--- a/trafficintelligence/moving.py	Wed Jul 04 15:37:04 2018 -0400
+++ b/trafficintelligence/moving.py	Wed Jul 04 16:06:23 2018 -0400
@@ -1141,12 +1141,13 @@
     and a usertype (e.g. road user) coded as a number (see userTypeNames)
     '''
 
-    def __init__(self, num = None, timeInterval = None, positions = None, velocities = None, geometry = None, userType = userType2Num['unknown']):
+    def __init__(self, num = None, timeInterval = None, positions = None, velocities = None, geometry = None, userType = userType2Num['unknown'], nObjects = None):
         super(MovingObject, self).__init__(num, timeInterval)
         self.positions = positions
         self.velocities = velocities
         self.geometry = geometry
         self.userType = userType
+        self.setNObjects(nObjects) # a feature has None for nObjects
         self.features = None
         # compute bounding polygon from trajectory
 
@@ -1213,7 +1214,7 @@
             for t in secondObject.getTimeInterval():
             	positions.addPosition(secondObject.getPositionAtInstant(t))
             	velocities.addPosition(secondObject.getVelocityAtInstant(t))
-            newObject = MovingObject(newNum, TimeInterval(firstObject.getFirstInstant(), secondObject.getLastInstant()), positions, velocities)
+            newObject = MovingObject(newNum, TimeInterval(firstObject.getFirstInstant(), secondObject.getLastInstant()), positions, velocities, nObjects = 1)
             if hasattr(obj1, 'featureNumbers') and hasattr(obj2, 'featureNumbers'):
                 if newFeatureNum is not None:
                     newObject.featureNumbers = obj1.featureNumbers+obj2.featureNumbers+[newFeatureNum]
@@ -1223,7 +1224,7 @@
                 newObject.features = obj1.getFeatures()+obj2.getFeatures()+[MovingObject(newFeatureNum, TimeInterval(emptyInterval.first+1, emptyInterval.last-1), featurePositions, featureVelocities)]
         else: # time intervals overlap
             newTimeInterval = TimeInterval.union(obj1.getTimeInterval(), obj2.getTimeInterval())
-            newObject = MovingObject(newNum, newTimeInterval)
+            newObject = MovingObject(newNum, newTimeInterval, nObjects = 1) # hypothesis is that it's the same object being reunited
             if hasattr(obj1, 'featureNumbers') and hasattr(obj2, 'featureNumbers'):
                 newObject.featureNumbers = obj1.featureNumbers+obj2.featureNumbers
             if obj1.hasFeatures() and obj2.hasFeatures():
@@ -1243,7 +1244,7 @@
         intersection = TimeInterval.intersection(inter, self.getTimeInterval())
         if not intersection.empty():
             trajectoryInterval = TimeInterval(intersection.first-self.getFirstInstant(), intersection.last-self.getFirstInstant())
-            obj = MovingObject(self.num, intersection, self.positions.getTrajectoryInInterval(trajectoryInterval), self.geometry, self.userType)
+            obj = MovingObject(self.num, intersection, self.positions.getTrajectoryInInterval(trajectoryInterval), self.geometry, self.userType, self.nObjects)
             if self.velocities is not None:
                 obj.velocities = self.velocities.getTrajectoryInInterval(trajectoryInterval)
             return obj
@@ -1330,6 +1331,15 @@
     def setUserType(self, userType):
         self.userType = userType
 
+    def getNObjects(self):
+        return self.nObjects
+
+    def setNObjects(self, nObjects):
+        if nObjects is None or nObjects >= 1:
+            self.nObjects = nObjects
+        else:
+            print('Number of objects represented by object {} must be greater or equal to 1 ({})'.format(self.getNum(), nObjects))
+        
     def setFeatures(self, features, featuresOrdered = False):
         '''Sets the features in the features field based on featureNumbers
         if not all features are loaded from 0, one needs to renumber in a dict'''