diff --git a/include/calculation_time.hpp b/include/calculation_time.hpp
index d49c6d4..29bea0d 100644
--- a/include/calculation_time.hpp
+++ b/include/calculation_time.hpp
@@ -10,7 +10,7 @@ namespace TrRouting
   class CalculationTime {
     
     public:
-      
+      CalculationTime();
       //static CalculationTime algorithmCalculationTime;
       long long getDurationMicroseconds();
       long long getDurationMicrosecondsNoStop();
diff --git a/src/calculation_time.cpp b/src/calculation_time.cpp
index 6d3882a..dc47140 100644
--- a/src/calculation_time.cpp
+++ b/src/calculation_time.cpp
@@ -5,6 +5,15 @@
 namespace TrRouting
 {
 
+  CalculationTime::CalculationTime() :
+    startEpoch(0),
+    startStepEpoch(0),
+    endEpoch(0),
+    endStepEpoch(0),
+    calculationEpoch() {
+    //TODO Should we call start() on construction ??
+  }
+
   long long CalculationTime::getEpoch()
   {
     calculationEpoch = std::chrono::duration_cast< std::chrono::microseconds >(
@@ -25,14 +34,20 @@ namespace TrRouting
   
   long long CalculationTime::getDurationMicroseconds()
   {
-    assert(startEpoch && endEpoch && startEpoch >= 0 && endEpoch >= 0 && endEpoch >= startEpoch);
+    assert(startEpoch && endEpoch);
+    assert(startEpoch >= 0);
+    assert(endEpoch >= 0);
+    assert(endEpoch >= startEpoch);
     return endEpoch - startEpoch;
   }
   
   long long CalculationTime::getDurationMicrosecondsNoStop()
   {
     long long actualEpoch {getEpoch()};
-    assert(startEpoch && actualEpoch && startEpoch >= 0 && actualEpoch >= 0 && actualEpoch >= startEpoch);
+    assert(startEpoch && actualEpoch);
+    assert(startEpoch >= 0);
+    assert(actualEpoch >= 0);
+    assert(actualEpoch >= startEpoch);
     return actualEpoch - startEpoch;
   }
   
@@ -48,7 +63,10 @@ namespace TrRouting
   
   long long CalculationTime::getStepDurationMicroseconds()
   {
-    assert(startStepEpoch && endStepEpoch && startStepEpoch >= 0 && endStepEpoch >= 0 && endStepEpoch >= startStepEpoch);
+    assert(startStepEpoch && endStepEpoch);
+    assert(startStepEpoch >= 0);
+    assert(endStepEpoch >= 0);
+    assert(endStepEpoch >= startStepEpoch);
     return endStepEpoch - startStepEpoch;
   }