diff --git a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/state/UpdateActivityTimes.java b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/state/UpdateActivityTimes.java
index edf4c8de..814c29ad 100644
--- a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/state/UpdateActivityTimes.java
+++ b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/algorithm/state/UpdateActivityTimes.java
@@ -51,6 +51,9 @@ public class UpdateActivityTimes implements ActivityVisitor, StateUpdater {
         super();
         timeTracker = new ActivityTimeTracker(transportTime,activityCosts );
     }
+    public UpdateActivityTimes(ActivityTimeTracker activityTimeTracker) {
+        timeTracker = activityTimeTracker;
+    }
 
     public UpdateActivityTimes(ForwardTransportTime transportTime, ActivityTimeTracker.ActivityPolicy activityPolicy, VehicleRoutingActivityCosts activityCosts) {
         timeTracker = new ActivityTimeTracker(transportTime, activityPolicy, activityCosts);
diff --git a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/problem/constraint/VehicleDependentTimeWindowConstraints.java b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/problem/constraint/VehicleDependentTimeWindowConstraints.java
index 4574bfb6..91088b1c 100644
--- a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/problem/constraint/VehicleDependentTimeWindowConstraints.java
+++ b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/problem/constraint/VehicleDependentTimeWindowConstraints.java
@@ -32,12 +32,9 @@ import com.graphhopper.jsprit.core.problem.solution.route.state.RouteAndActivity
  * @author stefan
  */
 public class VehicleDependentTimeWindowConstraints implements HardActivityConstraint {
-
-    private RouteAndActivityStateGetter states;
-
-    private VehicleRoutingTransportCosts routingCosts;
-
-    private VehicleRoutingActivityCosts activityCosts;
+    protected RouteAndActivityStateGetter states;
+    protected VehicleRoutingTransportCosts routingCosts;
+    protected VehicleRoutingActivityCosts activityCosts;
 
     public VehicleDependentTimeWindowConstraints(RouteAndActivityStateGetter states, VehicleRoutingTransportCosts routingCosts, VehicleRoutingActivityCosts activityCosts) {
         super();
diff --git a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/util/ActivityTimeTracker.java b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/util/ActivityTimeTracker.java
index 130798d0..9d954ff5 100644
--- a/jsprit-core/src/main/java/com/graphhopper/jsprit/core/util/ActivityTimeTracker.java
+++ b/jsprit-core/src/main/java/com/graphhopper/jsprit/core/util/ActivityTimeTracker.java
@@ -37,15 +37,15 @@ public class ActivityTimeTracker implements ActivityVisitor {
 
     private TourActivity prevAct = null;
 
-    private double startAtPrevAct;
+    protected double startAtPrevAct;
 
-    private VehicleRoute route;
+    protected VehicleRoute route;
 
     private boolean beginFirst = false;
 
-    private double actArrTime;
+    protected double actArrTime;
 
-    private double actEndTime;
+    protected double actEndTime;
 
     private ActivityPolicy activityPolicy = ActivityPolicy.AS_SOON_AS_TIME_WINDOW_OPENS;