Organizations: Dept. of Information Science, University of North Texas, Denton, Texas, USA · Dept. of Data Science, University of North Texas, Denton, Texas, USA
Next-generation autonomous vehicles (AVs) rely on large volumes of multisource and multimodal (M2) data to support real-time decision-making. In practice, data quality (DQ) varies across sources and modalities due to environmental conditions and sensor limitations, yet AV research has largely prioritized algorithm design over DQ analysis. This work focuses on redundancy as a fundamental but underexplored DQ issue in AV datasets. Using the nuScenes and Argoverse 2 (AV2) datasets, we model and measure redundancy in multisource camera data and multimodal image-LiDAR data, and evaluate how removing redundant labels affects the YOLOv8 object detection task. Experimental results show that selectively removing redundant multisource image object labels from cameras with shared fields of view improves detection. In nuScenes, mAP50 gains from 0.66 to 0.70, 0.64 to 0.67, and from 0.53 to 0.55, on three representative overlap regions, while detection on other overlapping camera pairs remains at the baseline even under stronger pruning. In AV2, 4.1-8.6% of labels are removed, and mAP50 stays near the 0.64 baseline. Multimodal analysis also reveals substantial redundancy between image and LiDAR data. These findings demonstrate that redundancy is a measurable and actionable DQ factor with direct implications for AV performance. This work highlights the role of redundancy as a data quality factor in AV perception and motivates a data-centric perspective for evaluating and improving AV datasets. Code, data, and implementation details are publicly available at: https://github.com/yhZHOU515/RedundancyAD
Figures & tables
Fig. 1 : Illustration of multisource and multimodal data in autonomous vehicles. LiDAR point clouds, multi-camera images, RADAR, vehicle dynamics, user-related data, and external contextual inputs feed into the AV system. Redundancy arises from overlapping fields of view among multiple onboard cameras (green), as well as from multimodal sensing in which cameras and LiDAR (orange) observe the same objects. The rest colored blocks represent additional data sources and modalities.
Fig. 2 : Illustration of research design, using nuScenes dataset as examples. We first quantify redundancy in multisource and multimodal autonomous driving datasets (RQ1), then design data pruning to remove redundant observations (RQ2), and finally evaluate how redundancy removal affects object detection performance (RQ3).
Fig. 3 : The workflow of the research design on redundancy evaluation. nuScenes emphasizes 2D labeling and AV2 adopts 3D annotations. Beyond dataset-specific configurations, this workflow can be generalized to other AD datasets.
Dataset
Year
Sensors
Annotations
Size
Modalities
nuScenes-mini [ 13 ]
2020
6 cameras (12 Hz), 1 LiDAR, RADAR, GPS/IMU
3D bounding boxes, object attributes, tracking, HD maps
10 scenes, 404 frames
Multisource camera images
nuScenes-in-KITTI [ 63 ]
2021
Cameras, 1 LiDAR, GPS/IMU
2D/3D bounding boxes, calibration, tracking
85 scenes in KITTI format
Image and LiDAR
Argoverse 2 [ 64 ]
2023
9 cameras, 2 LiDARs (10 Hz), GPS/IMU
3D bounding boxes, tracking, map annotations, motion labels
1,000 scenes, 20,000 LiDAR sequences
Multisource camera images
TABLE I : Summary of datasets used for redundancy evaluation
Fig. 4 : Camera settings and overlapping FoVs in nuScenes. For datasets with different sensor layouts, the same redundancy modeling and measurement approach remains applicable by adjusting the geometric parameters.
Fig. 5 : Illustration of cropping based on overlapping angles of the cameras.
Aspect
nuScenes multisource
AV2 multisource
Sensor layout
6 calibrated surround-view cameras with predefined overlapping FoVs.
9 calibrated cameras (7 ring + 2 front stereo); surround-view configuration with denser overlap.
Source of supervision
Object identity inferred implicitly from dataset annotations and temporal alignment.
Explicit object identity via track_uuid from 3D ego-frame cuboids.
Annotation space
2D image-space object-centric observations derived from overlap regions.
3D-first cuboids in a unified ego frame, projected into each camera view to obtain 2D observations.
Redundancy unit
Multiple 2D observations of the same object instance across overlapping cameras.
Multiple projected 2D observations originating from the same 3D object instance across cameras.
Overlap pairing
Fixed camera overlap pairs defined by dataset specification.
Camera overlap pairs computed from calibration (yaw center and horizontal FoV) using angular overlap.
BCS computation
Boundary-aware 2D coverage score computed on valid image regions.
Boundary-aware 2D coverage score computed after projecting 3D cuboids and clipping to image bounds.
TABLE II : Comparison between the redundancy experiments on nuScenes and AV2 datasets. Both apply instance-level, BCS-guided pruning; AV2 adds calibration-driven overlap pairing and 3D-to-2D projection. All the experiments were conducted on a PC equipped with one NVIDIA GeForce 4090 RTX GPU and 24 GB of memory. Model configurations are fixed across experiments.
Fig. 6 : Example of cross-modal redundancy between the front camera (upper) and the top LiDAR (lower) in the nuScenes dataset. Colored lines indicate the corresponding objects observed by both sensors.
Dataset
Experiment
Prec.
Rec.
mAP 50
mAP 50:95
nuScenes
Train unpruned, Eval unpruned
0.780
0.630
0.720
0.450
nuScenes
Train pruned ( τBCS=0.8 on pair 4), Eval unpruned
0.867
0.800
0.770
0.638
AV2
Train unpruned, Eval unpruned
0.815
0.565
0.640
0.447
AV2
Train pruned ( τBCS=0.5 ), Eval unpruned
0.818
0.557
0.622
0.433
TABLE III : Multisource detection performance with and without BCS-guided pruning
Fig. 7 : Examples of high and low similarity samples in nuScenes.
Fig. 8 : Effects of removing redundant instances in overlapping FoV images on mAP 50 in nuScenes.
Train
τBCS
Del.
Rem.
Tracks
Prec.
Rec.
mAP 50
Baseline
–
0
187,265
95,266
0.815
0.565
0.640
Pruned
0.1
16,056
171,209
95,266
0.811
0.531
0.604
Pruned
0.2
14,345
172,920
95,266
0.788
0.544
0.605
Pruned
0.3
12,810
174,455
95,266
0.826
0.538
0.617
Pruned
0.4
11,018
176,247
95,266
0.823
0.545
0.618
Pruned
0.5
9,442
177,823
95,266
0.818
0.557
0.622
TABLE IV : AV2 multisource BCS pruning sweep. Training uses different τBCS values while evaluation is fixed to the same unpruned validation split. “Del.” and “Rem.” denote deleted and remaining camera-level 2D labels in the training set. “Tracks” is the number of unique 3D object tracks observed during training.
Fig. 9 : Redundancy in LiDAR and image data in nuScenes.
Fig. 10 : T-test of distance threshold and cross-modal redundancy in nuScenes.
Fig. 11 : The effects of removing close-range redundant LiDAR data in nuScenes on detection performance.
Department of Civil and Environmental Engineering, University of Wisconsin–Madison, Madison, WI, 53706, USA · Department of Civil and Architectural Engineering and Construction Management, University of Wyoming, Laramie, WY, 82071, USA · Kuaishou Technology, Beijing, 100085, China +1