diff --git a/tools/nusc_tracking/nms.py b/tools/nusc_tracking/nms.py
new file mode 100644
index 00000000..9b5d9008
--- /dev/null
+++ b/tools/nusc_tracking/nms.py
@@ -0,0 +1,82 @@
+import numpy as np
+
+def filter_detections(detections, score_thresh=0.0001, iou_thresh=0.1):
+    """Filter detections based on score and extra NMS."""
+    # Filter out low score detections
+    score_cond = np.array([det['detection_score'] > score_thresh
+                    for det in detections])
+    # Filter out detections with same class and location (NMS)
+    class_ids = np.array([det['label_preds'] for det in detections])
+    same_class_mat = np.equal(
+        class_ids.reshape(-1, 1),
+        class_ids.reshape(1, -1))
+    pos_x = np.array([det['translation'][0] for det in detections])
+    pos_y = np.array([det['translation'][1] for det in detections])
+    size_w = np.array([det['size'][0] for det in detections])
+    size_l = np.array([det['size'][1] for det in detections])
+    rot = np.array([det['rotation'][2] for det in detections])
+    ind_remove = np.zeros(len(detections), dtype=np.bool)
+    max_iou = np.zeros(len(detections))
+    for i in range(len(detections)):
+        if ind_remove[i]:
+            continue
+        iou_vec = np.zeros(len(detections))
+        for j in range(i+1, len(detections)):
+            dist = np.sqrt((pos_x[i] -
+                            pos_x[j])**2 +
+                            (pos_y[i] -
+                                pos_y[j])**2)
+            max_dim = np.max([size_w[i],
+                                size_l[i],
+                                size_w[j],
+                                size_l[j]])
+            if same_class_mat[i, j] and dist < max_dim and not ind_remove[j]:
+                iou_vec[j] = iou2d(
+                    [pos_x[i],
+                    pos_y[i],
+                    size_w[i],
+                    size_l[i],
+                    rot[i]],
+                    [pos_x[j],
+                    pos_y[j],
+                    size_w[j],
+                    size_l[j],
+                    rot[j]])
+        ind_remove += (iou_vec > iou_thresh)
+        max_iou[i] = np.max(iou_vec)
+    nms_cond = np.logical_not(ind_remove)
+    # Filter detections
+    x_cond = np.logical_and(score_cond, nms_cond)
+    detections = [det for det, cond in zip(detections, x_cond) if cond]
+    return detections
+
+
+def iou2d(box_a, box_b):
+    """
+    Compute 2D bounding box IoU.
+    
+    Args:
+        box_a (list[float]): Box A with format [x, y, w, l, r].
+        box_b (list[float]): Box B with format [x, y, w, l, r].
+    """
+    def box2corners2d(bbox):
+        """ the coordinates for bottom corners
+        """
+        bottom_center = np.array([bbox[0], bbox[1]])
+        cos, sin = np.cos(bbox[4]), np.sin(bbox[4])
+        pc0 = np.array([bbox[0] + cos * bbox[3] / 2 + sin * bbox[2] / 2,
+                        bbox[1] + sin * bbox[3] / 2 - cos * bbox[2] / 2])
+        pc1 = np.array([bbox[0] + cos * bbox[3] / 2 - sin * bbox[2] / 2,
+                        bbox[1] + sin * bbox[3] / 2 + cos * bbox[2] / 2])
+        pc2 = 2 * bottom_center - pc0
+        pc3 = 2 * bottom_center - pc1
+        return [pc0.tolist(), pc1.tolist(), pc2.tolist(), pc3.tolist()]
+    from shapely.geometry import Polygon
+    boxa_corners = np.array(box2corners2d(box_a))
+    boxb_corners = np.array(box2corners2d(box_b))
+    reca, recb = Polygon(boxa_corners), Polygon(boxb_corners)
+    overlap = reca.intersection(recb).area
+    area_a = reca.area
+    area_b = recb.area
+    iou = overlap / (area_a + area_b - overlap + 1e-10)
+    return iou
diff --git a/tools/nusc_tracking/pub_tracker.py b/tools/nusc_tracking/pub_tracker.py
index 4b77944d..04fe4b26 100644
--- a/tools/nusc_tracking/pub_tracker.py
+++ b/tools/nusc_tracking/pub_tracker.py
@@ -178,7 +178,7 @@ def step_centertrack(self, detections, time_lag):
             track['age'] = 1
             track['t_age'] = 0.0
             track['active'] =  0
-            if (M == 0 and track['detection_score'] > 0.3) or track['detection_score'] > 0.5:
+            if track['detection_score'] > 0.2:
                 track['active'] =  1
             track['detection_ids'] = [i]
             track['translation_history'] = [track['translation']]