WAM-Flow: Parallel Coarse-to-Fine Motion Planning via Discrete Flow Matching for Autonomous Driving

Yifang Xu1*Jiahao Cui1*Feipeng Cai2*Zhihao Zhu1Hanlin Shang1Shan Luan1
Mingwang Xu1Neng Zhang2Yaoyi Li2Jia Cai2Siyu Zhu1
1Fudan University  2Yinwang Intelligent Technology Co., Ltd 


## 📰 News - **`2026/02/01`**: 🎉🎉🎉 Release the pretrained models on [Huggingface](https://huggingface.co/fudan-generative-ai/WAM-Flow). - **`2025/12/06`**: 🎉🎉🎉 Paper submitted on [Arxiv](https://arxiv.org/pdf/2512.06112). ## 📅️ Roadmap | Status | Milestone | ETA | | :----: | :----------------------------------------------------------------------------------------------------: | :--------: | | ✅ | **[Release the SFT and inference code](https://github.com/fudan-generative-vision/WAM-Flow)** | 2025.12.19 | | ✅ | **[Pretrained models on Huggingface](https://huggingface.co/fudan-generative-ai/WAM-Flow)** | 2026.02.01 | | 🚀 | **[Release the evaluation code](https://huggingface.co/fudan-generative-ai/WAM-Flow)** | TBD | | 🚀 | **[Release the RL code](https://github.com/fudan-generative-vision/WAM-Flow)** | TBD | | 🚀 | **[Release the pre-processed training data](#training)** | TBD | ## 📸 Showcase ![teaser](assets/Figure_1.png) ## 🏆 Qualitative Results on NAVSIM ### NAVSIM-v1 benchmark results
navsim-v1
### NAVSIM-v2 benchmark results
navsim-v2
## 🔧️ Framework ![framework](assets/Figure_2.png) Our method takes as input a front-view image, a natural-language navigation command with a system prompt, and the ego-vehicle states, and outputs an 8-waypoint future trajectory spanning 4 seconds through parallel denoising. The model is first trained via supervised fine-tuning to learn accurate trajectory prediction. We then apply simulatorguided GRPO to further optimize closed-loop behavior. The GRPO reward function integrates safety constraints (collision avoidance, drivable-area compliance) with performance objectives (ego-progress, time-to-collision, comfort). ## Quick Start ### Installation Clone the repo: ```sh git clone https://github.com/fudan-generative-vision/WAM-Flow.git cd WAM-Flow ``` Install dependencies: ```sh conda create --name wam-flow python=3.10 conda activate wam-flow pip install -r requirements.txt ``` ### Model Download Download models using huggingface-cli: ```sh pip install "huggingface_hub[cli]" huggingface-cli download fudan-generative-ai/WAM-Flow --local-dir ./pretrained_model/wam-flow huggingface-cli download LucasJinWang/FUDOKI --local-dir ./pretrained_model/fudoki ``` ### Inference ```sh sh script/infer.sh ``` ### Training ```bash sh script/sft_debug.sh ``` ## 📝 Citation If you find our work useful for your research, please consider citing the paper: ``` @article{xu2025wam, title={WAM-Flow: Parallel Coarse-to-Fine Motion Planning via Discrete Flow Matching for Autonomous Driving}, author={Xu, Yifang and Cui, Jiahao and Cai, Feipeng and Zhu, Zhihao and Shang, Hanlin and Luan, Shan and Xu, Mingwang and Zhang, Neng and Li, Yaoyi and Cai, Jia and others}, journal={arXiv preprint arXiv:2512.06112}, year={2025} } ``` ## ⚠️ Social Risks and Mitigations The integration of Vision-Language-Action models into autonomous driving introduces ethical challenges, particularly regarding the opacity of neural decision-making and its impact on road safety. To mitigate these risks, it is imperative to implement explainable AI frameworks and robust safe protocols that ensure predictable vehicle behavior in long-tailed scenarios. Furthermore, addressing concerns over data privacy and public surveillance requires transparent data governance and rigorous de-identification practices. By prioritizing safety-critical alignment and ethical compliance, this research promotes the responsible development and deployment of VLA-based autonomous systems. ## 🤗 Acknowledgements We gratefully acknowledge the contributors to the [Recogdrive](https://github.com/xiaomi-research/recogdrive), [Janus](https://github.com/deepseek-ai/Janus), [FUDOKI](https://github.com/fudoki-hku/FUDOKI) and [flow_matching](https://github.com/facebookresearch/flow_matching) repositories, whose commitment to open source has provided us with their excellent codebases and pretrained models.