diff --git a/Pathfinding/Pathfinder.cs b/Pathfinding/Pathfinder.cs
index fa7044a..45b3c71 100644
--- a/Pathfinding/Pathfinder.cs
+++ b/Pathfinding/Pathfinder.cs
@@ -6,25 +6,41 @@ using WayType = OSMDatastructure.Tag.WayType;
 
 namespace Pathfinding;
 
-public static class Pathfinder
+//TODO check parameters for all functions and determine global fields
+public class Pathfinder
 {
 
-    public static PathResult AStar(string workingDir, Coordinates startCoordinates, Coordinates goalCoordinates,
+    public RegionManager regionManager;
+    public readonly string workingDir;
+    public PathResult? pathResult;
+    public Dictionary<OsmNode, double>? gScore;
+
+    public Pathfinder(string workingDirectory)
+    {
+        if (!Path.Exists(workingDirectory))
+            throw new DirectoryNotFoundException(workingDirectory);
+        regionManager = new(workingDirectory);
+        workingDir = workingDirectory;
+    }
+    
+    public Pathfinder AStar(Coordinates startCoordinates, Coordinates goalCoordinates,
         SpeedType vehicle, double heuristicRoadLevelPriority, double heuristicSameRoadPriority,
         double heuristicFewJunctionsPriority)
     {
         DateTime startCalc = DateTime.Now;
-        RegionManager regionManager = new RegionManager(workingDir);
+        regionManager = new RegionManager(workingDir);
         OsmNode? startNode = regionManager.ClosestNodeToCoordinates(startCoordinates, vehicle);
         OsmNode? goalNode = regionManager.ClosestNodeToCoordinates(goalCoordinates, vehicle);
         if (startNode is null || goalNode is null)
-            return new PathResult(DateTime.Now - startCalc, new List<PathNode>());
+        {
+            pathResult = new(DateTime.Now - startCalc, new List<PathNode>());
+            return this;
+        }
 
         PriorityQueue<OsmNode, double> openSetfScore = new();
         openSetfScore.Enqueue(startNode, 0);
         Dictionary<OsmNode, OsmNode> cameFromDict = new();
-        Dictionary<OsmNode, double> gScore = new();
-        gScore.Add(startNode, 0);
+        gScore = new() { { startNode, 0 } };
 
         while (openSetfScore.Count > 0)
         {
@@ -32,14 +48,8 @@ public static class Pathfinder
             if (currentNode.Equals(goalNode))
             {
                 Console.WriteLine("Path found.");
-                PathResult path = GetPath(cameFromDict, goalNode, regionManager, DateTime.Now - startCalc);
-                string fileName = $"{new DirectoryInfo(workingDir).Name}-{DateTime.Now.ToFileTime()}.result";
-                string outputFilepath = Path.Join(Directory.GetParent(workingDir)!.FullName, fileName);
-                path.name = outputFilepath;
-                path.AddGScores(gScore);
-                SaveGraph(path, outputFilepath);
-                path.regionManager = regionManager;
-                return path;
+                this.pathResult = GetPath(cameFromDict, goalNode, DateTime.Now - startCalc);
+                return this;
             }
 
             foreach (OsmEdge edge in currentNode.edges)
@@ -48,7 +58,7 @@ public static class Pathfinder
                 if (neighbor is not null)
                 {
                     double tentativeGScore =
-                        gScore[currentNode] + Weight(currentNode, neighbor, edge, vehicle, regionManager);
+                        gScore[currentNode] + Weight(currentNode, neighbor, edge, vehicle);
                     gScore.TryAdd(neighbor, double.MaxValue);
                     if (tentativeGScore < gScore[neighbor])
                     {
@@ -60,7 +70,7 @@ public static class Pathfinder
                             gScore[neighbor] = tentativeGScore;
                         else
                             gScore.Add(neighbor, tentativeGScore);
-                        double h = Heuristic(currentNode, neighbor, goalNode, edge, vehicle, regionManager,
+                        double h = Heuristic(currentNode, neighbor, goalNode, edge, vehicle,
                             heuristicRoadLevelPriority, heuristicFewJunctionsPriority, heuristicSameRoadPriority);
                         //Console.WriteLine($"Queue: {openSetfScore.Count:00000} Current Distance: {Utils.DistanceBetween(currentNode, goalNode):000000.00} Visited: {cameFromDict.Count:00000} Current heuristic: {h:00000.00}");
                         openSetfScore.Enqueue(neighbor, tentativeGScore + h);
@@ -69,20 +79,21 @@ public static class Pathfinder
             }
         }
 
-        return new PathResult(DateTime.Now - startCalc, new List<PathNode>());
+        pathResult = new(DateTime.Now - startCalc, new List<PathNode>());
+        return this;
     }
 
-    private static void SaveGraph(PathResult pathResult, string outputFilepath)
+    public void SaveResult(string path)
     {
-        FileStream fs = new FileStream(outputFilepath, FileMode.CreateNew);
+        FileStream fs = new (path, FileMode.CreateNew);
         JsonSerializer.Serialize(fs, pathResult, JsonSerializerOptions.Default);
         fs.Dispose();
-        Console.WriteLine($"Saved result to {outputFilepath}");
+        Console.WriteLine($"Saved result to {path}");
     }
 
-    private static PathResult GetPath(Dictionary<OsmNode, OsmNode> cameFromDict, OsmNode goalNode, RegionManager regionManager, TimeSpan calcFinished)
+    private PathResult GetPath(Dictionary<OsmNode, OsmNode> cameFromDict, OsmNode goalNode, TimeSpan calcFinished)
     {
-        List<PathNode> path = new List<PathNode>();
+        List<PathNode> path = new();
         OsmNode currentNode = goalNode;
         while (cameFromDict.ContainsKey(cameFromDict[currentNode]))
         {
@@ -100,15 +111,15 @@ public static class Pathfinder
         return new PathResult(calcFinished, path);
     }
 
-    private static double Weight(OsmNode fromNode, OsmNode neighborNode, OsmEdge edge, SpeedType vehicle, RegionManager regionManager)
+    private double Weight(OsmNode fromNode, OsmNode neighborNode, OsmEdge edge, SpeedType vehicle)
     {
         double distance = Utils.DistanceBetween(fromNode, neighborNode);
         double speed = regionManager.GetSpeedForEdge(fromNode, edge.wayId, vehicle);
-        double prio = GetPriorityVehicleRoad(edge, vehicle, regionManager.GetRegion(fromNode.coordinates)!);
+        //double prio = GetPriorityVehicleRoad(edge, vehicle, regionManager.GetRegion(fromNode.coordinates)!);
         return distance / speed;
     }
 
-    private static double Heuristic(OsmNode fromNode, OsmNode neighborNode, OsmNode goalNode, OsmEdge edge, SpeedType vehicle, RegionManager regionManager, double roadPriorityFactor, double junctionFactor, double sameRoadFactor)
+    private double Heuristic(OsmNode fromNode, OsmNode neighborNode, OsmNode goalNode, OsmEdge edge, SpeedType vehicle, double roadPriorityFactor, double junctionFactor, double sameRoadFactor)
     {
         double roadPriority = GetPriorityVehicleRoad(edge, vehicle, regionManager.GetRegion(fromNode.coordinates)!) * roadPriorityFactor;