diff --git a/src/Main/globals.cxx b/src/Main/globals.cxx
index 2e72e8276..c560f2765 100644
--- a/src/Main/globals.cxx
+++ b/src/Main/globals.cxx
@@ -35,6 +35,7 @@
 #include <simgear/structure/event_mgr.hxx>
 #include <simgear/sound/soundmgr_openal.hxx>
 #include <simgear/misc/ResourceManager.hxx>
+#include <simgear/props/propertyObject.hxx>
 
 #include <Aircraft/controls.hxx>
 #include <Airports/runways.hxx>
@@ -148,6 +149,7 @@ FGGlobals::FGGlobals() :
     channellist( NULL )    
 {
   simgear::ResourceManager::instance()->addProvider(new AircraftResourceProvider());
+  simgear::PropertyObjectBase::setDefaultRoot(props);
 }
 
 
diff --git a/src/Traffic/Schedule.cxx b/src/Traffic/Schedule.cxx
index 3b8e7636d..cb7fafb3d 100644
--- a/src/Traffic/Schedule.cxx
+++ b/src/Traffic/Schedule.cxx
@@ -187,9 +187,6 @@ bool FGAISchedule::init()
 
 bool FGAISchedule::update(time_t now, const SGVec3d& userCart)
 { 
-  if (!fgGetBool("/sim/traffic-manager/enabled"))
-    return true;
-  
   time_t 
     totalTimeEnroute, 
     elapsedTimeEnroute,
diff --git a/src/Traffic/TrafficMgr.cxx b/src/Traffic/TrafficMgr.cxx
index d9fcb6fff..765c870fd 100644
--- a/src/Traffic/TrafficMgr.cxx
+++ b/src/Traffic/TrafficMgr.cxx
@@ -75,7 +75,11 @@ using std::strcmp;
 /******************************************************************************
  * TrafficManager
  *****************************************************************************/
-FGTrafficManager::FGTrafficManager()
+FGTrafficManager::FGTrafficManager() :
+  inited(false),
+  enabled("/sim/traffic-manager/enabled"),
+  aiEnabled("/sim/ai/enabled"),
+  metarValid("/environment/metar/valid")
 {
     //score = 0;
     //runCount = 0;
@@ -125,6 +129,10 @@ FGTrafficManager::~FGTrafficManager()
 
 void FGTrafficManager::init()
 {
+    if (!enabled || !aiEnabled) {
+      return;
+    }
+  
     heuristicsVector heuristics;
     HeuristicMap heurMap;
 
@@ -218,13 +226,22 @@ void FGTrafficManager::init()
          compareSchedules);
     currAircraft = scheduledAircraft.begin();
     currAircraftClosest = scheduledAircraft.begin();
+    
+    inited = true;
 }
 
 void FGTrafficManager::update(double /*dt */ )
 {
-    if (fgGetBool("/environment/metar/valid") == false) {
+    if (!enabled || !aiEnabled || !metarValid) {
         return;
     }
+        
+    if (!inited) {
+    // lazy-initialization, we've been enabled at run-time
+      SG_LOG(SG_GENERAL, SG_INFO, "doing lazy-init of TrafficManager");
+      init();
+    }
+        
     time_t now = time(NULL) + fgGetLong("/sim/time/warp");
     if (scheduledAircraft.size() == 0) {
         return;
diff --git a/src/Traffic/TrafficMgr.hxx b/src/Traffic/TrafficMgr.hxx
index 862c87be4..a9bb9a305 100644
--- a/src/Traffic/TrafficMgr.hxx
+++ b/src/Traffic/TrafficMgr.hxx
@@ -47,6 +47,7 @@
 #define _TRAFFICMGR_HXX_
 
 #include <simgear/structure/subsystem_mgr.hxx>
+#include <simgear/props/propertyObject.hxx>
 #include <simgear/xml/easyxml.hxx>
 #include <simgear/misc/sg_path.hxx>
 
@@ -54,19 +55,19 @@
 #include "Schedule.hxx"
 
 
-typedef vector<int> IdList;
-typedef vector<int>::iterator IdListIterator;
+typedef std::vector<int> IdList;
+typedef std::vector<int>::iterator IdListIterator;
 
 class Heuristic
 {
 public:
-   string registration;
+   std::string registration;
    unsigned int runCount;
    unsigned int hits;
 };
 
-typedef vector<Heuristic> heuristicsVector;
-typedef vector<Heuristic>::iterator heuristicsVectorIterator;
+typedef std::vector<Heuristic> heuristicsVector;
+typedef std::vector<Heuristic>::iterator heuristicsVectorIterator;
 
 typedef std::map < std::string, Heuristic> HeuristicMap;
 typedef HeuristicMap::iterator             HeuristicMapIterator;
@@ -77,11 +78,13 @@ typedef HeuristicMap::iterator             HeuristicMapIterator;
 class FGTrafficManager : public SGSubsystem, public XMLVisitor
 {
 private:
+  bool inited;
+  
   ScheduleVector scheduledAircraft;
   ScheduleVectorIterator currAircraft, currAircraftClosest;
   vector<string> elementValueStack;
 
-  string mdl, livery, registration, callsign, fltrules, 
+  std::string mdl, livery, registration, callsign, fltrules, 
     port, timeString, departurePort, departureTime, arrivalPort, arrivalTime,
     repeat, acType, airline, m_class, flighttype, requiredAircraft, homePort;
   int cruiseAlt;
@@ -96,6 +99,7 @@ private:
   void readTimeTableFromFile(SGPath infilename);
   void Tokenize(const string& str, vector<string>& tokens, const string& delimiters = " ");
 
+  simgear::PropertyObject<bool> enabled, aiEnabled, metarValid;
 public:
   FGTrafficManager();
   ~FGTrafficManager();