diff --git a/waypoint_nav/scripts/tandem_run_manager.py b/waypoint_nav/scripts/tandem_run_manager.py
index b1c39f9..4b10af0 100755
--- a/waypoint_nav/scripts/tandem_run_manager.py
+++ b/waypoint_nav/scripts/tandem_run_manager.py
@@ -37,7 +37,7 @@
         self.costmap_client1 = dynamic_reconfigure.client.Client("/move_base/global_costmap/obstacle_layer1")
         self.costmap_client2 = dynamic_reconfigure.client.Client("/move_base/global_costmap/obstacle_layer2")
         ## Variable
-        self.front_angle = 40 # degree
+        self.front_angle = 20 # degree
         self.danger_dist = 1.0 # meter
         self.waypoint_num = 0
         self.front_range = None
@@ -49,16 +49,28 @@
     ## Subscribe current waypoint number
     def waypoint_num_callback(self, msg):
         if (self.no_tandem_area) or (msg.data == self.waypoint_num) or (self.stop): return
+        if (self.waypoint_num == 0) and (msg.data > 1):
+            for i in range(0, len(self.tandem_start_list)):
+                if (msg.data >= self.tandem_end_list[i]):
+                    self.tandem_id += 1
+                    continue
+                if (msg.data >= self.tandem_start_list[i]) and (msg.data < self.tandem_end_list[i]):
+                    self.tandem_id = i
+                    self.in_tandem_area = True
+                    self.update_costmap_config(False)
+                    rospy.loginfo("Enter tandem area.")
+                    break
+            self.waypoint_num = msg.data
+            return
+        
         if (msg.data == self.tandem_start_list[self.tandem_id]):
             self.in_tandem_area = True
-            self.costmap_client1.update_configuration({"enabled": False})
-            self.costmap_client2.update_configuration({"enabled": False})
+            self.update_costmap_config(False)
             rospy.loginfo("Enter tandem area.")
         
         elif (msg.data == self.tandem_end_list[self.tandem_id]):
             self.in_tandem_area = False
-            self.costmap_client1.update_configuration({"enabled": True})
-            self.costmap_client2.update_configuration({"enabled": True})
+            self.update_costmap_config(True)
             self.tandem_id += 1
             self.stop = (self.tandem_id >= len(self.tandem_start_list))  # if True, self.stop will never be False
             rospy.loginfo("Exit from tandem area.")
@@ -97,7 +109,12 @@
         except AttributeError:
             pass
         return
-
+    
+    
+    def update_costmap_config(self, enable: bool):
+        self.costmap_client1.update_configuration({"enabled": enable})
+        self.costmap_client2.update_configuration({"enabled": enable})
+        return