diff --git a/A00_Common/design/design_view_profile.ts b/A00_Common/design/design_view_profile.ts
index 319930f89..75eb2d58b 100644
--- a/A00_Common/design/design_view_profile.ts
+++ b/A00_Common/design/design_view_profile.ts
@@ -487,6 +487,7 @@ export async function mountProfileView(
       contourIntervalM: latestResponse.surface_params.contour_interval_m,
       smooth: latestResponse.surface_params.smooth,
       tools: [view3d.modal.button],
+      recommend: panel.recommend,
     });
 
     // ③ 종단면·횡단 자료 — 하단 패널을 3D보다 먼저 채운다.
diff --git a/B05_Profile/B05_Profile_Api_TerrainGrid.ts b/B05_Profile/B05_Profile_Api_TerrainGrid.ts
index ce49bbc13..647f5dcad 100644
--- a/B05_Profile/B05_Profile_Api_TerrainGrid.ts
+++ b/B05_Profile/B05_Profile_Api_TerrainGrid.ts
@@ -4,6 +4,7 @@
  *
  *   GET /projects/{id}/route/terrain-sources        → 설계 지형 · 격자 받을 자리(`grid`)
  *   GET /projects/{id}/surface/models/{mid}/grid    → DTM 격자 원시 이진(ETag · IndexedDB)
+ *   POST /projects/{id}/route/elevations            → 격자를 못 쓸 때 계산 묶음 ground 단계의 서버 길
  *
  * 주소에 manifest 서명을 붙임 — 보관함은 옛 저장본을 먼저 내므로(`fetchCachedBytes`) 지형이
  * 바뀐 뒤 옛 격자로 한 번 그리는 일을 막음. DTM 아닌 표현 · 못 받음 = null → 서버 표본 길.
@@ -12,6 +13,7 @@
 import { API_BASE_URL } from "@config/config_frontend";
 import { fetchCachedBytes } from "../A00_Common/b_asset_cache";
 import { type DtmGrid, parseDtmGrid } from "../common_util/common_util_surface_sampler";
+import type { GroundStageDeps } from "./logic/B05_Profile_Pipeline_RouteGround";
 
 export interface DesignTerrainGrid {
   /** 이 격자의 지형 — 편집 창 분석 지형이 이것과 같을 때만 씀. */
@@ -25,6 +27,8 @@ interface TerrainSourcesPayload {
 }
 
 const loaded = new Map<string, Promise<DesignTerrainGrid | null>>();
+/** 받기가 끝난 격자 — 끝나기 전엔 칸이 없음(그동안 서버 길). */
+const ready = new Map<string, DesignTerrainGrid | null>();
 
 async function download(projectId: string): Promise<DesignTerrainGrid | null> {
   const response = await fetch(`${API_BASE_URL}/projects/${projectId}/route/terrain-sources`, {
@@ -45,11 +49,53 @@ async function download(projectId: string): Promise<DesignTerrainGrid | null> {
 export function loadDesignTerrainGrid(projectId: string): Promise<DesignTerrainGrid | null> {
   let pending = loaded.get(projectId);
   if (!pending) {
-    pending = download(projectId).catch(() => {
-      loaded.delete(projectId);
-      return null;
-    });
+    pending = download(projectId).then(
+      (value) => {
+        ready.set(projectId, value);
+        return value;
+      },
+      () => {
+        loaded.delete(projectId);
+        return null;
+      },
+    );
     loaded.set(projectId, pending);
   }
   return pending;
 }
+
+/** 지금 쓸 수 있는 격자 — 받는 중이면 null 을 돌려주고 받기를 띄움(기다리지 않음). */
+export function designTerrainGridNow(projectId: string): DesignTerrainGrid | null {
+  if (!ready.has(projectId)) void loadDesignTerrainGrid(projectId);
+  return ready.get(projectId) ?? null;
+}
+
+/** 한 번에 물을 수 있는 점 수 — 서버 `MAX_POINTS` 와 같은 값. */
+const ELEVATION_CHUNK = 4000;
+
+/** 계산 묶음 ground 단계에 넣을 격자 · 서버 길(PLAN 346-1). 서버 길 값은 mm 자리(응답 그대로). */
+export function groundStageDeps(projectId: string): Pick<GroundStageDeps, "grid" | "remote"> {
+  return {
+    grid: () => designTerrainGridNow(projectId),
+    async remote(points, terrain, signal) {
+      const chunks: Array<Array<[number, number]>> = [];
+      for (let i = 0; i < points.length; i += ELEVATION_CHUNK) {
+        chunks.push(points.slice(i, i + ELEVATION_CHUNK));
+      }
+      const answers = await Promise.all(
+        chunks.map(async (chunk) => {
+          const response = await fetch(`${API_BASE_URL}/projects/${projectId}/route/elevations`, {
+            method: "POST",
+            credentials: "include",
+            headers: { "Content-Type": "application/json" },
+            body: JSON.stringify({ points: chunk, terrain }),
+            signal,
+          });
+          if (!response.ok) throw new Error(`지반고 요청 실패: HTTP ${response.status}`);
+          return ((await response.json()) as { z: Array<number | null> }).z;
+        }),
+      );
+      return answers.flat();
+    },
+  };
+}
diff --git a/B05_Profile/B05_Profile_UI_Panel.ts b/B05_Profile/B05_Profile_UI_Panel.ts
index d4e7cb6fd..7ee996cbf 100644
--- a/B05_Profile/B05_Profile_UI_Panel.ts
+++ b/B05_Profile/B05_Profile_UI_Panel.ts
@@ -23,6 +23,7 @@ import {
   parseOptional,
   type RoutePanelValues,
 } from "./B05_Profile_UI_Panel_Fields";
+import { createRecommendPart } from "./B05_Profile_UI_Panel_Recommend";
 import { createSettingsPart } from "./B05_Profile_UI_Panel_Settings";
 import { createViewControls } from "./B05_Profile_UI_Panel_View";
 
@@ -71,6 +72,7 @@ interface PanelCallbacks {
 export function createRoutePanel(callbacks: PanelCallbacks, shared: DesignPageShared) {
   const { viewControls, setCorridorPending } = createViewControls(callbacks);
   const settings = createSettingsPart(callbacks);
+  const recommend = createRecommendPart(); // 노선 추천 칸 — 동작은 노선 편집기가 건다(345-4)
   const {
     contourInterval,
     gradeClass,
@@ -119,11 +121,13 @@ export function createRoutePanel(callbacks: PanelCallbacks, shared: DesignPageSh
 
   // 좌측 패널 = 한 벌 등록부(`design_shared`) — 종단 보기 칸 재료만 넣는다. 아래 단추 넷 · 저장 ·
   // [확정]은 한 벌이 두 보기 몫을 모아 낸다.
-  Object.assign(shared.parts, { settings });
+  Object.assign(shared.parts, { settings, recommend });
   sharedPanel(shared);
 
   return {
     viewControls,
+    /** 「노선 추천」 칸 요소 — 노선 편집기(`_RouteEdit_Initial`)에 넘긴다. */
+    recommend,
     /** 「구조물 배치」 섹션 API(타입 주입·목록 교체·계곡 시설 병합·선택·추가/이동/삭제). */
     structures: structures as StructuresSection,
     /** 이어 공사 시작 기준(측점번호·누가거리 오프셋) 현재값. */
diff --git a/B05_Profile/B05_Profile_UI_Panel_Recommend.ts b/B05_Profile/B05_Profile_UI_Panel_Recommend.ts
new file mode 100644
index 000000000..3fa0ed2ae
--- /dev/null
+++ b/B05_Profile/B05_Profile_UI_Panel_Recommend.ts
@@ -0,0 +1,29 @@
+/* =============================================================================
+ * B05_Profile_UI_Panel_Recommend.ts
+ * 좌측 「노선 추천」 칸 재료(345-4 · 지운 「계획노선」 자리) — [노선 추천] 단추 · 「현재 추천: ○○」 ·
+ * [초기화]. 노선 편집 머리에 있던 것을 옮겼다. 동작(추천 창 · 초기값 싣기)은 편집기의
+ * `_RouteEdit_Initial` 이 이 요소를 받아 건다 — 여기는 생김새만.
+ * ========================================================================== */
+
+export interface RecommendPart {
+  recommendButton: HTMLButtonElement;
+  resetButton: HTMLButtonElement;
+  nowLine: HTMLElement;
+  /** 칸 몸 — 화면 순서대로. */
+  nodes: HTMLElement[];
+}
+
+export function createRecommendPart(): RecommendPart {
+  const nowLine = document.createElement("span");
+  nowLine.className = "b05-routeedit__rec-now";
+  const actions = document.createElement("div");
+  actions.className = "b05-route__rec-actions";
+  actions.innerHTML = `
+    <button type="button" class="ui-btn ui-btn--ghost" data-act="recommend" disabled
+      title="예상노선 추적 · 영선 · 토공 최소 · 기울기 최소 · 비중 계산 중 하나로 노선을 추천받아 미리 봅니다 — [적용]은 평면에 되돌리기 한 칸">노선 추천</button>
+    <button type="button" class="ui-btn ui-btn--ghost" data-act="reset" disabled
+      title="전처리 때 만든 초기값 노선(예상노선 추적)으로 되돌립니다 — 다시 계산은 [노선 반영]에서">초기화</button>`;
+  const recommendButton = actions.querySelector<HTMLButtonElement>('[data-act="recommend"]')!;
+  const resetButton = actions.querySelector<HTMLButtonElement>('[data-act="reset"]')!;
+  return { recommendButton, resetButton, nowLine, nodes: [nowLine, actions] };
+}
diff --git a/B05_Profile/B05_Profile_UI_Panel_Sections.ts b/B05_Profile/B05_Profile_UI_Panel_Sections.ts
index 67c28ff32..4085c18fe 100644
--- a/B05_Profile/B05_Profile_UI_Panel_Sections.ts
+++ b/B05_Profile/B05_Profile_UI_Panel_Sections.ts
@@ -1,16 +1,18 @@
 /* =============================================================================
  * B05_Profile_UI_Panel_Sections.ts
- * 종단 보기 좌측 패널의 **칸 정의**(등록부 `registerPanelSection`) — 페이지 설정.
+ * 종단 보기 좌측 패널의 **칸 정의**(등록부 `registerPanelSection`) — 페이지 설정 · 노선 추천.
  * 「구조물 배치」는 두 보기 공용이라 `design_sections.ts` 에 있다.
  *
- * 칸 차례(2026-08-18 사용자 확정): 구조물 배치 > 페이지 설정 > 아래 고정 영역.
+ * 칸 차례(2026-08-18 사용자 확정): 구조물 배치 > 페이지 설정 > 노선 추천 > 아래 고정 영역.
  * 「선택 포인트 상세 설정」(3D 노선 점 옮김 · 지움 · 저장 안 되는 길)은 지움(345-2) ·
- * 「계획노선」 칸 · [계획노선 편집]은 지움(345-3 — 노선 편집은 가운데 위 본문).
+ * 「계획노선」 칸 · [계획노선 편집]은 지움(345-3 — 노선 편집은 가운데 위 본문) · 그 자리에
+ * 「노선 추천」(345-4 · 편집 머리에서 옮김 · 재료 `_Panel_Recommend`).
  * 「경로 계산 설정」은 `Old/` 로 옮김(54-24). 재료는 `_Panel_Settings` 가 만들어 `ctx.parts` 로 건넨다.
  * ========================================================================== */
 
 import "../A00_Common/design/design_sections";
 import { createSectionFrame, part, registerPanelSection } from "../A00_Common/design/design_panel";
+import type { RecommendPart } from "./B05_Profile_UI_Panel_Recommend";
 import type { SettingsPart } from "./B05_Profile_UI_Panel_Settings";
 
 registerPanelSection({
@@ -24,3 +26,15 @@ registerPanelSection({
     return frame.root;
   },
 });
+
+registerPanelSection({
+  id: "route-recommend",
+  title: "노선 추천",
+  views: ["profile"],
+  order: 30,
+  build: (ctx, view) => {
+    const frame = createSectionFrame(view, "노선 추천");
+    frame.body.append(...part<RecommendPart>(ctx, "recommend").nodes);
+    return frame.root;
+  },
+});
diff --git a/B05_Profile/B05_Profile_UI_RouteEdit.ts b/B05_Profile/B05_Profile_UI_RouteEdit.ts
index e6ea19bb8..b2a88106c 100644
--- a/B05_Profile/B05_Profile_UI_RouteEdit.ts
+++ b/B05_Profile/B05_Profile_UI_RouteEdit.ts
@@ -67,7 +67,7 @@ import {
   routeLocksOf,
   writeRouteLocks,
 } from "./B05_Profile_UI_RouteEdit_Lock";
-import { createInitialPanel } from "./B05_Profile_UI_RouteEdit_Initial";
+import { createInitialPanel, type InitialPanelParams } from "./B05_Profile_UI_RouteEdit_Initial";
 import { createProfileStrip } from "./B05_Profile_UI_RouteEdit_ProfileStrip";
 import {
   applyArcLocks,
@@ -104,6 +104,8 @@ export interface RouteEditOptions {
   smooth?: boolean;
   /** 머리 도구줄 끝에 앉힐 부른 쪽 단추([3D] 등). */
   tools?: HTMLElement[];
+  /** 좌측 「노선 추천」 칸 요소 — [노선 추천] · [초기화] · 현재 추천(345-4). */
+  recommend: InitialPanelParams["controls"];
 }
 
 /** 편집기가 사는 보기 — 보임 · 숨김 · 떠남. */
@@ -115,7 +117,7 @@ export async function mountRouteEditor(
   host: RouteEditHost,
   projectId: string,
   onApplied: () => void | Promise<void>,
-  options: RouteEditOptions = {},
+  options: RouteEditOptions,
 ): Promise<void> {
   const stationIntervalM = options.stationIntervalM ?? 20;
   const chrome = createRouteEditChrome(parent, options.tools);
@@ -269,8 +271,9 @@ export async function mountRouteEditor(
   };
   /** 초기노선 갈래 — 로직 단추 · [초기화] · 비교값(계획서 20). 서버 묻기는 `_Initial` 몫. */
   const initial = createInitialPanel({
-    overlay,
+    controls: options.recommend,
     projectId,
+    planned: () => planned,
     planMinRadiusM: () => minRadiusM,
     apply: (snapshot, message) => restoreSnapshot(snapshot, message, true),
   });
diff --git a/B05_Profile/B05_Profile_UI_RouteEdit_Chrome.ts b/B05_Profile/B05_Profile_UI_RouteEdit_Chrome.ts
index 0148d3de1..96dabba3e 100644
--- a/B05_Profile/B05_Profile_UI_RouteEdit_Chrome.ts
+++ b/B05_Profile/B05_Profile_UI_RouteEdit_Chrome.ts
@@ -13,7 +13,8 @@ import { createButton } from "@ui/ui_template_elements";
  *
  * 자리(345-3) — 모달이 아니라 종단 보기 가운데 위 본문(옛 3D 자리)에 붙는다. 덮개 · 전체 화면 ·
  * 닫기 단추는 걷었다 · [취소] → [반영 전으로] · [확인] → [노선 반영] · 오른쪽 횡단 칸은 접는 칸.
- * 머리 끝 `tools` 자리에 부른 쪽 단추([3D])가 앉는다.
+ * 머리 `tools` 자리에 부른 쪽 단추([3D])가 앉는다. [노선 추천] · 현재 추천 · [초기화]는 좌측
+ * 「노선 추천」 칸으로 옮겼다(345-4 · `_Panel_Recommend`).
  * ========================================================================== */
 
 /** 회전 단추 아이콘 — **반만 도는 화살표**(2026-09-12 사용자 지시 ㉙). 한 바퀴를 다 그린
@@ -53,11 +54,8 @@ export function createRouteEditChrome(
     <div class="b05-routeedit__box" aria-label="계획노선 편집">
       <div class="b05-routeedit__head">
         <h3>계획노선</h3>
-        <span class="b05-routeedit__rec-now" data-rec-now></span>
         <span class="b05-routeedit__actions">
           <span data-slot="tools"></span>
-          <button type="button" class="ui-btn ui-btn--ghost" data-act="recommend" disabled
-            title="예상노선 추적 · 영선 · 토공 최소 · 기울기 최소 · 비중 계산 중 하나로 노선을 추천받아 미리 봅니다">노선 추천</button>
           <i class="b05-routeedit__divider" aria-hidden="true"></i>
           <label class="b05-routeedit__terrain" hidden
             title="편집 창 분석(등고선 · 지반고 · 기울기 · 횡단 미리보기 · 종단 띠 · 추천)에 쓸 지형 — 확정 지표면 · 종횡단은 안 바뀝니다">분석 지형
@@ -79,8 +77,6 @@ export function createRouteEditChrome(
             title="되돌리기 (Ctrl+Z)" disabled>↶ 되돌리기</button>
           <button type="button" class="ui-btn ui-btn--ghost" data-act="redo"
             title="다시하기 (Ctrl+Y)" disabled>↷ 다시하기</button>
-          <button type="button" class="ui-btn ui-btn--ghost" data-act="reset" disabled
-            title="전처리 때 만든 초기값 노선(예상노선 추적)으로 되돌립니다 — 다시 계산은 [노선 반영]에서">초기화</button>
           <button type="button" class="ui-btn ui-btn--ghost" data-act="cancel"
             title="마지막 [노선 반영] 뒤 고친 노선을 버리고 그때 노선으로 되돌립니다 — 되돌리기로 다시 살릴 수 있습니다">반영 전으로</button>
           <button type="button" class="ui-btn ui-btn--filled" data-act="apply"
diff --git a/B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts b/B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts
index 20d6e4766..86d135a55 100644
--- a/B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts
+++ b/B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts
@@ -1,7 +1,8 @@
 /* =============================================================================
  * B05_Profile_UI_RouteEdit_Initial.ts
- * 계획노선 편집 창의 **노선 추천 이음**(계획서 20 · 23-2) — 도구 막대 [노선 추천] 단추 →
- * 모달(`_Recommend`) · [초기화] · 「현재 추천: ○○」 · [확인]에 실을 지금 추천.
+ * 계획노선 편집의 **노선 추천 이음**(계획서 20 · 23-2) — 좌측 「노선 추천」 칸(345-4) [노선 추천] 단추 →
+ * 모달(`_Recommend`) · [초기화] · 「현재 추천: ○○」 · [노선 반영]에 실을 지금 추천. 칸 요소는
+ * 밖(`_Panel_Recommend`)에서 받는다.
  *
  * 모달의 알약이 서버에 갈래를 묻고(`/route/initial`) 미리 보기만 한다. [적용]을 눌러야 받은 노드를
  * **편집값에 싣고**(되돌리기 한 걸음) 캐시(`routeedit-initial`)에 적는다. [초기화]는 서버를 다시
@@ -42,8 +43,15 @@ import {
 import { openRecommendModal } from "./B05_Profile_UI_RouteEdit_Recommend";
 
 export interface InitialPanelParams {
-  overlay: HTMLElement;
+  /** 단추 · 글 요소 — 좌측 「노선 추천」 칸 것(345-4). */
+  controls: {
+    recommendButton: HTMLButtonElement;
+    resetButton: HTMLButtonElement;
+    nowLine: HTMLElement;
+  };
   projectId: string;
+  /** 지금 편집기 노드 — 추천 창이 「지금 노선」으로 같이 그린다. */
+  planned: () => Array<[number, number]>;
   /** `/route/plan` 이 준 최소 R — 서버 갈래 기준값이 오기 전 보일 값. */
   planMinRadiusM: () => number;
   /** 받은 노선을 편집값으로 싣는다 — 되돌리기 한 걸음으로 쌓인다. */
@@ -75,10 +83,8 @@ const copy = (snapshot: RouteEditSnapshot): RouteEditSnapshot =>
   JSON.parse(JSON.stringify(snapshot)) as RouteEditSnapshot;
 
 export function createInitialPanel(params: InitialPanelParams): InitialPanel {
-  const { overlay, projectId } = params;
-  const recommendButton = overlay.querySelector<HTMLButtonElement>('[data-act="recommend"]')!;
-  const resetButton = overlay.querySelector<HTMLButtonElement>('[data-act="reset"]')!;
-  const nowLine = overlay.querySelector<HTMLElement>("[data-rec-now]")!;
+  const { projectId } = params;
+  const { recommendButton, resetButton, nowLine } = params.controls;
 
   /** 창을 열 때 캐시에 있던 추천 — [취소]가 돌아갈 자리. */
   let openingChoice = readInitialChoice(projectId);
@@ -146,7 +152,7 @@ export function createInitialPanel(params: InitialPanelParams): InitialPanel {
         logic: (choice ?? base).logic,
         planMinRadiusM: params.planMinRadiusM(),
         expected: (plan?.expected ?? []).map(([x, y]) => [x, y]),
-        current: opening!.planned.map(([x, y]) => [x, y]),
+        current: params.planned().map(([x, y]) => [x, y]),
         request,
         onApply: (picked) => {
           choice = picked;
diff --git a/B05_Profile/B05_Profile_UI_RouteEdit_Recommend.ts b/B05_Profile/B05_Profile_UI_RouteEdit_Recommend.ts
index d42d94aef..edd9c9298 100644
--- a/B05_Profile/B05_Profile_UI_RouteEdit_Recommend.ts
+++ b/B05_Profile/B05_Profile_UI_RouteEdit_Recommend.ts
@@ -557,7 +557,8 @@ export function openRecommendModal(params: RecommendParams): void {
     },
   });
 
-  // 편집 창 단축키(Ctrl+Z 등)가 뒤에서 노선을 되돌리지 않게 막는다. 칸 안의 글자 되돌리기는 그대로.
+  // 본문 평면 · 종단도 단축키(Ctrl+Z 등 · 창에서 들음)가 뒤에서 되돌리지 않게 막는다 — 칸 안 글자
+  // 되돌리기는 그대로(345-4 · 이제 모달은 이 창 하나).
   (bodyEl as HTMLElement | null)
     ?.closest(".ui-modal__backdrop")
     ?.addEventListener("keydown", (event) => {
diff --git a/B05_Profile/B05_Profile_UI_Style_RouteRecommend.css b/B05_Profile/B05_Profile_UI_Style_RouteRecommend.css
index 5eef6bf43..301a55451 100644
--- a/B05_Profile/B05_Profile_UI_Style_RouteRecommend.css
+++ b/B05_Profile/B05_Profile_UI_Style_RouteRecommend.css
@@ -1,15 +1,20 @@
 /* 노선 추천 모달(계획서 23-2) — 알약 넷 · 미리 보기 지도 · 비중 · 제약 칸 · 비교값.
-   색은 전부 테마 토큰을 쓴다(밝음 · 어두움). 계획노선 편집 창(`.b05-routeedit`) 위에 뜬다. */
+   색은 전부 테마 토큰을 쓴다(밝음 · 어두움). 종단 보기 화면 위에 뜬다(모달 하나 · 345-4). */
 
-/* 편집 창 제목 옆 「현재 추천: ○○」. */
+/* 좌측 「노선 추천」 칸(345-4) — 「현재 추천: ○○」 + [노선 추천] [초기화]. */
 .b05-routeedit__rec-now {
   flex: none;
   color: var(--color-text-secondary);
   font-size: var(--text-caption);
-  white-space: nowrap;
 }
 
-/* 곡선 라벨 패널(`.b05-routeedit__label` = 모달 + 1) 위로 — 모달과 뒤 막이 함께 올라간다. */
+.b05-route__rec-actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--spacing-8);
+}
+
+/* 곡선 라벨 패널 · 페이지 막들 위로 — 모달과 뒤 막이 함께 올라간다. */
 .ui-modal__backdrop.b05-routerec-backdrop {
   z-index: calc(var(--z-modal, 1000) + 2);
 }
diff --git a/B05_Profile/logic/B05_Profile_Pipeline_RouteGround.ts b/B05_Profile/logic/B05_Profile_Pipeline_RouteGround.ts
new file mode 100644
index 000000000..47ec5b627
--- /dev/null
+++ b/B05_Profile/logic/B05_Profile_Pipeline_RouteGround.ts
@@ -0,0 +1,179 @@
+/* =============================================================================
+ * B05_Profile_Pipeline_RouteGround.ts
+ * 실시간 계산 묶음(PLAN 346-1)의 **route · ground 단계** — 계약 = `design_pipeline_types.ts`.
+ *
+ *   route  — 노선 초안(RouteDraft) → 그린 노선(원호 포함) · 누가거리. 선은 이미 있는 짝
+ *            `buildEditedPolyline`(↔ `common_util_route_polyline.py`) 그대로.
+ *   ground — 측점(지반 null) → 지반 채운 측점 · 종단 지반선(1 m). 표본 = 지형 격자 짝
+ *            (`common_util_surface_sampler.ts` · `B05_Profile_Sections_Ground.ts`) · 격자가 없거나
+ *            (아직 못 받음 · DTM 아님) 분석 지형 ≠ 설계 지형이면 주입받은 서버 표본(`remote`).
+ *            바뀐 범위 밖 측점 · 종단은 앞 출력 재사용(국부 연산) — 자리 · 축 · 지형이 같을 때만.
+ *
+ * 화면 · fetch · 세션 안 씀 — 격자 · 서버 길은 부르는 쪽이 넣음(`B05_Profile_Api_TerrainGrid.ts`).
+ * ========================================================================== */
+
+import type {
+  GroundOutput,
+  GroundSample,
+  PipelineStation,
+  RouteDraft,
+  RouteLine,
+  StageFn,
+  StationGround,
+  Vertex,
+} from "../../A00_Common/design/design_pipeline_types";
+import { type DtmGrid, heightAt } from "../../common_util/common_util_surface_sampler";
+import { buildEditedPolyline } from "../B05_Profile_UI_RouteEdit_Curve";
+import { applyArcLocks } from "../B05_Profile_UI_RouteEdit_Edits";
+import {
+  crossOffsets,
+  longitudinalPoints,
+  round6,
+  SECTION_CROSS_HALF_WIDTH_M,
+  SECTION_CROSS_SAMPLE_INTERVAL_M,
+} from "./B05_Profile_Sections_Ground";
+
+/* ── route ─────────────────────────────────────────────────────────────── */
+
+export interface RouteStageDeps {
+  /** 곡선 기본 반지름(m) — 편집기 `minRadiusM`(계획 기준 · 0 = 없음). */
+  minRadiusM(): number;
+  /** 초안이 없을 때(= 저장분 그대로) 그릴 노선 — 없으면 null. */
+  savedLine(): Vertex[] | null;
+}
+
+/** 정점마다 누가거리 — 첫 점 0. */
+export function routeLineOf(line: Vertex[]): RouteLine {
+  const chainage = [0];
+  for (let i = 1; i < line.length; i += 1) {
+    chainage.push(
+      chainage[i - 1] + Math.hypot(line[i][0] - line[i - 1][0], line[i][1] - line[i - 1][1]),
+    );
+  }
+  return { line, chainage, lengthM: chainage[chainage.length - 1] };
+}
+
+/** 초안 → 그린 노선. 길이를 붙든 곡선은 교각에 맞춰 R 을 다시 잡음(편집기 `markEdited` 와 같은 차례). */
+export function draftLine(draft: RouteDraft, minRadiusM: number): Vertex[] {
+  const nodes = draft.nodes.map((node): Vertex => [node[0], node[1]]);
+  const radius = [...draft.curveRadius];
+  applyArcLocks(nodes, [...draft.curveLock], [...draft.curveArc], radius);
+  return buildEditedPolyline(nodes, draft.curveOn, radius, minRadiusM).vertices;
+}
+
+export function createRouteStage(deps: RouteStageDeps): StageFn<"route"> {
+  return (ctx) => {
+    const draft = ctx.inputs.route;
+    const line = draft ? draftLine(draft, deps.minRadiusM()) : deps.savedLine();
+    if (!line || line.length < 2) throw new Error("그릴 노선이 없습니다.");
+    return routeLineOf(line);
+  };
+}
+
+/* ── ground ────────────────────────────────────────────────────────────── */
+
+export interface GroundStageDeps {
+  /** 지금 쓸 수 있는 설계 지형 격자 — 아직 못 받았거나 없으면 null(그동안은 서버 길). */
+  grid(): { grid: DtmGrid; design: "las" | "sheet" } | null;
+  /** 서버 표본(`/route/elevations`) — 점 차례 그대로 · 무효 null · `signal` 로 끊김. */
+  remote(
+    points: Vertex[],
+    terrain: string | null,
+    signal: AbortSignal,
+  ): Promise<Array<number | null>>;
+  /** 횡단 반폭(m) — 비면 서버 기본(20 m). */
+  crossHalfWidthM?(): number | null;
+}
+
+const samePlace = (a: PipelineStation, b: PipelineStation): boolean =>
+  a.x === b.x && a.y === b.y && a.left[0] === b.left[0] && a.left[1] === b.left[1];
+
+const outside = (chainageM: number, range: { fromM: number; toM: number } | null): boolean =>
+  range !== null && (chainageM < range.fromM || chainageM > range.toM);
+
+export function createGroundStage(deps: GroundStageDeps): StageFn<"ground"> {
+  /** 앞 출력이 쓴 지형 · 노선 · 반폭 — 다르면 재사용 안 함. */
+  let last: { terrain: string; line: Vertex[] | null; halfWidth: number } | null = null;
+
+  return async (ctx) => {
+    const stations = ctx.out.stations ?? [];
+    const line = ctx.out.route?.line ?? null;
+    const terrain = ctx.inputs.route?.terrain ?? null;
+    const halfWidth = deps.crossHalfWidthM?.() ?? SECTION_CROSS_HALF_WIDTH_M;
+    const offsets = crossOffsets(halfWidth, SECTION_CROSS_SAMPLE_INTERVAL_M);
+    const local = deps.grid();
+    const useGrid = local !== null && (terrain === null || terrain === local.design);
+
+    const tag = terrain ?? "design";
+    const reusable = ctx.prev !== null && last?.terrain === tag && last.halfWidth === halfWidth;
+    const range = ctx.range;
+    const prevByKey = new Map((reusable ? ctx.prev!.stations : []).map((s) => [s.key, s]));
+
+    // 다시 셀 측점 — 범위 안 · 앞 출력에 없음 · 자리나 축이 바뀜.
+    const kept = stations.map((station) => {
+      const before = prevByKey.get(station.key);
+      return before?.ground && outside(station.chainageM, range) && samePlace(before, station)
+        ? before.ground
+        : null;
+    });
+
+    const long = line ? longitudinalPoints(line) : { chainage: [], xy: [] as Vertex[], lengthM: 0 };
+    // 종단 — 노선이 그대로면 통째 · 범위 앞쪽은 같은 노선 위라 그대로.
+    const prevLong = reusable ? ctx.prev!.longitudinal : null;
+    const longKept: Array<number | null | undefined> = long.chainage.map((c, i) => {
+      if (!prevLong || prevLong.chainageM[i] !== round6(c)) return undefined;
+      if (last?.line === line || (range !== null && c < range.fromM)) return prevLong.z[i];
+      return undefined;
+    });
+
+    const points: Vertex[] = [];
+    stations.forEach((station, i) => {
+      if (kept[i]) return;
+      for (const offset of offsets) {
+        points.push([station.x + station.left[0] * offset, station.y + station.left[1] * offset]);
+      }
+    });
+    long.xy.forEach((xy, i) => {
+      if (longKept[i] === undefined) points.push(xy);
+    });
+
+    let heights: Array<number | null>;
+    if (useGrid) {
+      heights = points.map(([x, y]) => {
+        const z = heightAt(local!.grid, x, y);
+        return Number.isNaN(z) ? null : round6(z);
+      });
+    } else {
+      heights = points.length ? await deps.remote(points, terrain, ctx.signal) : [];
+    }
+
+    let cursor = 0;
+    const filled: PipelineStation[] = stations.map((station, i) => {
+      if (kept[i]) return { ...station, ground: kept[i] };
+      const zs = offsets.map(() => heights[cursor++] ?? null);
+      return { ...station, ground: stationGround(offsets, zs) };
+    });
+    const z = long.chainage.map((_, i) =>
+      longKept[i] === undefined ? (heights[cursor++] ?? null) : (longKept[i] as number | null),
+    );
+    last = { terrain: tag, line, halfWidth };
+    const output: GroundOutput = {
+      stations: filled,
+      longitudinal: { chainageM: long.chainage.map(round6), z },
+    };
+    return output;
+  };
+}
+
+/** offset 열 표고 → 계약 꼴(중심 · 좌 · 우 · 중심에서 바깥 차례 · offsetM 양수). */
+function stationGround(offsets: number[], zs: Array<number | null>): StationGround {
+  const left: GroundSample[] = [];
+  const right: GroundSample[] = [];
+  let centerZ: number | null = null;
+  offsets.forEach((offset, i) => {
+    if (Math.abs(offset) <= 1e-9) centerZ = zs[i];
+    else if (offset > 0) left.push({ offsetM: round6(offset), z: zs[i] });
+    else right.unshift({ offsetM: round6(-offset), z: zs[i] });
+  });
+  return { centerZ, left, right };
+}
diff --git a/B05_Profile/logic/B05_Profile_Sections_Ground.ts b/B05_Profile/logic/B05_Profile_Sections_Ground.ts
index 299f2bc57..64c6f3dc7 100644
--- a/B05_Profile/logic/B05_Profile_Sections_Ground.ts
+++ b/B05_Profile/logic/B05_Profile_Sections_Ground.ts
@@ -70,7 +70,7 @@ export interface GroundOptions {
 }
 
 /** 파이썬 `round(x, 6)` 자리. */
-const round6 = (value: number): number => Math.round(value * 1e6) / 1e6;
+export const round6 = (value: number): number => Math.round(value * 1e6) / 1e6;
 const round9 = (value: number): number => Math.round(value * 1e9) / 1e9;
 
 function sample(grid: DtmGrid, x: number, y: number): GroundSample {
@@ -100,7 +100,7 @@ function cleanLine(line: ReadonlyArray<Vertex>): {
 }
 
 /** 횡단 offset 열 — `np.arange(-hw, hw + si/2, si)` · hw 넘는 것 버림 · 0 없으면 끼움. */
-function crossOffsets(halfWidth: number, interval: number): number[] {
+export function crossOffsets(halfWidth: number, interval: number): number[] {
   const count = Math.ceil((halfWidth + interval * 0.5 + halfWidth) / interval);
   const offsets: number[] = [];
   for (let i = 0; i < count; i += 1) {
@@ -114,6 +114,33 @@ function crossOffsets(halfWidth: number, interval: number): number[] {
   return offsets;
 }
 
+/** 종단 표본 자리 — 누가거리(간격 · 끝점 포함) · 자리 = `_interpolate_xy`(축마다 `np.interp`). */
+export function longitudinalPoints(
+  line: ReadonlyArray<Vertex>,
+  intervalM: number = SECTION_LONG_SAMPLE_INTERVAL_M,
+): { chainage: number[]; xy: Vertex[]; lengthM: number } {
+  const { xs, ys, chainage: along } = cleanLine(line);
+  const chainage = stationsAlong(line, intervalM, true);
+  const xy = chainage.map((c): Vertex => [npInterp(c, along, xs), npInterp(c, along, ys)]);
+  return { chainage, xy, lengthM: along[along.length - 1] ?? 0 };
+}
+
+/** 측점 자리 · 좌측 축 — 자리 = `_interpolate_xy` · 축 = 측점 틀 짝(`stationFrameAt`). 못 재면 뺌. */
+export function placeStations(
+  line: ReadonlyArray<Vertex>,
+  stationsM: ReadonlyArray<number>,
+  longIntervalM: number = SECTION_LONG_SAMPLE_INTERVAL_M,
+): Array<{ chainage: number; origin: Vertex; left: Vertex }> {
+  const { xs, ys, chainage: along } = cleanLine(line);
+  const probe = Math.max(longIntervalM, 0.5);
+  return stationsM.flatMap((chainage) => {
+    const frame = stationFrameAt(line, chainage, probe);
+    if (!frame) return [];
+    const origin: Vertex = [npInterp(chainage, along, xs), npInterp(chainage, along, ys)];
+    return [{ chainage, origin, left: frame.left }];
+  });
+}
+
 /** 노선 지반선 — 종단 표본 · 측점마다 중심 · 좌측 축 · 횡단 표본. `stationsM` = 측점 누가거리. */
 export function sectionsGround(
   line: ReadonlyArray<Vertex>,
@@ -124,15 +151,12 @@ export function sectionsGround(
   const halfWidth = options.crossHalfWidthM ?? SECTION_CROSS_HALF_WIDTH_M;
   const interval = options.crossSampleIntervalM ?? SECTION_CROSS_SAMPLE_INTERVAL_M;
   const longInterval = options.longSampleIntervalM ?? SECTION_LONG_SAMPLE_INTERVAL_M;
-  const probe = Math.max(longInterval, 0.5);
 
-  // 자리 = `_interpolate_xy`(축마다 `np.interp`) · 좌측 축만 측점 틀 짝(`stationFrameAt`).
-  const { xs, ys, chainage: along } = cleanLine(line);
-  const at = (c: number): Vertex => [npInterp(c, along, xs), npInterp(c, along, ys)];
-  const samples: LongGroundSample[] = stationsAlong(line, longInterval, true).map((chainage) => {
-    const [x, y] = at(chainage);
-    return { chainage_m: round6(chainage), ...sample(grid, x, y) };
-  });
+  const long = longitudinalPoints(line, longInterval);
+  const samples: LongGroundSample[] = long.chainage.map((chainage, i) => ({
+    chainage_m: round6(chainage),
+    ...sample(grid, long.xy[i][0], long.xy[i][1]),
+  }));
 
   const offsets = crossOffsets(halfWidth, interval);
   let center = 0;
@@ -141,11 +165,9 @@ export function sectionsGround(
   });
 
   const stations: StationGround[] = [];
-  for (const chainage of stationsM) {
-    const frame = stationFrameAt(line, chainage, probe);
-    if (!frame) continue;
-    const [ox, oy] = at(chainage);
-    const [lx, ly] = frame.left;
+  for (const { chainage, origin, left } of placeStations(line, stationsM, longInterval)) {
+    const [ox, oy] = origin;
+    const [lx, ly] = left;
     const cross: CrossGroundPoint[] = [];
     const raw: number[] = [];
     for (const offset of offsets) {
@@ -176,7 +198,7 @@ export function sectionsGround(
       samples: cross,
     });
   }
-  return { length_m: round6(along[along.length - 1] ?? 0), samples, stations };
+  return { length_m: round6(long.lengthM), samples, stations };
 }
 
 /** `np.interp(x, xp, fp)` — xp 오름차순 · 범위 밖은 끝값 · 식 차례도 numpy 와 같음. */
diff --git a/resources/tester/helper_311_panel_folded.cjs b/resources/tester/helper_311_panel_folded.cjs
index 69dc88514..b7d2d8bbe 100644
--- a/resources/tester/helper_311_panel_folded.cjs
+++ b/resources/tester/helper_311_panel_folded.cjs
@@ -176,6 +176,7 @@ const panel = design.createDesignPanel(
     parts: {
       structures: { root: node("section"), listRoot: node() },
       settings: { nodes: [text("a")] },
+      recommend: { nodes: [text("rec")] },
       crossView: { row: text("cross-row") },
       standardSlot: text("std"),
     },
diff --git a/resources/tester/helper_design_view_parity.cjs b/resources/tester/helper_design_view_parity.cjs
index 840f6d142..14d3a32da 100644
--- a/resources/tester/helper_design_view_parity.cjs
+++ b/resources/tester/helper_design_view_parity.cjs
@@ -197,6 +197,7 @@ const built = panel.createDesignPanel(
     parts: {
       structures: sample(),
       settings: { nodes: [text("a"), text("b")] },
+      recommend: { nodes: [text("rec")] },
       crossView: { row: text("cross-row") },
       standardSlot: text("std"),
     },
diff --git a/resources/tester/test_311_panel_folded.py b/resources/tester/test_311_panel_folded.py
index 24290e4b0..7b4aaf40a 100644
--- a/resources/tester/test_311_panel_folded.py
+++ b/resources/tester/test_311_panel_folded.py
@@ -42,6 +42,7 @@ def out():
 def test_B05_B06_첫_그림_접힘(out):
     assert out["profileFirst"] == {
         "페이지 설정": True,
+        "노선 추천": False,  # 345-4 단추 칸 — 펼친 채
     }
     assert out["crossFirst"]["B06_View_Title"] is True
     assert out["crossFirst"]["B06_Std_Title"] is True  # 옛 기본 접힘 그대로
diff --git a/resources/tester/test_345_4_recommend_panel.py b/resources/tester/test_345_4_recommend_panel.py
new file mode 100644
index 000000000..341579d3a
--- /dev/null
+++ b/resources/tester/test_345_4_recommend_panel.py
@@ -0,0 +1,61 @@
+"""345-4 노선 추천 → 좌측 새 칸 「노선 추천」(지운 「계획노선」 자리) — [노선 추천] · 현재 추천 · [초기화].
+
+· 칸 요소는 `_Panel_Recommend` 가 만들고 편집기(`_RouteEdit_Initial`)가 밖에서 받아 건다
+· 추천 창은 공용 모달 하나 · [적용] = 본문 평면에 되돌리기 한 칸(`restoreSnapshot(…, true)` → 이력 한 걸음)
+· 추천 창의 「지금 노선」은 본문 편집기 지금 노드
+칸 생김새 · 차례는 `test_design_view_parity` · `test_311_panel_folded` 가 봄(화면 확인은 브레인).
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def _read(rel: str) -> str:
+    return (ROOT / rel).read_text(encoding="utf-8")
+
+
+def test_칸_자리와_재료():
+    sections = _read("B05_Profile/B05_Profile_UI_Panel_Sections.ts")
+    at = sections.index('id: "route-recommend"')
+    block = sections[at : at + 300]
+    assert 'title: "노선 추천"' in block and "order: 30," in block  # 지운 계획노선 자리
+    assert 'part<RecommendPart>(ctx, "recommend").nodes' in block
+    panel = _read("B05_Profile/B05_Profile_UI_Panel.ts")
+    assert "const recommend = createRecommendPart();" in panel
+    assert "Object.assign(shared.parts, { settings, recommend });" in panel
+    view = _read("A00_Common/design/design_view_profile.ts")
+    assert "recommend: panel.recommend," in view
+
+
+def test_편집기가_칸_요소를_밖에서_받음():
+    initial = _read("B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts")
+    assert "overlay" not in initial
+    assert "const { recommendButton, resetButton, nowLine } = params.controls;" in initial
+    assert "current: params.planned().map(([x, y]) => [x, y])," in initial  # 지금 노선
+    main = _read("B05_Profile/B05_Profile_UI_RouteEdit.ts")
+    assert "controls: options.recommend," in main
+    assert "planned: () => planned," in main
+    assert len(main.splitlines()) <= 700
+
+
+def test_적용은_본문_평면에_되돌리기_한_칸():
+    main = _read("B05_Profile/B05_Profile_UI_RouteEdit.ts")
+    assert "apply: (snapshot, message) => restoreSnapshot(snapshot, message, true)," in main
+    restore = main[main.index("function restoreSnapshot(") :]
+    restore = restore[: restore.index("\n  }\n")]
+    assert "applyEdit(message, record);" in restore
+    apply_edit = main[main.index("function applyEdit(") :]
+    assert "if (record) history?.commit(snapshotNow());" in apply_edit[:600]
+    initial = _read("B05_Profile/B05_Profile_UI_RouteEdit_Initial.ts")
+    on_apply = initial[initial.index("onApply: (picked) => {") :]
+    assert on_apply[:500].count("params.apply(") == 1
+
+
+def test_추천_창은_공용_모달_하나():
+    rec = _read("B05_Profile/B05_Profile_UI_RouteEdit_Recommend.ts")
+    assert rec.count("openModal(") == 1
+    # 뒤 판(평면 · 종단도) 단축키가 창 안 Ctrl+Z 를 받지 않게 — 창 막에서 끊음
+    assert '?.closest(".ui-modal__backdrop")' in rec and "key.stopPropagation();" in rec
diff --git a/resources/tester/test_346_1_route_ground_stage.py b/resources/tester/test_346_1_route_ground_stage.py
new file mode 100644
index 000000000..9f25a8298
--- /dev/null
+++ b/resources/tester/test_346_1_route_ground_stage.py
@@ -0,0 +1,290 @@
+"""PLAN 346-1 — 계산 묶음 route · ground 단계(`logic/B05_Profile_Pipeline_RouteGround.ts`).
+
+route = 노선 초안 → 그린 노선(서버 `build_planned_polyline` 편집 갈래와 같은 선).
+ground = 측점 → 지반 채움 · 종단 지반선(서버 `generate_sections` 와 같은 표본).
+격자 없음 · 분석 지형 다름 = 서버 길 · 바뀐 범위 밖 재사용 · 노선 1,078 m 한 번 시간.
+"""
+
+from __future__ import annotations
+
+import csv
+import json
+import re
+import subprocess
+import sys
+from pathlib import Path
+
+import numpy as np
+import pytest
+
+ROOT = Path(__file__).resolve().parents[2]
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from B05_Profile import B05_Profile_Engine_Sections_Core as core  # noqa: E402
+from common_util.common_util_route_polyline import build_planned_polyline  # noqa: E402
+from common_util.common_util_surface_sampler import DtmGridSampler, dtm_grid_bytes  # noqa: E402
+
+TS_FILE = ROOT / "B05_Profile" / "logic" / "B05_Profile_Pipeline_RouteGround.ts"
+TSC = ROOT / "config" / "node_modules" / "typescript" / "bin" / "tsc"
+PROJECT = ROOT / "storage/1/3/1bb0f876-983f-4ca5-9cc7-f59ee1f77e0a"
+REAL_GRID = PROJECT / "B04_PreProcess/models/dtm_classification_smooth.npz"
+REAL_ROUTE = PROJECT / "B05_Profile/route/planned_route_initial.csv"
+REAL_NODES = PROJECT / "B05_Profile/route/planned_route_initial_nodes.csv"
+_TOL = 1.5e-6
+MIN_RADIUS_M = 12.0
+
+_RUNNER = """
+import { readFileSync, writeFileSync } from "node:fs";
+import { parseDtmGrid, heightAt } from "./common_util/common_util_surface_sampler.js";
+import { placeStations } from "./B05_Profile/logic/B05_Profile_Sections_Ground.js";
+import {
+  createRouteStage, createGroundStage,
+} from "./B05_Profile/logic/B05_Profile_Pipeline_RouteGround.js";
+const bytes = readFileSync(process.argv[2]);
+const grid = parseDtmGrid(bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + bytes.length));
+const job = JSON.parse(readFileSync(process.argv[3], "utf8"));
+const n = job.nodes.length;
+const draft = {
+  rev: 1, nodes: job.nodes, curveOn: Array(n).fill(true), curveRadius: Array(n).fill(null),
+  curveLock: Array(n).fill(null), curveArc: Array(n).fill(null), stationSnap: false, terrain: null,
+};
+const routeStage = createRouteStage({ minRadiusM: () => job.minRadius, savedLine: () => job.line });
+const ctxOf = (extra) => ({
+  generation: 1, range: null, signal: new AbortController().signal,
+  inputs: { route: null, alignment: null, cross: null, pipes: null, structures: null },
+  out: {}, before: {}, prev: null, ...extra,
+});
+const route = routeStage(ctxOf({ inputs: { route: draft } }));
+const saved = routeStage(ctxOf({}));
+let noRoute = null;
+try { createRouteStage({ minRadiusM: () => 12, savedLine: () => null })(ctxOf({})); }
+catch (error) { noRoute = String(error.message); }
+
+const line = job.line;
+const stations = placeStations(line, job.stations).map((s, i) => ({
+  key: `k${i}`, chainageM: s.chainage, x: s.origin[0], y: s.origin[1], azimuthDeg: 0,
+  left: s.left, kind: "grid", id: null, ground: null,
+  planRadiusM: null, curveOuterSide: null, curveWideningM: null,
+}));
+const lineOut = { line, chainage: [], lengthM: 0 };
+let remoteCalls = [];
+const remote = async (points, terrain) => {
+  remoteCalls.push({ count: points.length, terrain });
+  return points.map(([x, y]) => {
+    const z = heightAt(grid, x, y);
+    return Number.isNaN(z) ? null : Math.round(z * 1000) / 1000;
+  });
+};
+let ready = null;
+const ground = createGroundStage({ grid: () => ready, remote });
+const run = (extra) => ground(ctxOf({ out: { route: lineOut, stations }, ...extra }));
+
+const out = { route, saved, noRoute };
+out.serverPath = await run({});           // 격자 받기 전 = 서버 길
+out.serverCalls = remoteCalls; remoteCalls = [];
+ready = { grid, design: "las" };
+out.gridPath = await run({});             // 받은 뒤 = 브라우저 길
+out.gridCalls = remoteCalls.length;
+out.sheetPath = await run({ inputs: { route: { ...draft, terrain: "sheet" } } });
+out.sheetCalls = remoteCalls; remoteCalls = [];
+
+// 범위 밖 재사용 — 서버 길로 앞 출력을 받고 범위 [fromM, ∞) 만 다시
+ready = null;
+const reuseStage = createGroundStage({ grid: () => ready, remote });
+const first = await reuseStage(ctxOf({ out: { route: lineOut, stations } }));
+remoteCalls = [];
+const moved = stations.map((s, i) => (i === 1 ? { ...s, x: s.x + 0.5 } : s));
+const second = await reuseStage(ctxOf({
+  out: { route: lineOut, stations: moved }, prev: first,
+  range: { sources: ["grade"], fromM: job.fromM, toM: Infinity, keys: [] },
+}));
+out.reuseCalls = remoteCalls;
+out.reuse = second;
+ready = { grid, design: "las" };
+out.movedFull = await createGroundStage({ grid: () => ready, remote })(
+  ctxOf({ out: { route: lineOut, stations: moved } }));
+
+const timing = createGroundStage({ grid: () => ready, remote });
+for (let i = 0; i < 5; i += 1) await timing(ctxOf({ out: { route: lineOut, stations } }));
+const t0 = performance.now();
+for (let i = 0; i < 20; i += 1) await timing(ctxOf({ out: { route: lineOut, stations } }));
+out.ms = (performance.now() - t0) / 20;
+writeFileSync(process.argv[4], JSON.stringify(out));
+"""
+
+
+def _run_ts(tmp_path: Path, npz: Path, job: dict) -> dict:
+    out = tmp_path / "js"
+    subprocess.run(  # noqa: S603 — 고정 실행 파일
+        [
+            "node",
+            str(TSC),
+            str(TS_FILE),
+            "--outDir",
+            str(out),
+            "--rootDir",
+            str(ROOT),
+            "--module",
+            "esnext",
+            "--target",
+            "es2022",
+            "--moduleResolution",
+            "bundler",
+            "--ignoreConfig",
+        ],
+        cwd=str(ROOT),
+        check=True,
+        capture_output=True,
+    )
+    for emitted in out.rglob("*.js"):
+        emitted.write_text(
+            re.sub(r'(from\s+"\.\.?/[^"]+)"', r'\1.js"', emitted.read_text(encoding="utf-8")),
+            encoding="utf-8",
+        )
+    (out / "runner.mjs").write_text(_RUNNER, encoding="utf-8")
+    grid = tmp_path / "grid.bin"
+    grid.write_bytes(dtm_grid_bytes(npz))
+    payload = tmp_path / "job.json"
+    result = tmp_path / "out.json"
+    payload.write_text(json.dumps(job), encoding="utf-8")
+    subprocess.run(  # noqa: S603
+        ["node", str(out / "runner.mjs"), str(grid), str(payload), str(result)],
+        cwd=str(ROOT),
+        check=True,
+        capture_output=True,
+    )
+    return json.loads(result.read_text(encoding="utf-8"))
+
+
+def _read_xy(path: Path) -> list[list[float]]:
+    with path.open(encoding="utf-8") as handle:
+        return [[float(row["x"]), float(row["y"])] for row in csv.DictReader(handle)]
+
+
+def _contract_rows(station: dict) -> list[tuple[float, float | None]]:
+    """계약 꼴(중심 · 좌 · 우) → 서버 꼴 (offset, z) 오름차순."""
+    ground = station["ground"]
+    rows = [(-s["offsetM"], s["z"]) for s in ground["right"]]
+    rows += [(0.0, ground["centerZ"])] + [(s["offsetM"], s["z"]) for s in ground["left"]]
+    return sorted(rows)
+
+
+def _close(a, b, tol: float) -> bool:
+    return (a is None and b is None) or (
+        a is not None and b is not None and abs(float(a) - float(b)) <= tol
+    )
+
+
+def _fake_case(tmp_path: Path) -> tuple[Path, list, list, float]:
+    """가짜 격자 — 칸 폭 고르지 않음 · 빈칸 띠 · 노선이 빈칸 · 격자 끝을 지나감."""
+    rng = np.random.default_rng(3461)
+    x = (np.cumsum(rng.uniform(0.95, 1.1, 260)) + 1000.0).astype(np.float32)
+    y = (np.cumsum(rng.uniform(0.95, 1.1, 140)) + 2000.0).astype(np.float32)
+    xx, yy = np.meshgrid(x.astype(np.float64), y.astype(np.float64))
+    z = 500 + 0.08 * (xx - 1000) + 0.3 * (yy - 2000) + rng.normal(0, 0.2, xx.shape)
+    mask = np.ones(z.shape, dtype=bool)
+    mask[60:70, 100:115] = False
+    npz = tmp_path / "dtm_fake.npz"
+    np.savez(npz, x=x, y=y, z=z.astype(np.float32), valid_mask=mask)
+    nodes = [[1010.0, 2020.0], [1090.0, 2040.0], [1150.0, 2110.0], [1250.0, 2135.0]]
+    built = build_planned_polyline(
+        [tuple(n) for n in nodes],
+        min_radius_m=MIN_RADIUS_M,
+        simplify=False,
+        curve_flags=[True] * 4,
+        radii=[None] * 4,
+    )
+    return npz, [list(v) for v in built.vertices], nodes, 120.0
+
+
+def _real_case(_tmp_path: Path) -> tuple[Path, list, list, float]:
+    if not (REAL_GRID.is_file() and REAL_ROUTE.is_file() and REAL_NODES.is_file()):
+        pytest.skip("검증_sub8 없음")
+    return REAL_GRID, _read_xy(REAL_ROUTE), _read_xy(REAL_NODES), 600.0
+
+
+@pytest.mark.skipif(not TSC.is_file(), reason="프론트엔드 의존성 미설치")
+@pytest.mark.parametrize("case", [_fake_case, _real_case], ids=["가짜", "검증_sub8"])
+def test_route_ground_단계가_서버와_같고_범위_밖을_재사용한다(tmp_path: Path, case) -> None:
+    npz, line, nodes, from_m = case(tmp_path)
+    expected = core.generate_sections(
+        np.asarray(line, dtype=np.float64), DtmGridSampler.from_npz(npz)
+    )
+    stations = [s["chainage_m"] for s in expected["longitudinal"]["stations"]]
+    job = {
+        "line": line,
+        "nodes": nodes,
+        "minRadius": MIN_RADIUS_M,
+        "stations": stations,
+        "fromM": from_m,
+    }
+    out = _run_ts(tmp_path, npz, job)
+
+    # route — 서버 편집 갈래와 같은 선 · 누가거리 · 저장분 대체 · 노선 없음
+    built = build_planned_polyline(
+        [tuple(node) for node in nodes],
+        min_radius_m=MIN_RADIUS_M,
+        simplify=False,
+        curve_flags=[True] * len(nodes),
+        radii=[None] * len(nodes),
+    )
+    route = out["route"]
+    assert len(route["line"]) == len(built.vertices)
+    assert (
+        max(
+            abs(a - b)
+            for p, q in zip(route["line"], built.vertices, strict=True)
+            for a, b in zip(p, q)
+        )
+        < 1e-9
+    )
+    steps = np.hypot(*np.diff(np.asarray(built.vertices), axis=0).T)
+    assert abs(route["lengthM"] - float(steps.sum())) < 1e-6
+    assert route["chainage"][0] == 0 and len(route["chainage"]) == len(route["line"])
+    assert out["saved"]["line"] == line
+    assert out["noRoute"]
+
+    # ground 브라우저 길 = 서버 generate_sections(측점 · 횡단 · 종단)
+    grid_path = out["gridPath"]
+    assert out["gridCalls"] == 0
+    assert len(grid_path["stations"]) == len(expected["cross_sections"])
+    problems: list[str] = []
+    for ts, py in zip(grid_path["stations"], expected["cross_sections"], strict=True):
+        rows = _contract_rows(ts)
+        assert len(rows) == len(py["samples"])
+        for (offset, z), sample in zip(rows, py["samples"], strict=True):
+            if not (
+                _close(offset, sample["offset_m"], _TOL)
+                and _close(z, sample["z"] if sample["valid"] else None, _TOL)
+            ):
+                problems.append(f"측점 {py['chainage_m']} offset {sample['offset_m']}: {z}")
+        if not _close(ts["ground"]["centerZ"], py["center_z"], _TOL):
+            problems.append(f"측점 {py['chainage_m']} 중심 {ts['ground']['centerZ']}")
+    long_py = expected["longitudinal"]["samples"]
+    long_ts = grid_path["longitudinal"]
+    assert len(long_ts["z"]) == len(long_py)
+    for c, z, sample in zip(long_ts["chainageM"], long_ts["z"], long_py, strict=True):
+        if not (_close(c, sample["chainage_m"], _TOL) and _close(z, sample["z"], _TOL)):
+            problems.append(f"종단 {sample['chainage_m']}: {z}")
+    assert not problems, "\n".join(problems[:30])
+
+    # 서버 길 — 격자 받기 전 · 분석 지형 다름 · 값은 mm 자리로 같음
+    count = len(stations) * 81 + len(long_py)
+    assert out["serverCalls"] == [{"count": count, "terrain": None}]
+    assert out["sheetCalls"] == [{"count": count, "terrain": "sheet"}]
+    for ts, gs in zip(out["serverPath"]["stations"], grid_path["stations"], strict=True):
+        for (_o1, a), (_o2, b) in zip(_contract_rows(ts), _contract_rows(gs), strict=True):
+            assert _close(a, b, 5e-4)
+
+    # 범위 밖 재사용 — 다시 묻는 것 = 범위 안 측점 + 범위 밖이어도 자리가 바뀐 측점 하나
+    again = sum(1 for c in stations if c >= from_m) + 1
+    assert out["reuseCalls"] == [{"count": again * 81, "terrain": None}]
+    for ts, full in zip(out["reuse"]["stations"], out["movedFull"]["stations"], strict=True):
+        for (_o1, a), (_o2, b) in zip(_contract_rows(ts), _contract_rows(full), strict=True):
+            assert _close(a, b, 5e-4), f"재사용 값 다름 {ts['chainageM']}"
+    assert out["reuse"]["longitudinal"]["z"] == out["serverPath"]["longitudinal"]["z"]
+
+    # 한 번 전체 ground(검증_sub8 = 노선 1,078 m · 측점 55) — 0.3 s 예산 안 넉넉히
+    assert out["ms"] < 50, f"ground 단계 {out['ms']:.1f} ms"
+    print(f"ground 단계 {out['ms']:.2f} ms · 측점 {len(stations)} · 종단 {len(long_py)}")
diff --git a/resources/tester/test_b05_routeedit_initial.py b/resources/tester/test_b05_routeedit_initial.py
index c6c896877..ae7d1c855 100644
--- a/resources/tester/test_b05_routeedit_initial.py
+++ b/resources/tester/test_b05_routeedit_initial.py
@@ -167,13 +167,18 @@ def test_미리_보기_지도_선(results):
 
 
 def test_도구_막대는_노선_추천_하나만():
-    """편집 창 도구 막대 — [노선 추천] 하나 · 추천 묶음(로직 단추 · 슬라이더 · 제약 칸) 없음 ·
-    「연 상태로」 없음. 그 묶음은 모달(`_Recommend`)로 옮겼다."""
+    """[노선 추천] 하나 · 추천 묶음(로직 단추 · 슬라이더 · 제약 칸) 없음 · 「연 상태로」 없음. 그 묶음은
+    모달(`_Recommend`)로 옮겼다. 345-4 — [노선 추천] · [초기화] · 현재 추천은 편집 머리에서 좌측
+    「노선 추천」 칸(`_Panel_Recommend`)으로 옮김."""
     page = os.path.join(HERE, "..", "..", "B05_Profile")
     chrome = open(os.path.join(page, "B05_Profile_UI_RouteEdit_Chrome.ts"), encoding="utf-8").read()
-    assert chrome.count('data-act="recommend"') == 1
+    for gone in ('data-act="recommend"', 'data-act="reset"', "data-rec-now"):
+        assert gone not in chrome
     assert "연 상태로" not in chrome and "history-reset" not in chrome
-    assert chrome.index('data-act="recommend"') < chrome.index('data-act="contour-minor"')
+    part = open(os.path.join(page, "B05_Profile_UI_Panel_Recommend.ts"), encoding="utf-8").read()
+    assert part.count('data-act="recommend" disabled') == 1  # 단추 하나
+    assert part.count('data-act="reset" disabled') == 1
+    assert part.index('data-act="recommend" disabled') < part.index('data-act="reset" disabled')
     initial = open(
         os.path.join(page, "B05_Profile_UI_RouteEdit_Initial.ts"), encoding="utf-8"
     ).read()
@@ -203,9 +208,10 @@ def test_노선_추천_다듬기_23_3():
         return open(os.path.join(page, name), encoding="utf-8").read()
 
     chrome = read("B05_Profile_UI_RouteEdit_Chrome.ts")
-    rec = chrome.index('data-act="recommend"')
-    divider = chrome.index("b05-routeedit__divider", rec)
-    assert rec < divider < chrome.index('data-act="contour-minor"')
+    # 345-4 — [노선 추천]은 좌측 칸 · 머리 구분선은 [3D](tools) 뒤 · 되돌리기 앞 둘 그대로
+    tools = chrome.index('data-slot="tools"')
+    divider = chrome.index("b05-routeedit__divider", tools)
+    assert tools < divider < chrome.index('data-act="contour-minor"')
     assert chrome.count("b05-routeedit__divider") == 2
     shared = read("B05_Profile_UI_RouteEdit_Recommend_Map.ts")
     for name in ("bindRouteEditNavigation", "createMapRotation", "fitCanvas", "metricToScreen"):
diff --git a/resources/tester/test_design_view_parity.py b/resources/tester/test_design_view_parity.py
index 4a7a636cf..7618fb22d 100644
--- a/resources/tester/test_design_view_parity.py
+++ b/resources/tester/test_design_view_parity.py
@@ -59,8 +59,8 @@ def results():
 def test_보기를_오가도_좌측_패널_단추_구조물_배치는_같은_노드(results):
     assert results["sameNodes"] == {"cross": True, "back": True}
     # 보기마다 새로 만들지 않는다 — 칸은 처음 보일 때 한 번만 서고 뒤로는 숨김 · 보임만.
-    # 아래 고정 영역 + 종단 칸 둘 + 횡단 칸 둘(345-2 선택 포인트 · 345-3 계획노선 칸 지움)
-    assert results["childCount"] == 1 + 2 + 2
+    # 아래 고정 영역 + 종단 칸 셋 + 횡단 칸 둘(345-2 선택 포인트 · 345-3 계획노선 지움 · 345-4 노선 추천)
+    assert results["childCount"] == 1 + 3 + 2
 
 
 def test_구조물_배치는_두_보기_모두_맨_위_같은_DOM(results):
@@ -80,6 +80,7 @@ def test_보기마다_제_칸만_보인다(results):
     assert views["profile"]["shownTitles"] == [
         "구조물 배치",
         "페이지 설정",
+        "노선 추천",
     ]
     assert views["cross"]["shownTitles"] == ["구조물 배치", "횡단 보기 설정", "표준 횡단면 설정"]
     assert views["back"]["shownTitles"] == views["profile"]["shownTitles"]