--- a/ai/default/default.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/ai/default/default.c	Sun Mar 19 13:48:08 2006 +0000
@@ -2182,7 +2182,7 @@
 
 	// Then remove and signals if there are any.
 	if (IsTileType(tile, MP_RAILWAY) &&
-			(_m[tile].m5&0xC0) == 0x40) {
+			GetRailTileType(tile) == RAIL_TYPE_SIGNALS) {
 		DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_REMOVE_SIGNALS);
 	}
 
@@ -3567,21 +3567,20 @@
 
 static void AiRemovePlayerRailOrRoad(Player *p, TileIndex tile)
 {
-	byte m5;
+	TrackBits rails;
 
 	if (IsTileType(tile, MP_RAILWAY)) {
 		if (!IsTileOwner(tile, _current_player)) return;
 
-		m5 = _m[tile].m5;
-		if ((m5 & 0xFC) != 0xC0) {
+		if (IsPlainRailTile(tile)) {
 is_rail_crossing:;
-			m5 = GetRailTrackStatus(tile);
-
-			if (m5 == 0xC || m5 == 0x30) return;
-
-			if (m5 & 0x25) {
+			rails = GetRailTrackStatus(tile);
+
+			if (rails == TRACK_BIT_HORZ || rails == TRACK_BIT_VERT) return;
+
+			if (rails & TRACK_BIT_3WAY_NE) {
 pos_0:
-				if (!(GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(1, 0))) & 0x19)) {
+				if ((GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(1, 0))) & TRACK_BIT_3WAY_SW) == 0) {
 					p->ai.cur_dir_a = 0;
 					p->ai.cur_tile_a = tile;
 					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
@@ -3589,9 +3588,9 @@
 				}
 			}
 
-			if (m5 & 0x2A) {
+			if (rails & TRACK_BIT_3WAY_SE) {
 pos_1:
-				if (!(GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(0, 1))) & 0x16)) {
+				if ((GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(0, 1))) & TRACK_BIT_3WAY_NW) == 0) {
 					p->ai.cur_dir_a = 1;
 					p->ai.cur_tile_a = tile;
 					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
@@ -3599,9 +3598,9 @@
 				}
 			}
 
-			if (m5 & 0x19) {
+			if (rails & TRACK_BIT_3WAY_SW) {
 pos_2:
-				if (!(GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(1, 0))) & 0x25)) {
+				if ((GetRailTrackStatus(TILE_MASK(tile + TileDiffXY(1, 0))) & TRACK_BIT_3WAY_NE) == 0) {
 					p->ai.cur_dir_a = 2;
 					p->ai.cur_tile_a = tile;
 					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
@@ -3609,9 +3608,9 @@
 				}
 			}
 
-			if (m5 & 0x16) {
+			if (rails & TRACK_BIT_3WAY_NW) {
 pos_3:
-				if (!(GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(0, 1))) & 0x2A)) {
+				if ((GetRailTrackStatus(TILE_MASK(tile - TileDiffXY(0, 1))) & TRACK_BIT_3WAY_SE) == 0) {
 					p->ai.cur_dir_a = 3;
 					p->ai.cur_tile_a = tile;
 					p->ai.state = AIS_REMOVE_SINGLE_RAIL_TILE;
@@ -3675,7 +3674,7 @@
 			return;
 		}
 
-		m5 = 0;
+		rails = 0;
 
 		switch (GetBridgeRampDirection(tile)) {
 			default:

--- a/disaster_cmd.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/disaster_cmd.c	Sun Mar 19 13:48:08 2006 +0000
@@ -582,8 +582,10 @@
 		tile_org = tile = RandomTile();
 		do {
 			if (IsTileType(tile, MP_RAILWAY) &&
-					(_m[tile].m5 & ~3) != 0xC0 && IS_HUMAN_PLAYER(GetTileOwner(tile)))
+					IsPlainRailTile(tile) &&
+					IS_HUMAN_PLAYER(GetTileOwner(tile))) {
 				break;
+			}
 			tile = TILE_MASK(tile+1);
 		} while (tile != tile_org);
 		v->dest_tile = tile;

--- a/oldloader.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/oldloader.c	Sun Mar 19 13:48:08 2006 +0000
@@ -1562,7 +1562,7 @@
 	for (i = 0; i < OLD_MAP_SIZE; i ++) {
 		if (IsTileType(i, MP_RAILWAY)) {
 			/* We save presignals different from TTDPatch, convert them */
-			if (GB(_m[i].m5, 6, 2) == 1) {
+			if (GetRailTileType(i) == RAIL_TYPE_SIGNALS) {
 				/* This byte is always zero in TTD for this type of tile */
 				if (_m[i].m4) /* Convert the presignals to our own format */
 					_m[i].m4 = (_m[i].m4 >> 1) & 7;

--- a/order_gui.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/order_gui.c	Sun Mar 19 13:48:08 2006 +0000
@@ -197,7 +197,8 @@
 		switch (GetTileType(tile)) {
 		case MP_RAILWAY:
 			if (v->type == VEH_Train && IsTileOwner(tile, _local_player)) {
-				if ((_m[tile].m5&0xFC)==0xC0) {
+				if (GetRailTileType(tile) == RAIL_TYPE_DEPOT_WAYPOINT &&
+						GetRailTileSubtype(tile) == RAIL_SUBTYPE_DEPOT) {
 					order.type = OT_GOTO_DEPOT;
 					order.flags = OF_PART_OF_ORDERS;
 					order.station = GetDepotByTile(tile)->index;

--- a/rail_cmd.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/rail_cmd.c	Sun Mar 19 13:48:08 2006 +0000
@@ -1084,15 +1084,10 @@
 		}
 
 		case RAIL_TYPE_DEPOT_WAYPOINT:
-			switch (m5 & RAIL_SUBTYPE_MASK) {
-				case RAIL_SUBTYPE_DEPOT:
-					return RemoveTrainDepot(tile, flags);
-
-				case RAIL_SUBTYPE_WAYPOINT:
-					return RemoveTrainWaypoint(tile, flags, false);
-
-				default:
-					return CMD_ERROR;
+			if (GetRailTileSubtype(tile) == RAIL_SUBTYPE_DEPOT) {
+				return RemoveTrainDepot(tile, flags);
+			} else {
+				return RemoveTrainWaypoint(tile, flags, false);
 			}
 
 		default:
@@ -1995,10 +1990,10 @@
 		}
 		return ret;
 	} else {
-		if (_m[tile].m5 & 0x40) {
+		if (GetRailTileSubtype(tile) == RAIL_SUBTYPE_DEPOT) {
+			return 0;
+		} else {
 			return GetRailWaypointBits(tile) * 0x101;
-		} else {
-			return 0;
 		}
 	}
 }
@@ -2034,7 +2029,7 @@
 
 		case RAIL_TYPE_DEPOT_WAYPOINT:
 		default:
-			td->str = ((_m[tile].m5 & RAIL_SUBTYPE_MASK) == RAIL_SUBTYPE_DEPOT) ?
+			td->str = (GetRailTileSubtype(tile) == RAIL_SUBTYPE_DEPOT) ?
 				STR_1023_RAILROAD_TRAIN_DEPOT : STR_LANDINFO_WAYPOINT;
 			break;
 	}

--- a/rail_gui.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/rail_gui.c	Sun Mar 19 13:48:08 2006 +0000
@@ -83,10 +83,8 @@
 
 static void PlaceExtraDepotRail(TileIndex tile, uint16 extra)
 {
-	byte b = _m[tile].m5;
-
-	if (GB(b, 6, 2) != RAIL_TYPE_NORMAL >> 6) return;
-	if (!(b & (extra >> 8))) return;
+	if (GetRailTileType(tile) != RAIL_TYPE_NORMAL) return;
+	if ((GetTrackBits(tile) & GB(extra, 8, 8)) == 0) return;
 
 	DoCommandP(tile, _cur_railtype, extra & 0xFF, NULL, CMD_BUILD_SINGLE_RAIL | CMD_AUTO | CMD_NO_WATER);
 }

--- a/road_cmd.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/road_cmd.c	Sun Mar 19 13:48:08 2006 +0000
@@ -334,14 +334,19 @@
 			}
 #undef M
 
-			if (ti.map5 == 2) {
-				if (pieces & ROAD_Y) goto do_clear;
-				roaddir = AXIS_X;
-			} else if (ti.map5 == 1) {
-				if (pieces & ROAD_X) goto do_clear;
-				roaddir = AXIS_Y;
-			} else {
-				goto do_clear;
+			if (GetRailTileType(tile) != RAIL_TYPE_NORMAL) goto do_clear;
+			switch (GetTrackBits(tile)) {
+				case TRACK_BIT_X:
+					if (pieces & ROAD_X) goto do_clear;
+					roaddir = AXIS_Y;
+					break;
+
+				case TRACK_BIT_Y:
+					if (pieces & ROAD_Y) goto do_clear;
+					roaddir = AXIS_X;
+					break;
+
+				default: goto do_clear;
 			}
 
 			if (flags & DC_EXEC) {

--- a/train_cmd.c	Sun Mar 19 13:44:11 2006 +0000
+++ b/train_cmd.c	Sun Mar 19 13:48:08 2006 +0000
@@ -1746,12 +1746,13 @@
 
 static bool NtpCallbFindDepot(TileIndex tile, TrainFindDepotData *tfdd, int track, uint length)
 {
-	if (IsTileType(tile, MP_RAILWAY) && IsTileOwner(tile, tfdd->owner)) {
-		if ((_m[tile].m5 & 0xFC) == 0xC0) {
-			tfdd->best_length = length;
-			tfdd->tile = tile;
-			return true;
-		}
+	if (IsTileType(tile, MP_RAILWAY) &&
+			IsTileOwner(tile, tfdd->owner) &&
+			GetRailTileType(tile) == RAIL_TYPE_DEPOT_WAYPOINT &&
+			GetRailTileSubtype(tile) == RAIL_SUBTYPE_DEPOT) {
+		tfdd->best_length = length;
+		tfdd->tile = tile;
+		return true;
 	}
 
 	return false;
@@ -2654,7 +2655,7 @@
 {
 	if (IsTileType(tile, MP_RAILWAY) &&
 			GetRailTileType(tile) == RAIL_TYPE_SIGNALS) {
-		uint i = FindFirstBit2x64((_m[tile].m5 + (_m[tile].m5 << 8)) & _reachable_tracks[dir]);
+		uint i = FindFirstBit2x64(GetTrackBits(tile) * 0x101 & _reachable_tracks[dir]);
 		UpdateSignalsOnSegment(tile, _otherside_signal_directions[i]);
 	}
 }