基于公路三维线元和视觉特性的动态视距建模及其安全设计方法研究

Sight distance (SD) is an important geometric alignment parameter in highway design. It influences the driving safety. To improve and modify the deficiency of Stop Sight Distance (SSD) model and the design quality, the SSD parameters for passenger car and truck are investigated originally and checked reasonably in the project application. Combined operating speed, braking deceleration rate, influences of sight distance at night, grade and etc, the comprehensive modified two-dimensional (2D) SSD models are modified. Based on the highway three-dimensional (3D) alignment cells, the highway central line and vehicle trajectory 3D describing models are set up. The 3D dynamic sight distance (DSD) model is made by considering the influence of cross-section elements and roadside affiliated facilities and etc., based on the 3D alignment cell and visual characteristic of driver. Based on the Geographic Information System (GIS) spatial 3D analysis, the DSD models are calculated and analyzed. By surveying sight distance of highway project, the 3D DSD model is tested and checked. The safety questions between highway sight distance and driving are analyzed comprehensively. The values of 3D DSD model calculation, surveying values and 2D modified SSD design values are compared for checking and evaluating the safety. Finally, based on the DSD restricted risk probability model, the sight distance design method is put forward on the basis of the safety reliability. The results have great theoretical and practical significance, which can improve the highway alignment design quality and traffic safety.

视距是影响公路行车安全的重要线形设计指标，为进一步改进和完善现有规范计算停车视距的不足，提高道路线形设计质量，本项目考虑小客车和货车停车视距模型基础参数取值合理性，结合运行速度、制动减速度、夜间视距影响参数和纵坡等因素，修正现有规范的二维设计停车视距模型。在公路线形单元三维化基础上，建立公路中心线元和行车轨迹线三维表征模型。基于三维线元和驾驶员视觉特性，构建考虑线元横断面和路侧附属设施多影响因素的三维动态视距计算模型。基于GIS空间三维分析功能，进行模型计算和视距动态分析，并依据实际测量视距进行模型检验和校核。综合分析公路视距与行车安全性问题，对比三维动态视距模型计算值、实测的视距值以及修正二维设计视距值，进行视距检查和安全评价。最后分析三维动态视距受限危险概率，提出基于保证率的公路视距安全设计方法。本项目的研究成果对于提高公路线形设计质量和交通安全具有重要理论意义和实践价值。

视距是影响公路行车安全的重要线形设计指标，为进一步改进和完善现有规范计算停车视距的不足，提高道路线形设计质量，本项目考虑小客车和货车停车视距模型基础参数取值合理性，结合运行速度、驾驶员视觉特性、制动减速度、纵向摩阻系数、夜间视距影响参数和纵坡等因素，修正现有规范的二维设计停车视距模型。在公路线形单元三维化基础上，建立公路中心线元和行车轨迹线三维表征模型。基于三维线元和驾驶员视觉特性，构建考虑线元横断面和路侧附属设施多影响因素的三维动态视距计算模型。进行模型计算和视距动态分析，并依据实际测量视距进行模型检验和校核。综合分析公路视距与行车安全性问题，对比三维动态视距模型计算值、实测的视距值以及修正二维设计视距值，进行视距检查和安全评价。本项目的研究成果对于提高公路线形设计质量和交通安全具有重要理论意义和实践价值。