diff --git a/selfdrive/ui/qt/onroad/model.cc b/selfdrive/ui/qt/onroad/model.cc
index e1039ee1a2..73c25d9367 100644
--- a/selfdrive/ui/qt/onroad/model.cc
+++ b/selfdrive/ui/qt/onroad/model.cc
@@ -51,47 +51,91 @@ void ModelRenderer::update_leads(const cereal::RadarState::Reader &radar_state,
   }
 }
 
-void ModelRenderer::update_model(const cereal::ModelDataV2::Reader &model, const cereal::RadarState::LeadData::Reader &lead) {
+QPolygonF ModelRenderer::smoothPolygon(const QPolygonF &current, const QPolygonF &previous, float alpha) {
+  if (previous.isEmpty() || current.size() != previous.size()) {
+    return current;  // nothing to smooth against
+  }
+
+  QPolygonF smoothed;
+  smoothed.reserve(current.size());
+  for (int i = 0; i < current.size(); ++i) {
+    const QPointF &c = current[i];
+    const QPointF &p = previous[i];
+    smoothed << QPointF(alpha * p.x() + (1 - alpha) * c.x(),
+                        alpha * p.y() + (1 - alpha) * c.y());
+  }
+  return smoothed;
+}
+
+void ModelRenderer::update_model(const cereal::ModelDataV2::Reader &model,
+                                 const cereal::RadarState::LeadData::Reader &lead) {
   const auto &model_position = model.getPosition();
   float max_distance;
   if (QString::fromStdString(Params().get("VisualStyle")).toInt() == 0) {
-    max_distance = std::clamp(*(model_position.getX().end() - 1), MIN_DRAW_DISTANCE, MAX_DRAW_DISTANCE);
+    max_distance = std::clamp(*(model_position.getX().end() - 1),
+                              MIN_DRAW_DISTANCE, MAX_DRAW_DISTANCE);
   } else {
     max_distance = std::clamp(*(model_position.getX().end() - 1), 0.0f, 300.0f);
   }
 
-  // update lane lines
+  // --- update lane lines ---
   const auto &lane_lines = model.getLaneLines();
   const auto &line_probs = model.getLaneLineProbs();
   int max_idx = get_path_length_idx(lane_lines[0], max_distance);
+
   for (int i = 0; i < std::size(lane_line_vertices); i++) {
-    lane_line_probs[i] = line_probs[i];
-    if (QString::fromStdString(Params().get("VisualStyle")).toInt() == 2) {
-      mapLineToPolygon(lane_lines[i], 0.075 * lane_line_probs[i], 0, &lane_line_vertices[i], max_idx);
-    } else {
-      mapLineToPolygon(lane_lines[i], 0.025 * lane_line_probs[i], 0, &lane_line_vertices[i], max_idx);
+    // smooth probability too
+    lane_line_probs[i] = 0.9f * lane_line_probs[i] + 0.1f * line_probs[i];
+
+    float width = (QString::fromStdString(Params().get("VisualStyle")).toInt() == 2)
+                    ? 0.075f * lane_line_probs[i]
+                    : 0.025f * lane_line_probs[i];
+
+    mapLineToPolygon(lane_lines[i], width, 0, &lane_line_vertices[i], max_idx);
+
+    if (prev_polys_valid) {
+      lane_line_vertices[i] =
+          smoothPolygon(lane_line_vertices[i], prev_lane_vertices[i], 0.8f);
     }
   }
 
-  // update road edges
+  // --- update road edges ---
   const auto &road_edges = model.getRoadEdges();
   const auto &edge_stds = model.getRoadEdgeStds();
+
   for (int i = 0; i < std::size(road_edge_vertices); i++) {
     road_edge_stds[i] = edge_stds[i];
-    if (QString::fromStdString(Params().get("VisualStyle")).toInt() == 2) {
-      mapLineToPolygon(road_edges[i], 0.1, 0, &road_edge_vertices[i], max_idx);
-    } else {
-      mapLineToPolygon(road_edges[i], 0.025, 0, &road_edge_vertices[i], max_idx);
+
+    float width = (QString::fromStdString(Params().get("VisualStyle")).toInt() == 2)
+                    ? 0.1f
+                    : 0.025f;
+
+    mapLineToPolygon(road_edges[i], width, 0, &road_edge_vertices[i], max_idx);
+
+    if (prev_polys_valid) {
+      road_edge_vertices[i] =
+          smoothPolygon(road_edge_vertices[i], prev_edge_vertices[i], 0.8f);
     }
   }
 
-  // update path
+  // --- update path ---
   if (lead.getStatus()) {
-    const float lead_d = lead.getDRel() * 2.;
-    max_distance = std::clamp((float)(lead_d - fmin(lead_d * 0.35, 10.)), 0.0f, max_distance);
+    const float lead_d = lead.getDRel() * 2.f;
+    max_distance = std::clamp((float)(lead_d - fmin(lead_d * 0.35f, 10.f)),
+                              0.0f, max_distance);
   }
   max_idx = get_path_length_idx(model_position, max_distance);
-  mapLineToPolygon(model_position, 0.9, path_offset_z, &track_vertices, max_idx, false);
+  mapLineToPolygon(model_position, 0.9f, path_offset_z, &track_vertices, max_idx, false);
+
+  if (prev_polys_valid) {
+    track_vertices = smoothPolygon(track_vertices, prev_track_vertices, 0.85f);
+  }
+
+  // save for next frame
+  prev_lane_vertices = lane_line_vertices;
+  prev_edge_vertices = road_edge_vertices;
+  prev_track_vertices = track_vertices;
+  prev_polys_valid = true;
 }
 
 void ModelRenderer::drawLaneLines(QPainter &painter) {
diff --git a/selfdrive/ui/qt/onroad/model.h b/selfdrive/ui/qt/onroad/model.h
index e40f832c37..302380ed29 100644
--- a/selfdrive/ui/qt/onroad/model.h
+++ b/selfdrive/ui/qt/onroad/model.h
@@ -59,8 +59,10 @@ protected:
   float road_edge_stds[2] = {};
   float path_offset_z = 1.22f;
   QPolygonF track_vertices;
-  QPolygonF lane_line_vertices[4] = {};
-  QPolygonF road_edge_vertices[2] = {};
+  // QPolygonF lane_line_vertices[4] = {};
+  // QPolygonF road_edge_vertices[2] = {};
+  std::array<QPolygonF, 4> lane_line_vertices = {};
+  std::array<QPolygonF, 2> road_edge_vertices = {};
   QPointF lead_vertices[2] = {};
   Eigen::Matrix3f car_space_transform = Eigen::Matrix3f::Zero();
   QRectF clip_region;
@@ -69,4 +71,13 @@ protected:
   QPointF lead_status_pos;
   QString lead_status_text;
   QColor lead_status_color;
+
+   // --- NEW: smoothing support ---
+  std::array<QPolygonF, 4> prev_lane_vertices;
+  std::array<QPolygonF, 2> prev_edge_vertices;
+  QPolygonF prev_track_vertices;
+  bool prev_polys_valid = false;
+
+  // helper for smoothing polygons
+  QPolygonF smoothPolygon(const QPolygonF &current, const QPolygonF &previous, float alpha);
 };