diff --git a/connection_scan_algorithm/include/calculator.hpp b/connection_scan_algorithm/include/calculator.hpp
index 1c66a29..fcd6487 100644
--- a/connection_scan_algorithm/include/calculator.hpp
+++ b/connection_scan_algorithm/include/calculator.hpp
@@ -127,8 +127,8 @@ namespace TrRouting
 
     std::vector<NodeTimeDistance> accessFootpaths; // pair: accessNodeIndex, walkingTravelTimeSeconds, walkingDistanceMeters
     std::vector<NodeTimeDistance> egressFootpaths; // pair: egressNodeIndex, walkingTravelTimeSeconds, walkingDistanceMeters
-    std::unordered_map<Node::uid_t, JourneyStep> forwardJourneysSteps; 
-    std::unordered_map<Node::uid_t, JourneyStep> reverseJourneysSteps;
+    std::vector<JourneyStep> forwardJourneysSteps; // indexed by Node::uid
+    std::vector<JourneyStep> reverseJourneysSteps; // indexed by Node::uid
 
   };
 
diff --git a/connection_scan_algorithm/include/journey_step.hpp b/connection_scan_algorithm/include/journey_step.hpp
index 1b75bc9..e423029 100644
--- a/connection_scan_algorithm/include/journey_step.hpp
+++ b/connection_scan_algorithm/include/journey_step.hpp
@@ -21,6 +21,7 @@ namespace TrRouting {
                                          transferTravelTime(_transferTravelTime),
                                          sameNodeTransfer(_sameNodeTransfer),
                                          transferDistance(_transferDistance) { }
+    JourneyStep() : JourneyStep(std::nullopt, std::nullopt, std::nullopt, -1, false, -1) {}
 
     //TODO Why is there Final in the function name. Is that appropriate?
     std::optional<std::reference_wrapper<const Connection>> getFinalEnterConnection() const {return finalEnterConnection;}
diff --git a/connection_scan_algorithm/src/forward_calculation.cpp b/connection_scan_algorithm/src/forward_calculation.cpp
index 8e6d91e..bbe8259 100644
--- a/connection_scan_algorithm/src/forward_calculation.cpp
+++ b/connection_scan_algorithm/src/forward_calculation.cpp
@@ -137,7 +137,7 @@ namespace TrRouting
                     nodesTentativeTime[transferableNode.node.uid] = footpathTravelTime + connectionArrivalTime;
 
                     //TODO DO we need a make_optional here??
-                    forwardJourneysSteps.insert_or_assign(transferableNode.node.uid, JourneyStep(currentTripQueryOverlay.enterConnection, *connection, std::cref(trip), footpathTravelTime, (nodeArrival == transferableNode.node), footpathDistance));
+                    forwardJourneysSteps.at(transferableNode.node.uid) = JourneyStep(currentTripQueryOverlay.enterConnection, *connection, std::cref(trip), footpathTravelTime, (nodeArrival == transferableNode.node), footpathDistance);
                   }
 
                   if (
@@ -316,7 +316,7 @@ namespace TrRouting
                     nodesTentativeTime[transferableNode.node.uid] = footpathTravelTime + connectionArrivalTime;
 
                     //TODO DO we need a make_optional here??
-                    forwardJourneysSteps.insert_or_assign(transferableNode.node.uid, JourneyStep(currentTripQueryOverlay.enterConnection, *connection, std::cref(trip), footpathTravelTime, (nodeArrival == transferableNode.node), footpathDistance));
+                    forwardJourneysSteps.at(transferableNode.node.uid) = JourneyStep(currentTripQueryOverlay.enterConnection, *connection, std::cref(trip), footpathTravelTime, (nodeArrival == transferableNode.node), footpathDistance);
                   }
 
                   if (
diff --git a/connection_scan_algorithm/src/resets.cpp b/connection_scan_algorithm/src/resets.cpp
index c847137..544aa9e 100644
--- a/connection_scan_algorithm/src/resets.cpp
+++ b/connection_scan_algorithm/src/resets.cpp
@@ -79,7 +79,7 @@ namespace TrRouting
       int footpathTravelTimeSeconds;
       int footpathDistanceMeters;
       nodesAccess.clear();
-      forwardJourneysSteps.clear();
+      forwardJourneysSteps.assign(Node::getMaxUid() + 1, JourneyStep());
       nodesTentativeTime.assign(Node::getMaxUid() + 1, MAX_INT); //Assign default values to all indexes
       
       for (auto & accessFootpath : accessFootpaths)
@@ -90,7 +90,7 @@ namespace TrRouting
         nodesAccess.emplace(accessFootpath.node.uid, NodeTimeDistance(accessFootpath.node,
                                                                       footpathTravelTimeSeconds,
                                                                       footpathDistanceMeters));
-        forwardJourneysSteps.insert_or_assign(accessFootpath.node.uid, JourneyStep(std::nullopt, std::nullopt, std::nullopt, footpathTravelTimeSeconds, false, footpathDistanceMeters));
+        forwardJourneysSteps.at(accessFootpath.node.uid) = JourneyStep(std::nullopt, std::nullopt, std::nullopt, footpathTravelTimeSeconds, false, footpathDistanceMeters);
         nodesTentativeTime[accessFootpath.node.uid]    = departureTimeSeconds + footpathTravelTimeSeconds;
         if (footpathTravelTimeSeconds < minAccessTravelTime)
         {
@@ -115,7 +115,7 @@ namespace TrRouting
       int footpathTravelTimeSeconds;
       int footpathDistanceMeters;
       nodesEgress.clear();
-      reverseJourneysSteps.clear();
+      reverseJourneysSteps.assign(Node::getMaxUid() + 1, JourneyStep());
       nodesReverseTentativeTime.assign(Node::getMaxUid() + 1, -1); //Assign default values to all indexes
       for (auto & egressFootpath : egressFootpaths)
       {
@@ -126,7 +126,7 @@ namespace TrRouting
                                                                        footpathTravelTimeSeconds,
                                                                        footpathDistanceMeters));
 
-        reverseJourneysSteps.insert_or_assign(egressFootpath.node.uid, JourneyStep(std::nullopt, std::nullopt, std::nullopt, footpathTravelTimeSeconds, false, footpathDistanceMeters));
+        reverseJourneysSteps.at(egressFootpath.node.uid) = JourneyStep(std::nullopt, std::nullopt, std::nullopt, footpathTravelTimeSeconds, false, footpathDistanceMeters);
         nodesReverseTentativeTime[egressFootpath.node.uid] = arrivalTimeSeconds - footpathTravelTimeSeconds;
         if (footpathTravelTimeSeconds > maxEgressTravelTime)
         {
diff --git a/connection_scan_algorithm/src/reverse_calculation.cpp b/connection_scan_algorithm/src/reverse_calculation.cpp
index 960c1a6..eb58e29 100644
--- a/connection_scan_algorithm/src/reverse_calculation.cpp
+++ b/connection_scan_algorithm/src/reverse_calculation.cpp
@@ -81,11 +81,10 @@ namespace TrRouting
           {
             
             // Make sure the arrival of the connection can unboard and is a candidate for the journey. Nodes are candidate if they can either reach the destination by foot, or a connection that can reach the destination within the specified parameters.
-            auto rjsIte = reverseJourneysSteps.find(nodeArrival.uid);
-            if ((*connection).get().canUnboard() && rjsIte != reverseJourneysSteps.end())
+            if ((*connection).get().canUnboard())
             {
               // Extract journeyStep once from map
-              const JourneyStep & reverseStepAtArrival = rjsIte->second;
+              const JourneyStep & reverseStepAtArrival = reverseJourneysSteps.at(nodeArrival.uid);
               if (!tripExitConnection.has_value()) // <= to make sure we get the same result as forward calculation, which uses >
               {
                 currentTripQueryOverlay.exitConnection = *connection;
@@ -144,7 +143,7 @@ namespace TrRouting
                     footpathDistance = nodeDeparture.reverseTransferableNodes.at(footpathIndex).distance;
                     nodesReverseTentativeTime[transferableNode.node.uid] = connectionDepartureTime - footpathTravelTime - connectionMinWaitingTimeSeconds;
                     //TODO Do we need a make_optional<...>(connection) ??
-                    reverseJourneysSteps.insert_or_assign(transferableNode.node.uid, JourneyStep(*connection, currentTripQueryOverlay.exitConnection, std::cref(trip), footpathTravelTime, (nodeDeparture == transferableNode.node), footpathDistance));
+                    reverseJourneysSteps.at(transferableNode.node.uid) =  JourneyStep(*connection, currentTripQueryOverlay.exitConnection, std::cref(trip), footpathTravelTime, (nodeDeparture == transferableNode.node), footpathDistance);
                   }
                   if (
                     nodeDeparture == transferableNode.node
@@ -344,7 +343,7 @@ namespace TrRouting
                     footpathDistance = nodeDeparture.reverseTransferableNodes.at(footpathIndex).distance;
                     nodesReverseTentativeTime[transferableNode.node.uid] = connectionDepartureTime - footpathTravelTime - connectionMinWaitingTimeSeconds;
                     //TODO Do we need a make_optional<...>(connection) ??
-                    reverseJourneysSteps.insert_or_assign(transferableNode.node.uid, JourneyStep(*connection, currentTripQueryOverlay.exitConnection, std::cref(trip), footpathTravelTime, (nodeDeparture == transferableNode.node), footpathDistance));
+                    reverseJourneysSteps.at(transferableNode.node.uid) = JourneyStep(*connection, currentTripQueryOverlay.exitConnection, std::cref(trip), footpathTravelTime, (nodeDeparture == transferableNode.node), footpathDistance);
                   }
                   if (
                     nodeDeparture == transferableNode.node