--- a/src/ai/default/default.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/ai/default/default.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -2228,7 +2228,7 @@
 				return false;
 			_players_ai[p->index].cur_tile_a = TILE_MASK(_build_tunnel_endtile - TileOffsByDiagDir(_players_ai[p->index].cur_dir_a));
 			return true;
-		} else {
+		} else { // IsBridge(tile)
 			// Check if the bridge points in the right direction.
 			// This is not really needed the first place AiRemoveTileAndGoForward is called.
 			if (DiagDirToAxis(GetTunnelBridgeDirection(tile)) != (_players_ai[p->index].cur_dir_a & 1)) return false;

--- a/src/openttd.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/openttd.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -1667,8 +1667,8 @@
 
 				case MP_TUNNELBRIDGE:
 					/* Middle part of "old" bridges */
-					if (old_bridge && IsBridgeTile(t) && HasBit(_m[t].m5, 6)) break;
-					if ((IsTunnel(t) ? GetTunnelBridgeTransportType(t) : (old_bridge ? (TransportType)GB(_m[t].m5, 1, 2) : GetTunnelBridgeTransportType(t))) == TRANSPORT_ROAD) {
+					if (old_bridge && IsBridge(t) && HasBit(_m[t].m5, 6)) break;
+					if (((old_bridge && IsBridge(t)) ? (TransportType)GB(_m[t].m5, 1, 2) : GetTunnelBridgeTransportType(t)) == TRANSPORT_ROAD) {
 						SetRoadTypes(t, ROADTYPES_ROAD);
 					}
 					break;

--- a/src/pathfind.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/pathfind.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -313,7 +313,7 @@
 				 * entrance :-) */
 				return;
 			}
-		} else {
+		} else { // IsBridge(tile)
 			TileIndex tile_end;
 			if (GetTunnelBridgeDirection(tile) != direction ||
 					GetTunnelBridgeTransportType(tile) != tpf->tracktype) {
@@ -733,7 +733,7 @@
 					tile = flotr.tile;
 					/* tile now points to the exit tile of the tunnel */
 				}
-			} else {
+			} else { // IsBridge(tile)
 				TileIndex tile_end;
 				if (GetTunnelBridgeDirection(tile) != ReverseDiagDir(direction)) {
 					/* We are not just leaving the bridge */

--- a/src/road_cmd.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/road_cmd.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -132,10 +132,9 @@
 			break;
 
 		case MP_TUNNELBRIDGE:
-			{
-				if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
-				if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
-			} break;
+			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
+			if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
+			break;
 
 		default:
 			return CMD_ERROR;
@@ -498,18 +497,16 @@
 		case MP_STATION:
 			if (!IsDriveThroughStopTile(tile)) return CMD_ERROR;
 			if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
-			/* Don't allow "upgrading" the roadstop when vehicles are already driving on it */
+			/* Don't allow adding roadtype to the roadstop when vehicles are already driving on it */
 			if (!EnsureNoVehicleOnGround(tile)) return CMD_ERROR;
 			break;
 
 		case MP_TUNNELBRIDGE:
-			{
-				if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
-				if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
-
-				/* Don't allow "upgrading" the bridge/tunnel when vehicles are already driving on it */
-				if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
-			} break;
+			if (GetTunnelBridgeTransportType(tile) != TRANSPORT_ROAD) return CMD_ERROR;
+			if (HasBit(GetRoadTypes(tile), rt)) return_cmd_error(STR_1007_ALREADY_BUILT);
+			/* Don't allow adding roadtype to the bridge/tunnel when vehicles are already driving on it */
+			if (GetVehicleTunnelBridge(tile, GetOtherTunnelBridgeEnd(tile)) != NULL) return CMD_ERROR;
+			break;
 
 		default:
 do_clear:;
@@ -672,7 +669,7 @@
 						cost.AddCost(ret);
 					}
 					had_bridge = true;
-				} else {
+				} else { // IsTunnel(tile)
 					if ((!had_tunnel || GetTunnelBridgeDirection(tile) == DIAGDIR_SE || GetTunnelBridgeDirection(tile) == DIAGDIR_SW)) {
 						cost.AddCost(ret);
 					}

--- a/src/roadveh_cmd.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/roadveh_cmd.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -1520,7 +1520,7 @@
 			}
 		}
 
-		if ((IsTunnelTile(gp.new_tile) || IsBridgeTile(gp.new_tile)) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
+		if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
 			/* Vehicle has just entered a bridge or tunnel */
 			v->cur_image = v->GetImage(v->direction);
 			v->UpdateDeltaXY(v->direction);

--- a/src/train_cmd.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/train_cmd.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -3135,7 +3135,7 @@
 					min(v->cur_speed, GetBridge(GetBridgeType(v->tile))->speed);
 			}
 
-			if (!(IsTunnelTile(gp.new_tile) || IsBridgeTile(gp.new_tile)) || !HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
+			if (!IsTileType(gp.new_tile, MP_TUNNELBRIDGE) || !HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
 				v->x_pos = gp.x;
 				v->y_pos = gp.y;
 				VehiclePositionChanged(v);

--- a/src/tunnelbridge_cmd.cpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/tunnelbridge_cmd.cpp	Wed Jan 23 14:51:36 2008 +0000
@@ -701,7 +701,7 @@
 	if (IsTunnel(tile)) {
 		if (flags & DC_AUTO) return_cmd_error(STR_5006_MUST_DEMOLISH_TUNNEL_FIRST);
 		return DoClearTunnel(tile, flags);
-	} else if (IsBridge(tile)) { // XXX Is this necessary?
+	} else { // IsBridge(tile)
 		if (flags & DC_AUTO) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
 		return DoClearBridge(tile, flags);
 	}
@@ -879,7 +879,7 @@
 		AddSortableSpriteToDraw(SPR_EMPTY_BOUNDING_BOX, PAL_NONE, ti->x + BB_data[4], ti->y + BB_data[5], BB_data[6], BB_data[7], TILE_HEIGHT, ti->z);
 
 		DrawBridgeMiddle(ti);
-	} else if (IsBridge(ti->tile)) { // XXX is this necessary?
+	} else { // IsBridge(ti->tile)
 		const PalSpriteID *psid;
 		int base_offset;
 		bool ice = HasTunnelBridgeSnowOrDesert(ti->tile);
@@ -943,8 +943,6 @@
 		}
 
 		DrawBridgeMiddle(ti);
-	} else {
-		NOT_REACHED();
 	}
 }
 
@@ -1113,7 +1111,7 @@
 
 		/* In the tunnel entrance? */
 		if (5 <= pos && pos <= 10) return z;
-	} else {
+	} else { // IsBridge(tile)
 		DiagDirection dir = GetTunnelBridgeDirection(tile);
 		uint pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
 
@@ -1187,7 +1185,7 @@
 	if (IsTunnel(tile)) {
 		td->str = (GetTunnelBridgeTransportType(tile) == TRANSPORT_RAIL) ?
 			STR_5017_RAILROAD_TUNNEL : STR_5018_ROAD_TUNNEL;
-	} else {
+	} else { // IsBridge(tile)
 		td->str = _bridge_tile_str[GetTunnelBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
 	}
 	td->owner = GetTileOwner(tile);
@@ -1341,7 +1339,7 @@
 				return VETSB_ENTERED_WORMHOLE;
 			}
 		}
-	} else if (IsBridge(tile)) { // XXX is this necessary?
+	} else { // IsBridge(tile)
 		DiagDirection dir;
 
 		if (v->IsPrimaryVehicle()) {

--- a/src/yapf/follow_track.hpp	Wed Jan 23 13:20:51 2008 +0000
+++ b/src/yapf/follow_track.hpp	Wed Jan 23 14:51:36 2008 +0000
@@ -214,7 +214,7 @@
 						return false;
 					}
 				}
-			} else if (IsBridge(m_new_tile)) {
+			} else { // IsBridge(m_new_tile)
 				if (!m_is_bridge) {
 					DiagDirection ramp_enderdir = GetTunnelBridgeDirection(m_new_tile);
 					if (ramp_enderdir != m_exitdir) {