511NY DOT cameras + traffic events map layers (#183)

GET /traffic/511 serves a bbox slice of the statewide 511NY camera and event
feeds from an in-memory cache (cameras 1h, events 2m TTL, fetched lazily) --
public data, so no Firestore writes. A failed refresh keeps the last good data
and reports the error; a schema change (nothing parses) is an error, not an
empty layer. Frontend: opt-in "DOT Cameras" and "Traffic Events" overlays that
fetch only while shown, with an on-map notice when the feed is down or stale.
NY511_API_KEY is optional in config (the API answers without one today; the
terms require a registered key).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

drb-c2-core/.env.example

@@ -26,6 +26,7 @@ NODE_OFFLINE_THRESHOLD=90
 # Google Maps — for geocoding location strings extracted from transcripts
 # Enable "Geocoding API" in Cloud Console for this key
 GOOGLE_MAPS_API_KEY=
+NY511_API_KEY=
 
 # OpenAI — for transcription (Whisper), intelligence extraction, embeddings, and summaries
 OPENAI_API_KEY=

drb-c2-core/app/config.py

@@ -32,6 +32,9 @@ class Settings(BaseSettings):
 
     # Google Maps (geocoding)
     google_maps_api_key: Optional[str] = None
+    # 511NY developer key (server-26#183). Optional: the API answered without one
+    # as of 2026-09-27, but its terms require a registered key.
+    ny511_api_key: Optional[str] = None
 
     # Gemini (intelligence extraction, embeddings, incident summaries)
     gemini_api_key: Optional[str] = None

drb-c2-core/app/internal/mqtt_handler.py

@@ -114,7 +114,7 @@ class MQTTHandler:
                 "secondary_sdr_mode": payload.get("secondary_sdr_mode", "none"),
                 "secondary_sdr_priority": payload.get("secondary_sdr_priority", []),
                 "secondary_sdr_running": payload.get("secondary_sdr_running"),
-                "sdr_count": payload.get("sdr_count", 1),
+                "sdr_count": payload.get("sdr_count"),  # None until reported, never a guessed 1
                 "enforce_override_timeout": payload.get("enforce_override_timeout", True),
                 "is_overridden": False,
                 "override_system_id": None,

drb-c2-core/app/internal/ny511.py

@@ -0,0 +1,140 @@
+"""511NY (NYSDOT) traffic cameras and events, cached in memory (server-26#183).
+
+Public data, identical for every org, so it is NOT written to Firestore: the
+statewide feeds are ~3k cameras and ~2.3k events, and re-writing them every
+poll would be millions of writes a day for data nobody needs history of. The
+cache is filled lazily on request and refreshed per TTL, so an idle deploy
+makes no 511 calls at all.
+
+A failed refresh keeps serving the last good data and reports the error and
+its age to the caller -- an empty layer must never be the only symptom of a
+dead feed (the AI-silent-failures lesson).
+"""
+import asyncio
+import time
+from datetime import datetime
+from typing import Any, Dict, List, Optional
+
+import httpx
+
+from app.config import settings
+from app.internal.logger import logger
+
+_BASE = "https://511ny.org/api"
+CAMERAS_TTL_S = 60 * 60   # camera list is near-static
+EVENTS_TTL_S = 2 * 60     # accidents/closures change minute to minute
+RETRY_AFTER_FAILURE_S = 60
+_DESCRIPTION_MAX = 500
+
+
+class _Feed:
+    def __init__(self, path: str, ttl_s: int, normalize):
+        self.path = path
+        self.ttl_s = ttl_s
+        self.normalize = normalize
+        self.items: List[Dict[str, Any]] = []
+        self.fetched_at: Optional[float] = None   # epoch s of last SUCCESSFUL fetch
+        self.error: Optional[str] = None
+        self._next_attempt = 0.0
+        self._lock = asyncio.Lock()
+
+    async def get(self) -> "_Feed":
+        if time.time() < self._next_attempt:
+            return self
+        async with self._lock:
+            if time.time() < self._next_attempt:
+                return self   # another request refreshed while we waited
+            try:
+                self.items = await _fetch(self.path, self.normalize)
+                self.fetched_at = time.time()
+                self.error = None
+                self._next_attempt = time.time() + self.ttl_s
+            except Exception as e:
+                self._next_attempt = time.time() + min(self.ttl_s, RETRY_AFTER_FAILURE_S)
+                self.error = f"{type(e).__name__}: {e}"[:300]
+                logger.warning(f"511NY {self.path} refresh failed, serving {len(self.items)} cached: {self.error}")
+        return self
+
+
+async def _fetch(path: str, normalize) -> List[Dict[str, Any]]:
+    params = {"format": "json"}
+    if settings.ny511_api_key:
+        params["key"] = settings.ny511_api_key
+    async with httpx.AsyncClient(timeout=20.0) as client:
+        r = await client.get(f"{_BASE}/{path}", params=params)
+        r.raise_for_status()
+        raw = r.json()
+    if not isinstance(raw, list):
+        raise ValueError(f"expected a JSON list, got {type(raw).__name__}")
+    out = [n for n in (normalize(x) for x in raw) if n is not None]
+    if raw and not out:
+        # every record failed to normalize: the schema changed under us
+        raise ValueError(f"0 of {len(raw)} records parsed -- 511NY schema change?")
+    return out
+
+
+def _coords(x: Dict[str, Any]) -> Optional[tuple]:
+    try:
+        lat, lon = float(x["Latitude"]), float(x["Longitude"])
+    except (KeyError, TypeError, ValueError):
+        return None
+    if lat == 0 and lon == 0:
+        return None
+    return lat, lon
+
+
+def _local_iso(s: Any) -> Optional[str]:
+    """511NY stamps are 'DD/MM/YYYY HH:MM:SS' New York local time. Returned as a
+    naive ISO string (no offset) -- display-only, never compared to UTC."""
+    if not s:
+        return None
+    try:
+        return datetime.strptime(s, "%d/%m/%Y %H:%M:%S").isoformat()
+    except (TypeError, ValueError):
+        return None
+
+
+def normalize_camera(x: Dict[str, Any]) -> Optional[Dict[str, Any]]:
+    c = _coords(x)
+    if c is None or x.get("Disabled") or x.get("Blocked") or not x.get("ID"):
+        return None
+    return {
+        "id": x["ID"],
+        "lat": c[0],
+        "lon": c[1],
+        "name": x.get("Name") or "",
+        "roadway": x.get("RoadwayName") or "",
+        "direction": x.get("DirectionOfTravel") or "",
+        "image_url": x.get("Url"),      # 511NY serves the current still at this URL
+        "video_url": x.get("VideoUrl"),  # HLS playlist, when the camera streams
+    }
+
+
+def normalize_event(x: Dict[str, Any]) -> Optional[Dict[str, Any]]:
+    c = _coords(x)
+    if c is None or not x.get("ID"):
+        return None
+    desc = x.get("Description") or ""
+    return {
+        "id": x["ID"],
+        "lat": c[0],
+        "lon": c[1],
+        "type": x.get("EventType") or "",
+        "subtype": x.get("EventSubType") or "",
+        "severity": x.get("Severity") or "",
+        "roadway": x.get("RoadwayName") or "",
+        "direction": x.get("DirectionOfTravel") or "",
+        "county": x.get("CountyName") or "",
+        "description": desc[:_DESCRIPTION_MAX] + ("…" if len(desc) > _DESCRIPTION_MAX else ""),
+        "start_local": _local_iso(x.get("StartDate")),
+        "planned_end_local": _local_iso(x.get("PlannedEndDate")),
+        "updated_local": _local_iso(x.get("LastUpdated")),
+    }
+
+
+cameras = _Feed("getcameras", CAMERAS_TTL_S, normalize_camera)
+events = _Feed("getevents", EVENTS_TTL_S, normalize_event)
+
+
+def in_bbox(items: List[Dict[str, Any]], south: float, west: float, north: float, east: float) -> List[Dict[str, Any]]:
+    return [i for i in items if south <= i["lat"] <= north and west <= i["lon"] <= east]

drb-c2-core/app/main.py

@@ -17,7 +17,7 @@ from app.internal.auth import (
     require_node_service_or_firebase_token,
 )
 from app.routers import nodes, systems, calls, upload, tokens, incidents, alerts, admin, trips, places, links, users
-from app.routers import enrollment, media, org, waitlist, telemetry, replay
+from app.routers import enrollment, media, org, waitlist, telemetry, replay, traffic
 from app.internal import dynsec
 from app.internal import firestore as fstore
 
@@ -127,6 +127,7 @@ app.include_router(incidents.router, dependencies=[Depends(require_service_or_fi
 app.include_router(alerts.router,    dependencies=[Depends(require_service_or_firebase_token)])
 app.include_router(trips.router,     dependencies=[Depends(require_service_or_firebase_token)])
 app.include_router(places.router,    dependencies=[Depends(require_service_or_firebase_token)])
+app.include_router(traffic.router,   dependencies=[Depends(require_service_or_firebase_token)])
 app.include_router(upload.router)    # auth is per-node, handled inline
 app.include_router(admin.router)     # auth is per-endpoint (read: firebase, write: admin)
 app.include_router(replay.router)    # auth: admin only (every route spends or reads a replay run)

drb-c2-core/app/models.py

@@ -68,7 +68,7 @@ class NodeRecord(BaseModel):
     # checkin, which is the source of truth; set via PATCH /nodes/{id}.
     secondary_sdr_priority: List[str] = []
     secondary_sdr_running: Optional[List[str]] = None  # what the node reports actually running
-    sdr_count: int = 1  # self-reported by the node's checkin, best-effort
+    sdr_count: Optional[int] = None  # self-reported by the node's checkin; None = never reported
     enforce_override_timeout: bool = True
     is_overridden: bool = False
     override_system_id: Optional[str] = None

drb-c2-core/app/routers/traffic.py

@@ -0,0 +1,38 @@
+import asyncio
+from typing import Optional
+
+from fastapi import APIRouter, HTTPException, Query
+
+from app.internal import ny511
+
+router = APIRouter(prefix="/traffic", tags=["traffic"])
+
+# Per-layer cap per response. A statewide view is ~3k cameras; past this the
+# map is unreadable anyway, and the client is told the list was cut.
+MAX_ITEMS = 1500
+
+
+def _feed_status(feed: "ny511._Feed") -> dict:
+    return {"fetched_at": feed.fetched_at, "error": feed.error}
+
+
+@router.get("/511")
+async def get_511(
+    south: float = Query(..., ge=-90, le=90),
+    west: float = Query(..., ge=-180, le=180),
+    north: float = Query(..., ge=-90, le=90),
+    east: float = Query(..., ge=-180, le=180),
+    layers: Optional[str] = Query("cameras,events", description="comma list: cameras, events"),
+):
+    if south > north or west > east:
+        raise HTTPException(400, "bbox must satisfy south<=north and west<=east")
+    wanted = {s.strip() for s in (layers or "").split(",") if s.strip()}
+    feeds = {name: getattr(ny511, name) for name in ("cameras", "events") if name in wanted}
+    await asyncio.gather(*(f.get() for f in feeds.values()))
+
+    out: dict = {}
+    for name, feed in feeds.items():
+        hits = ny511.in_bbox(feed.items, south, west, north, east)
+        out[name] = hits[:MAX_ITEMS]
+        out[f"{name}_status"] = {**_feed_status(feed), "total_in_bbox": len(hits), "truncated": len(hits) > MAX_ITEMS}
+    return out

drb-c2-core/tests/test_ny511.py

@@ -0,0 +1,98 @@
+"""
+server-26#183 — 511NY cameras/events layer.
+
+The feed is scraped from a third party, so the tests pin the two failure shapes
+that would otherwise look like "no traffic right now": a refresh error must keep
+the last good data AND report the error, and a schema change (every record
+unparseable) must be an error, not an empty list.
+"""
+import asyncio
+from unittest.mock import AsyncMock, patch
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+from app.internal import ny511
+from app.internal.auth import require_service_or_firebase_token
+
+client = TestClient(app)
+
+CAM = {"Latitude": 41.03, "Longitude": -73.76, "ID": "NYSDOT-1", "Name": "I-287 at Exit 5",
+       "DirectionOfTravel": "Unknown", "RoadwayName": "I-287", "Url": "https://511ny.org/map/Cctv/1",
+       "VideoUrl": None, "Disabled": False, "Blocked": False}
+EVENT = {"Latitude": 41.019265, "Longitude": -73.797869, "ID": "TRANSCOM-1", "EventType": "roadwork",
+         "EventSubType": "Gas main repairs", "Severity": "Unknown", "RoadwayName": "NY 100",
+         "DirectionOfTravel": "Both directions", "CountyName": "Westchester", "Description": "x" * 900,
+         "StartDate": "28/09/2026 09:00:00", "PlannedEndDate": "", "LastUpdated": "26/09/2026 14:01:12"}
+
+
+def setup_function():
+    app.dependency_overrides[require_service_or_firebase_token] = lambda: {"admin": True}
+    for feed in (ny511.cameras, ny511.events):
+        feed.items, feed.fetched_at, feed.error, feed._next_attempt = [], None, None, 0.0
+
+
+def teardown_function():
+    app.dependency_overrides.pop(require_service_or_firebase_token, None)
+
+
+def test_normalize_camera_skips_disabled_blocked_and_zero_coords():
+    assert ny511.normalize_camera(CAM)["image_url"] == "https://511ny.org/map/Cctv/1"
+    assert ny511.normalize_camera({**CAM, "Disabled": True}) is None
+    assert ny511.normalize_camera({**CAM, "Blocked": True}) is None
+    assert ny511.normalize_camera({**CAM, "Latitude": 0, "Longitude": 0}) is None
+
+
+def test_normalize_event_parses_day_first_dates_and_truncates_description():
+    e = ny511.normalize_event(EVENT)
+    assert e["start_local"] == "2026-09-28T09:00:00"   # DD/MM, not MM/DD
+    assert e["planned_end_local"] is None
+    assert len(e["description"]) == ny511._DESCRIPTION_MAX + 1
+
+
+def test_failed_refresh_keeps_last_good_data_and_reports_error():
+    feed = ny511._Feed("getcameras", 3600, ny511.normalize_camera)
+    with patch.object(ny511, "_fetch", AsyncMock(return_value=[ny511.normalize_camera(CAM)])):
+        asyncio.run(feed.get())
+    feed._next_attempt = 0.0
+    with patch.object(ny511, "_fetch", AsyncMock(side_effect=RuntimeError("boom"))):
+        asyncio.run(feed.get())
+    assert len(feed.items) == 1 and feed.fetched_at is not None
+    assert "boom" in feed.error
+    assert feed._next_attempt - feed.fetched_at <= ny511.RETRY_AFTER_FAILURE_S + 5  # retries soon, not after the full TTL
+
+
+def test_schema_change_is_an_error_not_an_empty_layer():
+    class Resp:
+        def raise_for_status(self): pass
+        def json(self): return [{"lat": 1, "lng": 2}]   # renamed fields -> nothing parses
+
+    class Client:
+        async def __aenter__(self): return self
+        async def __aexit__(self, *a): pass
+        async def get(self, *a, **k): return Resp()
+
+    with patch.object(ny511.httpx, "AsyncClient", lambda **k: Client()):
+        try:
+            asyncio.run(ny511._fetch("getcameras", ny511.normalize_camera))
+            assert False, "expected a schema-change error"
+        except ValueError as e:
+            assert "schema" in str(e)
+
+
+def test_endpoint_filters_to_bbox_and_reports_status():
+    far = {**CAM, "ID": "NYSDOT-2", "Latitude": 42.9, "Longitude": -78.8}   # Buffalo
+    for feed, rows, norm in ((ny511.cameras, [CAM, far], ny511.normalize_camera), (ny511.events, [EVENT], ny511.normalize_event)):
+        feed.items = [norm(r) for r in rows]
+        feed.fetched_at, feed._next_attempt = 1.0, float("inf")
+    r = client.get("/traffic/511", params={"south": 40.9, "west": -74.0, "north": 41.4, "east": -73.4})
+    assert r.status_code == 200
+    body = r.json()
+    assert [c["id"] for c in body["cameras"]] == ["NYSDOT-1"]
+    assert body["cameras_status"] == {"fetched_at": 1.0, "error": None, "total_in_bbox": 1, "truncated": False}
+    assert len(body["events"]) == 1
+
+
+def test_endpoint_rejects_inverted_bbox():
+    r = client.get("/traffic/511", params={"south": 41.4, "west": -74.0, "north": 40.9, "east": -73.4})
+    assert r.status_code == 400

drb-frontend/components/MapView.tsx

@@ -21,6 +21,8 @@ import { MachineOutputNotice } from "@/components/ui/MachineOutputNotice";
 import { useAircraft } from "@/lib/useAircraft";
 import { useAircraftTrail } from "@/lib/useAircraftTrail";
 import { useVessels } from "@/lib/useVessels";
+import { use511 } from "@/lib/use511";
+import type { Ny511Event, Ny511FeedStatus } from "@/lib/types";
 
 // ── Leaflet icon fix ──────────────────────────────────────────────────────────
 delete (L.Icon.Default.prototype as unknown as Record<string, unknown>)._getIconUrl;
@@ -310,6 +312,130 @@ function VesselLayer() {
   );
 }
 
+// ── 511NY traffic layers (server-26#183) ─────────────────────────────────────
+// Overlay names double as the event keys for overlayadd/overlayremove.
+const OVERLAY_DOT_CAMERAS = "DOT Cameras";
+const OVERLAY_TRAFFIC_EVENTS = "Traffic Events";
+
+/** True while the named LayersControl overlay is checked. Overlays start unchecked. */
+function useOverlayShown(map: L.Map, name: string): boolean {
+  const [shown, setShown] = useState(false);
+  useEffect(() => {
+    const on = (e: L.LayersControlEvent) => e.name === name && setShown(true);
+    const off = (e: L.LayersControlEvent) => e.name === name && setShown(false);
+    map.on("overlayadd", on);
+    map.on("overlayremove", off);
+    return () => { map.off("overlayadd", on); map.off("overlayremove", off); };
+  }, [map, name]);
+  return shown;
+}
+
+function cameraIcon(): L.DivIcon {
+  return L.divIcon({
+    className: "",
+    html: `<svg width="16" height="12" viewBox="0 0 16 12"><rect x="0.5" y="1.5" width="11" height="9" rx="2" fill="#1e3a5f" stroke="#93c5fd" stroke-width="1"/><circle cx="6" cy="6" r="2.5" fill="none" stroke="#93c5fd" stroke-width="1.25"/><polygon points="12,4 15.5,2 15.5,10 12,8" fill="#93c5fd"/></svg>`,
+    iconSize: [16, 12],
+    iconAnchor: [8, 6],
+  });
+}
+
+// Shape + glyph per 511 event type, so the layer reads without colour alone.
+const EVENT_STYLE: Record<string, { glyph: string; fill: string; label: string }> = {
+  accidentsAndIncidents: { glyph: "!", fill: "#dc2626", label: "Accident / incident" },
+  closures: { glyph: "×", fill: "#ea580c", label: "Closure" },
+  roadwork: { glyph: "W", fill: "#ca8a04", label: "Roadwork" },
+  specialEvents: { glyph: "E", fill: "#7c3aed", label: "Special event" },
+  transitOperations: { glyph: "T", fill: "#0891b2", label: "Transit" },
+};
+const EVENT_STYLE_OTHER = { glyph: "i", fill: "#6b7280", label: "Other" };
+
+function trafficEventIcon(type: string): L.DivIcon {
+  const st = EVENT_STYLE[type] ?? EVENT_STYLE_OTHER;
+  return L.divIcon({
+    className: "",
+    html: `<svg width="16" height="16" viewBox="0 0 16 16"><rect x="1" y="1" width="14" height="14" rx="3" fill="${st.fill}" stroke="#000" stroke-width="1"/><text x="8" y="12" text-anchor="middle" font-size="11" font-weight="700" font-family="sans-serif" fill="#fff">${st.glyph}</text></svg>`,
+    iconSize: [16, 16],
+    iconAnchor: [8, 8],
+  });
+}
+
+function fmtLocal(iso: string | null): string | null {
+  if (!iso) return null;
+  const d = new Date(iso);   // naive ISO parses as browser-local; 511NY stamps are NY local
+  return isNaN(d.getTime()) ? null : d.toLocaleString([], { month: "short", day: "numeric", hour: "numeric", minute: "2-digit" });
+}
+
+/** Surfaces a dead or stale 511 feed on the map instead of an unexplained empty layer. */
+function FeedProblem({ map, label, status, fetchError }: { map: L.Map; label: string; status?: Ny511FeedStatus; fetchError: string | null }) {
+  let msg: string | null = null;
+  if (fetchError) msg = `${label}: could not reach server`;
+  else if (status?.error) {
+    const age = status.fetched_at ? `showing data from ${Math.round((Date.now() / 1000 - status.fetched_at) / 60)} min ago` : "no data yet";
+    msg = `${label}: 511NY feed error, ${age}`;
+  } else if (status?.truncated) msg = `${label}: showing ${1500} of ${status.total_in_bbox} — zoom in`;
+  if (!msg) return null;
+  return createPortal(
+    <div className="absolute bottom-8 left-3 z-[1001] bg-surface/90 border border-line rounded px-2 py-1 text-xs text-ink-2 pointer-events-none">{msg}</div>,
+    map.getContainer(),
+  );
+}
+
+function DotCameraLayer() {
+  const map = useMap();
+  const shown = useOverlayShown(map, OVERLAY_DOT_CAMERAS);
+  const { data, error } = use511(map, "cameras", shown);
+  return (
+    <>
+      {shown && <FeedProblem map={map} label="DOT cameras" status={data.cameras_status} fetchError={error} />}
+      {(data.cameras ?? []).map((c) => (
+        <Marker key={c.id} position={[c.lat, c.lon]} icon={cameraIcon()}>
+          <Popup minWidth={260} maxWidth={340}>
+            <div className="space-y-1">
+              <div className="font-semibold">{c.name}</div>
+              {c.roadway && <div className="text-xs text-ink-muted">{c.roadway}{c.direction && c.direction !== "Unknown" ? ` · ${c.direction}` : ""}</div>}
+              {c.image_url && (
+                // Popup content mounts on open, so the timestamp busts the cache per open.
+                // eslint-disable-next-line @next/next/no-img-element
+                <img src={`${c.image_url}?t=${Date.now()}`} alt={`Camera: ${c.name}`} className="w-full rounded border border-line" loading="lazy" />
+              )}
+              <div className="text-[10px] text-ink-muted">Snapshot: 511NY / NYSDOT</div>
+            </div>
+          </Popup>
+        </Marker>
+      ))}
+    </>
+  );
+}
+
+function TrafficEventLayer() {
+  const map = useMap();
+  const shown = useOverlayShown(map, OVERLAY_TRAFFIC_EVENTS);
+  const { data, error } = use511(map, "events", shown);
+  return (
+    <>
+      {shown && <FeedProblem map={map} label="Traffic events" status={data.events_status} fetchError={error} />}
+      {(data.events ?? []).map((e: Ny511Event) => {
+        const st = EVENT_STYLE[e.type] ?? EVENT_STYLE_OTHER;
+        const start = fmtLocal(e.start_local);
+        const end = fmtLocal(e.planned_end_local);
+        return (
+          <Marker key={e.id} position={[e.lat, e.lon]} icon={trafficEventIcon(e.type)} zIndexOffset={e.type === "accidentsAndIncidents" ? 200 : 0}>
+            <Popup minWidth={220} maxWidth={320}>
+              <div className="space-y-1">
+                <div className="font-semibold">{st.label}{e.subtype ? `: ${e.subtype}` : ""}</div>
+                <div className="text-xs text-ink-muted">{[e.roadway, e.direction, e.county].filter(Boolean).join(" · ")}</div>
+                {(start || end) && <div className="text-xs">{start ? `From ${start}` : ""}{end ? ` until ${end}` : ""}</div>}
+                <div className="text-xs whitespace-pre-line">{e.description}</div>
+                <div className="text-[10px] text-ink-muted">511NY{e.updated_local ? ` · updated ${fmtLocal(e.updated_local)}` : ""}</div>
+              </div>
+            </Popup>
+          </Marker>
+        );
+      })}
+    </>
+  );
+}
+
 function nodeFanIcon(members: NodeRecord[]): L.DivIcon {
   const n = members.length;
   const CARD = 13;
@@ -826,6 +952,18 @@ export default function MapView({ nodes, activeCalls, incidents = [], calls = []
             </FeatureGroup>
           </LayersControl.Overlay>
 
+          {/* Overlays: 511NY DOT cameras + traffic events (server-26#183), opt-in */}
+          <LayersControl.Overlay name={OVERLAY_DOT_CAMERAS}>
+            <FeatureGroup>
+              <DotCameraLayer />
+            </FeatureGroup>
+          </LayersControl.Overlay>
+          <LayersControl.Overlay name={OVERLAY_TRAFFIC_EVENTS}>
+            <FeatureGroup>
+              <TrafficEventLayer />
+            </FeatureGroup>
+          </LayersControl.Overlay>
+
           {/* Overlay: Weather Radar — NEXRAD via Iowa Env Mesonet; key forces remount on refresh */}
           <LayersControl.Overlay name="Weather Radar">
             <TileLayer

drb-frontend/components/SecondarySdrPriority.tsx

@@ -22,6 +22,9 @@ function rowsFrom(priority: string[]): Row[] {
 
 export function SecondarySdrPriority({ node, canEdit }: { node: NodeRecord; canEdit: boolean }) {
   const priority = node.secondary_sdr_priority ?? [];
+  // null/absent = the node has never reported (older firmware, container down
+  // at checkin): unknown, not "nothing running" (server-26#187).
+  const reported = node.secondary_sdr_running != null;
   const running = node.secondary_sdr_running ?? [];
   const [rows, setRows] = useState<Row[]>(() => rowsFrom(priority));
   const [dirty, setDirty] = useState(false);
@@ -62,8 +65,9 @@ export function SecondarySdrPriority({ node, canEdit }: { node: NodeRecord; canE
     }
   }
 
-  const sdrCount = node.sdr_count ?? 1;
-  const spare = Math.max(sdrCount - 1, 0);
+  // Only quote a count the node actually sent alongside its running list; a
+  // bare sdr_count may be the Firestore default, not a report.
+  const sdrCount = reported ? node.sdr_count : undefined;
   let rank = 0;
 
   return (
@@ -71,13 +75,24 @@ export function SecondarySdrPriority({ node, canEdit }: { node: NodeRecord; canE
       <h2 className="text-sm font-semibold text-gray-400 uppercase tracking-wider mb-1">Secondary SDRs</h2>
       <p className="text-xs text-gray-500 font-mono mb-3">
         OP25 always keeps its own SDR. Every other SDR runs the next enabled item, top first.
-        {" "}This node reports {sdrCount} SDR{sdrCount === 1 ? "" : "s"} ({spare} spare).
+        {" "}
+        {sdrCount != null
+          ? `This node reports ${sdrCount} SDR${sdrCount === 1 ? "" : "s"} (${Math.max(sdrCount - 1, 0)} spare).`
+          : "This node hasn't reported its SDRs yet."}
       </p>
       <div className="bg-gray-900 border border-gray-800 rounded-lg divide-y divide-gray-800 font-mono text-sm">
         {rows.map((row, i) => {
           const meta = MODES.find((x) => x.mode === row.mode)!;
           const isRunning = running.includes(row.mode);
-          const state = !row.enabled ? "Off" : dirty ? "Unsaved" : isRunning ? "Running" : "Waiting for SDR";
+          const state = !row.enabled
+            ? "Off"
+            : dirty
+              ? "Unsaved"
+              : !reported
+                ? "Not reported"
+                : isRunning
+                  ? "Running"
+                  : "Waiting for SDR";
           return (
             <div key={row.mode} className="flex items-center gap-3 px-4 py-2.5">
               <span className="w-4 text-right text-gray-600 text-xs">{row.enabled ? ++rank : ""}</span>

drb-frontend/lib/c2api.ts

@@ -1,5 +1,5 @@
 import { auth } from "@/lib/firebase";
-import type { AreaContext, TalkgroupPending } from "@/lib/types";
+import type { AreaContext, Ny511Response, TalkgroupPending } from "@/lib/types";
 
 const BASE = process.env.NEXT_PUBLIC_C2_URL ?? "http://localhost:8000";
 
@@ -370,6 +370,12 @@ export const c2api = {
   revokeEnrollmentToken: (tokenId: string) =>
     request(`/org/enrollment-tokens/${tokenId}`, { method: "DELETE" }),
 
+  // 511NY cameras/events inside a map bbox (server-26#183)
+  get511: (bbox: { south: number; west: number; north: number; east: number }, layers: string) =>
+    request<Ny511Response>(`/traffic/511?${new URLSearchParams({
+      south: String(bbox.south), west: String(bbox.west), north: String(bbox.north), east: String(bbox.east), layers,
+    })}`),
+
   // Public waitlist — no auth, see routers/waitlist.py
   joinWaitlist: (body: { email: string; org_name?: string; note?: string }) =>
     request<{ ok: boolean }>("/waitlist", { method: "POST", body: JSON.stringify(body) }),

drb-frontend/lib/types.ts

@@ -58,7 +58,7 @@ export interface NodeRecord {
   secondary_sdr_priority?: string[];
   /** What the node's last checkin reported actually running. */
   secondary_sdr_running?: string[] | null;
-  sdr_count?: number;
+  sdr_count?: number | null; // null = never reported
   enforce_override_timeout?: boolean;
   is_overridden?: boolean;
   override_system_id?: string | null;
@@ -98,6 +98,49 @@ export interface VesselTrack {
   last_seen: string;
 }
 
+// 511NY traffic layer (server-26#183) — GET /traffic/511, cached server-side,
+// not Firestore. *_local times are New York local, no offset: display only.
+export interface Ny511Camera {
+  id: string;
+  lat: number;
+  lon: number;
+  name: string;
+  roadway: string;
+  direction: string;
+  image_url: string | null;
+  video_url: string | null;
+}
+
+export interface Ny511Event {
+  id: string;
+  lat: number;
+  lon: number;
+  type: string;
+  subtype: string;
+  severity: string;
+  roadway: string;
+  direction: string;
+  county: string;
+  description: string;
+  start_local: string | null;
+  planned_end_local: string | null;
+  updated_local: string | null;
+}
+
+export interface Ny511FeedStatus {
+  fetched_at: number | null;  // epoch seconds of the last successful 511NY fetch
+  error: string | null;       // set when the latest refresh failed (data is then stale)
+  total_in_bbox: number;
+  truncated: boolean;
+}
+
+export interface Ny511Response {
+  cameras?: Ny511Camera[];
+  cameras_status?: Ny511FeedStatus;
+  events?: Ny511Event[];
+  events_status?: Ny511FeedStatus;
+}
+
 export interface VocabularyPendingTerm {
   term: string;
   source: "induction" | "correction";

drb-frontend/lib/use511.ts

@@ -0,0 +1,57 @@
+"use client";
+
+import { useEffect, useRef, useState } from "react";
+import type L from "leaflet";
+import { c2api } from "@/lib/c2api";
+import type { Ny511Response } from "@/lib/types";
+
+// 511NY cameras/events for the current map view (server-26#183). Unlike
+// useAircraft/useVessels this is not a Firestore listener: the data is public
+// and statewide, so c2-core caches it in memory and serves a bbox slice.
+// Fetches only while `enabled` (the overlay is on), on pan/zoom (debounced),
+// and on a poll matching the server's events TTL.
+const POLL_MS = 2 * 60 * 1000;
+const MOVE_DEBOUNCE_MS = 400;
+const BBOX_PAD = 0.2;   // fetch a little past the edges so small pans don't blank the layer
+
+export function use511(map: L.Map, layers: "cameras" | "events", enabled: boolean) {
+  const [data, setData] = useState<Ny511Response>({});
+  const [error, setError] = useState<string | null>(null);
+  const seq = useRef(0);
+
+  useEffect(() => {
+    if (!enabled) { setData({}); return; }
+    let debounce: ReturnType<typeof setTimeout> | undefined;
+
+    const load = async () => {
+      const b = map.getBounds().pad(BBOX_PAD);
+      const mine = ++seq.current;
+      try {
+        const res = await c2api.get511(
+          { south: b.getSouth(), west: b.getWest(), north: b.getNorth(), east: b.getEast() },
+          layers,
+        );
+        if (mine !== seq.current) return;   // a newer pan's response wins
+        setData(res);
+        setError(null);
+      } catch (e) {
+        if (mine !== seq.current) return;
+        console.error("use511:", e);
+        setError(e instanceof Error ? e.message : String(e));
+      }
+    };
+    const onMove = () => { clearTimeout(debounce); debounce = setTimeout(load, MOVE_DEBOUNCE_MS); };
+
+    load();
+    map.on("moveend", onMove);
+    const poll = setInterval(load, POLL_MS);
+    return () => {
+      map.off("moveend", onMove);
+      clearTimeout(debounce);
+      clearInterval(poll);
+      seq.current++;   // drop any in-flight response
+    };
+  }, [map, layers, enabled]);
+
+  return { data, error };
+}