公路平曲线路段大型车运行速度模型研究

从安全设计一致性理念出发,详细分析了驾驶员在高速公路自由流状态下平曲线路段的信息采集处理过程,认为大型车在平曲线路段的曲中点前后两部分运行速度是受不同的线形信息的影响,用大量的实测数据建立了相应的两阶段平曲线路段大型车运行速度统计模型。经过与实测速度对比验证,证明两阶段平曲线运行速度预测模型具有预测精度高、适用范围广的优点。这为利用运行速度制定公路线形设计标准提供了良好的数据支持,同时也为运行速度进行安全一致性审核提供了理论支撑。

Research on the Model of Truck Operating Speed on Horizontal Curve Section

Based on the safety design consistency concept,this paper analyzed the information collection and process under the free-flow condition on expressway.The factors influencing the speed on a horizontal curve were explored in this paper.When a driver driving into and away from a curve,information collected by the driver may be significantly different during the process due to changes of the alignments.The factors affecting the operating speed on horizontal curve section changed at different locations of the curve.It was assumed that any speed adjustment would be acceptable while driving over the two sections of curve,one from the start point of curvature to the midpoint,and the other from the mid point to the end of the curvature.A two-step statistical model was developed for prediction of operating speed on horizontal curve with different joint alignments.Compared with the result of the field data, the two-step model had the merit of high prediction accuracy with the 85th-percentile operating speed.The model could be applied in the operating speed based alignment design and traffic simulation.