Progressive Risk Estimation for Accident Anticipation
Authors: Samet Hicsonmez, Eray Çakar, Nermin Samet, Fatma Güney
Organizations: Independent Researcher, Paris, France · Department of Computer Engineering, KUIS AI, Koç University, Istanbul, Turkey · Valeo.ai, Paris, France
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.
Figures & tables
Figure 1: PRE-ACT : From binary accident prediction to progressive risk anticipation. Unlike the dominant paradigm of formulating accident anticipation as a binary classification of whether an accident will occur (baseline), we model risk as a temporally evolving signal that reflects when an accident is likely to occur. By explicitly enforcing temporal order and distance-to-crash awareness, our model reduces false alarms while progressively increasing risk as abnormal cues emerge. Scores are overlaid on frames as an alpha channel, with blue indicating safe and red indicating risky predictions.
Figure 2: Overview . We define the period before the fixed anticipation horizon th as the safe zone, and the interval from th to the accident time tacc as the critical zone with progressively increasing risk. During training, we extract spatio-temporal features using a video foundation model. Based on these features, the model classifies clips as safe or critical, assigns a continuous risk score, and ranks them using preference head outputs, encouraging higher scores for critical clips closer to the accident. Dashed arrows indicate components used only during training.
Figure 3: Varying α . Continuous risk curves with fast-increasing (red side) and slow-increasing (blue side) behavior obtained by varying α . The linear case is shown with a dashed line.
Figure 4: Problem with current evaluation metrics. Standard AUC evaluates predictions only within local temporal windows: negatives are sampled around anomaly onset ( tai−0.5 ) and positives close to the accident ( tacc−2 ), illustrated by the yellow hatched regions. As a result, the cyan , magenta , and green curves achieve similarly high AUC (near 1) and identical TTA, since they rise relative to the pre-anomaly region at comparable times ( orange line). However, their global behavior differs significantly. The cyan curve produces early false alarms before tai , while the magenta curve shows weak progression toward the accident. The green curve exhibits the desired behavior: low risk before tai , a clear increase after anomaly onset, and steadily rising risk as tacc ( red line) approaches.
Method
AUC 0.0s0.1
AUC 0.5s0.1
AUC 1.0s0.1
AUC 1.5s0.1
mAUC 0.1
mTTA 0.1
CAP
CAP [ 26 ]
0.042
0.040
0.030
0.037
0.036
0.637
DRIVE [ 43 ]
0.129
0.117
0.108
0.123
0.116
0.395
DSTA [ 9 ]
0.559
0.386
0.282
0.191
0.286
0.804
GSC [ 10 ]
0.609
0.418
0.297
0.199
0.305
0.817
TOP [ 11 ]
0.838
0.675
0.398
0.214
0.429
0.864
PRE-ACT
0.887
0.775
0.465
0.201
0.481
1.125
Table 1: Results on MM-AU. We report results on the CAP [ 26 ] (top) and DADA [ 39 ] (bottom) splits of MM-AU [ 12 ] . Our method consistently outperforms prior work across almost all metrics by substantial margins, with improvements becoming more pronounced closer to the accident.
Method
mAP
Runner-up
0.875
Winner
0.885
PRE-ACT
0.895
Table 2: Results on Nexar.
Train
Test
AUC 0.0s0.1
AUC 0.5s0.1
AUC 1.0s0.1
AUC 1.5s0.1
mAUC 0.1
mTTA 0.1
s
CAP
DADA
0.897
0.799
0.413
0.178
0.464
1.155
0.760
diff.
0.036
0.048
0.015
0.008
0.024
0.086
0.020
Nexar
-
0.529
0.336
0.218
0.361
1.020
0.650
diff.
-
0.082
0.236
0.151
0.149
0.265
0.049
Table 3: Cross-dataset generalization. We train our model on the largest subset, CAP, and evaluate it on DADA and Nexar. As indicated by the performance differences (diff.; increase and decrease ) relative to models trained on each dataset’s own training set, our model generalizes well to DADA, with a slight performance drop on Nexar due to a larger domain gap.
BCE
Prog.
Pref.
AUC 0.0s0.1
AUC 0.5s0.1
AUC 1.0s0.1
AUC 1.5s0.1
mAUC 0.1
mTTA 0.1
s
✓
✗
✗
0.807
0.690
0.392
0.176
0.419
1.105
0.694
✓
✓
✗
0.884
0.773
0.463
0.197
0.477
1.128
0.723
✓
✓
✓
0.887
0.775
0.465
0.201
0.481
1.125
0.724
Table 4: Ablation on progress and preference estimation. Compared to the BCE baseline, progress estimation (Prog.) significantly improves performance across all metrics. Adding preference estimation (Pref.) provides slight additional gains, achieving the best overall results.
Increase
α
AUC 0.0s0.1
AUC 0.5s0.1
AUC 1.0s0.1
AUC 1.5s0.1
mAUC 0.1
mTTA 0.1
s
Fast
10
0.858
0.750
0.459
0.203
0.471
1.120
0.722
5
0.877
0.768
0.467
0.204
0.480
1.125
0.724
4
0.882
0.772
0.466
0.204
0.481
1.125
0.724
3
0.887
0.775
0.465
0.201
0.481
1.125
0.724
2
0.893
0.778
0.461
0.198
0.479
1.124
0.725
1
0.898
0.778
0.454
0.193
0.475
1.122
0.726
Table 5: Results with varying risk functions. Fast-increasing risk functions with positive α improve longer-horizon anticipation, i.e. , ≥1 sec, while slow-increasing functions with negative α perform better at shorter horizons, i.e. , <1 sec. α=3 achieves the best overall performance.
Figure 5: Separation profile on CAP. BCE inflates pre-onset scores, whereas our model provides a smoother rise and improved accuracy near the accident, as shown zoomed-in.
Model
spre↓
spost↑
s↑
CAP
BCE
0.420
0.808
0.694
PRE-ACT
0.344
0.792
0.724
DADA
BCE
0.372
0.763
0.696
PRE-ACT
0.319
0.798
0.740
Table 6: Separation scores.
Appendix figures & tables3 assets
Supplementary material from the paper’s appendix.
Appendix
Dataset
λ
AUC 0.0sλ
AUC 0.5sλ
AUC 1.0sλ
AUC 1.5sλ
mAUC λ
mTTA λ
CAP [ 26 ]
0.01
0.721
0.500
0.106
0.025
0.210
0.817
0.1
0.887
0.775
0.465
0.201
0.481
1.125
1.0
0.976
0.945
0.852
0.701
0.833
1.820
DADA [ 39 ]
0.01
0.732
0.503
0.136
0.038
0.226
0.826
0.1
0.861
0.751
0.398
0.170
0.440
1.069
1.0
0.960
0.922
0.782
0.631
0.778
1.597
Appendix
Table 7: Performance across varying FPR. Despite drops at low FPR, our method maintains timely warnings, achieving 0.8 s mTTA at FPR ≤0.01 .
Dataset
Backbone
AUC 0.0s0.1
AUC 0.5s0.1
AUC 1.0s0.1
AUC 1.5s0.1
mAUC 0.1
mTTA 0.1
CAP [ 26 ]
DINOv2 [ 44 ]
0.837
0.573
0.272
0.136
0.327
0.721
V-JEPAv2 [ 45 ]
0.881
0.778
0.426
0.176
0.460
1.120
VideoMAE [ 40 ]
0.887
0.775
0.465
0.201
0.481
1.125
DADA [ 39 ]
DINOv2 [ 44 ]
0.674
0.358
0.179
0.117
0.218
0.850
V-JEPAv2 [ 45 ]
0.596
0.516
0.314
0.177
0.336
1.011
VideoMAE [ 40 ]
0.861
0.751
0.398
0.170
0.440
1.069
Appendix
Table 8: Varying backbone. Video models (V-JEPAv2 and VideoMAE) clearly outperform the image backbone (DINOv2), emphasizing spatio-temporal features; similar results across video encoders show backbone-agnostic behavior for our method.
Method
AP 0.5s
AP 1.0s
AP 1.5s
mAP
mAUC
mAUC 0.1
mTTA 0.1
s
PRE-ACT
0.919
0.911
0.854
0.895
0.895
0.510
1.285
0.665
Appendix
Table 9: Results using standard metrics on the Nexar [ 13 ] dataset.
Traffic accident anticipation predicts imminent collisions or rising crash risk early enough to support driver warnings and proactive road-safety decisions.
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.
Yiyang Zou, Tianhao Zhao, Peilun Xiao +9
School of Computer Science, Wuhan University · Zhongguancun Academy, Beijing, China · Didi Chuxing +1
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
Anticipating traffic accidents from dashcam videos is a critical challenge in intelligent transportation systems. Existing methods typically map visual context directly to a collision probability without explicitly modeling the future evolution of the driving scene. In this paper we propose FLaRA (Predicting Future Latent Representations for Accident Anticipation), a novel predictive architecture that shifts this paradigm by forecasting future latent representations for accident anticipation. Building upon the Video Joint-Embedding Predictive Architecture (V-JEPA2), our model conditions a predictor network on observed context frames to predict the forthcoming latent features of the scene. A classifier then operates on these predicted future representations rather than only on past observations. To ensure these forecasts remain grounded in realistic future dynamics, we introduce a joint training objective that simultaneously optimizes an auxiliary feature-level reconstruction loss and a cross-entropy classification loss. Extensive evaluations on the Nexar dataset, alongside cross-domain validations on the DAD, DADA-2000, and DoTA benchmarks, demonstrate that our approach achieves state-of-the-art performance while maintaining realistic early warning capabilities.
Lorenzo Caselli, Tomaso Trinci, Tommaso Bianconcini +4
Department of Information Engineering, University of Florence, Italy. · 2Verizon Connect, Florence, Italy.