25,6 @@
 #include "waypoint.h"
 #include "vehicle_gui.h"
 #include "train.h"
-#include "bridge.h"
 #include "newgrf_callbacks.h"
 #include "newgrf_engine.h"
 #include "newgrf_text.h"
@@ -92,7 +91,10 @@ void TrainPowerChanged(Vehicle* v)
 		/* Power is not added for articulated parts */
 		if (IsArticulatedPart(u)) continue;
 
-		if (IsLevelCrossingTile(u->tile)) {
+		if (IsBridgeTile(u->tile) && IsBridgeMiddle(u->tile) && DiagDirToAxis(DirToDiagDir(u->direction)) == GetBridgeAxis(u->tile)) {
+			if (!HasPowerOnRail(u->u.rail.railtype, GetRailTypeOnBridge(u->tile))) engine_has_power = false;
+			if (!HasPowerOnRail(v->u.rail.railtype, GetRailTypeOnBridge(u->tile))) wagon_has_power = false;
+		} else if (IsLevelCrossingTile(u->tile)) {
 			if (!HasPowerOnRail(u->u.rail.railtype, GetRailTypeCrossing(u->tile)))	engine_has_power = false;
 			if (!HasPowerOnRail(v->u.rail.railtype, GetRailTypeCrossing(u->tile)))	wagon_has_power = false;
 		} else {
@@ -1525,14 +1527,13 @@ static void ReverseTrainSwapVeh(Vehicle *v, int l, int r)
 		UpdateVarsAfterSwap(a);
 		UpdateVarsAfterSwap(b);
 
-		/* call the proper EnterTile function unless we are in a wormhole */
-		if (!(a->u.rail.track & 0x40)) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
-		if (!(b->u.rail.track & 0x40)) VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
+		VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
+		VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
 	} else {
 		if (!(a->u.rail.track & 0x80)) a->direction = ReverseDir(a->direction);
 		UpdateVarsAfterSwap(a);
 
-		if (!(a->u.rail.track & 0x40)) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
+		VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
 	}
 
 	/* Update train's power incase tiles were different rail type */
@@ -1850,6 +1851,8 @@ static TrainFindDepotData FindClosestTrainDepot(Vehicle *v, int max_distance)
 		return tfdd;
 	}
 
+	if (v->u.rail.track == 0x40) tile = GetVehicleOutOfTunnelTile(v);
+
 	if (_patches.yapf.rail_use_yapf) {
 		bool found = YapfFindNearestRailDepotTwoWay(v, max_distance, NPF_INFINITE_PENALTY, &tfdd.tile, &tfdd.reverse);
 		tfdd.best_length = found ? max_distance / 2 : -1; // some fake distance or NOT_FOUND
@@ -2567,7 +2570,9 @@ static byte AfterSetTrainPos(Vehicle *v, bool new_tile)
 	byte new_z, old_z;
 
 	// need this hint so it returns the right z coordinate on bridges.
+	_get_z_hint = v->z_pos;
 	new_z = GetSlopeZ(v->x_pos, v->y_pos);
+	_get_z_hint = 0;
 
 	old_z = v->z_pos;
 	v->z_pos = new_z;
@@ -2643,6 +2648,13 @@ static bool CheckCompatibleRail(const Vehicle *v, TileIndex tile)
 			// normal tracks, jump to owner check
 			break;
 
+		case MP_TUNNELBRIDGE:
+			if (IsBridge(tile) && IsBridgeMiddle(tile)) {
+				// is train going over the bridge?
+				if (v->z_pos > GetTileMaxZ(tile)) return true;
+			}
+			break;
+
 		case MP_STREET:
 			// tracks over roads, do owner check of tracks
 			return
@@ -2983,16 +2995,15 @@ static void TrainController(Vehicle *v)
 				v->direction = chosen_dir;
 			}
 		} else {
-			/* in tunnel on on a bridge */
+			/* in tunnel */
 			GetNewVehiclePos(v, &gp);
 
-			SetSpeedLimitOnBridge(v);
-
-			if (!(IsTunnelTile(gp.new_tile) || IsBridgeTile(gp.new_tile)) || !(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y) & 0x4)) {
+			// Check if to exit the tunnel...
+			if (!IsTunnelTile(gp.new_tile) ||
+					!(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y)&0x4) ) {
 				v->x_pos = gp.x;
 				v->y_pos = gp.y;
 				VehiclePositionChanged(v);
-				if (!(v->vehstatus & VS_HIDDEN)) EndVehicleMove(v);
 				continue;
 			}
 		}
@@ -3089,7 +3100,7 @@ static void DeleteLastWagon(Vehicle *v)
 	 * others are on it */
 	DisableTrainCrossing(v->tile);
 
-	if ( (v->u.rail.track == 0x40 && v->vehstatus & VS_HIDDEN) ) { // inside a tunnel
+	if (v->u.rail.track == 0x40) { // inside a tunnel
 		TileIndex endtile = CheckTunnelBusy(v->tile, NULL);
 
 		if (endtile == INVALID_TILE) return; // tunnel is busy (error returned)
@@ -3120,16 +3131,15 @@ static void ChangeTrainDirRandomly(Vehicle *v)
 	};
 
 	do {
-		/* We don't need to twist around vehicles if they're not visible */
-		if (!(v->vehstatus & VS_HIDDEN)) {
+		//I need to buffer the train direction
+		if (!(v->u.rail.track & 0x40)) {
 			v->direction = ChangeDir(v->direction, delta[GB(Random(), 0, 2)]);
+		}
+		if (!(v->vehstatus & VS_HIDDEN)) {
 			BeginVehicleMove(v);
 			UpdateTrainDeltaXY(v, v->direction);
 			v->cur_image = GetTrainImage(v, v->direction);
-			/* Refrain from updating the z position of the vehicle when on
-			   a bridge, because AfterSetTrainPos will put the vehicle under
-			   the bridge in that case */
-			if (!(v->u.rail.track & 0x40)) AfterSetTrainPos(v, false);
+			AfterSetTrainPos(v, false);
 		}
 	} while ((v = v->next) != NULL);
 }
@@ -3140,7 +3150,7 @@ static void HandleCrashedTrain(Vehicle *v)
 	uint32 r;
 	Vehicle *u;
 
-	if (state == 4 && !(v->u.rail.track & VS_HIDDEN)) {
+	if (state == 4 && v->u.rail.track != 0x40) {
 		CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
 	}
 
@@ -3227,15 +3237,10 @@ static bool TrainCheckIfLineEnds(Vehicle *v)
 
 	tile = v->tile;
 
-	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
-		DiagDirection dir;
-
-		if (IsTunnel(tile)) {
-			dir = GetTunnelDirection(tile);
-		} else {
-			dir = GetBridgeRampDirection(tile);
-		}
-		if (DiagDirToDir(dir) == v->direction) return true;
+	// tunnel entrance?
+	if (IsTunnelTile(tile) &&
+			DiagDirToDir(GetTunnelDirection(tile)) == v->direction) {
+		return true;
 	}
 
 	// depot?
diff --git a/tree_cmd.c b/tree_cmd.c
index 018835d5b..808243b14 100644
--- a/tree_cmd.c
+++ b/tree_cmd.c
@@ -2,7 +2,6 @@
 
 #include "stdafx.h"
 #include "openttd.h"
-#include "bridge_map.h"
 #include "clear_map.h"
 #include "table/strings.h"
 #include "table/sprites.h"
@@ -69,7 +68,6 @@ static void DoPlaceMoreTrees(TileIndex tile)
 
 		if (dist <= 13 &&
 				IsTileType(cur_tile, MP_CLEAR) &&
-				!IsBridgeAbove(cur_tile) &&
 				!IsClearGround(cur_tile, CLEAR_FIELDS) &&
 				!IsClearGround(cur_tile, CLEAR_ROCKS)) {
 			PlaceTree(cur_tile, r);
@@ -94,7 +92,6 @@ void PlaceTreesRandomly(void)
 		uint32 r = Random();
 		TileIndex tile = RandomTileSeed(r);
 		if (IsTileType(tile, MP_CLEAR) &&
-				!IsBridgeAbove(tile) &&
 				!IsClearGround(tile, CLEAR_FIELDS) &&
 				!IsClearGround(tile, CLEAR_ROCKS)) {
 			PlaceTree(tile, r);
@@ -108,9 +105,7 @@ void PlaceTreesRandomly(void)
 		do {
 			uint32 r = Random();
 			TileIndex tile = RandomTileSeed(r);
-			if (IsTileType(tile, MP_CLEAR) &&
-					!IsBridgeAbove(tile) &&
-					GetTropicZone(tile) == TROPICZONE_RAINFOREST) {
+			if (IsTileType(tile, MP_CLEAR) && GetTropicZone(tile) == TROPICZONE_RAINFOREST) {
 				PlaceTree(tile, r);
 			}
 		} while (--i);
@@ -180,8 +175,7 @@ int32 CmdPlantTree(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 					break;
 
 				case MP_CLEAR:
-					if (!IsTileOwner(tile, OWNER_NONE) ||
-							IsBridgeAbove(tile)) {
+					if (!IsTileOwner(tile, OWNER_NONE)) {
 						msg = STR_2804_SITE_UNSUITABLE;
 						continue;
 					}
@@ -486,7 +480,7 @@ static void TileLoop_Trees(TileIndex tile)
 
 						tile += ToTileIndexDiff(_tileloop_trees_dir[Random() & 7]);
 
-						if (!IsTileType(tile, MP_CLEAR) || IsBridgeAbove(tile)) return;
+						if (!IsTileType(tile, MP_CLEAR)) return;
 
 						switch (GetClearGround(tile)) {
 							case CLEAR_GRASS:
@@ -519,7 +513,6 @@ static void TileLoop_Trees(TileIndex tile)
 					case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
 					default: MakeClear(tile, CLEAR_SNOW, GetTreeDensity(tile)); break;
 				}
-				ClearBridgeMiddle(tile);
 			}
 			break;
 
@@ -542,7 +535,6 @@ void OnTick_Trees(void)
 	if (_opt.landscape == LT_DESERT &&
 			(r = Random(), tile = RandomTileSeed(r), GetTropicZone(tile) == TROPICZONE_RAINFOREST) &&
 			IsTileType(tile, MP_CLEAR) &&
-			!IsBridgeAbove(tile) &&
 			(ct = GetClearGround(tile), ct == CLEAR_GRASS || ct == CLEAR_ROUGH) &&
 			(tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
 		MakeTree(tile, tree, 0, 0, ct == CLEAR_ROUGH ? TREE_GROUND_ROUGH : TREE_GROUND_GRASS, 0);
@@ -555,7 +547,6 @@ void OnTick_Trees(void)
 	r = Random();
 	tile = TILE_MASK(r);
 	if (IsTileType(tile, MP_CLEAR) &&
-			!IsBridgeAbove(tile) &&
 			(ct = GetClearGround(tile), ct == CLEAR_GRASS || ct == CLEAR_ROUGH || ct == CLEAR_SNOW) &&
 			(tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
 		switch (ct) {
diff --git a/tunnelbridge_cmd.c b/tunnelbridge_cmd.c
index a0db5468b..168122a11 100644
--- a/tunnelbridge_cmd.c
+++ b/tunnelbridge_cmd.c
@@ -30,6 +30,11 @@
 
 #include "table/bridge_land.h"
 
+extern const byte _track_sloped_sprites[14];
+extern const SpriteID _water_shore_sprites[15];
+
+extern void DrawCanalWater(TileIndex tile);
+
 const Bridge orig_bridge[] = {
 /*
 	   year of availablity
@@ -192,6 +197,7 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
 	TileIndex tile;
 	TileIndexDiff delta;
 	uint bridge_len;
+	uint odd_middle_part;
 	Axis direction;
 	uint i;
 	int32 cost, terraformcost, ret;
@@ -283,26 +289,6 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
 		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
 	cost += terraformcost;
 
-	{
-		TileIndex Heads[] = {tile_start, tile_end};
-		int i;
-
-		for (i = 0; i < 2; i++) {
-			if (MayHaveBridgeAbove(Heads[i])) {
-				if (IsBridgeAbove(Heads[i])) {
-					TileIndex north_head = GetNorthernBridgeEnd(Heads[i]);
-					int z1, z2;
-
-					if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
-					z1 = GetBridgeHeight(north_head, GetBridgeAxis(Heads[i]));
-					z2 = GetBridgeHeight(Heads[i], direction);
-
-					if (z1 == z2) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-				}
-			}
-		}
-	}
 
 	/* do the drill? */
 	if (flags & DC_EXEC) {
@@ -319,42 +305,48 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
 		MarkTileDirtyByTile(tile_end);
 	}
 
+	// position of middle part of the odd bridge (larger than MAX(i) otherwise)
+	odd_middle_part = (bridge_len % 2) ? (bridge_len / 2) : bridge_len;
+
 	tile = tile_start;
 	delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
 	for (i = 0; i != bridge_len; i++) {
+		TransportType transport_under;
+		Owner owner_under = OWNER_NONE;
+		RailType rail_under = INVALID_RAILTYPE;
 		uint z;
 
 		tile += delta;
 
-		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
-
-		if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
-			/* Disallow crossing bridges for the time being */
-			return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) {
+			return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
 		}
 
 		switch (GetTileType(tile)) {
 			case MP_WATER:
 				if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
 				if (!(IsWater(tile) || IsCoast(tile))) goto not_valid_below;
+				transport_under = TRANSPORT_WATER;
+				owner_under = GetTileOwner(tile);
 				break;
 
 			case MP_RAILWAY:
-				if (!IsPlainRailTile(tile)) goto not_valid_below;
+				if (GetRailTileType(tile) != RAIL_TILE_NORMAL ||
+						GetTrackBits(tile) != (direction == AXIS_X ? TRACK_BIT_Y : TRACK_BIT_X)) {
+					goto not_valid_below;
+				}
+				transport_under = TRANSPORT_RAIL;
+				owner_under = GetTileOwner(tile);
+				rail_under = GetRailType(tile);
 				break;
 
 			case MP_STREET:
-				if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) goto not_valid_below;
-				break;
-
-			case MP_TUNNELBRIDGE:
-				if (IsTunnel(tile)) break;
-				if (direction == DiagDirToAxis(GetBridgeRampDirection(tile))) goto not_valid_below;
-				if (GetBridgeHeight(tile_start, direction) == GetBridgeHeight(tile, DiagDirToAxis(GetBridgeRampDirection(tile)))) goto not_valid_below;
-				break;
-
-			case MP_CLEAR:
-				if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+				if (GetRoadTileType(tile) != ROAD_TILE_NORMAL ||
+						GetRoadBits(tile) != (direction == AXIS_X ? ROAD_Y : ROAD_X)) {
+					goto not_valid_below;
+				}
+				transport_under = TRANSPORT_ROAD;
+				owner_under = GetTileOwner(tile);
 				break;
 
 			default:
@@ -363,11 +355,58 @@ not_valid_below:;
 				ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 				if (CmdFailed(ret)) return ret;
 				cost += ret;
+				transport_under = INVALID_TRANSPORT;
 				break;
 		}
 
 		if (flags & DC_EXEC) {
-			SetBridgeMiddle(tile, direction);
+			uint piece;
+
+			//bridges pieces sequence (middle parts)
+			// bridge len 1: 0
+			// bridge len 2: 0 1
+			// bridge len 3: 0 4 1
+			// bridge len 4: 0 2 3 1
+			// bridge len 5: 0 2 5 3 1
+			// bridge len 6: 0 2 3 2 3 1
+			// bridge len 7: 0 2 3 4 2 3 1
+			// #0 - always as first, #1 - always as last (if len>1)
+			// #2,#3 are to pair in order
+			// for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
+
+			if (i == 0) { // first tile
+				piece = 0;
+			} else if (i == bridge_len - 1) { // last tile
+				piece = 1;
+			} else if (i == odd_middle_part) { // we are on the middle of odd bridge: #5 on even pos, #4 on odd
+				piece = 5 - (i % 2);
+			} else {
+					// generate #2 and #3 in turns [i%2==0], after the middle of odd bridge
+					// this sequence swaps [... XOR (i>odd_middle_part)],
+					// for even bridges XOR does not apply as odd_middle_part==bridge_len
+					piece = 2 + ((i % 2 == 0) ^ (i > odd_middle_part));
+			}
+
+			if (transport == TRANSPORT_RAIL) {
+				MakeRailBridgeMiddle(tile, bridge_type, piece, direction, railtype);
+			} else {
+				MakeRoadBridgeMiddle(tile, bridge_type, piece, direction);
+			}
+			switch (transport_under) {
+				case TRANSPORT_RAIL: SetRailUnderBridge(tile, owner_under, rail_under); break;
+				case TRANSPORT_ROAD: SetRoadUnderBridge(tile, owner_under); break;
+
+				case TRANSPORT_WATER:
+					if (owner_under == OWNER_WATER) {
+						SetWaterUnderBridge(tile);
+					} else {
+						SetCanalUnderBridge(tile, owner_under);
+					}
+					break;
+
+				default: SetClearUnderBridge(tile); break;
+			}
+
 			MarkTileDirtyByTile(tile);
 		}
 	}
@@ -552,7 +591,7 @@ static int32 DoClearTunnel(TileIndex tile, uint32 flags)
 	return _price.clear_tunnel * (length + 1);
 }
 
-#if 0
+
 static uint GetBridgeHeightRamp(TileIndex t)
 {
 	/* Return the height there (the height of the NORTH CORNER)
@@ -560,7 +599,6 @@ static uint GetBridgeHeightRamp(TileIndex t)
 	 * the z coordinate is 1 height level too low. Compensate for that */
 	return TilePixelHeight(t) + (GetTileSlope(t, NULL) == SLOPE_WSE ? TILE_HEIGHT : 0);
 }
-#endif
 
 
 static int32 DoClearBridge(TileIndex tile, uint32 flags)
@@ -568,10 +606,47 @@ static int32 DoClearBridge(TileIndex tile, uint32 flags)
 	DiagDirection direction;
 	TileIndexDiff delta;
 	TileIndex endtile;
+	Vehicle *v;
 	Town *t;
 
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
+	if (IsBridgeMiddle(tile)) {
+		if (IsTransportUnderBridge(tile)) {
+			/* delete transport route under the bridge */
+			int32 cost;
+
+			// check if we own the tile below the bridge..
+			if (_current_player != OWNER_WATER && (!CheckTileOwnership(tile) || !EnsureNoVehicleOnGround(tile)))
+				return CMD_ERROR;
+
+			if (GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL) {
+				cost = _price.remove_rail;
+			} else {
+				cost = _price.remove_road * 2;
+			}
+
+			if (flags & DC_EXEC) {
+				SetClearUnderBridge(tile);
+				MarkTileDirtyByTile(tile);
+			}
+			return cost;
+		} else if (IsWaterUnderBridge(tile) && TilePixelHeight(tile) != 0) {
+			/* delete canal under bridge */
+
+			// check for vehicles under bridge
+			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
+
+			if (flags & DC_EXEC) {
+				SetClearUnderBridge(tile);
+				MarkTileDirtyByTile(tile);
+			}
+			return _price.clear_water;
+		}
+
+		tile = GetSouthernBridgeEnd(tile);
+	}
+
 	// floods, scenario editor can always destroy bridges
 	if (_current_player != OWNER_WATER && _game_mode != GM_EDITOR && !CheckTileOwnership(tile)) {
 		if (!(_patches.extra_dynamite || _cheats.magic_bulldozer.value) || !IsTileOwner(tile, OWNER_TOWN))
@@ -585,6 +660,18 @@ static int32 DoClearBridge(TileIndex tile, uint32 flags)
 	direction = GetBridgeRampDirection(tile);
 	delta = TileOffsByDir(direction);
 
+	/*	Make sure there's no vehicle on the bridge
+			Omit tile and endtile, since these are already checked, thus solving the problem
+			of bridges over water, or higher bridges, where z is not increased, eg level bridge
+	*/
+	/* Bridges on slopes might have their Z-value offset..correct this */
+	v = FindVehicleBetween(
+		tile    + delta,
+		endtile - delta,
+		GetBridgeHeightRamp(tile) + TILE_HEIGHT
+	);
+	if (v != NULL) return_cmd_error(VehicleInTheWayErrMsg(v));
+
 	t = ClosestTownFromTile(tile, (uint)-1); //needed for town rating penalty
 	// check if you're allowed to remove the bridge owned by a town.
 	// removal allowal depends on difficulty settings
@@ -603,8 +690,26 @@ static int32 DoClearBridge(TileIndex tile, uint32 flags)
 		DoClearSquare(tile);
 		DoClearSquare(endtile);
 		for (c = tile + delta; c != endtile; c += delta) {
-			ClearBridgeMiddle(c);
-			MarkTileDirtyByTile(c);
+			if (IsTransportUnderBridge(c)) {
+				if (GetTransportTypeUnderBridge(c) == TRANSPORT_RAIL) {
+					MakeRailNormal(c, GetTileOwner(c), GetRailBitsUnderBridge(c), GetRailType(c));
+				} else {
+					uint town = IsTileOwner(c, OWNER_TOWN) ? ClosestTownFromTile(c, (uint)-1)->index : 0;
+					MakeRoadNormal(c, GetTileOwner(c), GetRoadBitsUnderBridge(c), town);
+				}
+				MarkTileDirtyByTile(c);
+			} else {
+				if (IsClearUnderBridge(c)) {
+					DoClearSquare(c);
+				} else {
+					if (GetTileSlope(c, NULL) == SLOPE_FLAT) {
+						MakeWater(c);
+					} else {
+						MakeShore(c);
+					}
+					MarkTileDirtyByTile(c);
+				}
+			}
 		}
 
 		UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
@@ -657,7 +762,29 @@ int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
 			YapfNotifyTrackLayoutChange(endtile, endtrack);
 		}
 		return (length + 1) * (_price.build_rail >> 1);
-	} else if (IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+	} else if (IsBridge(tile) &&
+			IsBridgeMiddle(tile) &&
+			IsTransportUnderBridge(tile) &&
+			GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL) {
+		// only check for train under bridge
+		if (!CheckTileOwnership(tile) || !EnsureNoVehicleOnGround(tile))
+			return CMD_ERROR;
+
+		if (GetRailType(tile) == totype) return CMD_ERROR;
+
+		if (exec) {
+			TrackBits tracks;
+			SetRailType(tile, totype);
+			MarkTileDirtyByTile(tile);
+
+			// notify YAPF about the track layout change
+			for (tracks = GetRailBitsUnderBridge(tile); tracks != TRACK_BIT_NONE; tracks = KILL_FIRST_BIT(tracks))
+				YapfNotifyTrackLayoutChange(tile, FIND_FIRST_BIT(tracks));
+		}
+		return _price.build_rail >> 1;
+	} else if (IsBridge(tile) && IsBridgeRamp(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+		TileIndexDiff delta;
+		int32 cost;
 		uint z = TilePixelHeight(tile);
 
 		z += TILE_HEIGHT;
@@ -678,29 +805,53 @@ int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
 		if (GetRailType(tile) == totype) return CMD_ERROR;
 
 		if (exec) {
-			TileIndexDiff delta;
-
+			Track track, endtrack;
 			SetRailType(tile, totype);
 			SetRailType(endtile, totype);
 			MarkTileDirtyByTile(tile);
 			MarkTileDirtyByTile(endtile);
 
-			delta = TileOffsByDir(GetBridgeRampDirection(tile));
-			for (tile += delta; tile != endtile; tile += delta) {
-				MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
+			// notify YAPF about the track layout change
+			track = TrackdirToTrack(DiagdirToDiagTrackdir(GetBridgeRampDirection(tile)));
+			endtrack = TrackdirToTrack(DiagdirToDiagTrackdir(GetBridgeRampDirection(endtile)));
+			YapfNotifyTrackLayoutChange(tile, track);
+			YapfNotifyTrackLayoutChange(endtile, endtrack);
+		}
+		cost = 2 * (_price.build_rail >> 1);
+		delta = TileOffsByDir(GetBridgeRampDirection(tile));
+		for (tile += delta; tile != endtile; tile += delta) {
+			if (exec) {
+				SetRailTypeOnBridge(tile, totype);
+				MarkTileDirtyByTile(tile);
 			}
+			cost += _price.build_rail >> 1;
 		}
 
-		return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
+		return cost;
 	} else
 		return CMD_ERROR;
 }
 
 
-static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
+// fast routine for getting the height of a middle bridge tile. 'tile' MUST be a middle bridge tile.
+uint GetBridgeHeight(TileIndex t)
+{
+	return GetBridgeHeightRamp(GetSouthernBridgeEnd(t));
+}
+
+static const byte _bridge_foundations[2][16] = {
+// 0 1  2  3  4 5 6 7  8 9 10 11 12 13 14 15
+	{0,16,18,3,20,5,0,7,22,0,10,11,12,13,14},
+	{0,15,17,0,19,5,6,7,21,9,10,11, 0,13,14},
+};
+
+extern const byte _road_sloped_sprites[14];
+
+static void DrawBridgePillars(PalSpriteID image, const TileInfo *ti, int x, int y, int z)
 {
 	if (image != 0) {
-		bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
+		Axis axis = GetBridgeAxis(ti->tile);
+		bool drawfarpillar = !HASBIT(GetBridgeFlags(GetBridgeType(ti->tile)), 0);
 		int back_height, front_height;
 		int i = z;
 		const byte *p;
@@ -763,11 +914,17 @@ uint GetBridgeFoundation(Slope tileh, Axis axis)
   * <li>Bit 2: Set if the bridge head is sloped</li>
   * <li>Bit 3 and more: Railtype Specific subset</li>
   * </ul>
+  * For middle parts:
+  * <ul><li>Bits 0-1: need to be 0</li>
+  * <li>Bit 2: direction</li>
+  * <li>Bit 3 and above: Railtype Specific subset</li>
+  * </ul>
   * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
   */
 static void DrawTile_TunnelBridge(TileInfo *ti)
 {
 	uint32 image;
+	const PalSpriteID *b;
 	bool ice = _m[ti->tile].m4 & 0x80;
 
 	if (IsTunnel(ti->tile)) {
@@ -784,12 +941,19 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
 
 		AddSortableSpriteToDraw(image+1, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, 1, 1, 8, (byte)ti->z);
-		DrawBridgeMiddle(ti);
 	} else if (IsBridge(ti->tile)) { // XXX is this necessary?
 		int base_offset;
 
 		if (GetBridgeTransportType(ti->tile) == TRANSPORT_RAIL) {
-			base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
+			RailType rt;
+
+			if (IsBridgeRamp(ti->tile)) {
+				rt = GetRailType(ti->tile);
+			} else {
+				rt = GetRailTypeOnBridge(ti->tile);
+			}
+
+			base_offset = GetRailTypeInfo(rt)->bridge_offset;
 			assert(base_offset != 8); /* This one is used for roads */
 		} else {
 			base_offset = 8;
@@ -798,152 +962,124 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		/* as the lower 3 bits are used for other stuff, make sure they are clear */
 		assert( (base_offset & 0x07) == 0x00);
 
-		if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
-			int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
-			if (f) DrawFoundation(ti, f);
-		}
-
-		// HACK Wizardry to convert the bridge ramp direction into a sprite offset
-		base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
-
-		if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
-
-		/* Table number 6 always refers to the bridge heads for any bridge type */
-		image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
+		if (IsBridgeRamp(ti->tile)) {
+			if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
+				int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
+				if (f) DrawFoundation(ti, f);
+			}
 
-		if (!ice) {
-			DrawClearLandTile(ti, 3);
-		} else {
-			DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
-		}
+			// HACK Wizardry to convert the bridge ramp direction into a sprite offset
+			base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
 
-		if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+			if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
 
-		// draw ramp
-		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-		AddSortableSpriteToDraw(image, ti->x, ti->y, 16, 16, 7, ti->z);
+			/* Table number 6 always refers to the bridge heads for any bridge type */
+			image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
 
-		DrawBridgeMiddle(ti);
-	}
-}
+			if (!ice) {
+				DrawClearLandTile(ti, 3);
+			} else {
+				DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
+			}
 
+			if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
 
-//bridges pieces sequence (middle parts)
-// bridge len 1: 0
-// bridge len 2: 0 1
-// bridge len 3: 0 4 1
-// bridge len 4: 0 2 3 1
-// bridge len 5: 0 2 5 3 1
-// bridge len 6: 0 2 3 2 3 1
-// bridge len 7: 0 2 3 4 2 3 1
-// #0 - always as first, #1 - always as last (if len>1)
-// #2,#3 are to pair in order
-// for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
-static uint CalcBridgePiece(uint north, uint south)
-{
-	if (north == 1) {
-		return 0;
-	} else if (south == 1) {
-		return 1;
-	} else if (north < south) {
-		return north & 1 ? 3 : 2;
-	} else if (north > south) {
-		return south & 1 ? 2 : 3;
-	} else {
-		return north & 1 ? 5 : 4;
-	}
-}
-
-void DrawBridgeMiddle(const TileInfo* ti)
-{
-	const PalSpriteID* b;
-	PalSpriteID image;
-	uint base_offset;
-	TileIndex rampnorth;
-	TileIndex rampsouth;
-	Axis axis;
-	uint piece;
-	uint type;
-	int x;
-	int y;
-	uint z;
-
-	if (!IsBridgeAbove(ti->tile)) return;
-
-	rampnorth = GetNorthernBridgeEnd(ti->tile);
-	rampsouth = GetSouthernBridgeEnd(ti->tile);
-
-	axis = GetBridgeAxis(ti->tile);
-	piece = CalcBridgePiece(
-		DistanceManhattan(ti->tile, rampnorth),
-		DistanceManhattan(ti->tile, rampsouth)
-	);
-	type = GetBridgeType(rampsouth);
+			// draw ramp
+			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+			AddSortableSpriteToDraw(image, ti->x, ti->y, 16, 16, 7, ti->z);
+		} else {
+			// bridge middle part.
+			Axis axis = GetBridgeAxis(ti->tile);
+			uint z;
+			int x,y;
+
+			if (IsTransportUnderBridge(ti->tile)) {
+				uint f = _bridge_foundations[axis][ti->tileh];
+
+				if (f != 0) DrawFoundation(ti, f);
+
+				if (GetTransportTypeUnderBridge(ti->tile) == TRANSPORT_RAIL) {
+					const RailtypeInfo* rti = GetRailTypeInfo(GetRailType(ti->tile));
+
+					if (ti->tileh == SLOPE_FLAT) {
+						image = (axis == AXIS_X ? SPR_RAIL_TRACK_Y : SPR_RAIL_TRACK_X);
+					} else {
+						image = SPR_RAIL_TRACK_Y + _track_sloped_sprites[ti->tileh - 1];
+					}
+					image += rti->total_offset;
+					if (ice) image += rti->snow_offset;
+				} else {
+					if (ti->tileh == SLOPE_FLAT) {
+						image = (axis == AXIS_X ? SPR_ROAD_Y : SPR_ROAD_X);
+					} else {
+						image = _road_sloped_sprites[ti->tileh - 1] + 0x53F;
+					}
+					if (ice) image += 19;
+				}
+				DrawGroundSprite(image);
+			} else {
+				if (IsClearUnderBridge(ti->tile)) {
+					image = (ice ? SPR_FLAT_SNOWY_TILE : SPR_FLAT_GRASS_TILE);
+					DrawGroundSprite(image + _tileh_to_sprite[ti->tileh]);
+				} else {
+					if (ti->tileh == SLOPE_FLAT) {
+						DrawGroundSprite(SPR_FLAT_WATER_TILE);
+						if (ti->z != 0) DrawCanalWater(ti->tile);
+					} else {
+						DrawGroundSprite(_water_shore_sprites[ti->tileh]);
+					}
+				}
+			}
 
-	if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
-		base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
-	} else {
-		base_offset = 8;
-	}
+			if (axis != AXIS_X) base_offset += 4;
 
-	b = base_offset + GetBridgeSpriteTable(type, piece);
-	if (axis != AXIS_X) b += 4;
+			/*  base_offset needs to be 0 due to the structure of the sprite table see table/bridge_land.h */
+			assert( (base_offset & 0x03) == 0x00);
+			// get bridge sprites
+			b = GetBridgeSpriteTable(GetBridgeType(ti->tile), GetBridgePiece(ti->tile)) + base_offset;
 
-	x = ti->x;
-	y = ti->y;
-	z = GetBridgeHeight(rampsouth, axis) - 3;
+			z = GetBridgeHeight(ti->tile) + 5;
 
-	image = b[0];
-	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-	if (axis == AXIS_X) {
-		AddSortableSpriteToDraw(image, x, y, 16, 11, 1, z);
-	} else {
-		AddSortableSpriteToDraw(image, x, y, 11, 16, 1, z);
-	}
+			// draw rail or road component
+			image = b[0];
+			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+			if (axis == AXIS_X) {
+				AddSortableSpriteToDraw(image, ti->x, ti->y, 16, 11, 1, z);
+			} else {
+				AddSortableSpriteToDraw(image, ti->x, ti->y, 11, 16, 1, z);
+			}
 
-	image = b[1];
-	if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+			x = ti->x;
+			y = ti->y;
+			image = b[1];
+			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
 
-	// draw roof, the component of the bridge which is logically between the vehicle and the camera
-	if (axis == AXIS_X) {
-		y += 12;
-		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
-	} else {
-		x += 12;
-		if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
-	}
+			// draw roof, the component of the bridge which is logically between the vehicle and the camera
+			if (axis == AXIS_X) {
+				y += 12;
+				if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
+			} else {
+				x += 12;
+				if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
+			}
 
-	if (GetRailType(rampsouth) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+			if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC || GetRailTypeOnBridge(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
 
-	if (ti->z + 5 == z) {
-		// draw poles below for small bridges
-		image = b[2];
-		if (image != 0) {
-			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-			DrawGroundSpriteAt(image, x, y, z);
+			if (ti->z + 5 == z) {
+				// draw poles below for small bridges
+				image = b[2];
+				if (image != 0) {
+					if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+					DrawGroundSpriteAt(image, x, y, z);
+				}
+			} else if (_patches.bridge_pillars) {
+				// draw pillars below for high bridges
+				DrawBridgePillars(b[2], ti, x, y, z);
+			}
 		}
-	} else if (_patches.bridge_pillars) {
-		// draw pillars below for high bridges
-		DrawBridgePillars(b[2], ti, axis, type, x, y, z);
 	}
 }
 
-
-uint SetSpeedLimitOnBridge(Vehicle *v)
-{
-	uint bridge_speed;
-	if (v->vehstatus & VS_HIDDEN) return v->max_speed; /* in tunnel */
-
-	bridge_speed = _bridge[GetBridgeType(v->tile)].speed;
-
-	if (v->type == VEH_Road) bridge_speed *= 2; /* XXX give vehicles proper speeds */
-
-	if (v->cur_speed > bridge_speed) v->cur_speed = bridge_speed;
-	return bridge_speed;
-}
-
-
-
 static uint GetSlopeZ_TunnelBridge(const TileInfo* ti)
 {
 	TileIndex tile = ti->tile;
@@ -958,30 +1094,44 @@ static uint GetSlopeZ_TunnelBridge(const TileInfo* ti)
 		// In the tunnel entrance?
 		if (5 <= pos && pos <= 10) return z;
 	} else {
-		DiagDirection dir = GetBridgeRampDirection(tile);
-		uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
-
-		// On the bridge ramp?
-		if (5 <= pos && pos <= 10) {
-			uint delta;
-
-			if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
-
-			if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
-			switch (dir) {
-				default:
-				case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
-				case DIAGDIR_SE: delta = y / 2; break;
-				case DIAGDIR_SW: delta = x / 2; break;
-				case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+		if (IsBridgeRamp(tile)) {
+			DiagDirection dir = GetBridgeRampDirection(tile);
+			uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
+
+			// On the bridge ramp?
+			if (5 <= pos && pos <= 10) {
+				uint delta;
+
+				if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
+
+				if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
+				switch (dir) {
+					default:
+					case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
+					case DIAGDIR_SE: delta = y / 2; break;
+					case DIAGDIR_SW: delta = x / 2; break;
+					case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+				}
+				return z + 1 + delta;
+			} else {
+				uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
+
+				if (f != 0) {
+					if (f < 15) return z + TILE_HEIGHT;
+					tileh = _inclined_tileh[f - 15];
+				}
 			}
-			return z + 1 + delta;
 		} else {
-			uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
+			// HACK on the bridge?
+			if (_get_z_hint >= z + TILE_HEIGHT + (tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT)) return _get_z_hint;
 
-			if (f != 0) {
-				if (f < 15) return z + TILE_HEIGHT;
-				tileh = _inclined_tileh[f - 15];
+			if (IsTransportUnderBridge(tile)) {
+				uint f = _bridge_foundations[GetBridgeAxis(tile)][tileh];
+
+				if (f != 0) {
+					if (f < 15) return z + TILE_HEIGHT;
+					tileh = _inclined_tileh[f - 15];
+				}
 			}
 		}
 	}
@@ -1040,6 +1190,9 @@ static void GetTileDesc_TunnelBridge(TileIndex tile, TileDesc *td)
 			STR_5017_RAILROAD_TUNNEL : STR_5018_ROAD_TUNNEL;
 	} else {
 		td->str = _bridge_tile_str[GetBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
+
+		// the owner is stored at the end of the bridge
+		if (IsBridgeMiddle(tile)) tile = GetSouthernBridgeEnd(tile);
 	}
 	td->owner = GetTileOwner(tile);
 }
@@ -1074,6 +1227,10 @@ static void TileLoop_TunnelBridge(TileIndex tile)
 			}
 			break;
 	}
+
+	if (IsBridge(tile) && IsBridgeMiddle(tile) && IsWaterUnderBridge(tile)) {
+		TileLoop_Water(tile);
+	}
 }
 
 static void ClickTile_TunnelBridge(TileIndex tile)
@@ -1084,13 +1241,37 @@ static void ClickTile_TunnelBridge(TileIndex tile)
 
 static uint32 GetTileTrackStatus_TunnelBridge(TileIndex tile, TransportType mode)
 {
+	uint32 result;
+
 	if (IsTunnel(tile)) {
 		if (GetTunnelTransportType(tile) == mode) {
 			return DiagDirToAxis(GetTunnelDirection(tile)) == AXIS_X ? 0x101 : 0x202;
 		}
 	} else if (IsBridge(tile)) { // XXX is this necessary?
-		if (GetBridgeTransportType(tile) != mode) return 0;
-		return (DiagDirToAxis(GetBridgeRampDirection(tile)) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y) * 0x101;
+		if (IsBridgeRamp(tile)) {
+			if (GetBridgeTransportType(tile) != mode) return 0;
+			return (DiagDirToAxis(GetBridgeRampDirection(tile)) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y) * 0x101;
+		} else {
+			result = 0;
+			if (GetBridgeTransportType(tile) == mode) {
+				result = (GetBridgeAxis(tile) == AXIS_X ? TRACK_BIT_X : TRACK_BIT_Y) * 0x101;
+			}
+			if (IsTransportUnderBridge(tile)) {
+				if (GetTransportTypeUnderBridge(tile) != mode) return result;
+			} else {
+				if (IsClearUnderBridge(tile)) {
+					return result;
+				} else {
+					if (mode != TRANSPORT_WATER) return result;
+				}
+			}
+			/* If we've not returned yet, there is a compatible
+			 * transport or water beneath, so we can add it to
+			 * result */
+			/* Why is this xor'd ? Can't it just be or'd? */
+			result ^= (GetBridgeAxis(tile) == AXIS_X ? 0x202 : 0x101);
+		}
+		return result;
 	} else {
 		assert(0); /* This should never occur */
 	}
@@ -1104,7 +1285,16 @@ static void ChangeTileOwner_TunnelBridge(TileIndex tile, PlayerID old_player, Pl
 	if (new_player != OWNER_SPECTATOR) {
 		SetTileOwner(tile, new_player);
 	}	else {
-		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+		if (IsBridge(tile) && IsBridgeMiddle(tile) && IsTransportUnderBridge(tile)) {
+			// the stuff BELOW the middle part is owned by the deleted player.
+			if (GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL) {
+				SetClearUnderBridge(tile);
+			} else {
+				SetTileOwner(tile, OWNER_NONE);
+			}
+		} else {
+			DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+		}
 	}
 }
 
@@ -1124,15 +1314,14 @@ static const byte _tunnel_fractcoord_7[4] = {0x52, 0x85, 0x96, 0x49};
 
 static uint32 VehicleEnter_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y)
 {
-	int z = GetSlopeZ(x, y) - v->z_pos;
-
-	if (myabs(z) > 2) return 8;
-
 	if (IsTunnel(tile)) {
+		int z = GetSlopeZ(x, y) - v->z_pos;
 		byte fc;
 		DiagDirection dir;
 		DiagDirection vdir;
 
+		if (myabs(z) > 2) return 8;
+
 		if (v->type == VEH_Train) {
 			fc = (x & 0xF) + (y << 4);
 
@@ -1193,53 +1382,30 @@ static uint32 VehicleEnter_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y
 			}
 		}
 	} else if (IsBridge(tile)) { // XXX is this necessary?
-		DiagDirection dir;
-
 		if (v->type == VEH_Road || (v->type == VEH_Train && IsFrontEngine(v))) {
-			/* modify speed of vehicle */
-			uint16 spd = _bridge[GetBridgeType(tile)].speed;
-
-			if (v->type == VEH_Road) spd *= 2;
-			if (v->cur_speed > spd) v->cur_speed = spd;
-		}
-
-		dir = GetBridgeRampDirection(tile);
-		if (DirToDiagDir(v->direction) == dir) {
-			switch (dir) {
-				default:
-				case DIAGDIR_NE: if ((x & 0xF) != 0)             return 0; break;
-				case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
-				case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
-				case DIAGDIR_NW: if ((y & 0xF) != 0)             return 0; break;
+			if (IsBridgeRamp(tile) || v->z_pos > GetTileMaxZ(tile)) {
+				/* modify speed of vehicle */
+				uint16 spd = _bridge[GetBridgeType(tile)].speed;
+				if (v->type == VEH_Road) spd *= 2;
+				if (v->cur_speed > spd) v->cur_speed = spd;
 			}
-			if (v->type == VEH_Train) {
-				v->u.rail.track = 0x40;
-				CLRBIT(v->u.rail.flags, VRF_GOINGUP);
-				CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
-			} else {
-				v->u.road.state = 0xFF;
-			}
-			return 4;
-		} else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
-			v->tile = tile;
-			if (v->type == VEH_Train) {
-				if (v->u.rail.track == 0x40) {
-					v->u.rail.track = (DiagDirToAxis(dir) == AXIS_X ? 1 : 2);
-					return 4;
-				}
-			} else {
-				if (v->u.road.state == 0xFF) {
-					v->u.road.state = _road_exit_tunnel_state[dir];
-					v->u.road.frame = 0;
-					return 4;
-				}
-			}
-			return 0;
 		}
 	}
 	return 0;
 }
 
+TileIndex GetVehicleOutOfTunnelTile(const Vehicle *v)
+{
+	TileIndex tile;
+	TileIndexDiff delta = (v->direction & 2) ? TileDiffXY(0, 1) : TileDiffXY(1, 0);
+	byte z = v->z_pos;
+
+	for (tile = v->tile;; tile += delta) {
+		if (IsTunnelTile(tile) && GetTileZ(tile) == z) break;
+	}
+	return tile;
+}
+
 const TileTypeProcs _tile_type_tunnelbridge_procs = {
 	DrawTile_TunnelBridge,					/* draw_tile_proc */
 	GetSlopeZ_TunnelBridge,					/* get_slope_z_proc */
diff --git a/variables.h b/variables.h
index 85eac88a9..c42f590c7 100644
--- a/variables.h
+++ b/variables.h
@@ -309,6 +309,7 @@ VARDEF bool _exit_game;
 VARDEF SmallFiosItem _file_to_saveload;
 VARDEF byte _make_screenshot;
 
+VARDEF byte _get_z_hint; // used as a hint to getslopez to return the right height at a bridge.
 
 VARDEF char *_newgrf_files[32];
 
diff --git a/vehicle.h b/vehicle.h
index 487ad7797..e295fb686 100644
--- a/vehicle.h
+++ b/vehicle.h
@@ -287,6 +287,7 @@ uint32 VehicleEnterTile(Vehicle *v, TileIndex tile, int x, int y);
 
 StringID VehicleInTheWayErrMsg(const Vehicle* v);
 Vehicle *FindVehicleBetween(TileIndex from, TileIndex to, byte z);
+TileIndex GetVehicleOutOfTunnelTile(const Vehicle *v);
 
 bool UpdateSignalsOnSegment(TileIndex tile, DiagDirection direction);
 void SetSignalsOnBothDir(TileIndex tile, byte track);
diff --git a/water_cmd.c b/water_cmd.c
index 8953f9ec5..26ef26d0c 100644
--- a/water_cmd.c
+++ b/water_cmd.c
@@ -20,7 +20,7 @@
 #include "train.h"
 #include "water_map.h"
 
-static const SpriteID _water_shore_sprites[] = {
+const SpriteID _water_shore_sprites[15] = {
 	0,
 	SPR_SHORE_TILEH_1,
 	SPR_SHORE_TILEH_2,
@@ -65,8 +65,6 @@ int32 CmdBuildShipDepot(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 	if (!IsClearWaterTile(tile) || !IsClearWaterTile(tile2))
 		return_cmd_error(STR_3801_MUST_BE_BUILT_ON_WATER);
 
-	if (IsBridgeAbove(tile) || IsBridgeAbove(tile2)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
 	ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 	if (CmdFailed(ret)) return CMD_ERROR;
 	ret = DoCommand(tile2, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
@@ -141,12 +139,6 @@ static int32 DoBuildShiplift(TileIndex tile, DiagDirection dir, uint32 flags)
 		return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
 	}
 
-	if ((MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) ||
-	    (MayHaveBridgeAbove(tile - delta) && IsBridgeAbove(tile - delta)) ||
-	    (MayHaveBridgeAbove(tile + delta) && IsBridgeAbove(tile + delta))) {
-		return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-	}
-
 	if (flags & DC_EXEC) {
 		MakeLock(tile, _current_player, dir);
 		MarkTileDirtyByTile(tile);
@@ -237,8 +229,6 @@ int32 CmdBuildCanal(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 
 	cost = 0;
 	BEGIN_TILE_LOOP(tile, size_x, size_y, TileXY(sx, sy)) {
-		int32 ret;
-
 		if (GetTileSlope(tile, NULL) != SLOPE_FLAT) {
 			return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
 		}
@@ -246,16 +236,38 @@ int32 CmdBuildCanal(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 		// can't make water of water!
 		if (IsTileType(tile, MP_WATER)) continue;
 
-		ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
-		if (CmdFailed(ret)) return ret;
-		cost += ret;
+		/* is middle piece of a bridge? */
+		if (IsBridgeTile(tile) && IsBridgeMiddle(tile)) {
+			if (IsTransportUnderBridge(tile)) {
+				return_cmd_error(STR_5800_OBJECT_IN_THE_WAY);
+			}
 
-		if (flags & DC_EXEC) {
-			if (TileHeight(tile) == 0) {
-				MakeWater(tile);
-			} else {
-				MakeCanal(tile, _current_player);
+			if (IsWaterUnderBridge(tile)) return_cmd_error(STR_1007_ALREADY_BUILT);
+
+			if (flags & DC_EXEC) {
+				if (TileHeight(tile) == 0) {
+					SetWaterUnderBridge(tile);
+				} else {
+					SetCanalUnderBridge(tile, _current_player);
+				}
 			}
+		} else {
+			/* no bridge, try to clear it. */
+			int32 ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+
+			if (CmdFailed(ret)) return ret;
+			cost += ret;
+
+			if (flags & DC_EXEC) {
+				if (TileHeight(tile) == 0) {
+					MakeWater(tile);
+				} else {
+					MakeCanal(tile, _current_player);
+				}
+			}
+		}
+
+		if (flags & DC_EXEC) {
 			MarkTileDirtyByTile(tile);
 			MarkTilesAroundDirty(tile);
 		}
@@ -340,9 +352,17 @@ static int32 ClearTile_Water(TileIndex tile, byte flags)
 static bool IsWateredTile(TileIndex tile)
 {
 	switch (GetTileType(tile)) {
-		case MP_WATER:   return !IsCoast(tile);
-		case MP_STATION: return IsOilRig(tile) || IsDock(tile) || IsBuoy_(tile);
-		default:         return false;
+		case MP_WATER:
+			return !IsCoast(tile);
+
+		case MP_STATION:
+			return IsOilRig(tile) || IsDock(tile) || IsBuoy_(tile);
+
+		case MP_TUNNELBRIDGE:
+			return IsBridge(tile) && IsBridgeMiddle(tile) && IsWaterUnderBridge(tile);
+
+		default:
+			return false;
 	}
 }
 
@@ -418,13 +438,11 @@ static void DrawTile_Water(TileInfo *ti)
 		case WATER_CLEAR:
 			DrawGroundSprite(SPR_FLAT_WATER_TILE);
 			if (ti->z != 0) DrawCanalWater(ti->tile);
-			DrawBridgeMiddle(ti);
 			break;
 
 		case WATER_COAST:
 			assert(!IsSteepSlope(ti->tileh));
 			DrawGroundSprite(_water_shore_sprites[ti->tileh]);
-			DrawBridgeMiddle(ti);
 			break;
 
 		case WATER_LOCK: {
@@ -534,10 +552,27 @@ static void TileLoopWaterHelper(TileIndex tile, const TileIndexDiffC *offs)
 				}
 				break;
 
+			case MP_TUNNELBRIDGE:
+				if (IsBridge(target) && IsBridgeMiddle(target) && IsClearUnderBridge(target)) {
+					SetWaterUnderBridge(target);
+					MarkTileDirtyByTile(target);
+				}
+				break;
+
 			default:
 				break;
 		}
 	} else {
+		if (IsBridgeTile(target) && IsBridgeMiddle(target)) {
+			if (IsWaterUnderBridge(target) ||
+					(IsTransportUnderBridge(target) && GetTransportTypeUnderBridge(target) == TRANSPORT_WATER)) { // XXX does this happen at all?
+				return;
+			}
+			SetWaterUnderBridge(target);
+			MarkTileDirtyByTile(target);
+			return;
+		}
+
 		_current_player = OWNER_WATER;
 		{
 			Vehicle *v = FindVehicleOnTileZ(target, 0);
diff --git a/waypoint.c b/waypoint.c
index 519abedfb..7d4efd0a1 100644
--- a/waypoint.c
+++ b/waypoint.c
@@ -9,7 +9,6 @@
 #include "map.h"
 #include "order.h"
 #include "rail_map.h"
-#include "bridge_map.h"
 #include "saveload.h"
 #include "station.h"
 #include "tile.h"
@@ -202,8 +201,6 @@ int32 CmdBuildTrainWaypoint(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 			return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
 	}
 
-	if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
-
 	/* Check if there is an already existing, deleted, waypoint close to us that we can reuse. */
 	wp = FindDeletedWaypointCloseTo(tile);
 	if (wp == NULL) {
diff --git a/yapf/follow_track.hpp b/yapf/follow_track.hpp
index 8cc5f7451..2b22d4fe4 100644
--- a/yapf/follow_track.hpp
+++ b/yapf/follow_track.hpp
@@ -27,7 +27,7 @@ struct CFollowTrackT : public FollowTrack_t
 		m_new_tile = INVALID_TILE;
 		m_new_td_bits = TRACKDIR_BIT_NONE;
 		m_exitdir = INVALID_DIAGDIR;
-		m_is_station = m_is_bridge = m_is_tunnel = false;
+		m_is_station = m_is_tunnel = false;
 		m_tiles_skipped = 0;
 	}
 
@@ -60,9 +60,6 @@ protected:
 	/** Follow the m_exitdir from m_old_tile and fill m_new_tile and m_tiles_skipped */
 	FORCEINLINE void FollowTileExit()
 	{
-		m_is_station = m_is_bridge = m_is_tunnel = false;
-		m_tiles_skipped = 0;
-
 		// extra handling for tunnels in our direction
 		if (IsTunnelTile(m_old_tile)) {
 			DiagDirection tunnel_enterdir = GetTunnelDirection(m_old_tile);
@@ -76,22 +73,11 @@ protected:
 			}
 			assert(ReverseDiagDir(tunnel_enterdir) == m_exitdir);
 		}
+		// not a tunnel or station
+		m_is_tunnel = false;
+		m_tiles_skipped = 0;
 
-		// extra handling for bridge ramp in our direction
-		if (IsBridgeTile(m_old_tile)) {
-			DiagDirection bridge_enterdir = GetBridgeRampDirection(m_old_tile);
-			if (bridge_enterdir == m_exitdir) {
-				// we are entering the bridge ramp
-				m_new_tile = GetOtherBridgeEnd(m_old_tile);
-				uint32 bridge_length = GetBridgeLength(m_old_tile, m_new_tile);
-				m_tiles_skipped = bridge_length;
-				m_is_bridge = true;
-				return;
-			}
-			assert(ReverseDiagDir(bridge_enterdir) == m_exitdir);
-		}
-
-		// normal or station tile, do one step
+		// normal or station tile
 		TileIndexDiff diff = TileOffsByDir(m_exitdir);
 		m_new_tile = TILE_ADD(m_old_tile, diff);
 
@@ -162,7 +148,22 @@ protected:
 		// rail transport is possible only on tiles with the same owner as vehicle
 		if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh->owner) {
 			// different owner
-			return false;
+			if (IsBridgeTile(m_new_tile)) {
+				if (IsBridgeMiddle(m_new_tile)) {
+						// bridge middle has no owner - tile is owned by the owner of the under-bridge track
+					if (GetBridgeAxis(m_new_tile) != DiagDirToAxis(m_exitdir)) {
+						// so it must be under bridge track (and wrong owner)
+						return false;
+					}
+					// in the middle of the bridge - when we came here, it should be ok
+				} else {
+					// different owner, on the bridge ramp
+					return false;
+				}
+			} else {
+				// different owner, not a bridge
+				return false;
+			}
 		}
 
 		// rail transport is possible only on compatible rail types
@@ -210,7 +211,7 @@ protected:
 				m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
 				m_exitdir = exitdir;
 				m_tiles_skipped = 0;
-				m_is_tunnel = m_is_bridge = m_is_station = false;
+				m_is_tunnel = m_is_station = false;
 				return true;
 			}
 		}
@@ -244,10 +245,20 @@ public:
 		int max_speed = INT_MAX; // no limit
 
 		// for now we handle only on-bridge speed limit
-		if (!IsWaterTT() && IsBridgeTile(m_old_tile)) {
-			int spd = _bridge[GetBridgeType(m_old_tile)].speed;
-			if (IsRoadTT()) spd *= 2;
-			if (max_speed > spd) max_speed = spd;
+		if (IsBridgeTile(m_old_tile) && !IsWaterTT() && IsDiagonalTrackdir(m_old_td)) {
+			bool is_on_bridge = true;
+			if (IsBridgeMiddle(m_old_tile)) {
+				// get track axis
+				Axis track_axis = DiagDirToAxis(TrackdirToExitdir(m_old_td));
+				// get under-bridge axis
+				Axis bridge_axis =  GetBridgeAxis(m_old_tile);
+				if (track_axis != bridge_axis) is_on_bridge = false;
+			}
+			if (is_on_bridge) {
+				int spd = _bridge[GetBridgeType(m_old_tile)].speed;
+				if (IsRoadTT()) spd *= 2;
+				if (max_speed > spd) max_speed = spd;
+			}
 		}
 
 		// if min speed was requested, return it
diff --git a/yapf/yapf.h b/yapf/yapf.h
index f9aec4dcc..4fc0b0043 100644
--- a/yapf/yapf.h
+++ b/yapf/yapf.h
@@ -34,9 +34,9 @@ typedef struct FollowTrack_t
 	Trackdir      m_old_td;
 	TileIndex     m_new_tile;
 	TrackdirBits  m_new_td_bits;
+//	TrackdirBits  m_red_td_bits;
 	DiagDirection m_exitdir;
 	bool          m_is_tunnel;
-	bool          m_is_bridge;
 	bool          m_is_station;
 	int           m_tiles_skipped;
 } FollowTrack_t;
diff --git a/yapf/yapf_road.cpp b/yapf/yapf_road.cpp
index d0a06c0f4..e25e57ed0 100644
--- a/yapf/yapf_road.cpp
+++ b/yapf/yapf_road.cpp
@@ -429,9 +429,7 @@ uint YapfRoadVehDistanceToTile(const Vehicle* v, TileIndex tile)
 Depot* YapfFindNearestRoadDepot(const Vehicle *v)
 {
 	TileIndex tile = v->tile;
-#if 0 /* NOT NEEDED, function does/did nothing */
 	if (v->u.road.state == 255) tile = GetVehicleOutOfTunnelTile(v);
-#endif
 	Trackdir trackdir = GetVehicleTrackdir(v);
 	if ((GetTileTrackStatus(tile, TRANSPORT_ROAD) & TrackdirToTrackdirBits(trackdir)) == 0)
 		return NULL;