diff --git a/src/commands/path-junction-maintenance.ts b/src/commands/path-junction-maintenance.ts
new file mode 100644
index 00000000..ae9215bc
--- /dev/null
+++ b/src/commands/path-junction-maintenance.ts
@@ -0,0 +1,40 @@
+import { cloneScenePath, type ScenePath } from "../document/paths";
+import type { SceneDocument } from "../document/scene-document";
+import {
+  cloneSplineCorridorJunction,
+  type SplineCorridorJunctionRegistry
+} from "../document/spline-corridor-junctions";
+import { reattachSplineCorridorJunctionsToPaths } from "../spline-corridor/spline-corridor-junctions";
+
+export function cloneSplineCorridorJunctionRegistry(
+  junctions: SplineCorridorJunctionRegistry
+): SplineCorridorJunctionRegistry {
+  return Object.fromEntries(
+    Object.entries(junctions).map(([junctionId, junction]) => [
+      junctionId,
+      cloneSplineCorridorJunction(junction)
+    ])
+  );
+}
+
+export function setScenePathAndReattachJunctions(
+  document: SceneDocument,
+  path: ScenePath
+): SceneDocument {
+  const nextPath = cloneScenePath(path);
+  const nextPaths = {
+    ...document.paths,
+    [nextPath.id]: nextPath
+  };
+
+  return {
+    ...document,
+    paths: nextPaths,
+    splineCorridorJunctions: reattachSplineCorridorJunctionsToPaths({
+      paths: Object.values(nextPaths),
+      junctions: document.splineCorridorJunctions,
+      changedPathIds: [nextPath.id],
+      terrains: Object.values(document.terrains)
+    })
+  };
+}