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arXiv · 2506.21618

TrajTok: Technical Report for 2025 Waymo Open Sim Agents Challenge

Zhiyuan Zhang·Xiaosong Jia·Guanyu Chen·Qifeng Li·Junchi Yan
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Abstract

In this technical report, we introduce TrajTok, a trajectory tokenizer for discrete next-token-prediction based behavior generation models, which combines data-driven and rule-based methods with better coverage, symmetry and robustness, along with a spatial-aware label smoothing method for cross-entropy loss. We adopt the tokenizer and loss for the SMART model and reach a superior performance with realism score of 0.7852 on the Waymo Open Sim Agents Challenge 2025. We will open-source the code in the future.

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Zhiyuan Zhang, Xiaosong Jia, Guanyu Chen, Qifeng Li, Junchi Yan. 2025-06-23. TrajTok: Technical Report for 2025 Waymo Open Sim Agents Challenge. https://arxiv.org/abs/2506.21618

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