diff --git a/planning/behavior_path_planner/src/planner_manager.cpp b/planning/behavior_path_planner/src/planner_manager.cpp
index 026999790299c..692a5ce0798c4 100644
--- a/planning/behavior_path_planner/src/planner_manager.cpp
+++ b/planning/behavior_path_planner/src/planner_manager.cpp
@@ -636,15 +636,21 @@ void PlannerManager::resetRootLanelet(const std::shared_ptr<PlannerData> & data)
 
   const auto root_lanelet = updateRootLanelet(data);
 
+  // if root_lanelet is not route lanelets, reset root lanelet.
+  // this can be caused by rerouting.
+  const auto & route_handler = data->route_handler;
+  if (!route_handler->isRouteLanelet(root_lanelet_.get())) {
+    root_lanelet_ = root_lanelet;
+    return;
+  }
+
   // check ego is in same lane
   if (root_lanelet_.get().id() == root_lanelet.id()) {
     return;
   }
 
-  const auto route_handler = data->route_handler;
-  const auto next_lanelets = route_handler->getRoutingGraphPtr()->following(root_lanelet_.get());
-
   // check ego is in next lane
+  const auto next_lanelets = route_handler->getRoutingGraphPtr()->following(root_lanelet_.get());
   for (const auto & next : next_lanelets) {
     if (next.id() == root_lanelet.id()) {
       return;
diff --git a/planning/route_handler/include/route_handler/route_handler.hpp b/planning/route_handler/include/route_handler/route_handler.hpp
index 6ad42e1f8b03c..c60c0e431108e 100644
--- a/planning/route_handler/include/route_handler/route_handler.hpp
+++ b/planning/route_handler/include/route_handler/route_handler.hpp
@@ -325,6 +325,7 @@ class RouteHandler
     const lanelet::ConstLanelet & prev_lane, const lanelet::ConstLanelet & next_lane) const;
   lanelet::ConstLanelets getShoulderLanelets() const;
   bool isShoulderLanelet(const lanelet::ConstLanelet & lanelet) const;
+  bool isRouteLanelet(const lanelet::ConstLanelet & lanelet) const;
 
   // for path
   PathWithLaneId getCenterLinePath(
diff --git a/planning/route_handler/src/route_handler.cpp b/planning/route_handler/src/route_handler.cpp
index e1fbf7f1dccc6..3027ca0b96560 100644
--- a/planning/route_handler/src/route_handler.cpp
+++ b/planning/route_handler/src/route_handler.cpp
@@ -1800,6 +1800,11 @@ bool RouteHandler::isShoulderLanelet(const lanelet::ConstLanelet & lanelet) cons
   return lanelet::utils::contains(shoulder_lanelets_, lanelet);
 }
 
+bool RouteHandler::isRouteLanelet(const lanelet::ConstLanelet & lanelet) const
+{
+  return lanelet::utils::contains(route_lanelets_, lanelet);
+}
+
 lanelet::ConstLanelets RouteHandler::getPreviousLaneletSequence(
   const lanelet::ConstLanelets & lanelet_sequence) const
 {