基于时空消耗法及运行效率的路网容量

Road Network Capacity Based on the Time-Space Consumption and the Traffic Operation Efficiency Theory

时空消耗法是计算路网容量的重要模型,为了提高传统时空消耗法计算路网容量的准确性,克服其计算过程中忽略道路等级,未考虑车辆在不同等级道路上运行差异性的问题,提出基于道路分级的时空消耗改进模型.车头间距为模型中的关键参数之一,是得到合理路网容量的基础,为此,针对车头间距标定的方法进行了研究:将运行效率理论作为参数标定的基础,并结合Van Aerde(VA)交通流模型得到车头间距与运行效率之间函数关系.针对北京地区,基于上述理论计算得到快速路、主干路以及次干路运行效率达到最大时对应的车头间距分别为27. 92、25. 56、21. 88 m.最后,以新规划的北京城市副中心--通州区的核心区域(155 km^2)内的路网作为模型的应用案例,根据交通调查等方法得到的数据及信息,应用改进后的模型计算得到该区域内主干路、次干路的路网容量为56~60万辆次/d.

Time-space consumption method is one of the most essential methods for calculating the capacity. To promote the accuracy of the calculation result and cope with the defect of traditional method that neglects vehicles’ operating heterogeneities on different levels of the road,a graded time-space consumption method was proposed. The space headway is a key parameter that is the basis for obtaining reasonable results so that the calibration method for space headway is proposed incorporated with the efficiency theory. The functional relationship between efficiency and space headway was obtained associated with Van Aerde traffic flow model. For road network in Beijing,based on the proposed model,the space headways of vehicles operating on express ways,arterials and sub-arterials were obtained and they are 27. 92,25. 56,and 21. 88 m,respectively. Finally,taking the new planned Beijing sub hub,core area of Tong Zhou district( 155 km^2) as case study,the total road network capacity of arterial and sub-arterial was calculated by using the modified time-space consumption method and the result is 0. 56-0. 60 million pcu times per day according to the data from investigation.