diff --git a/crates/ghostlight-dungeon/src/compiler.rs b/crates/ghostlight-dungeon/src/compiler.rs
index c7ec1fe..f1a7d0d 100644
--- a/crates/ghostlight-dungeon/src/compiler.rs
+++ b/crates/ghostlight-dungeon/src/compiler.rs
@@ -1118,7 +1118,7 @@ impl WorldCompiler {
             .await?;
         let snapshot = format!("campaign:{}:revision:{}", campaign.id, campaign.revision);
         let base_prompt = format!(
-            "Compile only the requested bounded destination region. Every new location id must be new. Return explicit origin_routes owned by origin id {} into the new region, and give every such destination a reciprocal route back to the origin with the same positive travel time. Route IDs are globally unique. Do not rewrite existing geography. Every place has a non-empty name, valid container, and concrete persistent features. Any locally observable clue must already exist as a fact and list exact discoverable_at_location_ids from the combined existing and new topology; later action assessment can reveal facts but cannot invent them. CAMPAIGN LOCATIONS:\n{}\nREQUEST:\n{}\nEVIDENCE:\n{}",
+            "Compile only the requested bounded destination region. Every new location id must be new. Return explicit origin_routes owned by origin id {} into the new region, and give every such destination a reciprocal route back to the origin with the same positive travel time. Route IDs are stable keys local to their exact origin location; the same local key may exist under another origin without naming the same route. Do not rewrite existing geography. Every place has a non-empty name, valid container, and concrete persistent features. Any locally observable clue must already exist as a fact and list exact discoverable_at_location_ids from the combined existing and new topology; later action assessment can reveal facts but cannot invent them. CAMPAIGN LOCATIONS:\n{}\nREQUEST:\n{}\nEVIDENCE:\n{}",
             origin_location_id,
             serde_json::to_string(&campaign.locations)?,
             destination_request,
@@ -2447,12 +2447,17 @@ pub fn validate_region_expansion(
         .iter()
         .map(|location| (location.id.as_str(), location))
         .collect::<BTreeMap<_, _>>();
-    let existing_route_ids = campaign
+    let existing_origin_route_ids = campaign
         .locations
-        .values()
-        .flat_map(|location| location.routes.keys().map(String::as_str))
-        .collect::<BTreeSet<_>>();
-    let mut new_route_ids = BTreeSet::new();
+        .get(&expansion.origin_location_id)
+        .map(|location| {
+            location
+                .routes
+                .keys()
+                .map(String::as_str)
+                .collect::<BTreeSet<_>>()
+        })
+        .unwrap_or_default();
     if expansion.origin_routes.is_empty() {
         return Err(anyhow!(
             "destination expansion has no explicit route from the origin"
@@ -2460,8 +2465,7 @@ pub fn validate_region_expansion(
     }
     for (route_id, route) in &expansion.origin_routes {
         if route_id.trim().is_empty()
-            || existing_route_ids.contains(route_id.as_str())
-            || !new_route_ids.insert(route_id.as_str())
+            || existing_origin_route_ids.contains(route_id.as_str())
             || route.travel_minutes == 0
             || route.distance.trim().is_empty()
             || !new_ids.contains(route.destination_id.as_str())
@@ -2505,8 +2509,6 @@ pub fn validate_region_expansion(
         }
         for (route_id, route) in &location.routes {
             if route_id.trim().is_empty()
-                || existing_route_ids.contains(route_id.as_str())
-                || !new_route_ids.insert(route_id.as_str())
                 || route.travel_minutes == 0
                 || route.distance.trim().is_empty()
                 || !known(&route.destination_id)
@@ -5065,6 +5067,26 @@ mod tests {
         );
     }
 
+    #[test]
+    fn region_expansion_route_keys_are_local_to_their_origin() {
+        let campaign = crate::resolution::tests::campaign(0, 1);
+        let mut expansion = valid_region_expansion();
+        let outward = expansion
+            .origin_routes
+            .remove("route:center-annex")
+            .unwrap();
+        expansion.origin_routes.insert("road".into(), outward);
+        let returning = expansion.locations[0]
+            .routes
+            .remove("route:annex-center")
+            .unwrap();
+        expansion.locations[0]
+            .routes
+            .insert("road".into(), returning);
+
+        validate_region_expansion(&campaign, &expansion).unwrap();
+    }
+
     #[test]
     fn region_expansion_rejects_containment_cycles() {
         let campaign = crate::resolution::tests::campaign(0, 1);
diff --git a/crates/ghostlight-dungeon/src/kernel.rs b/crates/ghostlight-dungeon/src/kernel.rs
index 21ce569..5039a25 100644
--- a/crates/ghostlight-dungeon/src/kernel.rs
+++ b/crates/ghostlight-dungeon/src/kernel.rs
@@ -7246,6 +7246,23 @@ mod tests {
                 travel_minutes: 20,
             },
         );
+        seed.locations.insert(
+            "yard".into(),
+            Location {
+                id: "yard".into(),
+                name: "Yard".into(),
+                container_id: None,
+                routes: BTreeMap::from([(
+                    "harbor".into(),
+                    Route {
+                        destination_id: "harbor".into(),
+                        distance: "farther away".into(),
+                        travel_minutes: 45,
+                    },
+                )]),
+                persistent_features: vec!["freight apron".into()],
+            },
+        );
         let membership = two_player_membership(&mut seed);
         let campaign_id = seed.id;
         let start_time = seed.world_time;
diff --git a/crates/ghostlight-dungeon/src/legacy_transition.rs b/crates/ghostlight-dungeon/src/legacy_transition.rs
index d64c782..f47ebd2 100644
--- a/crates/ghostlight-dungeon/src/legacy_transition.rs
+++ b/crates/ghostlight-dungeon/src/legacy_transition.rs
@@ -94,7 +94,12 @@ pub fn lower_group_travel(
     let route_minutes = campaign
         .locations
         .get(origin_location_id)
-        .and_then(|location| location.routes.get(&route_id))
+        .and_then(|location| {
+            location
+                .routes
+                .values()
+                .find(|route| route.destination_id == destination_location_id)
+        })
         .map(|route| route.travel_minutes)
         .ok_or_else(|| anyhow!("group travel route vanished"))?;
     if route_minutes != travel_minutes {
@@ -300,7 +305,7 @@ pub fn lower_region_expansion(
     for (route_id, route) in &expansion.origin_routes {
         mutations.push(WorldMutation::ChangeTopology {
             operation: TopologyMutationOperation::Add,
-            edge_id: route_id.clone(),
+            edge_id: component_route_id(&expansion.origin_location_id, route_id),
             from_place: origin.clone(),
             to_place: place_subject(&route.destination_id),
             distance: Some(route.distance.clone()),
@@ -311,7 +316,7 @@ pub fn lower_region_expansion(
         for (route_id, route) in &location.routes {
             mutations.push(WorldMutation::ChangeTopology {
                 operation: TopologyMutationOperation::Add,
-                edge_id: route_id.clone(),
+                edge_id: component_route_id(&location.id, route_id),
                 from_place: place_subject(&location.id),
                 to_place: place_subject(&route.destination_id),
                 distance: Some(route.distance.clone()),
@@ -362,13 +367,18 @@ fn project_accepted_region_expansion(
             .place_profiles
             .get(&subject)
             .ok_or_else(|| anyhow!("accepted expansion lost a place profile"))?;
-        let routes = next
-            .topology
-            .values()
-            .filter(|edge| edge.from_place == subject && edge.open)
-            .map(|edge| {
+        let routes = requested
+            .routes
+            .keys()
+            .map(|route_id| {
+                let edge_id = component_route_id(&requested.id, route_id);
+                let edge = next
+                    .topology
+                    .get(&edge_id)
+                    .filter(|edge| edge.from_place == subject && edge.open)
+                    .ok_or_else(|| anyhow!("accepted expansion lost a local route"))?;
                 Ok((
-                    edge.id.clone(),
+                    route_id.clone(),
                     crate::domain::Route {
                         destination_id: edge.to_place.id.clone(),
                         distance: edge.distance.clone(),
@@ -398,9 +408,10 @@ fn project_accepted_region_expansion(
         .get_mut(&expansion.origin_location_id)
         .ok_or_else(|| anyhow!("accepted expansion origin vanished"))?;
     for route_id in expansion.origin_routes.keys() {
+        let edge_id = component_route_id(&expansion.origin_location_id, route_id);
         let edge = next
             .topology
-            .get(route_id)
+            .get(&edge_id)
             .filter(|edge| edge.from_place.id == expansion.origin_location_id && edge.open)
             .ok_or_else(|| anyhow!("accepted expansion lost an origin route"))?;
         origin.routes.insert(
@@ -1083,12 +1094,16 @@ fn exact_route_id(campaign: &Campaign, origin: &str, destination: &str) -> Resul
         .get(origin)
         .and_then(|location| {
             location.routes.iter().find_map(|(route_id, route)| {
-                (route.destination_id == destination).then(|| route_id.clone())
+                (route.destination_id == destination).then(|| component_route_id(origin, route_id))
             })
         })
         .ok_or_else(|| anyhow!("strategic relocation has no exact topology edge"))
 }
 
+fn component_route_id(origin: &str, local_route_id: &str) -> String {
+    format!("route:{}:{origin}:{local_route_id}", origin.len())
+}
+
 pub fn digest_serializable<T: serde::Serialize + ?Sized>(value: &T) -> Result<String> {
     let bytes = rmp_serde::to_vec_named(value)?;
     Ok(format!("sha256:{:x}", Sha256::digest(bytes)))
@@ -1174,17 +1189,8 @@ fn foreground_mutations(
             .actors
             .get(actor_id)
             .ok_or_else(|| anyhow!("outcome actor vanished"))?;
-        let location = campaign
-            .locations
-            .get(&actor.location_id)
-            .ok_or_else(|| anyhow!("actor origin vanished"))?;
-        let route_id = location
-            .routes
-            .iter()
-            .find_map(|(route_id, route)| {
-                (route.destination_id == *destination_id).then(|| route_id.clone())
-            })
-            .ok_or_else(|| anyhow!("outcome movement has no exact route"))?;
+        let route_id = exact_route_id(campaign, &actor.location_id, destination_id)
+            .map_err(|_| anyhow!("outcome movement has no exact route"))?;
         mutations.push(WorldMutation::Relocate {
             subject: actor_subject(actor_id),
             from_place: place_subject(&actor.location_id),
@@ -1695,10 +1701,11 @@ fn component_snapshot(campaign: &Campaign) -> Result<ComponentWorldState> {
     }
     for location in campaign.locations.values() {
         for (route_id, route) in &location.routes {
+            let edge_id = component_route_id(&location.id, route_id);
             state.topology.insert(
-                route_id.clone(),
+                edge_id.clone(),
                 TopologyComponentState {
-                    id: route_id.clone(),
+                    id: edge_id,
                     from_place: place_subject(&location.id),
                     to_place: place_subject(&route.destination_id),
                     distance: route.distance.clone(),
diff --git a/crates/ghostlight-dungeon/src/surface.rs b/crates/ghostlight-dungeon/src/surface.rs
index 157b251..a20f23d 100644
--- a/crates/ghostlight-dungeon/src/surface.rs
+++ b/crates/ghostlight-dungeon/src/surface.rs
@@ -234,18 +234,19 @@ pub fn player_surface_for_actor(campaign: &Campaign, viewer_actor_id: &str) -> V
     } else {
         let default_destination_id = location
             .routes
-            .keys()
+            .values()
             .next()
+            .map(|route| route.destination_id.as_str())
             .expect("non-empty routes have a first destination");
         children.push(json!({
             "id":"dungeon.travel.destination",
             "kind":"control.select",
             "props":{"label":"Group destination","value":default_destination_id},
             "stateBindings":[local_draft("destination_location_id","choice")],
-            "children":location.routes.iter().filter_map(|(destination_id,route)|campaign.locations.get(destination_id).map(|destination|json!({
-                "id":format!("dungeon.travel.option.{destination_id}"),
+            "children":location.routes.values().filter_map(|route|campaign.locations.get(&route.destination_id).map(|destination|json!({
+                "id":format!("dungeon.travel.option.{}",route.destination_id),
                 "kind":"control.option",
-                "props":{"value":destination_id,"label":format!("{} · {} minutes · {}",destination.name,route.travel_minutes,route.distance)},
+                "props":{"value":route.destination_id,"label":format!("{} · {} minutes · {}",destination.name,route.travel_minutes,route.distance)},
                 "children":[]
             }))).collect::<Vec<_>>()
         }));
@@ -272,7 +273,7 @@ pub fn player_surface_for_actor(campaign: &Campaign, viewer_actor_id: &str) -> V
       "world_revision":campaign.revision,
       "viewer_actor_id":viewer_actor_id,
       "player_location_id":player.location_id,
-      "reachable_destinations":location.routes.iter().filter_map(|(destination_id,route)|campaign.locations.get(destination_id).map(|destination|json!({"id":destination_id,"name":destination.name,"travel_minutes":route.travel_minutes,"distance":route.distance}))).collect::<Vec<_>>(),
+      "reachable_destinations":location.routes.values().filter_map(|route|campaign.locations.get(&route.destination_id).map(|destination|json!({"id":route.destination_id,"name":destination.name,"travel_minutes":route.travel_minutes,"distance":route.distance}))).collect::<Vec<_>>(),
       "resolution":{
         "policy":campaign.resolution_policy,
         "effective_budget":effective_budget,
@@ -781,7 +782,7 @@ mod tests {
             },
         );
         campaign.locations.get_mut("center").unwrap().routes.insert(
-            "harbor".into(),
+            "road-to-harbor".into(),
             crate::domain::Route {
                 destination_id: "harbor".into(),
                 distance: "nearby".into(),
diff --git a/docs/architecture/ghostlight-transition-algebra.md b/docs/architecture/ghostlight-transition-algebra.md
index d2e36d8..5f52f63 100644
--- a/docs/architecture/ghostlight-transition-algebra.md
+++ b/docs/architecture/ghostlight-transition-algebra.md
@@ -245,6 +245,13 @@ Components are sparse. A place does not need knowledge; a proposition does not
 need occupancy. Component applicability is determined by subject kind and the
 specific admitted entity, not by a universal bag of optional fields.
 
+Route keys are scoped to their owning origin location. Canonical route identity
+is therefore the pair `(origin_location_id, local_route_id)`, never the bare
+map key. The transition overlay encodes that pair into a collision-free edge
+identity before validation and maps accepted edges back to the original local
+keys. Surface projections use each route's exact `destination_id`; they do not
+reinterpret a local route key as a destination or global edge ID.
+
 ## The mutation vocabulary
 
 `WorldMutation` is a closed tagged union. Each variant owns one semantic
diff --git a/notes/ghostlight-current-system-map.md b/notes/ghostlight-current-system-map.md
index badc0a8..0ceccb6 100644
--- a/notes/ghostlight-current-system-map.md
+++ b/notes/ghostlight-current-system-map.md
@@ -1019,7 +1019,12 @@ proposition content, evidence references, discovery locations, containment,
 route identity, distance, and topology are validated on the component overlay;
 the aggregate `Location`, `Route`, and `WorldFact` rows are reconstructed only
 from accepted component state. The previous direct location/fact insertion
-loops are gone.
+loops are gone. A route map key is local to its exact origin. The component
+overlay derives its edge identity from `(origin_location_id, local_route_id)`;
+the player surface uses the route's exact destination field, and accepted
+region expansion restores the original local key. Reusing `road`, `harbor`, or
+a destination-shaped key under another location cannot overwrite an unrelated
+edge or make a surface-advertised route fail transition admission.
 
 Initial compiler publication is a bounded creation transaction, not a fictional
 world transition. `CampaignRegistry` owns discoverability, installs the