diff --git a/app/src/main/java/de/hems/trafficsim/MainActivity.java b/app/src/main/java/de/hems/trafficsim/MainActivity.java
index caf7537..a693a4d 100644
--- a/app/src/main/java/de/hems/trafficsim/MainActivity.java
+++ b/app/src/main/java/de/hems/trafficsim/MainActivity.java
@@ -12,12 +12,14 @@ import java.util.Observer;
 public class MainActivity extends AppCompatActivity implements Observer {
 
     protected Track track;
+    protected VehicleTimeRecord records;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         this.track = new Track(20);
+        this.records = null;
         this.track.addObserver(this);
 
     }
@@ -32,14 +34,19 @@ public class MainActivity extends AppCompatActivity implements Observer {
                     + "\n";
             ;
         }
+        String t = "";      //vtr arraylist to string
+        String text = s + "\n" + t;
         TextView view = (TextView) findViewById(R.id.debugTextView);
-        view.setText(s);
+        view.setText(text);
         view.invalidate();
     }
 
     public void onStepButtonClick (View view) {
-        for (int j = 0; j < 3000; j++) {
+        for (int j = 0; j < 1; j++) {
             this.track.timeElapse(50);
         }
     }
-}
\ No newline at end of file
+
+
+}
+
diff --git a/app/src/main/java/de/hems/trafficsim/Track.java b/app/src/main/java/de/hems/trafficsim/Track.java
index 0255ebf..aaf508c 100644
--- a/app/src/main/java/de/hems/trafficsim/Track.java
+++ b/app/src/main/java/de/hems/trafficsim/Track.java
@@ -1,11 +1,13 @@
 package de.hems.trafficsim;
 
 import java.util.ArrayList;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Observable;
 
 public class Track extends Observable {
     protected List<Vehicle> vehicles;
+    protected List<List<VehicleTimeRecord>> vtr_list;
 
 
     public List<Vehicle> getVehicles() {
@@ -15,6 +17,7 @@ public class Track extends Observable {
 
     public Track(int numberVehicles) {
         this.vehicles = createVehiclesList(numberVehicles);
+        this.vtr_list = new LinkedList<>();
     }
 
     protected List<Vehicle> createVehiclesList(int numberVehicles){
@@ -27,7 +30,7 @@ public class Track extends Observable {
         return result;
     }
 
-    public void timeElapse(float timeStep) {
+    public void timeElapse(int timeStep) {
         for(int i=0; i<vehicles.size();i++) {
             Vehicle v = vehicles.get(i);
             int forerunnerIndex = i + 1;
@@ -41,9 +44,12 @@ public class Track extends Observable {
             }
             v.updateVelocity(distanceForerunner);
         }
-
+        List <VehicleTimeRecord> records = new ArrayList<>(vehicles.size());
+        this.vtr_list.add(records);
         for(Vehicle v: vehicles){
             v.timeElapse(50);
+            VehicleTimeRecord vtr = new VehicleTimeRecord(v.id, v.position, v.curVelocity, timeStep);
+            records.add(vtr);
         }
 
         this.setChanged();
diff --git a/app/src/main/java/de/hems/trafficsim/VehicleTimeRecord.java b/app/src/main/java/de/hems/trafficsim/VehicleTimeRecord.java
index c3ae160..3d1678c 100644
--- a/app/src/main/java/de/hems/trafficsim/VehicleTimeRecord.java
+++ b/app/src/main/java/de/hems/trafficsim/VehicleTimeRecord.java
@@ -13,12 +13,14 @@ public class VehicleTimeRecord {
         return timestep;
     }
 
+    protected int id;
     protected float position;
     protected float velocity;
-    protected float timestep;
+    protected int timestep;
 
-    public VehicleTimeRecord(float position, float velocity, float timestep) {
-        this.position = position;
+    public VehicleTimeRecord(int id, float position, float velocity, int timestep) {
+        this.id = id;
+        this.position = position;   //needed???
         this.velocity = velocity;
         this.timestep = timestep;
     }