--- a/src/bridge_cmd.c	Wed Jan 03 20:00:29 2007 +0000
+++ b/src/bridge_cmd.c	Thu Jan 11 13:16:26 2007 +0000
@@ -361,8 +361,11 @@
 		}
 	}
 
-	SetSignalsOnBothDir(tile_start, AxisToTrack(direction));
-	YapfNotifyTrackLayoutChange(tile_start, AxisToTrack(direction));
+	if (flags & DC_EXEC) {
+		Track track = AxisToTrack(direction);
+		SetSignalsOnBothDir(tile_start, track);
+		YapfNotifyTrackLayoutChange(tile_start, track);
+	}
 
 	/* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
 	 * It's unnecessary to execute this command every time for every bridge. So it is done only