以河北省各种类型双车道二级公路为背景,根据大量现场观测数据,在分析与研究汽车二级专用和一般混合交通二级公路交通流特性的基础上,提出了采用间隙理论计算通行能力的不适应性,代之以实现观测数据的拟合分析来确定其通行能力的计算方法。还根据数值集合场原理,提出了速度自由度的概念,并由此确定与划分道路服务水平,继之提出了计算服务通行能力的数学模型和相应的技术指标。 Based on a large number of on-site observation data and on the basis of analyzing and studying the traffic flow characteristics of the second-class and second-class general mixed traffic vehicles in Hebei Province, this paper proposes a method to calculate the traffic capacity Of the incompatibility, replaced by the realization of fitting data analysis to determine the capacity of its calculation method. According to the principle of numerical convergence field, the concept of speed degree of freedom is proposed, and then the service level of road is determined and divided. Then the mathematical model and the corresponding technical index for calculating service capacity are put forward.