diff --git a/common/lc_library.cpp b/common/lc_library.cpp
index aefcdfa0..7685289c 100644
--- a/common/lc_library.cpp
+++ b/common/lc_library.cpp
@@ -279,7 +279,7 @@ bool lcPiecesLibrary::Load(const QString& LibraryPath, bool ShowProgress)
 	UpdateStudStyleSource();
 	lcLoadDefaultCategories();
 	lcSynthInit();
-	lcTrainTrackInit(this);
+	lcTrainTrackInfo::Initialize(this);
 
 	return true;
 }
@@ -1888,7 +1888,7 @@ bool lcPiecesLibrary::LoadBuiltinPieces()
 	lcLoadDefaultColors(lcStudStyle::Plain);
 	lcLoadDefaultCategories(true);
 	lcSynthInit();
-	lcTrainTrackInit(this);
+	lcTrainTrackInfo::Initialize(this);
 
 	return true;
 }
diff --git a/common/lc_traintrack.cpp b/common/lc_traintrack.cpp
index 1449aee0..a9afac5b 100644
--- a/common/lc_traintrack.cpp
+++ b/common/lc_traintrack.cpp
@@ -8,13 +8,14 @@
 // todo:
 // add the rest of the 9v and 12v tracks, look into 4.5v
 // see if we should remove some of the 12v tracks to avoid bloat
-// data driven sleepers
 // lcView::GetPieceInsertTransform should use track connections when dragging a new track over an existing one
 // better insert gizmo mouse detection
 // auto replace cross when going over a straight section
 // set focus connection after adding
 
-void lcTrainTrackInit(lcPiecesLibrary* Library)
+std::map<quint32, PieceInfo*> lcTrainTrackInfo::mSleepers;
+
+void lcTrainTrackInfo::Initialize(lcPiecesLibrary* Library)
 {
 	QFile ConfigFile(QLatin1String(":/resources/traintrack.json"));
 
@@ -73,6 +74,21 @@ void lcTrainTrackInit(lcPiecesLibrary* Library)
 			}
 		}
 	}
+
+	QJsonObject JsonSleepers = Root["Sleepers"].toObject();
+
+	mSleepers.clear();
+
+	for (QJsonObject::const_iterator SleepersIt = JsonSleepers.constBegin(); SleepersIt != JsonSleepers.constEnd(); ++SleepersIt)
+	{
+		quint32 Group = qHash(SleepersIt.key());
+		QString PartId = SleepersIt->toString();
+
+		PieceInfo* SleeperInfo = Library->FindPiece(PartId.toLatin1(), nullptr, false, false);
+
+		if (SleeperInfo)
+			mSleepers[Group] = SleeperInfo;
+	}
 }
 
 int lcTrainTrackInfo::GetPieceConnectionIndex(const lcPiece* Piece1, int ConnectionIndex1, const lcPiece* Piece2)
@@ -137,7 +153,12 @@ std::vector<lcTrainTrackInsert> lcTrainTrackInfo::GetPieceInsertTransforms(lcPie
 
 	if (CurrentConnectionType.Sleeper == lcTrainTrackConnectionSleeper::NeedsSleeper && NewConnections[NewConnectionIndex].Type.Sleeper == lcTrainTrackConnectionSleeper::NeedsSleeper)
 	{
-		PieceInfo* SleeperInfo = lcGetPiecesLibrary()->FindPiece("4166a.dat", nullptr, false, false); // todo: data driven
+		std::map<quint32, PieceInfo*>::const_iterator SleeperIt = mSleepers.find(CurrentConnectionType.Group);
+
+		if (SleeperIt == mSleepers.end())
+			return Pieces;
+
+		PieceInfo* SleeperInfo = SleeperIt->second;
 
 		if (!SleeperInfo)
 			return Pieces;
diff --git a/common/lc_traintrack.h b/common/lc_traintrack.h
index 06c1f2cb..cb58c41d 100644
--- a/common/lc_traintrack.h
+++ b/common/lc_traintrack.h
@@ -37,6 +37,7 @@ class lcTrainTrackInfo
 public:
 	lcTrainTrackInfo() = default;
 
+	static void Initialize(lcPiecesLibrary* Library);
 	static std::vector<lcTrainTrackInsert> GetPieceInsertTransforms(lcPiece* CurrentPiece, PieceInfo* Info, quint32 Section);
 	static std::optional<lcMatrix44> GetConnectionTransform(PieceInfo* CurrentInfo, const lcMatrix44& CurrentTransform, quint32 CurrentConnectionIndex, PieceInfo* Info, quint32 NewConnectionIndex);
 	static std::optional<lcMatrix44> CalculateTransformToConnection(const lcMatrix44& ConnectionTransform, PieceInfo* Info, quint32 ConnectionIndex);
@@ -83,6 +84,5 @@ protected:
 	}
 
 	std::vector<lcTrainTrackConnection> mConnections;
+	static std::map<quint32, PieceInfo*> mSleepers;
 };
-
-void lcTrainTrackInit(lcPiecesLibrary* Library);
diff --git a/resources/traintrack.json b/resources/traintrack.json
index c78d8fb9..340fa1b8 100644
--- a/resources/traintrack.json
+++ b/resources/traintrack.json
@@ -297,5 +297,9 @@
 				}
 			]
 		}
+	},
+	"Sleepers":
+	{
+		"12V": "4166a.dat"
 	}
 }