diff --git a/src/elrail.cpp b/src/elrail.cpp
--- a/src/elrail.cpp
+++ b/src/elrail.cpp
@@ -124,6 +124,9 @@ static TrackBits GetRailTrackBitsUnivers
  */
 static TrackBits MaskWireBits(TileIndex t, TrackBits tracks)
 {
+	/* Single track bits are never masked out. */
+	if (likely(HasAtMostOneBit(tracks))) return tracks;
+
 	if (!IsPlainRailTile(t)) return tracks;
 
 	TrackdirBits neighbour_tdb = TRACKDIR_BIT_NONE;