Generic approach study for influence characteristics and optimization of guide signs information: case study of separated subgrade sections on freeways

The freeway “Separate Subgrade” section presents complex environment, where simplistic sign proves inadequate for effectively conveying precise information to drivers. To enhance traffic information efficacy, the Traffic Control Device Selection Model − Traffic Information (TCDSM-TI), has been proposed as a generalized approach. This method is implemented to systematically layer and overlay sign information, with measurable improvements observed in driving behavior patterns. The model’s logical validation is completed when sign information satisfies drivers’ travel requirements and reaches an optimized threshold range. Ultimately, traffic sign performance improvement is evaluated to identify the most suitable the most suitable sign design scheme. Results indicates that for the separated subgrade sections, based on existing facilities, the integration of 800-meter and 200-meter warning sign information significantly improves guidance. This integration facilitates earlier driver awareness, promotes clearer route selection, and improves operational stability. Furthermore, navigation systems corresponding to the optimized signage have been implemented, resulting in substantial improvements in driver behavior and traffic operation status. Overall, drivers demonstrate a 3.77% increase in speed regulation ability, a 3.68% improvement in the speed control ability, a 4.73% increase in the lateral stability, and especially a 36.49% increase in the lateral operation safety. Additionally, the TCDSM-TI approach provides a valuable framework for addressing information delivery under complex road conditions, thereby supporting standardized design and optimizing the utilization of traffic guide signs system.