diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index 3b47d0f..ca38761 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -20,6 +20,7 @@ public class System {
     
     private User current_user = new User();
     private String api_key;
+    private ArrayList<String> distances = new ArrayList<>();
 
     public System(String api_key) {
         this.api_key = api_key;
@@ -54,7 +55,9 @@ public class System {
         return true;
     }
 
-    public void sign_out_user(){}
+    public void sign_out_user(){
+        this.distances = new ArrayList<>();
+    }
 
     public boolean change_user_details(String username, String password, String hometown, int zip, 
                                 String car_name, double car_co2_km, double car_avg_kmh, double bike_avg_kmh){
@@ -82,42 +85,37 @@ public class System {
 
     public ArrayList<String> random_destinations_car(){
         
-        ArrayList<String> result = new ArrayList<>();
-        
-        InputStream inputStream = Main.class.getResourceAsStream("/zip.csv");
+        calc_all_distances();
 
-        try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
-            String line;
-            while ((line = reader.readLine()) != null && result.size()<3) {
-                
-                line = line.replace("\"", "");
-                
-                if(Double.parseDouble(distance(line.split(";")[0]).replace(" km", "")) > 150)
-                    result.add(line);
-                
-            }
-        } catch (Exception e) {}
+        ArrayList<String> mem = new ArrayList<>();
+        ArrayList<String> result = new ArrayList<>();
+
+        for(int i = 0; i<this.distances.size(); i++){
+            if(Double.parseDouble(this.distances.get(i).split(";")[2])>150)
+                mem.add(this.distances.get(i));
+        }
         
+        for(int i = 0; i<3; i++)
+            result.add(mem.get((int) (Math.random()*mem.size())));
+
         return result;
     }
 
     public ArrayList<String> random_destinations_bike(){
-        ArrayList<String> result = new ArrayList<>();
         
-        InputStream inputStream = Main.class.getResourceAsStream("/zip.csv");
+        calc_all_distances();
 
-        try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
-            String line;
-            while ((line = reader.readLine()) != null && result.size()<3) {
-                
-                line = line.replace("\"", "");
-                
-                if(Double.parseDouble(distance(line.split(";")[0]).replace(" km", "")) < 100)
-                    result.add(line);
-                
-            }
-        } catch (Exception e) {}
+        ArrayList<String> mem = new ArrayList<>();
+        ArrayList<String> result = new ArrayList<>();
+
+        for(int i = 0; i<this.distances.size(); i++){
+            if(Double.parseDouble(this.distances.get(i).split(";")[2])<100)
+                mem.add(this.distances.get(i));
+        }
         
+        for(int i = 0; i<3; i++)
+            result.add(mem.get((int) (Math.random()*mem.size())));
+
         return result;
     }
 
@@ -298,6 +296,25 @@ public class System {
     
     }
 
+    public void calc_all_distances(){
+
+        if(!this.distances.isEmpty())
+            return;
+
+        InputStream inputStream = Main.class.getResourceAsStream("/zip.csv");
+
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {
+            String line;
+            while ((line = reader.readLine()) != null) {
+                
+                line = line.replace("\"", "");
+                
+                this.distances.add(line.split(";")[0] + ";" + line.split(";")[1] + ";" + Double.parseDouble(distance(line.split(";")[0]).replace(" km", "")));
+                
+            }
+        } catch (Exception e) {}
+    }
+    
     public String[] travel_time(String destination_zip){
         
         String[] result = new String[2];
diff --git a/src/test/java/de/hs_mannheim/domain/SystemTest.java b/src/test/java/de/hs_mannheim/domain/SystemTest.java
index 3ac1f7e..bf443c5 100644
--- a/src/test/java/de/hs_mannheim/domain/SystemTest.java
+++ b/src/test/java/de/hs_mannheim/domain/SystemTest.java
@@ -9,19 +9,17 @@ import org.junit.jupiter.api.Test;
 
 public class SystemTest {
     
+    System current_system = new System("35a75437476f12302f72e55d368485db");
+    
     @Test
     public void weather_forecast(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         assertNotEquals("Es ist ein Fehler aufgetreten!",current_system.weather_forecast("68161"));
     }
 
     @Test
     public void current_weather(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         current_system.set_current_user_zip("68161");
 
         assertNotEquals("Es ist ein Fehler aufgetreten!",current_system.current_weather());
@@ -30,8 +28,6 @@ public class SystemTest {
     @Test
     public void search(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         ArrayList<String> list = current_system.search("Mannheim");
         
         assertEquals("68159", list.get(0).split(";")[0]);
@@ -42,8 +38,6 @@ public class SystemTest {
     @Test
     public void distance(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         current_system.set_current_user_zip("68161");
         
         assertEquals("88.46 km", current_system.distance("60306")); // Frankfurt 
@@ -55,8 +49,6 @@ public class SystemTest {
     @Test
     public void travel_time(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         current_system.set_current_user_zip("68161");
         current_system.set_current_user_car_avg_kmh(100);
         current_system.set_current_user_bike_avg_kmh(20);
@@ -71,8 +63,6 @@ public class SystemTest {
     @Test
     public void calc_l_consumption(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         current_system.set_current_user_zip("68161");
         current_system.set_current_user_car_avg_kmh(100);
         current_system.set_current_user_car_l_100km(10);
@@ -85,8 +75,6 @@ public class SystemTest {
     @Test
     public void random_destinations(){
 
-        System current_system = new System("35a75437476f12302f72e55d368485db");
-
         current_system.set_current_user_zip("68161");
      
         assertEquals(3, current_system.random_destinations_car().size()); // random_destinations_car gibt genau 3 destinations zurück