SimScale: Learning to Drive via Real-World Simulation at Scale
Authors: name: Haochen Tian; name: Tianyu Li; name: Haochen Liu; name: Jiazhi Yang; name: Yihang Qiu; name: Guang Li; name: Junli Wang; name: Yinfeng Gao; name: Zhang Zhang; name: Liang Wang; name: Hangjun Ye; name: Tieniu Tan; name: Long Chen; name: Hongyang Li
Published: 2025-11-28 17:17:38

Abstract: Achieving fully autonomous driving systems requires learning rational decisions in a wide span of scenarios, including safety-critical and out-of-distribution ones. However, such cases are underrepresented in real-world corpus collected by human experts. To complement for the lack of data diversity, we introduce a novel and scalable simulation framework capable of synthesizing massive unseen states upon existing driving logs. Our pipeline utilizes advanced neural rendering with a reactive environment to generate high-fidelity multi-view observations controlled by the perturbed ego trajectory. Furthermore, we develop a pseudo-expert trajectory generation mechanism for these newly simulated states to provide action supervision. Upon the synthesized data, we find that a simple co-training strategy on both real-world and simulated samples can lead to significant improvements in both robustness and generalization for various planning methods on challenging real-world benchmarks, up to +6.8 EPDMS on navhard and +2.9 on navtest. More importantly, such policy improvement scales smoothly by increasing simulation data only, even without extra real-world data streaming in. We further reveal several crucial findings of such a sim-real learning system, which we term SimScale, including the design of pseudo-experts and the scaling properties for different policy architectures. Our simulation data and code would be released.