Organizations: School of Computer Science, Wuhan University · Zhongguancun Academy, Beijing, China · Didi Chuxing · University of Science and Technology of China
Accident anticipation aims to predict impending collisions from dashcam videos and trigger early alerts. Existing methods rely on binary supervision with manually annotated "anomaly onset" frames, which are subjective and inconsistent, leading to inaccurate risk estimation. In contrast, we propose RiskProp, a novel collision-anchored self-supervised risk propagation paradigm for early accident anticipation, which removes the need for anomaly onset annotations and leverages only the reliably annotated collision frame. RiskProp models temporal risk evolution through two observation-driven losses: first, since future frames contain more definitive evidence of an impending accident, we introduce a future-frame regularization loss that uses the model's next-frame prediction as a soft target to supervise the current frame, enabling backward propagation of risk signals; second, inspired by the empirical trend of rising risk before accidents, we design an adaptive monotonic constraint to encourage a non-decreasing progression over time. Experiments on CAP and Nexar demonstrate that RiskProp achieves state-of-the-art performance and produces smoother, more discriminative risk curves, improving both early anticipation and interpretability.
Figures & tables
Figure 1: Form of supervision of previous works and ours. (a) Most previous methods treat all frames in accident-free videos as negative samples with label 0, and treat frames in accident videos—from the annotated anomaly onset frame to the collision frame—as positive samples with labeled 1. (b) Our method treats the model’s prediction for the next frame as a supervision signal for the current frame, which enables the risk values to propagate gradually backward from the collision frame.
Figure 2: Overview of our RiskProp framework. The encoder-only model takes a snippet of consecutive frames and predicts the current frame’s risk score. To train such a model without “anomaly onset” labels and with only the objective collision frame label, two losses are proposed: The Future-Frame Regularization Loss uses the next-frame’s detached prediction as a self-supervised target for high-risk signals backward propagation, while the Adaptive Monotonic Constraint Loss imposes a monotonicity constraint to ensure a non-decreasing overall risk trend. And we adopt the Binary Cross-Entropy loss to provide explicit supervision only at the collision frame. This enables stable, physically plausible risk curves without manual onset annotations.
Figure 3: Illustration of sampling strategy for the adaptive monotonic constraint loss. For a randomly selected d∈[dmin,dmax] , a starting frame t1 is sampled from [0,T(1−d)] , and t2=t1+dT . This encourages learning across various temporal distances.
Method
CAP [ 8 ]
Nexar [ 26 ]
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
AdaLEA [ 33 ]
0.379
0.807
0.857
1.115
0.378
0.828
0.832
0.858
XAI [ 18 ]
0.352
0.821
0.864
1.082
0.346
0.824
0.802
0.839
DSTA [ 17 ]
0.361
0.895
0.882
0.894
0.242
0.783
0.764
0.493
GSC [ 36 ]
0.378
0.881
0.890
0.911
0.322
0.802
0.811
0.815
CAP [ 8 ]
0.332
0.811
0.852
0.933
0.315
0.817
0.793
0.801
Table 1: Quantitative results comparison of different methods on the CAP [ 8 ] dataset and the Nexar [ 26 ] dataset.
Exp.
FFR
AMC
Anomaly Onset Label
Fixed Interval Label
Only Collision Label
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
I
0.441
0.829
0.871
1.162
0.412
0.816
0.872
1.173
0.358
0.783
0.832
1.009
II
✓
0.436
0.828
0.866
1.137
0.436
0.828
0.872
1.173
0.383
0.790
0.832
1.055
III
✓
0.444
0.830
0.872
1.174
0.455
0.847
0.886
1.212
0.474
0.850
0.850
1.202
IV
✓
✓
0.484
0.856
0.887
1.198
0.480
0.851
0.890
1.203
0.483
0.853
0.890
1.207
Table 2: Ablation study about different annotation strategies on the CAP [ 8 ] dataset, where FFR denotes Future-Frame Regularization, and AMC denotes Adaptive Monotonic Constraint.
Exp.
FFR
AMC
Anomaly Onset Label
Fixed Interval Label
Only Collision Label
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
mAUC 0.1
mAUC
mAP
mTTA 0.1 (s)
I
0.388
0.826
0.822
0.773
0.420
0.837
0.827
0.741
0.298
0.789
0.781
0.610
II
✓
0.408
0.844
0.842
0.902
0.445
0.815
0.830
0.815
0.302
0.797
0.785
0.654
III
✓
0.434
0.846
0.850
0.897
0.434
0.865
0.856
0.920
0.453
0.847
0.854
0.836
IV
✓
✓
0.479
0.872
0.876
0.951
0.454
0.875
0.874
0.931
0.472
0.869
0.870
0.958
Table 3: Ablation study about different annotation strategies on the Nexar [ 26 ] dataset, where FFR denotes Future-Frame Regularization, and AMC denotes Adaptive Monotonic Constraint.
Figure 4: Frame- and Dataset-Level Risk Prediction. Left: On a representative accident video, supervised baselines produce early false peaks before clear risk emerges. Our RiskProp model prediction remains low during safe periods and rises sharply only when discriminative cues appear, yielding a temporally coherent risk curve. Right: Dataset-wide average risk curves on CAP and Nexar, aligned to accident timestamps. RiskProp suppresses early false positives and delivers a steeper, better-calibrated rise near the event, enabling earlier, more reliable warnings.
Accident anticipation aims to recognize anomalous driving cues before a crash while avoiding false alarms during normal driving. Existing approaches typically formulate this task as binary classification, focusing on whether an accident will occur rather than when it will occur. We propose PRE-ACT, a framework that models accident risk as a continuously evolving signal that increases as the crash approaches. By explicitly enforcing temporal ordering and distance-to-accident awareness, our method progressively raises risk while suppressing premature alarms, leading to significant improvements on MM-AU subsets and Nexar. We further introduce a Separation Score to evaluate the global behavior of predicted risk curves beyond local temporal windows. Code and visualizations are available at https://github.com/giddyyupp/PRE-ACT.
Samet Hicsonmez, Eray Çakar, Nermin Samet +1
Independent Researcher, Paris, France · Department of Computer Engineering, KUIS AI, Koç University, Istanbul, Turkey · Valeo.ai, Paris, France
Collision anticipation in autonomous driving requires not only accurate early warnings but also interpretable reasoning about what risk factors are being tracked and how risk evolves over time. Existing methods fall short in this regard: feature-driven models are opaque, post-hoc explanations often lack fidelity, and concept-based methods are mostly designed for static recognition rather than dynamic driving scenes. We propose CARA (Concept-Aware Risk Attention), an intrinsically interpretable spatio-temporal framework for collision anticipation. CARA derives domain-grounded risk concepts from accident narratives, aligns them with video frames via vision-language similarity, and organizes them into evolving concept trajectories. These trajectories provide explicit risk evidence that guides spatial attention, temporal attention, and anticipation, allowing semantic concepts to directly influence both where the model attends and how it predicts risk over time. By treating semantic risk factors as dynamic intermediate evidence rather than auxiliary post-hoc explanations, CARA tightly couples interpretability with the predictive process. Extensive experiments on three benchmarks show that CARA consistently improves anticipation accuracy and warning earliness over strong baselines, while providing sparse and semantically grounded concept evidence.
Zhishan Tao, Ruoyu Wang, Yucheng Wu +6
Shanghai Jiao Tong University · The University of Hong Kong · Fudan University +3
Traffic accidents are a leading cause of fatalities and injuries across the globe. Therefore, the ability to anticipate hazardous situations in advance is essential. Automated accident anticipation enables timely intervention through driver alerts and collision avoidance maneuvers, forming a key component of advanced driver assistance systems. In autonomous driving, such predictive capabilities support proactive safety behaviors, such as initiating defensive driving and human takeover when required. Using dash-cam video as input offers a cost-effective solution, but it is challenging due to the complexity of real-world driving scenes. Accident anticipation systems need to operate in real-time. However, current methods involve extracting features from each detected object, which is computationally intensive. We propose VAGNet, a deep neural network that learns to predict accidents from dash-cam video using global features of traffic scenes without requiring explicit object-level features. The network consists of transformer and graph modules, and we use the vision foundation model VideoMAE-V2 for global feature extraction. Experiments on four benchmark datasets (DAD, DoTA, DADA, and Nexar) show that our method anticipates accidents with higher average precision while being computationally more efficient compared to existing methods. It also achieves higher mean time-to-accident scores in most cases, while being competitive in others.
Vipooshan Vipulananthan, Charith D. Chitraranjan
Department of Computer Science and Engineering, University of Moratuwa, Katubedda 10400, Sri Lanka