Index: src/town_cmd.cpp
===================================================================
--- src/town_cmd.cpp	(Revision 23345)
+++ src/town_cmd.cpp	(Arbeitskopie)
@@ -780,7 +780,7 @@
 	}
 
 	Slope cur_slope = _settings_game.construction.build_on_slopes ? GetFoundationSlope(tile) : GetTileSlope(tile);
-	bool ret = !IsNeighborRoadTile(tile, dir, t->layout == TL_ORIGINAL ? 1 : 2);
+	bool ret = !IsNeighborRoadTile(tile, dir, t->layout == TL_ORIGINAL ? 1 : 3);
 	if (cur_slope == SLOPE_FLAT) return ret;
 
 	/* If the tile is not a slope in the right direction, then