diff --git a/src/edu/kit/informatik/model/ModelRailwaySimulation.java b/src/edu/kit/informatik/model/ModelRailwaySimulation.java
index 367b57d..2fc501d 100644
--- a/src/edu/kit/informatik/model/ModelRailwaySimulation.java
+++ b/src/edu/kit/informatik/model/ModelRailwaySimulation.java
@@ -13,6 +13,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -430,12 +431,8 @@ public class ModelRailwaySimulation {
      */
     private List<Set<Train>> getCollisionsOfOneStep() {
         List<Set<Train>> collisions = new ArrayList<>();
-        Map<Train, Set<Rail>> occupiedRails = new HashMap<>();
-        for (Train train : trains.values()) {
-            if (train.isPlaced()) {
-                occupiedRails.put(train, train.getOccupiedRails());
-            }
-        }
+        Map<Train, Set<Rail>> occupiedRails = trains.values().stream().filter(Train::isPlaced)
+                .collect(Collectors.toMap(Function.identity(), Train::getOccupiedRails));
         // perform step
         Map<Train, Set<Rail>> nextOccupiedRails = new HashMap<>();
         trains.values().stream().filter(Train::isPlaced).forEach(train -> {
diff --git a/src/edu/kit/informatik/model/Train.java b/src/edu/kit/informatik/model/Train.java
index c438920..8f9d44b 100644
--- a/src/edu/kit/informatik/model/Train.java
+++ b/src/edu/kit/informatik/model/Train.java
@@ -290,12 +290,9 @@ public final class Train {
         }
         // update occupied blocks, first removing the rail block left behind
         Rail leavingRail = railNetwork.findContainingRail(lastPosition);
-        if (leavingRail != null) {
-            // check whether we really leave rail
-            if (!leavingRail.contains(secondToLastPosition)) {
-                // we are really leaving this rail
-                occupiedRails.remove(leavingRail);
-            } // else: we are still on the rail
+        if (leavingRail != null && !leavingRail.contains(secondToLastPosition)) {
+            // we are leaving this rail
+            occupiedRails.remove(leavingRail);
         } else if (getLength() == 1 && railNetwork.findContainingRail(secondToLastPosition) == null) {
             // we evidently just moved into another rail
             occupiedRails.clear();
@@ -308,21 +305,10 @@ public final class Train {
             // we evidently just moved into another rail
             Rail[] nextTouchingRails = railNetwork.findTouchingRails(nextPosition);
             Rail[] alreadyTouchingRails = railNetwork.findTouchingRails(secondToLastPosition);
-            // TODO: do we need all of these cases???
-            if (nextTouchingRails[0] == alreadyTouchingRails[0]) {
-                occupiedRails.add(nextTouchingRails[0]);
-            } else if (nextTouchingRails.length == 2) {
-                if (nextTouchingRails[1] == alreadyTouchingRails[0]) {
-                    occupiedRails.add(nextTouchingRails[1]);
-                } else if (alreadyTouchingRails.length == 2) {
-                    if (alreadyTouchingRails[1] == nextTouchingRails[0]) {
-                        occupiedRails.add(nextTouchingRails[0]);
-                    } else if (alreadyTouchingRails[1] == nextTouchingRails[1]) {
-                        occupiedRails.add(nextTouchingRails[1]);
-                    }
-                }
-            }
-        } // else: only touching rail
+            Arrays.stream(nextTouchingRails)
+                    .filter(rail -> Arrays.stream(alreadyTouchingRails).anyMatch(rail2 -> rail == rail2))
+                    .forEach(occupiedRails::add);
+        } // else: only touching new rail
     }
 
     /**