(svn r7573) -Merged the bridge branch. Allows to build bridges of arbitrary rail/road combinations (including signals)
authorcelestar
Wed, 27 Dec 2006 12:38:02 +0000
changeset 5385 3868f2e6db9b
parent 5384 10b6d955e1ac
child 5386 c16ec5d9c6ea
(svn r7573) -Merged the bridge branch. Allows to build bridges of arbitrary rail/road combinations (including signals)
BUGS
ai/default/default.c
bridge.h
bridge_map.c
bridge_map.h
clear_cmd.c
debug.h
docs/landscape.html
docs/landscape_grid.html
elrail.c
landscape.c
misc.c
npf.c
openttd.c
pathfind.c
rail.c
rail_cmd.c
rail_map.h
road_cmd.c
road_map.c
roadveh_cmd.c
saveload.c
station_cmd.c
table/sprites.h
terraform_gui.c
town_cmd.c
train_cmd.c
tree_cmd.c
tunnelbridge_cmd.c
unmovable_cmd.c
variables.h
vehicle.h
water_cmd.c
waypoint.c
yapf/follow_track.hpp
yapf/yapf.h
yapf/yapf_costbase.hpp
yapf/yapf_rail.cpp
yapf/yapf_road.cpp
--- a/BUGS	Wed Dec 27 12:22:25 2006 +0000
+++ b/BUGS	Wed Dec 27 12:38:02 2006 +0000
@@ -2,6 +2,14 @@
 
 KNOWN BUGS / PROBLEMS:
 
+bridges:
+- Clearing tiles which may not have a bridge above can cause random bridge pieces to appear, which leads to crash in the long run
+
+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)
+
+TODO:
+- Reallow the AI to build signals under bridges (about ai/default/default.c:1600) as
+  r4911 manually disallows it (not via the command)
--- a/ai/default/default.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/ai/default/default.c	Wed Dec 27 12:38:02 2006 +0000
@@ -2183,9 +2183,7 @@
 				return false;
 			p->ai.cur_tile_a = TILE_MASK(_build_tunnel_endtile - TileOffsByDiagDir(p->ai.cur_dir_a));
 			return true;
-		}
-
-		if (IsBridgeRamp(tile)) {
+		} else {
 			// 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;
@@ -3704,7 +3702,6 @@
 	} else if (IsTileType(tile, MP_TUNNELBRIDGE)) {
 		if (!IsTileOwner(tile, _current_player) ||
 				!IsBridge(tile) ||
-				!IsBridgeRamp(tile) ||
 				GetBridgeTransportType(tile) != TRANSPORT_RAIL) {
 			return;
 		}
--- a/bridge.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/bridge.h	Wed Dec 27 12:38:02 2006 +0000
@@ -27,5 +27,6 @@
 extern Bridge _bridge[MAX_BRIDGES];
 
 uint GetBridgeFoundation(Slope tileh, Axis axis);
+uint SetSpeedLimitOnBridge(Vehicle *);
 
 #endif /* BRIDGE_H */
--- a/bridge_map.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/bridge_map.c	Wed Dec 27 12:38:02 2006 +0000
@@ -3,22 +3,28 @@
 #include "stdafx.h"
 #include "openttd.h"
 #include "bridge_map.h"
+#include "variables.h"
 
 
 TileIndex GetBridgeEnd(TileIndex tile, DiagDirection dir)
 {
 	TileIndexDiff delta = TileOffsByDiagDir(dir);
 
-	assert(DiagDirToAxis(dir) == GetBridgeAxis(tile));
-
+	dir = ReverseDiagDir(dir);
 	do {
 		tile += delta;
-	} while (!IsBridgeRamp(tile));
+	} while (!IsBridgeTile(tile) || GetBridgeRampDirection(tile) != dir);
 
 	return tile;
 }
 
 
+TileIndex GetNorthernBridgeEnd(TileIndex t)
+{
+	return GetBridgeEnd(t, ReverseDiagDir(AxisToDiagDir(GetBridgeAxis(t))));
+}
+
+
 TileIndex GetSouthernBridgeEnd(TileIndex t)
 {
 	return GetBridgeEnd(t, AxisToDiagDir(GetBridgeAxis(t)));
@@ -27,11 +33,19 @@
 
 TileIndex GetOtherBridgeEnd(TileIndex tile)
 {
-	TileIndexDiff delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
+	assert(IsBridgeTile(tile));
+	return GetBridgeEnd(tile, GetBridgeRampDirection(tile));
+}
 
-	do {
-		tile += delta;
-	} while (!IsBridgeRamp(tile));
+uint GetBridgeHeight(TileIndex t)
+{
+	uint h;
+	uint tileh = GetTileSlope(t, &h);
+	uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(t)));
 
-	return tile;
+	// one height level extra if the ramp is on a flat foundation
+	return
+		h + TILE_HEIGHT +
+		(IS_INT_INSIDE(f, 1, 15) ? TILE_HEIGHT : 0) +
+		(IsSteepSlope(tileh) ? TILE_HEIGHT : 0);
 }
--- a/bridge_map.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/bridge_map.h	Wed Dec 27 12:38:02 2006 +0000
@@ -11,6 +11,9 @@
 #include "tile.h"
 
 
+void DrawBridgeMiddle(const TileInfo* ti); // XXX
+
+
 static inline bool IsBridge(TileIndex t)
 {
 	assert(IsTileType(t, MP_TUNNELBRIDGE));
@@ -23,28 +26,22 @@
 }
 
 
-static inline bool IsBridgeRamp(TileIndex t)
+static inline bool MayHaveBridgeAbove(TileIndex t)
 {
-	assert(IsBridgeTile(t));
-	return !HASBIT(_m[t].m5, 6);
-}
-
-static inline bool IsBridgeMiddle(TileIndex t)
-{
-	assert(IsBridgeTile(t));
-	return HASBIT(_m[t].m5, 6);
+	return
+		IsTileType(t, MP_CLEAR) ||
+		IsTileType(t, MP_RAILWAY) ||
+		IsTileType(t, MP_STREET) ||
+		IsTileType(t, MP_WATER) ||
+		IsTileType(t, MP_TUNNELBRIDGE) ||
+		IsTileType(t, MP_UNMOVABLE);
 }
 
 
-/**
- * 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)
+static inline bool IsBridgeAbove(TileIndex t)
 {
-	assert(IsBridgeMiddle(t));
-	return GB(_m[t].m2, 0, 4);
+	assert(MayHaveBridgeAbove(t));
+	return GB(_m[t].extra, 6, 2) != 0;
 }
 
 
@@ -65,65 +62,22 @@
  */
 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)));
+	assert(IsBridgeTile(t));
+	return (DiagDirection)GB(_m[t].m5, 0, 2);
 }
 
 
 static inline Axis GetBridgeAxis(TileIndex t)
 {
-	assert(IsBridgeMiddle(t));
-	return (Axis)GB(_m[t].m5, 0, 1);
+	assert(IsBridgeAbove(t));
+	return (Axis)(GB(_m[t].extra, 6, 2) - 1);
 }
 
 
 static inline TransportType GetBridgeTransportType(TileIndex t)
 {
 	assert(IsBridgeTile(t));
-	return (TransportType)GB(_m[t].m5, 1, 2);
-}
-
-
-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 Track GetRailUnderBridge(TileIndex t)
-{
-	assert(GetTransportTypeUnderBridge(t) == TRANSPORT_RAIL);
-	return AxisToTrack(OtherAxis(GetBridgeAxis(t)));
-}
-
-static inline TrackBits GetRailBitsUnderBridge(TileIndex t)
-{
-	return TrackToTrackBits(GetRailUnderBridge(t));
+	return (TransportType)GB(_m[t].m5, 2, 2);
 }
 
 
@@ -133,6 +87,11 @@
 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);
@@ -143,58 +102,36 @@
  */
 TileIndex GetOtherBridgeEnd(TileIndex);
 
-uint GetBridgeHeight(TileIndex t);
+uint GetBridgeHeight(TileIndex tile);
+uint GetBridgeFoundation(Slope tileh, Axis axis);
 
-static inline void SetClearUnderBridge(TileIndex t)
+static inline void ClearSingleBridgeMiddle(TileIndex t, Axis 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);
+	assert(MayHaveBridgeAbove(t));
+	CLRBIT(_m[t].extra, 6 + a);
 }
 
-static inline void SetCanalUnderBridge(TileIndex t, Owner o)
+
+static inline void ClearBridgeMiddle(TileIndex t)
 {
-	assert(IsBridgeMiddle(t));
-	SetTileOwner(t, o);
-	SB(_m[t].m5, 3, 3, 0 << 2 | 1);
-	SB(_m[t].m3, 0, 4, 0);
+	ClearSingleBridgeMiddle(t, AXIS_X);
+	ClearSingleBridgeMiddle(t, AXIS_Y);
 }
 
-static inline void SetRailUnderBridge(TileIndex t, Owner o, RailType r)
+static inline void SetBridgeMiddle(TileIndex t, Axis a)
 {
-	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 SetRoadUnderBridge(TileIndex t, Owner o)
-{
-	assert(IsBridgeMiddle(t));
-	SetTileOwner(t, o);
-	SB(_m[t].m5, 3, 3, 1 << 2 | TRANSPORT_ROAD);
-	SB(_m[t].m3, 0, 4, 0);
+	assert(MayHaveBridgeAbove(t));
+	SETBIT(_m[t].extra, 6 + a);
 }
 
 
 static inline void MakeBridgeRamp(TileIndex t, Owner o, uint bridgetype, DiagDirection d, TransportType tt)
 {
-	uint northsouth = (d == DIAGDIR_NE || d == DIAGDIR_NW);
-
 	SetTileType(t, MP_TUNNELBRIDGE);
 	SetTileOwner(t, o);
 	_m[t].m2 = bridgetype << 4;
 	_m[t].m4 = 0;
-	_m[t].m5 = 1 << 7 | 0 << 6 | northsouth << 5 | tt << 1 | DiagDirToAxis(d);
+	_m[t].m5 = 1 << 7 | tt << 2 | d;
 }
 
 static inline void MakeRoadBridgeRamp(TileIndex t, Owner o, uint bridgetype, DiagDirection d)
@@ -210,26 +147,4 @@
 }
 
 
-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 /* BRIDGE_MAP_H */
--- a/clear_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/clear_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -12,6 +12,7 @@
 #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"
@@ -276,25 +277,32 @@
 		}
 	}
 
-	if (direction == -1) {
+	{
 		/* Check if tunnel would take damage */
 		int count;
 		TileIndex *ti = ts.tile_table;
 
 		for (count = ts.tile_table_count; count != 0; count--, ti++) {
-			uint z, t;
 			TileIndex tile = *ti;
 
-			z = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
-			t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
-			if (t <= z) z = t;
-			t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
-			if (t <= z) z = t;
-			t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
-			if (t <= z) z = t;
+			if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
+				return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+			}
 
-			if (IsTunnelInWay(tile, z * TILE_HEIGHT)) {
-				return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
+			if (direction == -1) {
+				uint z, t;
+
+				z = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
+				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
+				if (t <= z) z = t;
+				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
+				if (t <= z) z = t;
+				t = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
+				if (t <= z) z = t;
+
+				if (IsTunnelInWay(tile, z * TILE_HEIGHT)) {
+					return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
+				}
 			}
 		}
 	}
@@ -534,6 +542,7 @@
 	}
 
 	DrawClearLandFence(ti);
+	DrawBridgeMiddle(ti);
 }
 
 static uint GetSlopeZ_Clear(TileIndex tile, uint x, uint y)
--- a/debug.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/debug.h	Wed Dec 27 12:38:02 2006 +0000
@@ -20,11 +20,7 @@
 #ifdef NO_DEBUG_MESSAGES
 	#define DEBUG(name, level, ...)
 #else
-	#if defined(__GNUC__) && (__GNUC__ < 3)
-		#define DEBUG(name, level, args...) if ((level == 0) || ( _debug_ ## name ## _level >= level)) debug(#name, args)
-	#else
-		#define DEBUG(name, level, ...) if (level == 0 || _debug_ ## name ## _level >= level) debug(#name, __VA_ARGS__)
-	#endif
+	#define DEBUG(name, level, ...) if (level == 0 || _debug_ ## name ## _level >= level) debug(#name, __VA_ARGS__)
 
 	extern int _debug_ai_level;
 	extern int _debug_driver_level;
--- a/docs/landscape.html	Wed Dec 27 12:22:25 2006 +0000
+++ b/docs/landscape.html	Wed Dec 27 12:38:02 2006 +0000
@@ -554,31 +554,12 @@
 <li>m3 bits 3..0 = <a href="#TrackType">track type</a> for railway tunnel, must be 0 for road tunnel</li>
 <li>m4 bit 7 set = on snow or desert</li>
 </ul>
-m5 bit 7 set: bridge
-<ul><li>
-m5 bit 6 clear: bridge ending
-<ul>
-<li>m5 bit 5: clear - northern, set - southern ending</li>
-<li>m3 bits 3..0 = <a href="#TrackType">type of track</a> on the bridge, must be 0 for road bridge</li>
-<li>m1: <a href="#OwnershipInfo">owner</a> of the bridge</li>
-</ul>
-m5 bit 6 set: bridge middle part
-<ul>
-<li>m5 bit 5 clear:
+m5 bit 7 set: bridge ramp
 <ul>
-<li>m5 bits 4..3: land under bridge: <tt>0</tt> - grass, snow or desert, <tt>1</tt> - water</li>
-</ul>
-m5 bit 5 set:
-<ul>
-<li>m5 bits 4..3: transport route under bridge: <tt>0</tt> - railway, <tt>1</tt> - road</li>
-</ul>
-<li>m3 bits 7..4 = <a href="#TrackType">type of track</a> on the bridge, must be 0 for road bridge</li>
-<li>m3 bits 3..0 = <a href="#TrackType">type of track</a> under the bridge, if any</li>
-<li>m2 bits 3..0: bridge piece (<tt>0</tt>..<tt>5</tt>)
-<li>m1: <a href="#OwnershipInfo">owner</a> of the land under bridge</li>
-</ul></li>
-<li>m5 bits 2..1: <tt>0</tt> - railway bridge, <tt>1</tt> - road bridge</li>
-<li>m5 bit 0: clear - bridge in the X direction, set - bridge in the Y direction</li>
+<li>m1: <a href="#OwnershipInfo">owner</a> of the bridge</li>
+<li>m3 bits 3..0 = <a href="#TrackType">type of track</a> on the bridge, must be 0 for road bridge</li>
+<li>m5 bits 3..2: <tt>0</tt> - railway bridge, <tt>1</tt> - road bridge</li>
+<li>m5 bit 0..1: DiagDirection onto the bridge</li>
 <li>m2 bits 7..4: <a name="BridgeType">bridge type</a>:
 <table>
 <tr><th align=left>Type&nbsp;</th><th align=left>Max. speed (mph)&nbsp;</th><th align=left>Description</th></tr>
--- a/docs/landscape_grid.html	Wed Dec 27 12:22:25 2006 +0000
+++ b/docs/landscape_grid.html	Wed Dec 27 12:38:02 2006 +0000
@@ -225,7 +225,7 @@
       <td class="bits">-inherit-</td>
     </tr>
     <tr>
-      <td rowspan=3>9</td>
+      <td rowspan=2>9</td>
       <td class="caption">tunnel</td>
       <td class="bits">XXXX XXXX</td>
       <td class="bits"><span class="free">OOOO OOOO OOOO OOOO</span></td>
@@ -241,16 +241,7 @@
       <td class="bits"><span class="free">OOOO</span> XXXX</td>
       <td class="bits">X<span class="free">OOO OOOO</span></td>
       <td class="bits">XXXX XXXX</td>
-      <td class="bits">XXX<span class="free">O O</span>XXX</td>
-    </tr>
-    <tr>
-      <td>bridge middle part</td>
-      <td class="bits">XXXX XXXX</td>
-      <td class="bits"><span class="free">OOOO OOOO</span> <span class="abuse">XXXX XXXX</span></td>
-      <td class="bits">XXXX XXXX</td>
-      <td class="bits">X<span class="free">OOO OOOO</span></td>
-      <td class="bits">XXXX XXXX</td>
-      <td class="bits">XXXX XXXX</td>
+      <td class="bits">X<span class="free">OOO</span> XXXX</td>
     </tr>
     <tr>
       <td>A</td>
--- a/elrail.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/elrail.c	Wed Dec 27 12:38:02 2006 +0000
@@ -95,18 +95,10 @@
 				return AxisToTrackBits(DiagDirToAxis(GetTunnelDirection(t)));
 			} else {
 				if (GetRailType(t) != RAILTYPE_ELECTRIC) return 0;
-				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 AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(t)));
+				if (override != NULL && DistanceMax(t, GetOtherBridgeEnd(t)) > 1) {
+					*override = 1 << GetBridgeRampDirection(t);
 				}
+				return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(t)));
 			}
 
 		case MP_STREET:
@@ -135,17 +127,15 @@
 		if (IsTunnel(tile)) {
 			*tileh = SLOPE_FLAT;
 		} else {
-			if (IsBridgeRamp(tile)) {
-				if (*tileh != SLOPE_FLAT) {
-					*tileh = SLOPE_FLAT;
-				} else {
-					switch (GetBridgeRampDirection(tile)) {
-						case DIAGDIR_NE: *tileh = SLOPE_NE; break;
-						case DIAGDIR_SE: *tileh = SLOPE_SE; break;
-						case DIAGDIR_SW: *tileh = SLOPE_SW; break;
-						case DIAGDIR_NW: *tileh = SLOPE_NW; break;
-						default: break;
-					}
+			if (*tileh != SLOPE_FLAT) {
+				*tileh = SLOPE_FLAT;
+			} else {
+				switch (GetBridgeRampDirection(tile)) {
+					case DIAGDIR_NE: *tileh = SLOPE_NE; break;
+					case DIAGDIR_SE: *tileh = SLOPE_SE; break;
+					case DIAGDIR_SW: *tileh = SLOPE_SW; break;
+					case DIAGDIR_NW: *tileh = SLOPE_NW; break;
+					default: NOT_REACHED();
 				}
 			}
 		}
@@ -205,7 +195,7 @@
 		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) && IsBridgeRamp(neighbour) &&
+			    IsBridgeTile(neighbour) &&
 			    GetBridgeRampDirection(neighbour) == ReverseDiagDir(i)) {
 				continue;
 			}
@@ -232,7 +222,7 @@
 
 		/* Read the foundataions if they are present, and adjust the tileh */
 		if (IsTileType(neighbour, MP_RAILWAY) && GetRailType(neighbour) == RAILTYPE_ELECTRIC) foundation = GetRailFoundation(tileh[TS_NEIGHBOUR], trackconfig[TS_NEIGHBOUR]);
-		if (IsBridgeTile(neighbour) && IsBridgeRamp(neighbour)) {
+		if (IsBridgeTile(neighbour)) {
 			foundation = GetBridgeFoundation(tileh[TS_NEIGHBOUR], DiagDirToAxis(GetBridgeRampDirection(neighbour)));
 		}
 
@@ -260,6 +250,14 @@
 		 * 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));
+
+			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];
@@ -284,11 +282,10 @@
 	}
 
 	/* Don't draw a wire under a low bridge */
-	if (IsBridgeTile(ti->tile) &&
-			IsBridgeMiddle(ti->tile) &&
-			!(_display_opt & DO_TRANS_BUILDINGS) &&
-			GetBridgeHeight(ti->tile) <= TilePixelHeight(ti->tile) + TILE_HEIGHT) {
-		return;
+	if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !(_display_opt & DO_TRANS_BUILDINGS)) {
+		uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));
+
+		if (height <= TilePixelHeight(ti->tile) + TILE_HEIGHT) return;
 	}
 
 	/* Drawing of pylons is finished, now draw the wires */
@@ -335,7 +332,7 @@
 		sss = &CatenarySpriteData[WIRE_X_FLAT_SW + (num % 2) + offset];
 	}
 
-	height = GetBridgeHeight(ti->tile);
+	height = GetBridgeHeight(end);
 
 	AddSortableSpriteToDraw( sss->image, ti->x + sss->x_offset, ti->y + sss->y_offset,
 		sss->x_size, sss->y_size, sss->z_size, height + sss->z_offset
@@ -363,6 +360,13 @@
 
 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);
+		}
+	}
 	if (_patches.disable_elrails) return;
 
 	switch (GetTileType(ti->tile)) {
@@ -380,12 +384,10 @@
 			break;
 
 		case MP_TUNNELBRIDGE:
-			if (IsBridge(ti->tile) && IsBridgeMiddle(ti->tile) && GetRailTypeOnBridge(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenaryOnBridge(ti);
+		case MP_STREET:
+		case MP_STATION:
 			break;
 
-		case MP_STREET:  break;
-		case MP_STATION: break;
-
 		default: return;
 	}
 	DrawCatenaryRailway(ti);
--- a/landscape.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/landscape.c	Wed Dec 27 12:38:02 2006 +0000
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "bridge_map.h"
 #include "heightmap.h"
 #include "clear_map.h"
 #include "functions.h"
@@ -414,6 +415,8 @@
 		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);
 	}
--- a/misc.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/misc.c	Wed Dec 27 12:38:02 2006 +0000
@@ -551,16 +551,26 @@
 	uint size = MapSize();
 	uint i;
 
-	for (i = 0; i != size;) {
-		uint8 buf[1024];
-		uint j;
+	if (CheckSavegameVersion(42)) {
+		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);
+			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;
+
+			SlArray(buf, lengthof(buf), SLE_UINT8);
+			for (j = 0; j != lengthof(buf); j++) _m[i++].extra = buf[j];
 		}
 	}
 }
@@ -570,17 +580,12 @@
 	uint size = MapSize();
 	uint i;
 
-	SlSetLength(size / 4);
+	SlSetLength(size);
 	for (i = 0; i != size;) {
-		uint8 buf[1024];
+		uint8 buf[4096];
 		uint j;
 
-		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;
-		}
+		for (j = 0; j != lengthof(buf); j++) buf[j] = _m[i++].extra;
 		SlArray(buf, lengthof(buf), SLE_UINT8);
 	}
 }
--- a/npf.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/npf.c	Wed Dec 27 12:38:02 2006 +0000
@@ -181,6 +181,11 @@
 	}
 }
 
+static inline uint NPFBridgeCost(AyStarNode *current)
+{
+	return NPF_TILE_LENGTH * GetBridgeLength(current->tile, GetOtherBridgeEnd(current->tile));
+}
+
 static uint NPFSlopeCost(AyStarNode* current)
 {
 	TileIndex next = current->tile + TileOffsByDiagDir(TrackdirToExitdir(current->direction));
@@ -265,11 +270,7 @@
 	/* Determine base length */
 	switch (GetTileType(tile)) {
 		case MP_TUNNELBRIDGE:
-			if (IsTunnel(tile)) {
-				cost = NPFTunnelCost(current);
-			} else {
-				cost = NPF_TILE_LENGTH;
-			}
+			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
 			break;
 
 		case MP_STREET:
@@ -310,12 +311,8 @@
 	/* Determine base length */
 	switch (GetTileType(tile)) {
 		case MP_TUNNELBRIDGE:
-			if (IsTunnel(tile)) {
-				cost = NPFTunnelCost(current);
-				break;
-			}
-			/* Fall through if above if is false, it is a bridge
-			 * then. We treat that as ordinary rail */
+			cost = IsTunnel(tile) ? NPFTunnelCost(current) : NPFBridgeCost(current);
+			break;
 
 		case MP_RAILWAY:
 			cost = _trackdir_length[trackdir]; /* Should be different for diagonal tracks */
@@ -472,17 +469,7 @@
 
 		case MP_TUNNELBRIDGE:
 			if ((IsTunnel(tile) && GetTunnelTransportType(tile) == TRANSPORT_RAIL) ||
-					(IsBridge(tile) && (
-						(
-							IsBridgeRamp(tile) &&
-							GetBridgeTransportType(tile) == TRANSPORT_RAIL
-						) || (
-							IsBridgeMiddle(tile) &&
-							IsTransportUnderBridge(tile) &&
-							GetTransportTypeUnderBridge(tile) == TRANSPORT_RAIL &&
-							GetBridgeAxis(tile) != DiagDirToAxis(enterdir)
-						)
-					))) {
+					(IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL)) {
 				return IsTileOwner(tile, owner);
 			}
 			break;
@@ -526,6 +513,7 @@
 	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);
@@ -536,6 +524,10 @@
 		 * 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
@@ -583,8 +575,14 @@
 	/* 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 (IsTunnelTile(dst_tile) && GetTileZ(dst_tile) < GetTileZ(src_tile)) {
-		return;
+	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;
+			}
+		}
 	}
 
 	/* check correct rail type (mono, maglev, etc) */
--- a/openttd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/openttd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -55,6 +55,12 @@
 #include "fontcache.h"
 #include "newgrf_config.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 CallLandscapeTick(void);
@@ -1294,6 +1300,80 @@
 		}
 	}
 
+	if (CheckSavegameVersion(42)) {
+		TileIndex map_end = MapSize();
+		TileIndex tile;
+		Vehicle* v;
+
+		for (tile = 0; tile != map_end; tile++) {
+			if (MayHaveBridgeAbove(tile)) ClearBridgeMiddle(tile);
+			if (IsBridgeTile(tile)) {
+				if (HASBIT(_m[tile].m5, 6)) { // middle part
+					Axis axis = (Axis)GB(_m[tile].m5, 0, 1);
+
+					if (HASBIT(_m[tile].m5, 5)) { // 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 {
+							TownID 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 {
+							MakeCanal(tile, GetTileOwner(tile));
+						}
+					}
+					SetBridgeMiddle(tile, axis);
+				} else { // ramp
+					Axis axis = (Axis)GB(_m[tile].m5, 0, 1);
+					uint north_south = GB(_m[tile].m5, 5, 1);
+					DiagDirection dir = ReverseDiagDir(XYNSToDiagDir(axis, north_south));
+					TransportType type = (TransportType)GB(_m[tile].m5, 1, 2);
+
+					_m[tile].m5 = 1 << 7 | type << 2 | dir;
+				}
+			}
+		}
+
+		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: NOT_REACHED();
+					case DIAGDIR_NE: if ((v->x_pos & 0xF) !=  0)            continue; break;
+					case DIAGDIR_SE: if ((v->y_pos & 0xF) != TILE_SIZE - 1) continue; break;
+					case DIAGDIR_SW: if ((v->x_pos & 0xF) != TILE_SIZE - 1) continue; break;
+					case DIAGDIR_NW: if ((v->y_pos & 0xF) !=  0)            continue; break;
+				}
+			} else if (v->z_pos > GetSlopeZ(v->x_pos, v->y_pos)) {
+				v->tile = GetNorthernBridgeEnd(v->tile);
+			} else {
+				continue;
+			}
+			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;
@@ -1344,15 +1424,6 @@
 						}
 					} 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));
 						}
 					}
--- a/pathfind.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/pathfind.c	Wed Dec 27 12:38:02 2006 +0000
@@ -258,21 +258,27 @@
 	RememberData rd;
 	TileIndex tile_org = tile;
 
-	// 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;
+	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);
 		}
-		tile = SkipToEndOfTunnel(tpf, tile, direction);
 	}
 	tile += TileOffsByDiagDir(direction);
 
@@ -283,11 +289,7 @@
 
 		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))
-				/* 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;
+				if (GetTileOwner(tile_org) != GetTileOwner(tile)) return;
 	}
 
 	// check if the new tile can be entered from that direction
@@ -670,7 +672,6 @@
 	uint track;
 	TileIndex tile_org;
 	StackedItem si;
-	FindLengthOfTunnelResult flotr;
 	int estimation;
 
 
@@ -708,22 +709,40 @@
 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 (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 (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 (!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
@@ -751,12 +770,9 @@
 				// Check that the tile contains exactly one track
 				if (bits == 0 || KILL_FIRST_BIT(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 (!HASBIT(tpf->railtypes, IsTileType(tile, MP_STREET) ? GetRailTypeCrossing(tile) : GetRailType(tile))) {
-						bits = 0;
-						break;
-					}
+				if (!HASBIT(tpf->railtypes, IsTileType(tile, MP_STREET) ? GetRailTypeCrossing(tile) : GetRailType(tile))) {
+					bits = 0;
+					break;
 				}
 
 				///////////////////
--- a/rail.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/rail.c	Wed Dec 27 12:38:02 2006 +0000
@@ -104,7 +104,6 @@
 
 RailType GetTileRailType(TileIndex tile, Trackdir trackdir)
 {
-	DiagDirection exitdir = TrackdirToExitdir(trackdir);
 	switch (GetTileType(tile)) {
 		case MP_RAILWAY:
 			return GetRailType(tile);
@@ -120,26 +119,9 @@
 
 		case MP_TUNNELBRIDGE:
 			if (IsTunnel(tile)) {
-				if (GetTunnelTransportType(tile) == TRANSPORT_RAIL) {
-					return GetRailType(tile);
-				}
+				if (GetTunnelTransportType(tile) == TRANSPORT_RAIL) return GetRailType(tile);
 			} else {
-				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);
-						}
-					}
-				}
+				if (GetBridgeTransportType(tile) == TRANSPORT_RAIL) return GetRailType(tile);
 			}
 			break;
 
--- a/rail_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/rail_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -247,36 +247,13 @@
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
 	switch (GetTileType(tile)) {
-		case MP_TUNNELBRIDGE:
-			if (!IsBridge(tile) ||
-					!IsBridgeMiddle(tile) ||
-					AxisToTrackBits(OtherAxis(GetBridgeAxis(tile))) != 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, railtype);
-			} 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)) {
 				return CMD_ERROR;
 			}
 			if (!IsTileOwner(tile, _current_player) ||
-					!IsCompatibleRail(GetRailType(tile), railtype)) {
+					GetRailType(tile) != railtype) {
 				// Get detailed error message
 				return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 			}
@@ -366,20 +343,6 @@
 	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 ||
@@ -617,6 +580,8 @@
 	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;
 
@@ -1414,6 +1379,7 @@
 			);
 		}
 	}
+	DrawBridgeMiddle(ti);
 }
 
 
@@ -1513,19 +1479,11 @@
 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 (tile != dest->tile) return NULL;
+	if (v->tile != dest->tile) return NULL;
 
 	/* Are we on the same piece of track? */
 	if (dest->track & v->u.rail.track * 0x101) return v;
@@ -1541,15 +1499,18 @@
 	dest.tile = tile;
 	dest.track = track;
 
-	/** @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);
+	/* 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);
+		}
 
 		dest.track = 1 << (direction & 1); // get the trackbit the vehicle would have if it has not entered the tunnel yet (ie is still visible)
 
@@ -1559,9 +1520,9 @@
 		// 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 "hidden" vehicle
+		// now check all tiles from start to end for a warping vehicle
 		// NOTE: the hashes for tiles may overlap, so this could maybe be optimised a bit by not checking every tile?
-		dest.track = 0x40; // trackbit for vehicles "hidden" inside a tunnel
+		dest.track = 0x40;   //Vehicle inside a tunnel or on a bridge
 		for (; tile != end; tile += TileOffsByDiagDir(direction)) {
 			if (VehicleFromPos(tile, &dest, SignalVehicleCheckProc) != NULL)
 				return true;
--- a/rail_map.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/rail_map.h	Wed Dec 27 12:38:02 2006 +0000
@@ -87,11 +87,6 @@
 	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);
@@ -103,11 +98,6 @@
 	SB(_m[t].m4, 0, 4, r);
 }
 
-static inline void SetRailTypeOnBridge(TileIndex t, RailType r)
-{
-	SB(_m[t].m3, 4, 4, r);
-}
-
 
 static inline TrackBits GetTrackBits(TileIndex tile)
 {
--- a/road_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/road_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -105,103 +105,73 @@
 	if (p1 >> 4) return CMD_ERROR;
 	pieces = p1;
 
-	if (!IsTileType(tile, MP_STREET) && !IsTileType(tile, MP_TUNNELBRIDGE)) return CMD_ERROR;
+	if (!IsTileType(tile, MP_STREET)) return CMD_ERROR;
 
 	owner = IsLevelCrossingTile(tile) ? GetCrossingRoadOwner(tile) : GetTileOwner(tile);
 
 	if (owner == OWNER_TOWN && _game_mode != GM_EDITOR) {
-		/* Are we removing a piece of road below a bridge, or not. If below
-		 * a bridge we need to calculate the town's index as it is not saved
-		 * in the map array (no space) */
-		if (IsTileType(tile, MP_TUNNELBRIDGE)) {
-			t = ClosestTownFromTile(tile, _patches.dist_local_authority);
-		} else {
-			t = GetTownByTile(tile);
-		}
+		t = GetTownByTile(tile);
 	} else {
 		t = NULL;
 	}
 
 	if (!CheckAllowRemoveRoad(tile, pieces, &edge_road)) return CMD_ERROR;
 
-	switch (GetTileType(tile)) {
-		case MP_TUNNELBRIDGE:
-			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
+	if (!EnsureNoVehicle(tile)) return CMD_ERROR;
 
-			if (!IsBridge(tile) ||
-					!IsBridgeMiddle(tile) ||
-					!IsTransportUnderBridge(tile) ||
-					GetTransportTypeUnderBridge(tile) != TRANSPORT_ROAD ||
-					(pieces & ComplementRoadBits(GetRoadBitsUnderBridge(tile))) != 0) {
+	// 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;
+
+	switch (GetRoadTileType(tile)) {
+		case ROAD_TILE_NORMAL: {
+			RoadBits present = GetRoadBits(tile);
+			RoadBits c = pieces;
+
+			if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);
+
+			if (GetTileSlope(tile, NULL) != SLOPE_FLAT  &&
+					(present == ROAD_Y || present == ROAD_X)) {
+				c |= (c & 0xC) >> 2;
+				c |= (c & 0x3) << 2;
+			}
+
+			// limit the bits to delete to the existing bits.
+			c &= present;
+			if (c == 0) return CMD_ERROR;
+
+			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;
+		}
+
+		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);
-				SetClearUnderBridge(tile);
+
+				MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailTypeCrossing(tile));
 				MarkTileDirtyByTile(tile);
+				YapfNotifyTrackLayoutChange(tile, FIND_FIRST_BIT(GetTrackBits(tile)));
 			}
 			return _price.remove_road * 2;
-
-		case MP_STREET:
-			if (!EnsureNoVehicle(tile)) 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;
-
-			switch (GetRoadTileType(tile)) {
-				case ROAD_TILE_NORMAL: {
-					RoadBits present = GetRoadBits(tile);
-					RoadBits c = pieces;
-
-					if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);
-
-					if (GetTileSlope(tile, NULL) != SLOPE_FLAT &&
-							(present == ROAD_Y || present == ROAD_X)) {
-						c |= (c & 0xC) >> 2;
-						c |= (c & 0x3) << 2;
-					}
-
-					// limit the bits to delete to the existing bits.
-					c &= present;
-					if (c == 0) return CMD_ERROR;
-
-					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;
-				}
-
-				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);
-
-						MakeRailNormal(tile, GetTileOwner(tile), GetCrossingRailBits(tile), GetRailTypeCrossing(tile));
-						MarkTileDirtyByTile(tile);
-						YapfNotifyTrackLayoutChange(tile, FIND_FIRST_BIT(GetTrackBits(tile)));
-					}
-					return _price.remove_road * 2;
-				}
-
-				default:
-				case ROAD_TILE_DEPOT:
-					return CMD_ERROR;
-			}
-
-		default: return CMD_ERROR;
+		default:
+		case ROAD_TILE_DEPOT:
+			return CMD_ERROR;
 	}
 }
 
@@ -362,32 +332,6 @@
 			return _price.build_road * 2;
 		}
 
-		case MP_TUNNELBRIDGE:
-			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);
@@ -587,6 +531,8 @@
 	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;
 
@@ -820,6 +766,7 @@
 			break;
 		}
 	}
+	DrawBridgeMiddle(ti);
 }
 
 void DrawRoadDepotSprite(int x, int y, DiagDirection dir)
--- a/road_map.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/road_map.c	Wed Dec 27 12:38:02 2006 +0000
@@ -27,22 +27,12 @@
 			return DiagDirToRoadBits(GetRoadStopDir(tile));
 
 		case MP_TUNNELBRIDGE:
-			if (IsBridge(tile)) {
-				if (IsBridgeMiddle(tile)) {
-					if (!IsTransportUnderBridge(tile) ||
-							GetTransportTypeUnderBridge(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 (IsTunnel(tile)) {
 				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;
--- a/roadveh_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/roadveh_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -21,7 +21,9 @@
 #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_callbacks.h"
 #include "newgrf_engine.h"
@@ -322,8 +324,6 @@
 {
 	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;
@@ -444,14 +444,19 @@
 
 	if (v->type != VEH_Road || !CheckOwnership(v->owner)) return CMD_ERROR;
 
-	if (v->vehstatus & (VS_HIDDEN | VS_STOPPED) ||
+	if (v->vehstatus & 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;
@@ -518,11 +523,9 @@
 	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;
@@ -872,6 +875,7 @@
 
 	// 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) {
@@ -1339,8 +1343,7 @@
 			return;
 		}
 
-		if (IsTunnelTile(gp.new_tile) &&
-				VehicleEnterTile(v, gp.new_tile, gp.x, gp.y) & 4) {
+		if ((IsTunnelTile(gp.new_tile) || IsBridgeTile(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);
@@ -1351,6 +1354,7 @@
 		v->x_pos = gp.x;
 		v->y_pos = gp.y;
 		VehiclePositionChanged(v);
+		if (!(v->vehstatus & VS_HIDDEN)) EndVehicleMove(v);
 		return;
 	}
 
--- a/saveload.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/saveload.c	Wed Dec 27 12:38:02 2006 +0000
@@ -30,7 +30,7 @@
 #include "variables.h"
 #include <setjmp.h>
 
-const uint16 SAVEGAME_VERSION = 41;
+const uint16 SAVEGAME_VERSION = 42;
 uint16 _sl_version;       /// the major savegame version identifier
 byte   _sl_minor_version; /// the minor savegame version, DO NOT USE!
 
--- a/station_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/station_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -4,6 +4,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "bridge_map.h"
 #include "debug.h"
 #include "functions.h"
 #include "station_map.h"
@@ -795,6 +796,10 @@
 	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);
--- a/table/sprites.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/table/sprites.h	Wed Dec 27 12:38:02 2006 +0000
@@ -745,6 +745,27 @@
 	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?)*/
--- a/terraform_gui.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/terraform_gui.c	Wed Dec 27 12:38:02 2006 +0000
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "bridge_map.h"
 #include "clear_map.h"
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -73,11 +74,20 @@
 	size_y = (ey - sy) + 1;
 
 	BEGIN_TILE_LOOP(tile, size_x, size_y, TileXY(sx, sy)) {
-		if (IsTileType(tile, MP_CLEAR) || IsTileType(tile, MP_TREES)) {
-			MakeClear(tile, CLEAR_ROCKS, 3);
-			MarkTileDirtyByTile(tile);
-			success = true;
+		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;
 		}
+		MarkTileDirtyByTile(tile);
+		success = true;
 	} END_TILE_LOOP(tile, size_x, size_y, 0);
 
 	if (success) SndPlayTileFx(SND_1F_SPLAT, end);
--- a/town_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/town_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -26,6 +26,7 @@
 #include "water_map.h"
 #include "variables.h"
 #include "bridge.h"
+#include "bridge_map.h"
 #include "date.h"
 #include "table/town_land.h"
 #include "genworld.h"
@@ -1118,6 +1119,8 @@
 	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;
@@ -1160,6 +1163,8 @@
 
 		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;
 	}
@@ -1291,6 +1296,7 @@
 	// 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;
--- a/train_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/train_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -25,6 +25,7 @@
 #include "waypoint.h"
 #include "vehicle_gui.h"
 #include "train.h"
+#include "bridge.h"
 #include "newgrf_callbacks.h"
 #include "newgrf_engine.h"
 #include "newgrf_sound.h"
@@ -105,10 +106,7 @@
 		/* Power is not added for articulated parts */
 		if (IsArticulatedPart(u)) continue;
 
-		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 (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 {
@@ -1601,13 +1599,14 @@
 		UpdateVarsAfterSwap(a);
 		UpdateVarsAfterSwap(b);
 
-		VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
-		VehicleEnterTile(b, b->tile, b->x_pos, b->y_pos);
+		/* 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);
 	} else {
 		if (!(a->u.rail.track & 0x80)) a->direction = ReverseDir(a->direction);
 		UpdateVarsAfterSwap(a);
 
-		VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
+		if (!(a->u.rail.track & 0x40)) VehicleEnterTile(a, a->tile, a->x_pos, a->y_pos);
 	}
 
 	/* Update train's power incase tiles were different rail type */
@@ -1940,8 +1939,6 @@
 		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
@@ -2733,9 +2730,7 @@
 	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;
@@ -2811,13 +2806,6 @@
 			// 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
@@ -3158,15 +3146,16 @@
 				v->direction = chosen_dir;
 			}
 		} else {
-			/* in tunnel */
+			/* in tunnel on on a bridge */
 			GetNewVehiclePos(v, &gp);
 
-			// Check if to exit the tunnel...
-			if (!IsTunnelTile(gp.new_tile) ||
-					!(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y)&0x4) ) {
+			SetSpeedLimitOnBridge(v);
+
+			if (!(IsTunnelTile(gp.new_tile) || IsBridgeTile(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;
 			}
 		}
@@ -3263,7 +3252,7 @@
 	 * others are on it */
 	DisableTrainCrossing(v->tile);
 
-	if (v->u.rail.track == 0x40) { // inside a tunnel
+	if ( (v->u.rail.track == 0x40 && v->vehstatus & VS_HIDDEN) ) { // inside a tunnel
 		TileIndex endtile = CheckTunnelBusy(v->tile, NULL);
 
 		if (endtile == INVALID_TILE) return; // tunnel is busy (error returned)
@@ -3294,15 +3283,16 @@
 	};
 
 	do {
-		//I need to buffer the train direction
-		if (!(v->u.rail.track & 0x40)) {
+		/* We don't need to twist around vehicles if they're not visible */
+		if (!(v->vehstatus & VS_HIDDEN)) {
 			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);
-			AfterSetTrainPos(v, false);
+			/* 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);
 		}
 	} while ((v = v->next) != NULL);
 }
@@ -3313,7 +3303,7 @@
 	uint32 r;
 	Vehicle *u;
 
-	if (state == 4 && v->u.rail.track != 0x40) {
+	if (state == 4 && !(v->u.rail.track & VS_HIDDEN)) {
 		CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
 	}
 
@@ -3402,10 +3392,11 @@
 
 	tile = v->tile;
 
-	// tunnel entrance?
-	if (IsTunnelTile(tile) &&
-			DiagDirToDir(GetTunnelDirection(tile)) == v->direction) {
-		return true;
+	if (IsTileType(tile, MP_TUNNELBRIDGE)) {
+		DiagDirection dir;
+
+		dir = IsTunnel(tile) ? GetTunnelDirection(tile) : GetBridgeRampDirection(tile);
+		if (DiagDirToDir(dir) == v->direction) return true;
 	}
 
 	// depot?
--- a/tree_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/tree_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "bridge_map.h"
 #include "clear_map.h"
 #include "table/strings.h"
 #include "table/sprites.h"
@@ -75,6 +76,7 @@
 
 		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);
@@ -134,6 +136,7 @@
 		IncreaseGeneratingWorldProgress(GWP_TREE);
 
 		if (IsTileType(tile, MP_CLEAR) &&
+				!IsBridgeAbove(tile) &&
 				!IsClearGround(tile, CLEAR_FIELDS) &&
 				!IsClearGround(tile, CLEAR_ROCKS)) {
 			PlaceTree(tile, r);
@@ -167,7 +170,10 @@
 
 			IncreaseGeneratingWorldProgress(GWP_TREE);
 
-			if (IsTileType(tile, MP_CLEAR) && !IsClearGround(tile, CLEAR_FIELDS) && GetTropicZone(tile) == TROPICZONE_RAINFOREST) {
+			if (IsTileType(tile, MP_CLEAR) &&
+					!IsBridgeAbove(tile) &&
+					!IsClearGround(tile, CLEAR_FIELDS) &&
+					GetTropicZone(tile) == TROPICZONE_RAINFOREST) {
 				PlaceTree(tile, r);
 			}
 		} while (--i);
@@ -250,7 +256,8 @@
 					break;
 
 				case MP_CLEAR:
-					if (!IsTileOwner(tile, OWNER_NONE)) {
+					if (!IsTileOwner(tile, OWNER_NONE) ||
+							IsBridgeAbove(tile)) {
 						msg = STR_2804_SITE_UNSUITABLE;
 						continue;
 					}
@@ -547,7 +554,7 @@
 
 						tile += TileOffsByDir(Random() & 7);
 
-						if (!IsTileType(tile, MP_CLEAR)) return;
+						if (!IsTileType(tile, MP_CLEAR) || IsBridgeAbove(tile)) return;
 
 						switch (GetClearGround(tile)) {
 							case CLEAR_GRASS:
@@ -580,6 +587,7 @@
 					case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
 					default: MakeClear(tile, CLEAR_SNOW, GetTreeDensity(tile)); break;
 				}
+				ClearBridgeMiddle(tile);
 			}
 			break;
 
@@ -602,6 +610,7 @@
 	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);
@@ -614,6 +623,7 @@
 	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) {
--- a/tunnelbridge_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/tunnelbridge_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -16,6 +16,7 @@
 #include "map.h"
 #include "tile.h"
 #include "tunnel_map.h"
+#include "unmovable_map.h"
 #include "vehicle.h"
 #include "viewport.h"
 #include "command.h"
@@ -32,11 +33,6 @@
 
 #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
@@ -193,9 +189,7 @@
 	TileIndex tile;
 	TileIndexDiff delta;
 	uint bridge_len;
-	uint odd_middle_part;
 	Axis direction;
-	uint i;
 	int32 cost, terraformcost, ret;
 	bool allow_on_slopes;
 
@@ -288,6 +282,24 @@
 		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]);
+
+					if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+
+					if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
+						return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+					}
+				}
+			}
+		}
+	}
 
 	/* do the drill? */
 	if (flags & DC_EXEC) {
@@ -304,49 +316,43 @@
 		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;
+	for (tile = tile_start + delta; tile != tile_end; tile += delta) {
 		uint z;
 
-		tile += delta;
+		if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
 
-		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);
 		}
 
 		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 (GetRailTileType(tile) != RAIL_TILE_NORMAL ||
-						GetTrackBits(tile) != AxisToTrackBits(OtherAxis(direction))) {
-					goto not_valid_below;
-				}
-				transport_under = TRANSPORT_RAIL;
-				owner_under = GetTileOwner(tile);
-				rail_under = GetRailType(tile);
+				if (!IsPlainRailTile(tile)) goto not_valid_below;
 				break;
 
 			case MP_STREET:
-				if (GetRoadTileType(tile) != ROAD_TILE_NORMAL) goto not_valid_below;
-				if (HasRoadWorks(tile)) return_cmd_error(STR_ROAD_WORKS_IN_PROGRESS);
-				if (GetRoadBits(tile) != (direction == AXIS_X ? ROAD_Y : ROAD_X)) {
-					goto not_valid_below;
-				}
-				transport_under = TRANSPORT_ROAD;
-				owner_under = GetTileOwner(tile);
+				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 (z_start < GetBridgeHeight(tile)) goto not_valid_below;
+				break;
+
+			case MP_UNMOVABLE:
+				if (!IsOwnedLand(tile)) goto not_valid_below;
+				break;
+
+			case MP_CLEAR:
+				if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
 				break;
 
 			default:
@@ -355,58 +361,11 @@
 				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) {
-			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;
-			}
-
+			SetBridgeMiddle(tile, direction);
 			MarkTileDirtyByTile(tile);
 		}
 	}
@@ -608,87 +567,40 @@
 }
 
 
-static uint GetBridgeHeightRamp(TileIndex t)
+static bool IsVehicleOnBridge(TileIndex starttile, TileIndex endtile, uint z)
 {
-	uint h;
-	uint tileh = GetTileSlope(t, &h);
-	uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(t)));
-
-	// one height level extra if the ramp is on a flat foundation
-	return
-		h + TILE_HEIGHT +
-		(IS_INT_INSIDE(f, 1, 15) ? TILE_HEIGHT : 0) +
-		(IsSteepSlope(tileh) ? TILE_HEIGHT : 0);
+	const Vehicle *v;
+	FOR_ALL_VEHICLES(v) {
+		if ((v->tile == starttile || v->tile == endtile) && v->z_pos == z) {
+			_error_message = VehicleInTheWayErrMsg(v);
+			return true;
+		}
+	}
+	return false;
 }
 
-
 static int32 DoClearBridge(TileIndex tile, uint32 flags)
 {
 	DiagDirection direction;
 	TileIndexDiff delta;
 	TileIndex endtile;
-	Vehicle *v;
 	Town *t = NULL;
 
 	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) && !IsTileOwner(tile, OWNER_WATER)) {
-			/* 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);
-	}
-
 	if (!CheckAllowRemoveTunnelBridge(tile)) return CMD_ERROR;
 
 	endtile = GetOtherBridgeEnd(tile);
 
-	if (!EnsureNoVehicle(tile) || !EnsureNoVehicle(endtile)) return CMD_ERROR;
+	if (!EnsureNoVehicle(tile) ||
+			!EnsureNoVehicle(endtile) ||
+			IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+		return CMD_ERROR;
+	}
 
 	direction = GetBridgeRampDirection(tile);
 	delta = TileOffsByDiagDir(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
-	 */
-	v = FindVehicleBetween(
-		tile    + delta,
-		endtile - delta,
-		GetBridgeHeightRamp(tile)
-	);
-	if (v != NULL) return_cmd_error(VehicleInTheWayErrMsg(v));
-
 	if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
 		t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
 
@@ -712,30 +624,8 @@
 		DoClearSquare(tile);
 		DoClearSquare(endtile);
 		for (c = tile + delta; c != endtile; c += delta) {
-			if (IsTransportUnderBridge(c)) {
-				if (GetTransportTypeUnderBridge(c) == TRANSPORT_RAIL) {
-					MakeRailNormal(c, GetTileOwner(c), GetRailBitsUnderBridge(c), GetRailType(c));
-				} else {
-					TownID 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) {
-						if (IsTileOwner(c, OWNER_WATER)) {
-							MakeWater(c);
-						} else {
-							MakeCanal(c, GetTileOwner(c));
-						}
-					} else {
-						MakeShore(c);
-					}
-					MarkTileDirtyByTile(c);
-				}
-			}
+				ClearBridgeMiddle(c);
+			MarkTileDirtyByTile(c);
 		}
 
 		UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
@@ -790,26 +680,7 @@
 			YapfNotifyTrackLayoutChange(endtile, track);
 		}
 		return (length + 1) * (_price.build_rail >> 1);
-	} 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) {
-			SetRailType(tile, totype);
-			MarkTileDirtyByTile(tile);
-
-			YapfNotifyTrackLayoutChange(tile, GetRailUnderBridge(tile));
-		}
-		return _price.build_rail >> 1;
-	} else if (IsBridge(tile) && IsBridgeRamp(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
-		TileIndexDiff delta;
-		int32 cost;
+	} else if (IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
 
 		if (!CheckTileOwnership(tile)) return CMD_ERROR;
 
@@ -817,14 +688,16 @@
 
 		if (!EnsureNoVehicle(tile) ||
 				!EnsureNoVehicle(endtile) ||
-				FindVehicleBetween(tile, endtile, GetBridgeHeightRamp(tile)) != NULL) {
-			return_cmd_error(STR_8803_TRAIN_IN_THE_WAY);
+				IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+			return CMD_ERROR;
 		}
 
 		if (GetRailType(tile) == totype) return CMD_ERROR;
 
 		if (exec) {
+			TileIndexDiff delta;
 			Track track;
+
 			SetRailType(tile, totype);
 			SetRailType(endtile, totype);
 			MarkTileDirtyByTile(tile);
@@ -833,43 +706,24 @@
 			track = AxisToTrack(DiagDirToAxis(GetBridgeRampDirection(tile)));
 			YapfNotifyTrackLayoutChange(tile, track);
 			YapfNotifyTrackLayoutChange(endtile, track);
-		}
-		cost = 2 * (_price.build_rail >> 1);
-		delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
-		for (tile += delta; tile != endtile; tile += delta) {
-			if (exec) {
-				SetRailTypeOnBridge(tile, totype);
-				MarkTileDirtyByTile(tile);
+
+			delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
+			for (tile += delta; tile != endtile; tile += delta) {
+				MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
 			}
-			cost += _price.build_rail >> 1;
 		}
 
-		return cost;
+		return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
 	} else {
 		return CMD_ERROR;
 	}
 }
 
 
-// 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[][31] = {
-	// 0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15                              _S              _W      _N  _E
-	{  0, 16, 18,  3, 20,  5,  0,  7, 22,  0, 10, 11, 12, 13, 14,  0,  0,  0,  0,  0,  0,  0,  0, 18,  0,  0,  0, 16,  0, 22, 20 },
-	{  0, 15, 17,  0, 19,  5,  6,  7, 21,  9, 10, 11,  0, 13, 14,  0,  0,  0,  0,  0,  0,  0,  0, 17,  0,  0,  0, 15,  0, 21, 19 }
-};
-
-extern const byte _road_sloped_sprites[14];
-
-static void DrawBridgePillars(PalSpriteID image, const TileInfo *ti, int x, int y, int z)
+static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
 {
 	if (image != 0) {
-		Axis axis = GetBridgeAxis(ti->tile);
-		bool drawfarpillar = !HASBIT(GetBridgeFlags(GetBridgeType(ti->tile)), 0);
+		bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
 		int back_height, front_height;
 		int i = z;
 		const byte *p;
@@ -939,17 +793,11 @@
  * <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)) {
@@ -966,19 +814,12 @@
 		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) {
-			RailType rt;
-
-			if (IsBridgeRamp(ti->tile)) {
-				rt = GetRailType(ti->tile);
-			} else {
-				rt = GetRailTypeOnBridge(ti->tile);
-			}
-
-			base_offset = GetRailTypeInfo(rt)->bridge_offset;
+			base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
 			assert(base_offset != 8); /* This one is used for roads */
 		} else {
 			base_offset = 8;
@@ -987,129 +828,163 @@
 		/* as the lower 3 bits are used for other stuff, make sure they are clear */
 		assert( (base_offset & 0x07) == 0x00);
 
-		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);
-			}
-
-			// 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 (!ice) {
-				DrawClearLandTile(ti, 3);
-			} else {
-				DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
-			}
-
-			if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
-
-			// draw ramp
-			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
-			/* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
-			 * it doesn't disappear behind it
-			 */
-			AddSortableSpriteToDraw(
-				image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, 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 (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
+			int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
+			if (f != 0) DrawFoundation(ti, f);
+		}
 
-					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 || !IsTileOwner(ti->tile, OWNER_WATER)) DrawCanalWater(ti->tile);
-					} else {
-						DrawGroundSprite(_water_shore_sprites[ti->tileh]);
-					}
-				}
-			}
-
-			if (axis != AXIS_X) base_offset += 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;
+		// HACK Wizardry to convert the bridge ramp direction into a sprite offset
+		base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
 
-			z = GetBridgeHeight(ti->tile) - 3;
-
-			// 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);
-			}
-
-			x = ti->x;
-			y = ti->y;
-			image = b[1];
-			if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+		if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
 
-			// 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(ti->tile) == RAILTYPE_ELECTRIC || GetRailTypeOnBridge(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+		/* Table number 6 always refers to the bridge heads for any bridge type */
+		image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
 
-			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);
-			}
+		if (!ice) {
+			DrawClearLandTile(ti, 3);
+		} else {
+			DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
 		}
+
+		if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+		// draw ramp
+		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+		/* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
+		 * it doesn't disappear behind it
+		 */
+		AddSortableSpriteToDraw(
+			image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, ti->z
+		);
+
+		DrawBridgeMiddle(ti);
 	}
 }
 
+
+/** Compute bridge piece. Computes the bridge piece to display depending on the position inside the bridge.
+ * 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)
+ * @param north Northernmost tile of bridge
+ * @param south Southernmost tile of bridge
+ * @return Index of bridge piece
+ */
+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);
+
+	if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
+		base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
+	} else {
+		base_offset = 8;
+	}
+
+	b = base_offset + GetBridgeSpriteTable(type, piece);
+	if (axis != AXIS_X) b += 4;
+
+	x = ti->x;
+	y = ti->y;
+	z = GetBridgeHeight(rampsouth) - 3;
+
+	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);
+	}
+
+	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);
+	}
+
+	if (GetRailType(rampsouth) == 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);
+		}
+	} 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(TileIndex tile, uint x, uint y)
 {
 	uint z;
@@ -1124,58 +999,35 @@
 		// In the tunnel entrance?
 		if (5 <= pos && pos <= 10) return z;
 	} else {
-		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 (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
-				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));
+		DiagDirection dir = GetBridgeRampDirection(tile);
+		uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
 
-				if (f != 0) {
-					if (IsSteepSlope(tileh)) {
-						z += TILE_HEIGHT;
-					} else if (f < 15) {
-						return z + TILE_HEIGHT;
-					}
-					tileh = _inclined_tileh[f - 15];
-				}
-			}
-		} else {
-			uint ground_z;
+		// On the bridge ramp?
+		if (5 <= pos && pos <= 10) {
+			uint delta;
 
-			// HACK on the bridge?
-			ground_z = z + TILE_HEIGHT;
-			if (tileh != SLOPE_FLAT) ground_z += TILE_HEIGHT;
-			if (IsSteepSlope(tileh)) ground_z += TILE_HEIGHT;
-			if (_get_z_hint >= ground_z) return _get_z_hint;
+			if (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
+			if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
 
-			if (IsTransportUnderBridge(tile)) {
-				uint f = _bridge_foundations[GetBridgeAxis(tile)][tileh];
+			if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
+			switch (dir) {
+				default: NOT_REACHED();
+				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 (IsSteepSlope(tileh)) {
-						z += TILE_HEIGHT;
-					} else if (f < 15) {
-						return z + TILE_HEIGHT;
-					}
-					tileh = _inclined_tileh[f - 15];
+			if (f != 0) {
+				if (IsSteepSlope(tileh)) {
+					z += TILE_HEIGHT;
+				} else if (f < 15) {
+					return z + TILE_HEIGHT;
 				}
+				tileh = _inclined_tileh[f - 15];
 			}
 		}
 	}
@@ -1185,29 +1037,19 @@
 
 static Slope GetSlopeTileh_TunnelBridge(TileIndex tile, Slope tileh)
 {
-	uint f;
-
 	if (IsTunnel(tile)) {
 		return tileh;
 	} else {
-		if (IsBridgeRamp(tile)) {
-			if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
-				return tileh;
-			} else {
-				f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
-			}
+		if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
+			return tileh;
 		} else {
-			if (IsTransportUnderBridge(tile)) {
-				f = _bridge_foundations[GetBridgeAxis(tile)][tileh];
-			} else {
-				return tileh;
-			}
+			uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
+
+			if (f == 0) return tileh;
+			if (f < 15) return SLOPE_FLAT;
+			return _inclined_tileh[f - 15];
 		}
 	}
-
-	if (f == 0) return tileh;
-	if (f < 15) return SLOPE_FLAT;
-	return _inclined_tileh[f - 15];
 }
 
 
@@ -1255,9 +1097,6 @@
 			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);
 }
@@ -1285,10 +1124,6 @@
 			}
 			break;
 	}
-
-	if (IsBridge(tile) && IsBridgeMiddle(tile) && IsWaterUnderBridge(tile)) {
-		TileLoop_Water(tile);
-	}
 }
 
 static void ClickTile_TunnelBridge(TileIndex tile)
@@ -1303,21 +1138,8 @@
 		if (GetTunnelTransportType(tile) != mode) return 0;
 		return AxisToTrackBits(DiagDirToAxis(GetTunnelDirection(tile))) * 0x101;
 	} else {
-		if (IsBridgeRamp(tile)) {
-			if (GetBridgeTransportType(tile) != mode) return 0;
-			return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
-		} else {
-			uint32 result = 0;
-
-			if (GetBridgeTransportType(tile) == mode) {
-				result = AxisToTrackBits(GetBridgeAxis(tile)) * 0x101;
-			}
-			if ((IsTransportUnderBridge(tile) && mode == GetTransportTypeUnderBridge(tile)) ||
-					(IsWaterUnderBridge(tile)     && mode == TRANSPORT_WATER && GetTileSlope(tile, NULL) == SLOPE_FLAT)) {
-				result |= AxisToTrackBits(OtherAxis(GetBridgeAxis(tile))) * 0x101;
-			}
-			return result;
-		}
+		if (GetBridgeTransportType(tile) != mode) return 0;
+		return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
 	}
 }
 
@@ -1328,16 +1150,7 @@
 	if (new_player != PLAYER_SPECTATOR) {
 		SetTileOwner(tile, new_player);
 	} else {
-		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);
-		}
+		DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
 	}
 }
 
@@ -1357,14 +1170,15 @@
 
 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);
 
@@ -1426,46 +1240,53 @@
 			}
 		}
 	} else if (IsBridge(tile)) { // XXX is this necessary?
+		DiagDirection dir;
+
 		if (v->type == VEH_Road || (v->type == VEH_Train && IsFrontEngine(v))) {
-			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;
+			/* 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: NOT_REACHED();
+				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 (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;
 }
 
-/** Retrieve the exit-tile of the vehicle from inside a tunnel
- * Very similar to GetOtherTunnelEnd(), but we use the vehicle's
- * direction for determining which end of the tunnel to find
- * @param v the vehicle which is inside the tunnel and needs an exit
- * @return the exit-tile of the tunnel based on the vehicle's direction */
-TileIndex GetVehicleOutOfTunnelTile(const Vehicle *v)
-{
-#if 1
-	return v->tile;
-#else
-	TileIndex tile = v->tile;
-	DiagDirection dir = DirToDiagDir(v->direction);
-	TileIndexDiff delta = TileOffsByDiagDir(dir);
-	byte z = v->z_pos;
-
-	dir = ReverseDiagDir(dir);
-	while (
-		!IsTunnelTile(tile) ||
-		GetTunnelDirection(tile) != dir ||
-		GetTileZ(tile) != z
-	) {
-		tile += delta;
-	}
-
-	return tile;
-#endif
-}
-
 const TileTypeProcs _tile_type_tunnelbridge_procs = {
 	DrawTile_TunnelBridge,           /* draw_tile_proc */
 	GetSlopeZ_TunnelBridge,          /* get_slope_z_proc */
--- a/unmovable_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/unmovable_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "bridge_map.h"
 #include "table/strings.h"
 #include "table/sprites.h"
 #include "functions.h"
@@ -144,6 +145,7 @@
 				PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile)) + PALETTE_MODIFIER_COLOR + SPR_BOUGHT_LAND,
 				ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 10, GetSlopeZ(ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2)
 			);
+			DrawBridgeMiddle(ti);
 			break;
 
 		default: {
--- a/variables.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/variables.h	Wed Dec 27 12:38:02 2006 +0000
@@ -314,7 +314,6 @@
 VARDEF bool _exit_game;
 VARDEF SmallFiosItem _file_to_saveload;
 
-VARDEF byte _get_z_hint; // used as a hint to getslopez to return the right height at a bridge.
 
 
 VARDEF Vehicle *_place_clicked_vehicle;
--- a/vehicle.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/vehicle.h	Wed Dec 27 12:38:02 2006 +0000
@@ -300,7 +300,6 @@
 
 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);
--- a/water_cmd.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/water_cmd.c	Wed Dec 27 12:38:02 2006 +0000
@@ -21,7 +21,7 @@
 #include "water_map.h"
 #include "newgrf.h"
 
-const SpriteID _water_shore_sprites[15] = {
+static const SpriteID _water_shore_sprites[] = {
 	0,
 	SPR_SHORE_TILEH_1,
 	SPR_SHORE_TILEH_2,
@@ -66,6 +66,8 @@
 	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);
@@ -140,6 +142,12 @@
 		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);
@@ -230,6 +238,8 @@
 
 	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);
 		}
@@ -237,38 +247,16 @@
 		// can't make water of water!
 		if (IsTileType(tile, MP_WATER) && (!IsTileOwner(tile, OWNER_WATER) || HASBIT(p2, 0))) continue;
 
-		/* is middle piece of a bridge? */
-		if (IsBridgeTile(tile) && IsBridgeMiddle(tile)) {
-			if (IsTransportUnderBridge(tile)) {
-				return_cmd_error(STR_5800_OBJECT_IN_THE_WAY);
-			}
-
-			if (IsWaterUnderBridge(tile) && (!IsTileOwner(tile, OWNER_WATER) || HASBIT(p2, 0))) return_cmd_error(STR_1007_ALREADY_BUILT);
-
-			if (flags & DC_EXEC) {
-				if (TileHeight(tile) == 0 && HASBIT(p2, 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 && HASBIT(p2, 0)) {
-					MakeWater(tile);
-				} else {
-					MakeCanal(tile, _current_player);
-				}
-			}
-		}
+		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);
+			}
 			MarkTileDirtyByTile(tile);
 			MarkTilesAroundDirty(tile);
 		}
@@ -366,14 +354,8 @@
 					return false;
 			}
 
-		case MP_STATION:
-			return IsOilRig(tile) || IsDock(tile) || IsBuoy_(tile);
-
-		case MP_TUNNELBRIDGE:
-			return IsBridge(tile) && IsBridgeMiddle(tile) && IsWaterUnderBridge(tile);
-
-		default:
-			return false;
+		case MP_STATION: return IsOilRig(tile) || IsDock(tile) || IsBuoy_(tile);
+		default:         return false;
 	}
 }
 
@@ -449,6 +431,7 @@
 		case WATER_CLEAR:
 			DrawGroundSprite(SPR_FLAT_WATER_TILE);
 			if (ti->z != 0 || !IsTileOwner(ti->tile, OWNER_WATER)) DrawCanalWater(ti->tile);
+			DrawBridgeMiddle(ti);
 			break;
 
 		case WATER_COAST:
@@ -458,6 +441,7 @@
 			} else {
 				DrawGroundSprite(_water_shore_sprites[ti->tileh]);
 			}
+			DrawBridgeMiddle(ti);
 			break;
 
 		case WATER_LOCK: {
@@ -570,27 +554,10 @@
 				}
 				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);
--- a/waypoint.c	Wed Dec 27 12:22:25 2006 +0000
+++ b/waypoint.c	Wed Dec 27 12:38:02 2006 +0000
@@ -9,6 +9,7 @@
 #include "map.h"
 #include "order.h"
 #include "rail_map.h"
+#include "bridge_map.h"
 #include "saveload.h"
 #include "station.h"
 #include "tile.h"
@@ -206,6 +207,8 @@
 		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) {
--- a/yapf/follow_track.hpp	Wed Dec 27 12:22:25 2006 +0000
+++ b/yapf/follow_track.hpp	Wed Dec 27 12:38:02 2006 +0000
@@ -27,7 +27,7 @@
 		m_new_tile = INVALID_TILE;
 		m_new_td_bits = TRACKDIR_BIT_NONE;
 		m_exitdir = INVALID_DIAGDIR;
-		m_is_station = m_is_tunnel = false;
+		m_is_station = m_is_bridge = m_is_tunnel = false;
 		m_tiles_skipped = 0;
 	}
 
@@ -60,6 +60,9 @@
 	/** 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);
@@ -73,11 +76,22 @@
 			}
 			assert(ReverseDiagDir(tunnel_enterdir) == m_exitdir);
 		}
-		// not a tunnel or station
-		m_is_tunnel = false;
-		m_tiles_skipped = 0;
 
-		// normal or station tile
+		// 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
 		TileIndexDiff diff = TileOffsByDiagDir(m_exitdir);
 		m_new_tile = TILE_ADD(m_old_tile, diff);
 
@@ -152,22 +166,7 @@
 		// rail transport is possible only on tiles with the same owner as vehicle
 		if (IsRailTT() && GetTileOwner(m_new_tile) != m_veh->owner) {
 			// different owner
-			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;
-			}
+			return false;
 		}
 
 		// rail transport is possible only on compatible rail types
@@ -215,7 +214,7 @@
 				m_new_td_bits = TrackdirToTrackdirBits(ReverseTrackdir(m_old_td));
 				m_exitdir = exitdir;
 				m_tiles_skipped = 0;
-				m_is_tunnel = m_is_station = false;
+				m_is_tunnel = m_is_bridge = m_is_station = false;
 				return true;
 			}
 		}
@@ -249,20 +248,10 @@
 		int max_speed = INT_MAX; // no limit
 
 		// for now we handle only on-bridge speed limit
-		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 (!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 min speed was requested, return it
--- a/yapf/yapf.h	Wed Dec 27 12:22:25 2006 +0000
+++ b/yapf/yapf.h	Wed Dec 27 12:38:02 2006 +0000
@@ -95,6 +95,7 @@
 	TrackdirBits        m_new_td_bits;   ///< the new set of available trackdirs
 	DiagDirection       m_exitdir;       ///< exit direction (leaving the old tile)
 	bool                m_is_tunnel;     ///< last turn passed tunnel
+	bool                m_is_bridge;     ///< last turn passed bridge ramp
 	bool                m_is_station;    ///< last turn passed station
 	int                 m_tiles_skipped; ///< number of skipped tunnel or station tiles
 } FollowTrack_t;
--- a/yapf/yapf_costbase.hpp	Wed Dec 27 12:22:25 2006 +0000
+++ b/yapf/yapf_costbase.hpp	Wed Dec 27 12:38:02 2006 +0000
@@ -9,7 +9,7 @@
 	FORCEINLINE static bool stSlopeCost(TileIndex tile, Trackdir td)
 	{
 		if (IsDiagonalTrackdir(td)) {
-			if (IsBridgeTile(tile) && IsBridgeRamp(tile)) {
+			if (IsBridgeTile(tile)) {
 				// it is bridge ramp, check if we are entering the bridge
 				if (GetBridgeRampDirection(tile) != TrackdirToExitdir(td)) return false; // no, we are living it, no penalty
 				// we are entering the bridge
--- a/yapf/yapf_rail.cpp	Wed Dec 27 12:22:25 2006 +0000
+++ b/yapf/yapf_rail.cpp	Wed Dec 27 12:38:02 2006 +0000
@@ -243,8 +243,6 @@
 	return reverse;
 }
 
-static TileIndex YapfGetVehicleOutOfTunnelTile(const Vehicle *v, bool bReverse);
-
 bool YapfFindNearestRailDepotTwoWay(Vehicle *v, int max_distance, int reverse_penalty, TileIndex* depot_tile, bool* reversed)
 {
 	*depot_tile = INVALID_TILE;
@@ -252,12 +250,8 @@
 
 	Vehicle* last_veh = GetLastVehicleInChain(v);
 
-	bool first_in_tunnel = v->u.rail.track == 0x40;
-	bool last_in_tunnel = last_veh->u.rail.track == 0x40;
-
-	// tile where the engine and last wagon are
-	TileIndex tile = first_in_tunnel ? YapfGetVehicleOutOfTunnelTile(v, false) : v->tile;
-	TileIndex last_tile = last_in_tunnel ? YapfGetVehicleOutOfTunnelTile(last_veh, true) : last_veh->tile;
+	TileIndex tile = v->tile;
+	TileIndex last_tile = last_veh->tile;
 
 	// their trackdirs
 	Trackdir td = GetVehicleTrackdir(v);
@@ -276,38 +270,6 @@
 	return ret;
 }
 
-/** Retrieve the exit-tile of the vehicle from inside a tunnel
-* Very similar to GetOtherTunnelEnd(), but we use the vehicle's
-* direction for determining which end of the tunnel to find
-* @param v the vehicle which is inside the tunnel and needs an exit
-* @param bReverse should we search for the tunnel exit in the opposite direction?
-* @return the exit-tile of the tunnel based on the vehicle's direction
-* taken from tunnelbridge_cmd.c where the function body was disabled by
-* #if 1 #else #endif (at r5951). Added bReverse argument to allow two-way
-* operation (YapfFindNearestRailDepotTwoWay).                              */
-static TileIndex YapfGetVehicleOutOfTunnelTile(const Vehicle *v, bool bReverse)
-{
-	TileIndex tile = v->tile;
-	DiagDirection dir = DirToDiagDir((Direction)v->direction);
-	TileIndexDiff delta = TileOffsByDiagDir(dir);
-	byte z = v->z_pos;
-
-	if (bReverse) {
-		delta = -delta;
-	} else {
-		dir = ReverseDiagDir(dir);
-	}
-	while (
-		!IsTunnelTile(tile) ||
-		GetTunnelDirection(tile) != dir ||
-		GetTileZ(tile) != z
-		) {
-			tile += delta;
-	}
-	return tile;
-}
-
-
 /** if any track changes, this counter is incremented - that will invalidate segment cost cache */
 int CSegmentCostCacheBase::s_rail_change_counter = 0;
 
--- a/yapf/yapf_road.cpp	Wed Dec 27 12:22:25 2006 +0000
+++ b/yapf/yapf_road.cpp	Wed Dec 27 12:38:02 2006 +0000
@@ -428,7 +428,6 @@
 Depot* YapfFindNearestRoadDepot(const Vehicle *v)
 {
 	TileIndex tile = v->tile;
-	if (v->u.road.state == 255) tile = GetVehicleOutOfTunnelTile(v);
 	Trackdir trackdir = GetVehicleTrackdir(v);
 	if ((GetTileTrackStatus(tile, TRANSPORT_ROAD) & TrackdirToTrackdirBits(trackdir)) == 0)
 		return NULL;