diff --git a/planning/behavior_path_start_planner_module/README.md b/planning/behavior_path_start_planner_module/README.md
index f4aa3936bee56..2f90cc2ee3cf2 100644
--- a/planning/behavior_path_start_planner_module/README.md
+++ b/planning/behavior_path_start_planner_module/README.md
@@ -2,17 +2,23 @@
## Purpose / Role
-The Start Planner module is designed to generate a path from the current ego position to the driving lane, avoiding static obstacles and implementing safety checks against dynamic obstacles. (Note: The feature of safety checks against dynamic obstacles is currently a work in progress.)
-This module is activated when a new route is received.
+The Start Planner module is designed to generate a path from the current ego position to the driving lane, avoiding static obstacles and stopping in response to dynamic obstacles when a collision is detected.
-Use cases are as follows
+Use cases include:
-- start smoothly from the current ego position to centerline.
- ![case1](./images/start_from_road_lane.drawio.svg)
- pull out from the side of the road lane to centerline.
- ![case2](./images/start_from_road_side.drawio.svg)
+
+
+
- pull out from the shoulder lane to the road lane centerline.
- ![case3](./images/start_from_road_shoulder.drawio.svg)
+
+
## Design
diff --git a/planning/behavior_path_start_planner_module/images/start_from_road_lane.drawio.svg b/planning/behavior_path_start_planner_module/images/start_from_road_lane.drawio.svg
deleted file mode 100644
index 7a89cc2183acf..0000000000000
--- a/planning/behavior_path_start_planner_module/images/start_from_road_lane.drawio.svg
+++ /dev/null
@@ -1,34 +0,0 @@
-