YOLO-LLTS: Real-Time Low-Light Traffic Sign Detection via Prior-Guided Enhancement and Multibranch Feature Interaction

Traffic sign detection is essential for autonomous driving and advanced driver assistance systems (ADASs). However, existing methods struggle to address the challenges of poor image quality and insufficient information under low-light conditions, leading to a decline in detection accuracy and affecting driving safety. To address this issue, we propose YOLO-LLTS, an end-to-end real-time traffic sign detection algorithm specifically designed for low-light environments. YOLO-LLTS introduces three main contributions: the high-resolution feature map for small object detection (HRFM-SOD) module retains more information about distant or tiny traffic signs compared to traditional methods; the multibranch feature interaction attention (MFIA) module interacts features with different receptive fields to improve information utilization; the prior-guided feature enhancement (PGFE) module enhances detection accuracy by improving brightness, edges, contrast, and supplementing detailed information. Additionally, we construct a new dataset, Chinese Nighttime Traffic Sign Sample Set (CNTSSS), covering diverse nighttime scenarios. Experiments show that YOLO-LLTS achieves state-of-the-art performance, outperforming previous best methods by 2.7% mAP50 and 1.6% mAP50:95 on TT100K-night, 1.3% mAP50 and 1.9% mAP50:95 on CNTSSS, 7.5% mAP50 and 9.8% mAP50:95 on GTSDB-night, and superior results on CCTSDB2021. Deployment on edge devices confirms its real-time applicability and effectiveness. The code and the dataset are available at https://github.com/linzy88/YOLO-LLTS