This repository contains model for predicting vehicle collisions using dashcam footage, developed for the
Nexar Dashcam Collision Prediction Challenge . The model achieved a
11th place finish on the leaderboard with a score of
0.80 mean Average Precision (mAP)
Architecture :
VideoMAE-2 Large fine-tuned for binary classification (collision/near-miss vs. normal driving).
Feature Extraction : Utilized
TimeSformer for preprocessing input frames.
Input : 16 frames per video, each resized to 224x224 pixels.
Output : Probability score indicating the likelihood of a collision or near-miss event.
Event Type : Collision, near-miss, or normal driving
Event Time : Timestamp of the (near-)collision
Alert Time : Earliest time the event could be predicted.
For more details, refer to the
dataset paper .
Frame Extraction : Sampled 16 frames per video, focusing on the interval around the alert time.
Feature Extraction : Applied TimeSformer feature extractor to obtain pixel values.
Data Augmentation : Implemented transformations such as horizontal flip, rotation, color jitter, and resized cropping.
Normalization : Used ImageNet mean and standard deviation for normalization.
Framework : PyTorch with Hugging Face Transformers and Trainer API.
Training Configuration :
Batch Size: 4
Epochs: 15
Learning Rate: 3e-5
Weight Decay: 0.01
Evaluation Strategy: Per epoch
Metric for Best Model: Average Precision
Hardware : Trained on 2x NVIDIA T4 GPUs (~4.5 hours)
The model's performance was evaluated using Mean Average Precision (mAP) across different time-to-accident intervals:
The final score is the mean of the Average Precision (AP) values at these intervals, emphasizing early and accurate collision predictions
@misc{nexar2025dashcamcollisionprediction,
title={Nexar Dashcam Collision Prediction Dataset and Challenge},
author={Daniel C. Moura and Shizhan Zhu and Orly Zvitia},
year={2025},
eprint={2503.03848},
archivePrefix={arXiv},
primaryClass={cs.CV},
url={https://arxiv.org/abs/2503.03848}
}