diff --git a/planning/behavior_velocity_crosswalk_module/src/scene_crosswalk.cpp b/planning/behavior_velocity_crosswalk_module/src/scene_crosswalk.cpp
index cc1cc9f1ea950..4df404a3ccb27 100644
--- a/planning/behavior_velocity_crosswalk_module/src/scene_crosswalk.cpp
+++ b/planning/behavior_velocity_crosswalk_module/src/scene_crosswalk.cpp
@@ -34,6 +34,7 @@ using motion_utils::calcLateralOffset;
 using motion_utils::calcLongitudinalOffsetPoint;
 using motion_utils::calcLongitudinalOffsetPose;
 using motion_utils::calcSignedArcLength;
+using motion_utils::calcSignedArcLengthPartialSum;
 using motion_utils::findNearestSegmentIndex;
 using motion_utils::insertTargetPoint;
 using motion_utils::resamplePath;
@@ -731,15 +732,15 @@ Polygon2d CrosswalkModule::getAttentionArea(
 {
   const auto & ego_pos = planner_data_->current_odometry->pose.position;
   const auto ego_polygon = createVehiclePolygon(planner_data_->vehicle_info_);
+  const auto backward_path_length =
+    calcSignedArcLength(sparse_resample_path.points, size_t(0), ego_pos);
+  const auto length_sum = calcSignedArcLengthPartialSum(
+    sparse_resample_path.points, size_t(0), sparse_resample_path.points.size());
 
   Polygon2d attention_area;
   for (size_t j = 0; j < sparse_resample_path.points.size() - 1; ++j) {
-    const auto & p_ego_front = sparse_resample_path.points.at(j).point.pose;
-    const auto & p_ego_back = sparse_resample_path.points.at(j + 1).point.pose;
-    const auto front_length =
-      calcSignedArcLength(sparse_resample_path.points, ego_pos, p_ego_front.position);
-    const auto back_length =
-      calcSignedArcLength(sparse_resample_path.points, ego_pos, p_ego_back.position);
+    const auto front_length = length_sum.at(j) - backward_path_length;
+    const auto back_length = length_sum.at(j + 1) - backward_path_length;
 
     if (back_length < crosswalk_attention_range.first) {
       continue;